76. Local and Regional Flaps in Head and Neck

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Current Otolaryngology > XV. Facial Nerve > Chapter 68. Disorders of the Facial Nerve >

Disorders of the Facial Nerve: Introduction

Facial nerve dysfunction can dramatically affect a patient's quality of life. The human face is a focal point for expression and interpersonal communication whereas facial motor movement contributes to eye protection, speech articulation, chewing, and swallowing. Thus, the patient with a facial palsy suffers not only the functional consequences of impaired facial motion, but also the psychological impact of a skewed facial appearance.

Acute Facial Palsies

Essentials of Diagnosis

Bell's Palsy

• Acute onset, with unilateral paresis or paralysis of the face in a pattern consistent with peripheral nerve dysfunction (all branches affected).
• Rapid onset and evolution (< 48 hours).
• Facial palsy may be associated with acute neuropathies affecting other cranial nerves (particularly cranial nerves VX).

Herpes Zoster Oticus (Ramsay Hunt syndrome)

• Acute peripheral facial palsy associated with otalgia and varicella-like cutaneous lesions that involve the external ear, skin of the ear canal, or the soft palate.
• Involvement often extends to cranial nerves V, IX, and X, and cervical branches that have anastomotic communications with the facial nerve.
• Differentiated from Bell's palsy by characteristic cutaneous ulcers and a higher incidence of hearing loss or balance dysfunction.

General Considerations

There are a large variety of disorders that may be associated with unilateral facial palsies (Table 681). Bilateral facial palsy is much less common and occurs in less than 2% of patients presenting with an acute facial palsy (Table 682). Bilateral involvement typically reflects a systemic disorder with multiple manifestations. Because of their overlapping clinical presentation and treatment paradigms, Bell's palsy and herpes zoster oticus (also known as Ramsay Hunt syndrome) are considered together.

Table 681. Differential Diagnoses of Facial Paralysis.

Birth 

  Molding

  Forceps delivery

  Myotonic dystrophy

  Mebius syndrome (facial diplegia associated with other cranial nerve deficits)

Trauma 

  Cortical injuries

  Basilar skull fractures

  Brainstem injuries

  Penetrating injury to middle ear

  Facial injuries

  Altitude paralysis (barotrauma)

  Scuba diving (barotrauma)

Neurologic 

  Opercular syndrome (cortical lesion in facial motor area)

  Millard-Gubler syndrome (abducens palsy with contralateral hemiplegia due to lesion in base of pons involving corticospinal tract)

Infection 

  Malignant otitis externa

  Acute or chronic otitis media

  Cholesteatoma (acquired and congenital)

  Mastoiditis

  Meningitis

  Parotitis

  Chickenpox

  Herpes zoster oticus (Ramsay Hunt syndrome)

  Encephalitis

  Poliomyelitis (type I)

  Mumps

  Mononucleosis

  Leprosy

  HIV and AIDS

  Influenza

  Coxsackie virus

  Malaria

  Syphilis

  Scleroma

  Tuberculosis

  Botulism

  Mucormycosis

  Lyme disease

Genetic and Metabolic 

  Diabetes mellitus

  Hyperthyroidism

  Pregnancy

  Hypertension

  Alcoholic neuropathy

  Bulbopontine paralysis

  Oculopharyngeal muscular dystrophy

Vascular 

  Anomalous sigmoid sinus

  Benign intracranial hypertension

  Intratemporal aneurysm of internal carotid artery

  Embolization for epistaxis (external carotid artery branches)

Neoplastic 

  Acoustic neuroma

  Glomus jugulare tumor

  Leukemia

  Meningioma

  Hemangioblastoma

  Hemangioma

  Pontine glioma

  Sarcoma

  Hydradenoma (external canal)

  Facial nerve neuroma

  Teratoma

  Fibrous dysplasia

  von Recklinghausen disease

  Carcinomatous encephalitis (Bannworth syndrome)

  Cholesterol granuloma

  Carcinoma (invasive or metastatic, from breast, kidney, lung, stomach, larynx, prostate, thyroid)

Toxic 

  Thalidomide (Miehlke syndrome: cranial nerves VI and VII with atretic external ears)

  Tetanus

  Diphtheria

  Carbon monoxide

  Lead intoxication

Iatrogenic 

  Mandibular block anesthesia

  Antitetanus serum

  Vaccine treatment for rabies

  Otologic, neurotologic, skull base, and parotid surgery iontophoresis (local anesthesia)

  Embolization

Idiopathic 

  Familial Bell's palsy

  Melkersson-Rosenthal syndrome (recurrent facial palsy, furrowed tongue, faciolabial edema)

  Hereditary hypertrophic neuropathy (Charcot-Marie-Tooth disease, Dejerine-Scottas disease)

  Autoimmune syndromes of temporal arteritis, periarteritis nodosa, and other vasculitides

  Thrombotic thrombocytopenic purpura

  Landry-Guillain-Barr syndrome (ascending paralysis)

  Multiple sclerosis

  Myasthenia gravis

  Sarcoidosis (Heerfordt syndrome, uveoparotid fever)

  Wegener granulomatosis

  Eosinophilic granuloma

  Amyloidosis

  Hyperostoses (Paget disease, osteopetrosis)

  Kawasaki disease (infantile acute febrile mucocutaneous lymph node syndrome)

Reproduced, with permission, from May M: Differential diagnosis by history, physical findings, and laboratory results. In: May M, ed. The Facial Nerve. New York: Thieme-Stratton; 1986.

Table 682. Etiologies Associated with Bilateral Facial Palsies (May Be Simultaneous or Delayed).

Bell palsy

Diabetes mellitus

Sarcoidosis (Heerfordt syndrome)

Periarteritis nodosa

Guillain-Barr syndrome

Myasthenia gravis

Basilar skull fracture

Bulbar palsies

Porphyrias

Leukemia

Myotonic dystrophia

Meningitis

Mbius syndrome

Botulism

Infectious mononucleosis

Leprosy

Malaria

Poliomyelitis

Lyme disease

Syphilis

Postvaccination neuropathy

Isoniazid

Osteopetrosis

Bell's Palsy

No identifiable cause is present for approximately 6070% of cases of acute facial palsy. The clinical diagnosis of Bell's palsy is appropriately applied in such cases. Bell's palsy manifests as an acute, unilateral paresis or paralysis of the face in a pattern consistent with peripheral nerve dysfunction (Figure 681). The onset and evolution are rapidtypically less than 48 hours. Other cranial nerves, particularly the trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, and vagus nerves, may manifest deficits.

Figure 681.

(A) Prototypic case of Bell's palsy. This 28-year-old woman experienced the onset of an acute, left-sided paralysis of the face over a 24-hour period, in a pattern consistent with peripheral nerve dysfunction. Treatment consisted of oral steroid dosing at pharmacologic doses for 10 days, followed by a 2-week taper. (B) Full recovery of facial motor function 2 months after onset.

There may also be subtle but frequent associated dysfunction of cranial nerves V, VIII, IX, and X in association with Bell's palsy. Pain or numbness affecting the ear, mid-face, and tongue, as well as taste disturbances, are common. These observations suggest that the facial weakness seen in Bell's palsy is the inflammatory facial-motor component of a wider cranial polyneuropathy.

Recurrent Bell's palsy, both ipsilateral and contralateral, occurs in up to 12% of patients. Recurrences are more likely in patients with a family history of Bell's palsy, and the incidence of diabetes mellitus in recurrent Bell's palsy patients is 2.5 times that noted in nonrecurrent cases. Immunodeficiency is also associated with recurrences. As noted below, any recurrence warrants a complete workup for another etiology.

Herpes Zoster Oticus

Herpes zoster oticus (Ramsay Hunt syndrome) is a syndrome of acute peripheral facial palsy associated with otalgia and varicella-like cutaneous lesions. It accounts for approximately 1015% of acute facial palsy cases. The pathognomonic lesions may involve the external ear, particularly the meatal and preauricular skin, the skin of the ear canal, or the soft palate (Figure 682). Hearing loss, dysacusis, and vertigo reflect extension of the infection to involve the eighth cranial nerve. Involvement often extends to other cranial nerves (V, IX, and X) and cervical branches (2, 3, and 4) that have anastomotic communications with the facial nerve. Herpes zoster oticus is therefore differentiated from Bell's palsy by the characteristic cutaneous changes and a higher incidence of hearing and balance dysfunction and other cranial neuropathies.

Figure 682.

(A) Prototypic case of herpes zoster oticus. This 53-year-old woman experienced the onset of a right-sided facial paralysis with marked right-sided otalgia and throat pain. She presented 3 days after the onset of her symptoms and demonstrated minimal facial motor activity on evoked electromyography. Treatment consisted of oral steroid dosing at pharmacologic doses for 10 days, followed by a 2-week taper, and acyclovir given intravenously for 1 week. (B) Full recovery of facial motor function 4 months after onset. (C) Skin lesion of the right external meatus in the same patient with oticus in the crusting phase at the time of presentation.

Pathogenesis

Studies of the intratemporal facial nerve suggest that Bell's palsy and herpes zoster oticus result from impaired facial nerve conduction within the temporal bone. In the labyrinthine segment of the fallopian canal, the facial nerve occupies more than 80% of the cross-sectional area of the surrounding facial canal between the meatal foramen and the geniculate fossa (in contrast to less than 75% in the tympanic and vertical segments of the canal) (Figure 683). Because the narrow diameter of the meatal foramen (Figure 683A) and the presence of a circumferential band of periosteum that virtually seals the entry site and constricts the nerve at this location (Figure 684), the meatal foramen appears to constitute a pressure transition zone or "physiologic bottleneck" in the presence of neural edema. The ratio of the cross-sectional areas of the nerve to the meatal foramen is significantly smaller in pediatric temporal bones relative to those of adults, perhaps explaining the low incidence of Bell's palsy in pediatric populations.

Figure 683.

(A) Caliber of the (intratemporal) facial canal from the meatal foramen to the mastoid segment. (B) CT scan of temporal bones revealing the fallopian canal caliber for the labyrinthine segment proximal to the geniculate ganglion (white arrows).

Figure 684.

Surgical anatomy of the meatal foramen, labyrinthine segment, and geniculate fossa.

In patients with near-total degeneration undergoing facial nerve decompression for Bell's paralysis, electrical stimulation demonstrated a transition in responsiveness in the (decompressed) region of the meatal foramen. Sequential stimulation in a distal-to-proximal direction from the second genu to the meatal foramen consistently revealed substantially diminished responses proximal to the meatal foramen. These observations strongly implicate the meatal foramen as the primary pathophysiologic site in Bell's palsy.

Most postmortem studies from patients with Bell's palsy demonstrate that diffuse involvement of the facial nerve in its intratemporal course was typical. Evidence of an inflammatory neuritis suggesting a viral etiology is frequently evident, though not uniformly observed. One study in a patient who died 13 days after the onset of Bell's palsy demonstrated intraneural inflammatory changes with leukocytic infiltration and demyelinization in the proximal intratemporal portion of the nerve, consistent with a viral infection. Other studies have demonstrated intraneural vascular congestion and hemorrhage in the labyrinthine segment of the nerve. The likelihood of the meatal foramen also being the critical site for nerve injury in herpes zoster oticus is supported by neuropathologic findings demonstrating a sharp demarcation between the degenerated nerve distal to and normal nerve proximal to the meatal foramen. It is also possible that several pathologic events may be sequential and synergistic in manifesting a clinical facial palsy, and the disease may represent a spectrum of entities with varied pathogeneses. Although inflammation and ischemia likely dominate early processes in Bell's palsy, neural blockade and degeneration, as well as subsequent fibroblastic response, probably manifest later in the sequence. Given the confinement of the nerve trunk within the meatal foramen, it is likely that compression at this site is a critical if not determinative event in the genesis of Bell's palsy and is triggered by one or a combination of the above etiologies. Histopathologic findings suggest that the facial palsy component of herpes zoster oticus is manifested by a similar process of entrapment, with typically a higher risk of irreversible degeneration of nerve fibers.

Eicher SA, Coker NJ, Alford BR, Igarashi M, Smith RJH. A comparative study of the fallopian canal at the meatal foramen and labyrinthine segment in young children and adults. Arch Otolaryngol Head Neck Surg. 1990;116:1030. (This report, documenting the differences in facial nerve palsy between children and adults, suggests that the facial nerve is not as tightly contained at the meatal foramen in children and provides a possible explanation for the relative infrequency of Bell's palsy in this age group.) [PMID: 2383386]

Fisch U, Esslen E. Total intratemporal exposure of the facial nerve: pathologic findings in Bell's palsy. Arch Otolaryngol. 1972;95:335. (This classic report highlights the intraoperative and pathologic findings of the facial nerve during intratemporal decompression of the nerve.) [PMID: 5018255]

Fowler EP. The pathologic findings in case of facial paralysis. Trans Am Acad Ophthalmol Otolaryngol. 1963;67:187. (This classic study evaluates the pathophysiology of facial paresis in a case of facial palsy.)

Gantz B, Gmur A, Fisch U. Intraoperative evoked electromyography in Bell's palsy. Am J Otolaryngol. 1982;3:273. (In this report, the technique of intraoperative evoked electromyography is described in detail.) [PMID: 7149140]

Jackson CG, Hyams VJ, Johnson GD, Poe DS. Pathologic findings in the labyrinthine segment of the facial nerve in a case of facial paralysis. Ann Otol Rhinol Laryngol. 1990;99:327. (The histopathologic findings for a patient with acute facial paralysis caused by herpes zoster oticus who obtained no return of active facial function after 1 year are presented in this manuscript and are consistent with observations that the lesion producing Bell's palsy and herpes zoster oticus usually is situated at the meatal foramen.) [PMID: 2337309]

Liston SL, Kleid MS. Histopathology of Bell's palsy. Laryngoscope. 1989;99:23. (The histopathology of the facial nerve 1 week after the onset of Bell's palsy is reported.) [PMID: 2642582]

McKeever P, Proctor B, Proud G. Cranial nerve lesions in Bell's palsy. Otolaryngol Head Neck Surg. 1987;97:326. (This report documents all associated cranial nerve deficits in patients who present with Bell's palsy.) [PMID: 3118317]

Niparko JK, Kileny PR, Kemink JL, Lee SH, Graham MD. Neurophysiologic intraoperative monitoring: II. Facial nerve function. Am J Otol. 1989;10:55. (This report outlines the use of facial nerve monitoring in neurotologic surgery.) [PMID: 2655465]

Proctor B, Corgill DA, Proud G. The pathology of Bell's palsy. Trans Am Acad Ophthalmol Otolaryngol. 1976;82:70. (This classic study examines the pathophysiology of Bell's palsy.) [PMID: 969098]

Proctor B, Nager GT. The facial canal: normal anatomy variations and anomalies. Ann Otol Rhinol Laryngol. 1982;97:33. (This classic study provides a detailed descriptive anatomy with emphasis on the relations of the facial canal to adjacent structures, including the variations in the course of the facial canal.) [PMID: 6814328]

Wakisaka H, Hato N, Honda N et al. Demyelination associated with HSV-1-induced facial paralysis. Exp Neurol. 2002;178(1):68. (An experimental model of facial paralysis in mice demonstrates that facial nerve paralysis in this model is caused mainly by facial nerve demyelination in the descending segment). [PMID: 12460609]

Etiology

Viral Neuritis

There is significant resemblance between Bell's palsy and other viral neuropathies. Poliomyelitis, mumps, Epstein-Barr virus, and rubella infections can include progressive neural dysfunction, often with subtotal regeneration as is often observed with Bell's palsy and herpes zoster oticus. There are multiple lines of evidence for a viral etiology in Bell's palsy based on clinical observations and experimental models reported over the past 20 years. Rabbit facial nerve trunks inoculated with herpes simplex virus (HSV) demonstrate facial motor dysfunction that progressed to paralysis within the first week after inoculation. HSV Type I has been identified in isolates of the HSV from the nasopharynx of patients during the acute phase of Bell's palsy. A higher incidence of HSV antibodies has been identified in patients with Bell's palsy compared with gender- and age-matched controls. HSV has a well-known predilection for sensory neurons and can exist in a latent phase in sensory cell bodies of the ganglion. The facial nerve contains sensory neurons with cell bodies located in the geniculate ganglion, and it is believed that infection of the facial nerve, such as a geniculate ganglionitis, underlies Bell's palsy.

The presence of the HSV has been detected in epineurial biopsies from a patient undergoing facial nerve decompression for Bell's palsy. Lastly, ultrastructural studies of autopsy material from asymptomatic patients have demonstrated herpes simplex viral particles in sensory ganglia of regional cranial nerves, most notably the trigeminal ganglion. Thus, the preponderance of evidence highly suggests, but does not conclusively prove, that HSV is the cause of Bell's palsy.

The role of the varicella-zoster virus (VZV) as etiologic in herpes zoster oticus is supported strongly by the characteristic varicelliform rash. This rash assumes a dermatologic distribution in a pattern that mimics the distribution of afferent fibers of the facial nerve. Serologic confirmation of VZV infection is often, but not always, possible. Histologic studies indicate facial dysfunction with herpes zoster oticus to be the result of an entrapment neuropathy, with more pronounced nerve fiber degeneration than that typically found in histopathologic studies of Bell's palsy.

The HSV and VZV are both DNA viruses of the herpes virus group and differ subtly in their ultrastructural features. Although differences in biologic behavior suggest that neuritides resulting from these viruses should manifest clinically distinguishable differences in their presentation, infections from HSV and VZV may mimic one another. Furthermore, HSV, mumps, and cytomegalovirus infections may produce a clinical picture resembling herpes zoster oticus, whereas varicella-zoster neuritis may occur in the absence of a rash, occasionally making a clear distinction between these clinical entities difficult.

Alternative Etiologic Theories

Two other causes of Bell's palsy that have been proposed include ischemic insult and immunologic injury. Theories advocating ischemic insult as a cause argue that impaired neural conduction follows small-vessel ischemia. The facial nerve derives its blood supply from an extrinsic, circumneural vessel network derived from the labyrinthine middle meningeal and the stylomastoid arteries. The circumneural system in turn connects to an intrinsic vascular supply of small-vessel tributaries within the perineurial compartment. The pathologic process is thought to involve this intrinsic system of vessels: Pressure elevations within the intraneural compartments produces venous stasis, stagnation of capillary flow, and a cycle of additional edema and an elevation in intraneural pressure. Circulatory sludging and, ultimately, tissue damage through acidosis and anoxia ensue. In this theory, the mechanism by which the cascade of primary ischemia is initiated remains unclear.

An alternate theory proposes that immunologic injury may be a potential cofactor in Bell's palsy. Studies demonstrating neuropathologic findings of segmental demyelinization accompanied by lymphocytic infiltration of the perineurium support this etiology. Autoimmune mechanisms of nerve injury have also been suggested. Immunoassay methods have been used to detect acute-phase antibodies within the chorda tympani nerve from three of seven patients with Bell's palsy. Immune complexes found in the chorda tympani nerve fibers were characteristic of viral-antibody (Type III) immunologic reaction, suggesting an immune injury triggered by the presence of viral antigens.

Adour KK, Byl FM, Hilsinger RL, Kahn ZM, Sheldon MI. The true nature of Bell's palsy: analysis of 1000 consecutive patients. Laryngoscope. 1978;88:787. (This classic manuscript suggests that Bell's palsy be termed "idiopathic facial paralysis" and that it should be recognized as an acute benign cranial polyneuritis.)

Bance M, Rutka J. Speculation into the etiologic role of viruses in the development of Bell's palsy and disorders of inner ear dysfunction. J Otolaryngol. 1990;19:46. (Discussion of a case history of a patient who initially presented with an idiopathic facial palsy that years later developed into a spectrum of vestibular dysfunction associated with herpes zoster.) [PMID: 2179576]

Djupseland G, Berdal P, Johannsen TA et al. Virus infection as a cause of acute peripheral facial palsy. Acta Otolaryngol. 1976;102:403. (This study examines the relationship between acute facial palsy and evidence of varicella-zoster infection and also demonstrates that an inflammatory reaction preceded or coincided with the facial palsy in all patients.) [PMID: 938319]

Furuta Y, Ohtani F, Kawabata H, Fukuda S, Bergstrom T. High prevalence of varicella-zoster virus reactivation in herpes simplex virus-seronegative patients with acute peripheral facial palsy. Clin Infect Dis. 2000;30(3):529. (This study demonstrates that varicella-zoster virus is one of the major etiologic agents of clinically diagnosed Bell's palsy and that viral reactivation causes acute facial paralysis in most patients who lack antibodies to herpes simplex virus.) [PMID: 10722439]

Giannoni E, Corbacelli A. Aspects immunofluoroscopiques de la corde du tympan sur de sujets atteints de paralysie de Bell. Rev Laryngol Otol Rhinol. 1977;98:31. (This report examines the pathology of the chorda tympani nerve in patients with Bell's palsy.) [PMID: 323952]

Jackson CG. Facial nerve paralysis: diagnosis and treatment of lower motor neuron facial nerve lesions and facial paralysis. American Academy of Otolaryngology-Head & Neck Surgery Foundation, Washington, DC; 1986.

Kuhweide R, Van de Steene V, Vlaminck S, Casselman JW. Ramsay Hunt syndrome: pathophysiology of cochleovestibular symptoms. J Laryngol Otol. 2002;116(10):844. Review. (This study argues that the cochleovestibular symptoms in Ramsay Hunt syndrome may result from varicella-zoster virus transmission across the nerves inside the internal auditory canal and that prompt treatment with an antiviral-corticosteroid combination might be justified in any acute nonhydropic cochleovestibular syndrome. [PMID: 12437843]

Linder T, Bossart W, Bodmer D. Bell's palsy and herpes simplex virus: fact or mystery? Otol Neurotol. 2005;26(1):109. (This study used polymerase chain reaction to detect herpes virus (HSV) and varicella-zoster virus in patients with acute facial paralysis and concluded that HSV genomic DNA alone within the sensory ganglion along the facial nerve does not explain the direct association with Bell's palsy.) [PMID: 15699730]

Mair IW, Flugsrud LB. Peripheral facial palsy and herpes zoster infection. J Laryngol Otol. 1976;90:373. (This classic paper evaluates 133 consecutive cases of peripheral facial palsy and provides evidence for simultaneous infection with the varicella-zoster virus in nine patients [68%].) [PMID: 178812]

Njoo FL, Wertheim-van Dillen P, Devriese PP. Serology in facial paralysis caused by clinically presumed herpes zoster infection. Arch Otorhinolaryngol. 1988;245:230. (Retrospective study examines the relationship between facial palsy and varicella-zoster virus infection.) [PMID: 2845904]

Ohtani F, Furuta Y, Aizawa H, Fukuda S. Varicella-zoster virus load and cochleovestibular symptoms in Ramsay Hunt syndrome. Ann Otol Rhinol Laryngol. 2006;115(3):233. (This study shows that several different patterns in the development of eighth cranial nerve dysfunction are caused by progression of neuritis or labyrinthitis following varicella-zoster virus reactivation.) [PMID: 16572614]

Peitersen E. The natural history of Bell's palsy. Am J Otol. 1982;4:107. (This classic study describes the spontaneous course of idiopathic facial palsy without treatment of any kind and included 1011 patients seen over a 15-year period.) [PMID: 7148998]

Pitts DB, Adour KK, Hilsinger RL. Recurrent Bell's palsy: analysis of 140 patients. Laryngoscope. 1988;98(5):535. (This report documents the clinical presentation, treatment, and outcome in a group of 140 patients with recurrent Bell's palsy and outlines a new classification system for ease of computer analysis and a simplified discussion of recurrent facial paralysis.) [PMID: 3362016]

Robillard PRB, Hilsinger RL, Adour KK. Ramsay Hunt facial paralysis: clinical analysis of 185 patients. Otolaryngol Head Neck Surg. 1986;95:292. (This prospective study evaluating 185 patients with Ramsay Hunt syndrome found that the facial palsy of Ramsay Hunt syndrome was more severe, caused late neural denervation, and had a less favorable recovery profile than Bell [herpes simplex] facial palsy.) [PMID: 3108776]

Tovi F, Sidi J, Haikin H, Sarov B, Sarov I. Viral infection and acute peripheral facial palsy: a study with herpes simplex and varicella zoster viruses. Isr J Med Sci. 1980;16:576. (The role of herpes simplex virus and varicella-zoster virus in acute peripheral facial palsy was evaluated according to clinical symptomatology and serologic findings in a series of 70 patients seen over a 1-year period, suggesting a relationship between herpes simplex and varicella-zoster.) [PMID: 6252119]

Vahlne A, Edstrom S, Arstila P et al. Bell's palsy and herpes simplex virus. Arch Otolaryngol. 1981;107:79. (The possible association of some viral infections with the onset of Bell's palsy was examined in a study of 142 patients.) [PMID: 6258547]

Incidence & Risk Factors

A wide spectrum of health care providers manage cases of acute facial palsy; an assessment of the true incidence of Bell's palsy is therefore complicated by this wide distribution of specialists. Nonetheless, this disorder is recognized as one of the most common neuropathies and appears to be universal in its occurrence. The incidence is approximately 1540 per 100,000 individuals in the general population.

Age and gender influence the likelihood of contracting Bell's palsy; it is uncommon in patients under the age of 10 years but thereafter increases in incidence with age. Females in their teens and 20s carry a predilection for the disorder. Among middle-aged adults, there is a nearly equal distribution by gender with a slight male predominance in older age groups. Epidemiologic surveys indicate a seasonal variation in incidence in some geographic regions.

The risk posed by diabetes mellitus in developing Bell's palsy remains undetermined, although most studies suggest a heightened susceptibility. Several authors have demonstrated a correlation between pregnancy and acute facial palsy, particularly during the third trimester and with the presence of preeclampsia.

Immunodeficiency may also entail a heightened risk for acute facial palsy. Cranial neuropathies, including facial palsy, are observed with human immunodeficiency virus (HIV) infection, often in association with a symmetrical polyneuropathy. Facial dysfunction in this setting may also reflect either susceptibility to other infectious agents or the development of lymphoma. Facial palsy in association with HIV may occur in a clinical course characteristic of Bell's palsy or herpes zoster oticus. Neuropathies may appear at any stage of HIV infection: early after initial infection, as part of the chronic illness characterized by the acquired immunodeficiency syndrome (AIDS), or with AIDS-related meningitis. Case series suggest that facial palsy in the setting of HIV infection not associated with neoplasm demonstrates patterns of spontaneous recovery that are not unlike those of the general population.

Facial palsy associated with the conditions noted above is not necessarily diagnostic of Bell's palsy. Patients should be evaluated as completely as those who do not carry these risk factors, with the notable caveat of considering the risk and benefit of radiologic studies in pregnancy.

Clinical Findings

Patient Evaluation

The diagnosis of Bell's palsy is one of exclusion. Facial motor disturbance should be characterized as Bell's palsy only after the exclusion of traumatic, neoplastic, infectious, metabolic, and congenital etiologies. Strict attention to the evaluation, particularly the history and otoscopic and neurologic findings, often differentiates an acute facial palsy of another origin from a true case of Bell's palsy.

On the clinical examination, the severity of the facial nerve weakness should be recorded by one of the standard facial nerve grading schemes. In particular, one should assess for the ability to close the eyelid, because this has the greatest functional significance. Vesicles within the auricle or external auditory canal may reveal the diagnosis of herpes zoster oticus. Pain or numbness affecting the ear, mid-face, and tongue, as well as taste disturbances, are common. Other cranial nerve deficits should also be noted.

Laboratory Findings

Blood and cerebrospinal fluid (CSF) studies only rarely differentiate a facial palsy and are largely unwarranted for most cases of Bell's palsy. For atypical cases though, one should consider Lyme titers and a search for a paraneoplastic syndrome.

Imaging Studies

Routine radiologic evaluation is generally not recommended for most cases of acute facial palsy, particularly when the clinical course matches that of Bell's palsy or herpes zoster oticus. However, if the patient's recovery is incomplete over 3 months' time, the palsy becomes recurrent, or associated cranial nerve deficits develop, then scans are warranted. Magnetic resonance imaging (MRI) scanning with dye enhancement should include the brain, the skull base, and the temporal bone to rule out a lesion along the entire course of the facial nerve. High-resolution computed tomography (CT) scanning may be useful to define the bony detail in the course of the facial nerve within the fallopian (facial) canal.

Treatment

Pretreatment Assessment

Both pharmacologic and surgical treatments are designed to reduce the likelihood of residual facial dysfunction in susceptible patients with acute facial palsies. Prior reports have documented the reasons underlying the difficulty in assessing the efficacy of steroids and other therapeutic modalities for Bell's palsy. Evaluation of the response is complicated by the potential for spontaneous remission for most acute palsies. Impediments such as the fragmentation of care of facial palsy patients as well as the difficulty in obtaining early assessment and maintaining strict experimental conditions have thwarted systematic, definitive studies.

To assess the response to treatment, patients with facial palsy should be initially stratified using clinical and electrophysiologic criteria (see Chapter 67, Anatomy, Physiology, & Testing of the Facial Nerve). The assessment of the ultimate outcome requires sensitive and objective measures and a classification system that is universally accepted. As with any study of treatment effect, inconclusive or negative results may reflect insensitive measures of outcome.

A variety of facial nerve classification schemes have been proposed. The difficulty, of course, lies in translating facial impairment into a classification that is continuous and enables precise comparisons of functional recovery. Presently, the House-Brackmann grading system has been adopted by the American Academy of Otolaryngology-Head and Neck Surgery and has found the greatest acceptance among otolaryngologists in the United States (Table 683).

Table 683. The House-Brackmann Facial Nerve Grading Scale.

Grade	Function
I	Normal
II	Normal tone and symmetry at rest
	Slight weakness on close inspection
	Good to moderate movement of forehead
	Complete eye closure with minimum effort
	Slight asymmetry of mouth with movement
III	Normal tone and symmetry at rest
	Obvious but not disfiguring facial asymmetry
	Synkinesis may be noticeable but not severe, hemifacial spasm or contracture
	Slight to moderate forehead motion
	Complete eye closure with effort
	Slight weakness of mouth with maximum effort
IV	Normal tone and symmetry at rest
	Asymmetry is disfiguring or results in obvious facial weakness
	No perceptible forehead movement
	Incomplete eye closure
	Asymmetrical motion of mouth with maximum effort
V	Asymmetrical facial appearance at rest
	Slight, barely noticeable movement
	No forehead movement
	Incomplete eye closure
	Slight movement of mouth with effort
VI	No facial function perceptible

Reproduced, with permission, from House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985;93:146.

Non-Surgical Measures

Steroid Therapy

Most early studies of the value of steroids in treating Bell's palsy were based on comparisons of treated patients with retrospective controls. Although double-blinded, randomized, controlled clinical trials have demonstrated a significantly higher rate of complete functional recovery in glucocorticoid-treated patients compared with the control group in most studies, the lack of randomization and concurrent controls and the dose of glucocorticoid used have not completely resolved the question.

Prospective, randomized trials have suggested, though not with statistical significance, that using larger doses of steroids with dextran and pentoxifylline demonstrated improved rates of recovery in the treated groups. Other double-blinded trials have demonstrated beneficial effects of glucocorticoid therapy as long as therapy was initiated early in the course of the palsy.

Oral prednisone has been used extensively to treat patients with Bell's palsy and herpes zoster oticus. Proof of efficacy is, however, controversial. Several series have compared the use of oral steroids with either no treatment or placebo; some have purported to show benefit in reducing residual weakness or aberrant regeneration and others suggest no benefit.

Meta-analytic reviews of steroids in the treatment of Bell's palsy suggest that they may have the following effects: (1) reducing the risk of denervation if initiated early on, (2) preventing or lessening synkinesis, (3) preventing progression of incomplete to complete paralysis, (4) hastening recovery, and (5) preventing autonomic synkinesis (crocodile tearing). However, no single investigation has yet been conducted with adequate size and experimental design to conclusively prove or disprove the effectiveness of steroids. However, in light of the low risk of side effects and minimal costs involved, prednisone is commonly started at the initial visiteven in patients with partial palsyon the chance that a complete palsy might evolve within a few days. The initiation of steroid therapy during the first 24 hours of symptoms might confer a higher likelihood of recovery. In patients with Ramsay Hunt syndrome, higher rates of full recovery have been noted by some studies for patients receiving intravenous therapy.

Glucocorticoid Steroids

Glucocorticoid steroids exert an inhibitory effect on virtually every phase of the inflammatory response and thus have assumed an important role in treating a vast range of inflammatory and immune-mediated disorders. The precise mechanism by which steroids exert beneficial effects is incompletely defined in many of the conditions for which they are prescribed. The pharmacologic effects of steroids make them attractive agents for ameliorating symptoms associated with the acute phases of Bell's palsy and herpes zoster oticus and, theoretically, for improving the likelihood of full recovery. In addition to their anti-inflammatory properties, the glucocorticoid steroids also exert a facilitatory action on the neuromuscular junction. These combined effects may contribute to the recovery of neuromusculature function in disorders such as inflammatory polyradiculoneuropathies (the Landry-Guillain-Barr syndrome), the pathology of which is marked by inflammatory, segmental demyelinization.

The desired goal of glucocorticoid therapy for acute facial paralysis is to induce effective anti-inflammatory control. To provide such control, the inflammatory process should be countered with consistent, pharmacologic levels of an anti-inflammatory agent, beginning as soon as possible. Once the inflammatory process is checked and the stimulus for inflammation removed, therapy can be discontinued. However, abrupt withdrawal may be followed by a rebound of disease activity. To prevent reacceleration of the inflammatory process, a tapered withdrawal of the daily glucocorticoid dose over 1014 days is recommended.

Based on the theoretical active phase of the herpes simplex and varicella-zoster viruses (3 and 14 days, respectively), the following strategy for steroid treatment of Bell's palsy and herpes zoster oticus has been proposed: oral prednisone (1 mg/kg/d) divided into 3 doses per day for 710 days. The daily dose should then be tapered to zero over the following 10 days. Theoretically, this dosing regimen maximizes anti-inflammatory activity while minimizing side effects and is consistent with anti-inflammatory schedules that are effective in controlling acute hypersensitivity as well as autoimmune and other inflammatory disorders.

When administered intravenously, methylprednisolone is prescribed at 1 g/d administered intravenously as either a single dose or in 3 divided doses for 37 days, followed by an oral prednisone taper.

Side Effects of Steroid Therapy

Side effects that are likely to be manifest during short-term steroid treatment include hyperglycemic action. Given the high incidence of glucose intolerance in some series of acute facial palsy patients, steroids should be initially prescribed with caution. Other acute side effects include CNS changes such as psychotic breaks, fluid and electrolyte disturbances, acne, increased intraocular pressure, and gastrointestinal irritation. Corticosteroids are category C drugs in pregnant patients.

An adverse effect of glucocorticoid administration that deserves special consideration is a heightened susceptibility to infection. Glucocorticoids should be used with caution in patients with existing gastrointestinal infections and in cases of latent tuberculosis. The effects of glucocorticoids on cellular and humoral components of inflammation may lessen host immunity to bacterial, viral, and fungal infections. Latent infections may become reactivated and spread. Moreover, suppression of the inflammatory response may conceal symptoms and signs of infection.

Although effects on host resistance have been demonstrated in experimental trials, typical daily doses of glucocorticoids (1 mg/kg/d of prednisone or its equivalent) given for 2 weeks or less are only rarely associated with an increased susceptibility to infection. The risk of steroid-induced dissemination of viruses presents a particular concern in treating acute facial palsies of viral origin. The risk of virus dissemination is significant with steroid therapy beyond 1 month and in immunosuppressed patients. Otherwise, clinical experience suggests that the risk of this complication is minimal and that steroids can ameliorate postherpetic neuralgia.

Antiviral Therapy

Antiviral therapy represents a newer adjunct in treating acute facial palsy of viral origin. Based on its spectrum of activity and low toxicity, acyclovir, a synthetic purine nucleoside analogue, has found clinical use in treating herpes zoster oticus. In cell culture, acyclovir inhibits the herpes simplex Types I and II, varicella-zoster, and Epstein-Barr viruses and cytomegalovirus.

Indications for the use of acyclovir include herpes simplex viral infections in genital herpes, immunocompromised patients, herpes simplex encephalitis, and varicella-zoster infections in immunocompromised patients. Early reports suggest that acyclovir may mitigate neurologic deficits produced by herpes zoster oticus.

Intravenous Antiviral Agents

Intravenous acyclovir (10 mg/kg every 8 hours for 7 days) produced substantially greater functional return in patients treated within the first 72 hours after the onset of paralysis. Moreover, preliminary reports have demonstrated early recovery of facial nerve function and reversal of sensorineural hearing loss associated with herpes zoster oticus in response to the drug early on, though these are nonrandomized trials. Given the high incidence of nerve degeneration associated with this disorder, these results appear promising. The efficacy of acyclovir in treating herpes zoster oticus and its potential role in treating Bell's palsy are currently under evaluation.

Oral Antiviral Agents

Oral antiviral agents are significantly less costly and more convenient than intravenous agents. An exception to the general preference for oral antiviral agents exists in immunocompromised patients with severe or widespread herpes zoster oticus. Newer antiviral drugs, including valacyclovir, famciclovir, and penciclovir, are better absorbed after oral administration than acyclovir and have increasingly been used in treating Ramsay Hunt syndrome. However, these drugs are more expensive than acyclovir. Valacyclovir may be superior to acyclovir in limiting zoster pain.

Acyclovir has also been used for the treatment of Bell's palsy. When compared with patients who received oral prednisone alone, some studies have identified a higher recovery rate as well as reduced rates of synkinesis in Bell's palsy patients given oral acyclovir plus prednisone. Conflicting studies have found little benefit from adding oral acyclovir to prednisone in Bell's palsy.

Synthesizing the myriad clinical trials on the topic, one can say that oral acyclovir appears reasonably indicated in all cases of herpes zoster oticus. Although proof of efficacy is limited in Bell's palsy, low risks and costs associated with acyclovir suggest that it may be reasonable to include its use in patients with complete facial paralysis. Acyclovir is prescribed at 400 mg or 800 mg 5 times daily and administered orally for 710 days in Bell's palsy. Alternately, acyclovir may be prescribed at 3001000 mg (510 mg/kg) three times daily administered intravenously. Higher acyclovir doses (ie, 4000 mg per day orally) are recommended for patients suffering from herpes zoster oticus. Intravenous dosing is often indicated for immunocompromised individuals with severe infection. The main side effects of antiviral agents are nausea, malaise, injection site reactions, and mild renal insufficiency. Acyclovir is a category B drug in pregnant patients.

Physical Therapy

Electrical Stimulation

Transcutaneous electrical (galvanic) stimulation of the facial muscles has been used in an effort to maintain membrane conductivity and reduce muscle atrophy. It has also been used to potentially limit residua such as persistent paresis in patients with long-standing facial palsy. There exist few compelling, comparative trials to support this practice, although interest in this measure persists. Electrical stimulation may also improve function in chronic facial palsy. Patients left with partial deficits often benefit from physical therapy. Electromyographic and mirror feedback has been used to facilitate muscle reeducation to assist in the recovery of symmetric facial tone and expression.

Eye Care

The cornea is vulnerable to drying and foreign body irritation in acute facial palsy due to orbicularis oculi dysfunction. Corneal desiccation and abrasion can result from incidental contact, particularly during sleep and can progress to cataract formation. Measures that confer corneal protection are recommended. Examination of the cornea by slit-lamp biomicroscopy and either fluorescein or rose Bengal staining provides the most sensitive measure for the early detection of corneal compromise. For mild facial paresis, therapy is generally not needed, unless dysfunction of cranial nerve V is present because the combination of a facial weakness and dysesthesia dramatically increases the risk of corneal exposure and ulceration. For moderate to severe deficits, a corneal moistening regimen should consist of a moisture chamber, artificial tears during the daytime, and ocular ointments at night. Sunglasses or other protective eyewear should be worn to protect the eyes in the outdoors. The lower eyelid can be gently elevated with adhesive tape running obliquely from the lower lid to the orbital rim, temporarily improving lid closure.

In longer-standing cases of facial palsy, lubrication and occlusion are insufficient to protect the cornea. Implanting a gold weight in the upper lip, which induces ptosis, and reducing the exposed area of cornea may augment lid suturing. This procedure is often augmented by elevating the lower lid via a lateral canthopexy, in which the tarsal ligament is suspended to the periorbital periosteum. Joining the upper and lower lid margins laterally (tarsorrhaphy) may be performed to narrow the palpebral fissure. The standard procedure calls for suturing a margin of upper and lower lid together from the lateral canthus inward. The width of the tarsorrhaphy is adjusted to optimize the degree of lid closure. If neural recovery ensues, the tarsorrhaphy can be reversed.

Surgical Measures

Mounting anatomic and electrophysiologic evidence of a specific anatomic lesion site in Bell's palsy has guided the choice of procedures for surgical intervention. These approaches now focus on decompressing the meatal foramen and adjacent labyrinthine segment of the nerve for cases thought to have a poor prognosis for complete recovery with medical treatment alone.

Nerve Decompression

Surgical approaches to treating acute facial palsy are based on the premise that axonal ischemia can be reduced by the decompression of nerve segments presumed to be inflamed and entrapped. Facial nerve decompression, aimed at alleviating Bell's palsy and herpes zoster oticus, has been variably embraced for more than 70 years. The role of surgery has evolved in concert with developments in electrophysiologic testing and techniques of enhanced surgical exposure of the facial nerve.

Preoperative Considerations

Evoked electromyography (EEMG) may be used to help stratify patients who might benefit from facial nerve decompression. Surgical treatment is offered when evoked response amplitudes are 10% (or less) of the normal side. This criterion is based on the observation that approximately one half of patients who progressed to a nadir of 95100% degeneration within 2 weeks of the onset of the paralysis demonstrated a permanent, unsatisfactory recovery of facial function. Furthermore, most patients who reach a 90% level of degeneration progressed beyond 94% degeneration in the EEMG profile. Therefore, the proposal that immediate surgical decompression be performed as soon as the 90% level of degeneration has been reached entailed unnecessary surgery in, at most, 10% of patients. All patients who underwent decompression when degeneration reached 90% demonstrated a satisfactory return of facial movement. The 90% rate of satisfactory outcome with surgery compared favorably with the 50% chance of satisfactory return noted in patients who were not operated on and who were matched by EEMG profile. Surgery performed on eight patients in the third week after onset of the palsy, when degeneration exceeded 90%, did not significantly improve the return of facial function. However, two patients in this group demonstrated an exceptional return of facial movement after decompression. These observations suggest that studies of more patients with delayed degeneration are needed before the role of surgical decompression can be assessed definitively in this subset of patients.

Transmastoid Approach

Both transmastoid and middle fossa approaches have been described, although transmastoid approaches are thought to provide limited exposure of the meatal foramen owing to the interposed labyrinth. The transmastoid approach to the geniculate ganglion and the labyrinthine segment obviates a craniotomy, but requires removal of the incus in poorly pneumatized bones to facilitate exposure of the facial nerve proximal to the cochleariform process. Some studies have shown that facial nerve decompression using the transmastoid approach improved recovery in patients whose maximal nerve stimulation responses were reduced by 75% or more. However, long-term follow-up of these patients failed to evidence significant benefit from this procedure as compared to the spontaneous recovery rate found in other studies.

Middle Cranial Fossa Approach

The middle cranial fossa approach to the meatal, labyrinthine, and geniculate segments of the nerve facilitates direct decompression with small though significant risk to the labyrinth (Figure 685A). Permanent ipsilateral auditory and vestibular loss, meningitis, and subarachnoid hemorrhage are potential complications of facial nerve decompression via a middle cranial fossa approach. This approach also permits direct stimulation of the facial nerve proximal to the meatal foramen, enabling verification of the site of impairment if a complete loss of response to electrical stimulation has not yet occurred. Intraoperative stimulus trials typically reveal severely decreased to absent responses proximal to the foramen. However, stimulation distal to the foramen typically evokes potentials of substantially greater amplification (Figure 685B).

Figure 685.

(A) Schematic of the approach to the intracanalicular and labyrinthine segments of the facial nerve via a middle cranial fossa. P, Pregeniculate (proximal) site of stimulation. D, Distal site of stimulation at the tympanic segment of the facial nerve. (B) Electrically evoked responses obtained after decompression of the meatal foramen in a patient with Bell's paralysis and > 90% reduction on preoperative EEMG. Responses of reduced amplitude to pregeniculate stimulation suggest the lesion is in the labyrinthine segment of the facial nerve.

(A: Adapted, with permission, from Fisch U, Esslen E. Total intratemporal exposure of the facial nerve: Pathologic findings in Bell palsy. Arch Otolaryngol. 1972;95:335; B: Adapted, with permission, from Gantz B, Gmur A, Fisch U. Intraoperative electromyography in Bell's palsy. Am J Otolaryngol. 1982;3:273.)

Nerve Grafting

Facial motor reinnervation may be accomplished by grafting a section of normal peripheral nerve over a damaged area, or bringing fibers from the intact facial nerve across the midline to innervate the paralyzed side, or by direct anastomosis of the ipsilateral hypoglossal nerve with the peripheral facial nerve. Nerve grafting may be augmented by muscle transfer procedures, since atrophy of facial muscles may render the muscle fibers less amenable to reinnervation. A wide variety of reconstructive procedures, including rhytidectomy, blepharoplasty, brow lift, and facial slings, can improve resting tone and symmetry.

Aberrant regeneration may give rise to inappropriate patterns of reinnervation wherein specific muscle groups receive excessive neural inputs. Spasm and synkinesis with facial nerve recovery often produce undesired eye closure (Figure 686). This form of aberrant facial nerve regeneration can often be managed with subcutaneous or intramuscular botulinum toxin injections. Botulinum toxin, which induces temporary paresis in targeted muscles for up to 6 months, can reduce disability with tonic contractions, hemifacial spasm, and synkinesis. Side effects of botulinum toxin are rare and typically reveal severely decreased to absent responses proximal to the foramen. However, stimulation distal to the foramen typically evokes potentials of substantially greater amplification.

Figure 686.

38-year-old woman 1 year after recovery from Bell's paralysis with synkinetic closure of left eye with lip movement.

Prognosis

Most series that have assessed surgical decompression of the facial nerve in Bell's palsy have been small and retrospective and have targeted subjects most likely to suffer residual deficits (ie, patients with complete palsies and severe reductions in neural conductivity as demonstrated by electrophysiologic testing). Results that have used the middle fossa approach have included multicenter, prospective data, although subjects were nonrandomized. In these studies, patients recovered completely or with slight residual deficits in 91% of the surgical group, but in only 42% of a similar, medically treated group, suggesting a benefit of decompression using this surgical approach. Because of the difficult nature of designing such a controlled trial, the precise role of facial nerve decompression in the management of Bell's palsy and herpes zoster oticus remains unclear at present.

Adour KK, Byl FM, Hilsinger RL, Kahn ZM, Sheldon MI. The true nature of Bell's palsy: analysis of 1000 consecutive patients. Laryngoscope. 1978;88:787. (This classic study of 1502 patients with Bell's palsy led to the conclusion that Bell's palsy is an acute benign cranial polyneuritis probably caused by reactivation of the herpes simplex virus and that the dysfunction of the motor cranial nerves [V, VII, X] may represent inflammation and demyelinization rather than ischemic compression.) [PMID: 642672]

Adour KK, Diamond C. Decompression of the facial nerve in Bell's palsy: a historical review. Otolaryngol Head Neck Surg. 1982;90:453. (This article reviews, in chronologic order, the history and present status of facial nerve decompression in the surgical management of patients with Bell's palsy.) [PMID: 6817276]

Adour KK, Ruboyianes JM, Von Doersten PG et al. Bell's palsy treatment with acyclovir and prednisone compared with prednisone alone: a double-blind, randomized, controlled trial. Ann Otol Rhinol Laryngol. 1996;105(5):371. (This double-blind study compared the final outcome of 99 patients with Bell's palsy treated with either acyclovir-prednisone or placebo-prednisone, and demonstrated that the outcome in acyclovir-prednisone-treated patients was superior to that in placebo-prednisone-treated patients.) [PMID: 8651631]

Allen D, Dunn L. Acyclovir or valacyclovir for Bell's palsy (idiopathic facial paralysis). Cochrane Database Syst Rev. 2004;(3):CD001869. (This meta-analysis of the use of antiviral medications for Bell's palsy suggests that more data are needed from a large multicenter randomized, controlled, and blinded study with at least 12 months' follow-up before a definitive recommendation can be made regarding the effect of acyclovir or valacyclovir on Bell's palsy.) [PMID: 15266457]

Brach JS, Van Swearingen JM. Physical therapy for facial paralysis: a tailored treatment approach. Phys Ther. 1999;79(4):397. (This case report describes a classification system used to guide treatment and to monitor recovery of an individual with facial paralysis and describes how the use of this classification system may help simplify the rehabilitation process.) [PMID: 10201545]

Brown J. Bell's palsy: a five-year review of 174 consecutive cases; an attempted double-blind study. Laryngoscope. 1982;92:1369. (This paper examines 174 consecutive cases of Bell's palsy that were clinically divided into a group with incomplete facial palsy and a group with complete facial palsy, outlining the prognosis in each group.) [PMID: 6757616]

Claman H. Glucocorticosteroids II: the clinical responses. Hosp Pract. 1983;18(7):143. (This paper reviews the use and treatment responses of the class of glucocorticosteroid medications.) [PMID: 6407967]

Fauci A, Dale D, Balow J. Glucocorticosteroid therapy: mechanisms of action and clinical considerations. Ann Intern Med. 1976;84:304. (This review outlines the mechanisms of action of steroids and their use in various clinical scenarios.) [PMID: 769625]

Fisch U. Surgery for Bell's palsy. Arch Otolaryngol. 1981;107:1. (This electroneuronographic study of the spontaneous course of Bell's palsy shows that the chance of a satisfactory spontaneous return of facial function is reduced by 50% when 95% or more maximal degeneration is reached within two weeks of onset.) [PMID: 7469872]

Fisch U, Esslen E. Total intratemporal exposure of the facial nerve: pathologic findings in Bell's palsy. Arch Otolaryngol. 1972;95:335. (This report highlights the intraoperative and pathologic findings of the facial nerve during intratemporal decompression of the nerve.) [PMID: 5018255]

Gantz B, Rubinstein J, Gidley P, Woodworth G. Surgical management of Bell's palsy. Laryngoscope. 1999;109(8):1177. (This prospective study examines surgical decompression of the facial nerve in a population of patients with Bell's palsy who exhibit the electrophysiologic features associated with poor outcomes.) [PMID: 10443817]

House JW. Facial nerve grading systems. Laryngoscope. 1983;93:1056. (This classic study outlines the basis of the House-Brackmann facial nerve grading scale, the most widely used facial grading scale used.) [PMID: 3921901]

House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985;93:146. (This classic study outlines the basis of the House-Brackmann facial nerve grading scale, the most widely used facial grading scale used.) [PMID: 3921901]

Kartush J, Linstrom C, McCann P, Graham M. Early gold weight eyelid implantation for facial paralysis. Otolaryngol Head Neck Surg. 1990;103(6):1016. (This study evaluates the use of the gold weight for facial reanimation in patients with facial palsy.) [PMID: 2126116]

Keczkes K, Basheer AM. Do corticosteroids prevent postherpetic neuralgia? Br J Dermatol. 1980;102:551. (This study evaluates 20 patients who received prednisolone for the treatment of postherpetic neuralgia, compared with 20 patients who received carbamazepine.) [PMID: 7387900]

Kinishi M, Hosomi H, Amatsu M, Tani M, Koike K. Conservative treatment of Ramsay Hunt syndrome. Jibiinkoka Gakkai Kaiho. 1992;95(1):65. (This study evaluates the use of a "steroid-dextran" in 172 cases of Bell's palsy.) [PMID: 1709354]

Laskawi R, Damenz W, Roggenkamper P, Baetz A. Botulinum toxin treatment in patients with facial synkinesis. Eur Arch Otorhinolaryngol Suppl. 1994;S195:9. (This study outlines the treatment rationale and technique of botulinum [Botox] toxin to treat facial synkinesis.) [PMID: 10774349]

May M. Total facial nerve exploration: transmastoid, extralabyrinthine, and subtemporal. Laryngoscope. 1979;89:906. (This paper describes a transmastoid operation that provides exposure of the labyrinthine segment of the facial nerve without performance of a craniotomy.) [PMID: 312987]

May M, Klein SR, Taylor FH. Idiopathic (Bell's) facial palsy: natural history defies steroid or surgical treatment. Laryngoscope. 1985;95:406. (The results from this and prior studies indicate transmastoid facial nerve surgery is not recommended to treat Bell's palsy because no benefits have been identified that outweigh the risks of surgery.) [PMID: 3982183]

Morrow M. Bell's palsy and herpes zoster oticus. Current treatment options. Neurology. 2000;2(5):407. (This report outlines the author's approach to treating patients with Bell's palsy and herpes zoster oticus, including the use of oral prednisone in those patients with complete facial palsy and no contraindications to their use, and the use of antivirals [acyclovir].) [PMID: 11096766]

Peitersen E. The natural history of Bell's palsy. Am J Otol. 1982;4:107. (This classic study describes the spontaneous course of idiopathic facial palsy without treatment of any kind and included 1011 patients seen over a 15-year period.) [PMID: 7148998]

Ramos Macias A, de Miguel Martinez I, Martin Sanchez AM, Gomez Gonzalez JL, Martin Galan A. The incorporation of acyclovir into the treatment of peripheral paralysis: a study of 45 cases. Acta Otorrinolaringol Esp. 1992;43(2):117. (The relation between use of acyclovir and facial nerve palsy prognosis was studied, but found no added benefit in patients treated with acyclovir compared with steroids.) [PMID: 1605959]

Salinas RA, Alvarez G, Ferreira J. Corticosteroids for Bell's palsy (idiopathic facial paralysis). 2004;18(4):CD001942. (This recent meta-analysis of randomized controlled trials did not show significant benefit from treating Bell's palsy with corticosteroids. More randomized controlled trials with a greater number of patients are needed to determine reliably whether there is real benefit (or harm) from corticosteroid therapy in patients with Bell's palsy.) [PMID: 15495021]

Stankiewicz J. Steroids and idiopathic facial paralysis. Otolaryngol Head Neck Surg. 1983;91:672. (This article reviews 92 papers that study steroids used for facial paralysis.) [PMID: 6320082]

Targan R, Alon G, Kay S. Effect of long-term electrical stimulation on motor recovery and improvement of clinical residuals in patients with unresolved facial nerve palsy. Otolaryngol Head Neck Surg. 2000;122(2):246. (This study investigated the efficacy of a pulsatile electrical current to shorten neuromuscular conduction latencies and minimize clinical residuals in patients with chronic facial nerve damage caused by Bell's palsy or acoustic neuroma excision.) [PMID: 10652399]

Tyring SK, Beutner KR, Tucker BA, Anderson WC, Crooks R. Antiviral therapy for herpes zoster: randomized, controlled clinical trial of valacyclovir and famciclovir therapy in immunocompetent patients 50 years and older. Arch Fam Med. 2000;9(9):863. (This randomized study compares the efficacy and safety of valacyclovir hydrochloride and famciclovir for the treatment of herpes zoster.) [PMID: 11031393]

Wolf S, Wagner J, Davidson S et al. Treatment of Bell's palsy with prednisone: a prospective randomized study. Neurology. 1978;28:158. (Two hundred thirty-nine patients with Bell's palsy were randomly distributed into prednisone-treated and control groups and studied.) [PMID: 340980]

Wood M, Shukla S, Fiddian A, Crooks R. Treatment of acute herpes zoster: effect of early (less than 48 hours) versus late (48- to 72-hour) therapy. (Acyclovir significantly shortened the time to complete resolution of zoster-associated pain compared with placeboand valacyclovir was superior to acyclovir in this regardeven when therapy was delayed up to 72 hours after the onset of rash.) [PMID: 9852981]

Yanagihara N, Honda N, Hato N, Murakami S. Edematous swelling of the facial nerve in Bell's palsy. Acta Otolaryngol. 2000;120:667. (Considering the etiology and the analysis of edematous swelling, the authors propose that the course of Bell's palsy be differentiated into an acute phase [the first 3 weeks after onset], a subacute phase [from 4th9th weeks] and a chronic phase [after 10th week].) [PMID: 11039881]

Other Facial Nerve Disorders

Next to Bell's palsy, the most common causes of acute, peripheral facial paralysis are trauma, herpes zoster oticus, bacterial infection, perinatal factors, and neoplastic involvement of the nerve. An acute facial palsy due to trauma or infection often presents with characteristic findings that readily point to a diagnosis. In contrast, differentiating neoplastic involvement of the facial nerve from Bell's palsy frequently poses a dilemma. Several other disorders (described below) should be considered in the clinical evaluation of an acute facial palsy. It must always be remembered that Bell's palsy is a diagnosis of exclusion, and one should therefore consider the following disorders in the context of the presenting symptoms and signs of the patient.

Facial Nerve Neoplasms

A variety of neoplasms may induce a facial palsy, which is occasionally acute in onset (Table 681 and Figure 687). It is estimated that there is an incidence of sudden facial palsy in 27% of patients found to have neoplastic involvement of the nervea surprisingly high incidence given the slow growth and encapsulation of most tumors responsible for the palsy.

Figure 687.

(A) A 42-year-old woman before onset of facial dysfunction. (B) Left facial paralysis of 1-year's duration mistakenly attributed to Bell's palsy. Severe facial skewing due to complete loss of facial motor tone is apparent. (C) The severity of the patient's facial nerve dysfunction allows for only passive closure of the left eye. (D) CT scan of temporal bones demonstrating facial nerve neuroma involving the tympanic segment (arrow). (E) CT scan of temporal bones revealing expansion of fallopian canal within the mastoid segment that is filled with soft-tissue density. (F) After resection of facial schwannoma from meatal foramen to stylomastoid foramen, a sural nerve graft was placed. Reinnervation did not occur, requiring lower lid acanthopelyx and (gold) weighting of upper eyelid to achieve eye closure. (G) Early postoperative view after left temporalis transposition to achieve lower facial soft tissue support.

Although patients with Bell's palsy may present with a variety of associated symptoms, atypical presentations warrant consideration of other causes, particularly neoplasms. A facial palsy produced by a neoplasm may differ only subtly from Bell's palsy. There are characteristic historical and clinical features that suggest that a neoplasm is responsible for a facial palsy: (1) progression of a facial palsy over 3 weeks or longer; (2) no return of facial function within 36 months of the onset of paralysis; (3) failure to resolve an incomplete paresis within 2 months; (4) facial hyperkinesia, particularly hemifacial spasm, antecedent to the palsy; (5) associated dysfunction of regional cranial nerves; (6) prolonged otalgia or facial pain; (7) a mass in the middle ear, external ear canal, digastric region, or parotid gland; and (8) recurrent ipsilateral palsy.

Although Bell's palsy may recur, a recurrent palsy indicates the need for an exhaustive tumor search with radiologic evaluation. When the diagnosis of a neoplasm is delayed or missed, the neoplasm carries the potential consequences of extension into the labyrinth and cranial fossae. Extension into the cerebellopontine angle diminishes the opportunity for effective reanimation with direct neural anastomosis, underscoring both the need for vigilance in cases of atypical facial palsy and the importance of early diagnosis.

Facial nerve hemangiomas may also present with facial palsy. A classic presentation of a patient with a facial nerve hemangioma is one of recurrent and progressively more severe episodes of unilateral facial palsy. Treatment involves surgical excision, often at the expense of residual facial nerve function.

Angeli SI, Brackmann DE. Is surgical excision of facial nerve schwannomas always indicated? Otolaryngol Head Neck Surg. 1997;117(6):S144. (This article outlines the indications for surgical excision of facial nerve schwannomas.) [PMID: 9419130]

Isaacson B, Telian SA, McKeever PE, Arts HA. Hemangiomas of the geniculate ganglion. Otol Neurotol. 2005;26(4):796. (Review of the presentation and clinical course of six patients with hemangiomas of the geniculate ganglion.) [PMID: 16015187]

Jackson CG, Glasscock ME, Hughes GB, Sismanis A. Facial paralysis of neoplastic origin: diagnosis and management. Laryngoscope. 1980;90:1581. (This classic article outlines the basis for differentiating facial palsy with a neoplastic origin from that with an idiopathic origin [ie, Bell's palsy].) [PMID: 6999266]

Liu R, Fagan P. Facial nerve schwannoma: surgical excision versus conservative management. Ann Otol Rhinol Laryngol. 2001;110(11):1025. (This study compares a series of 22 patients with facial nerve schwannoma, of whom 12 underwent definitive excision and 10 were managed more conservatively.) [PMID: 11713912]

Perez R, Chen JM, Nedzelski JM. Intratemporal facial nerve schwannoma: a management dilemma. Otol Neurotol. 2005;26(1):121. (This report outlines the clinical management of 24 patients with facial nerve schwannomas). [PMID: 15699732]

Salib RJ, Tziambazis E, McDermott AL, Chavda SV, Irving RM. The crucial role of imaging in detection of facial nerve hemangiomas. J Laryngol Otol. 2001;115(6):510. (This report supports the assertion that the definitive diagnosis of a facial nerve tumor rests exclusively with high-resolution imaging of the temporal bone using enhanced MRI and thin-sectioned CT scanning.) [PMID: 11429083]

Wiggins RH 3rd, Harnsberger HR, Salzman KL, Shelton C, Kertesz TR, Glastonbury CM. The many faces of facial nerve schwannoma. AJNR Am J Neuroradiol. 2006;27(3):694. (This paper reviews the clinical presentation and radiographic appearance of 24 patients with facial nerve schwannomas.) [PMID: 16552018]

Melkersson-Rosenthal Syndrome

General Considerations

Melkersson-Rosenthal syndrome (MRS) is a granulomatous neuromucocutaneus systemic disorder characterized by a variable course that includes unilateral facial palsy, episodic or progressive facial edema, and lingua plicata (scrotal or fissured tongue). The syndrome is usually sporadic in occurrence, although familial occurrence has been described.

Pathogenesis

Patients with MRS demonstrate orofacial granulomatosis, including oral lesions with noncaseating granulomas, features often associated with Crohn's disease, sarcoidosis, focal dental sepsis, and food or contact allergies. Recent studies have shown a possible link with mycobacterial infection. The syndrome may also reflect a more generalized autonomic dysfunction that manifests as vasomotor instability rather than a purely inflammatory condition. Further support for this assertion comes from the association of MRS with migraine headaches and megacolon.

Clinical Findings

Patients may variably present with several symptoms that mark the syndrome. Lingua plicata is most likely to occur early in life, whereas facial edema generally occurs after the initial episode of facial weakness (Figures 688 and 689). Facial dysfunction may be heralded by the onset of a facial swelling, but more typically precedes the swelling by months or years.

Figure 688.

Facial paralysis in newborns and young infants can be difficult to detect at rest owing to high facial tone in these age groups. Right facial paralysis in a neonate with medulloblastoma of the caudal brainstem is shown. A right esotropia indicates a right abducens paralysis combined with right facial nerve paralysis. (A) Face at rest. (B) An asymmetric crying facies.

Figure 689.

(A) An 8-year-old girl during the initial episode of right facial paralysis associated with lower facial and lip swelling. This patient experienced three subsequent episodes of right facial paralysis with swelling on a yearly basis. (B) At age 12, evoked electromyography demonstrated poor responsiveness on the right side in association with an episode of paralysis. Facial nerve decompression via a middle cranial fossa approach was performed. No subsequent episodes of facial palsy have been noted over the ensuing 5 years. (C) Patient at age 13 years. (D) Patient at age 15 years. (E and F) Patient at age 17 revealing full facial movement, with some synkinetic eye closure with lip movement.

Episodes of facial paresis or paralysis typically begin in childhood or adolescence. Edema of the lips and palatal mucosa produces a ruddy appearance. Swelling often extends to the cheeks, eyelids, nose, and chin and may be dramatic. Progressive disfigurement can result from recurrent facial swelling. Facial weakness assumes a peripheral distribution and can be differentiated from Bell's palsy only when other manifestations of the syndrome are apparent or noted on the history. Although a relapsing course is usual, good to excellent recovery is typical. However, cases of progressive dysfunction have been described.

Treatment

The treatment of facial palsy associated with MRS is empiric. Anti-inflammatory (steroid) therapy has been used with mixed success. Antibiotics, antihistamines (tetracycline derivatives), sulfasalazine (an aspirin-like compound), and clofazimine (used to treat leprosy) have all been used with varying degrees of success. Reports of surgical decompression of the meatal and labyrinthine segments suggest a benefit in preventing further recurrence of the palsy.

Apaydin R, Bahadir S, Kaklikkaya N, Bilen N, Bayramgurler D. Possible role of Mycobacterium tuberculosis complex in Melkersson-Rosenthal syndrome demonstrated with Gen-Probe amplified Mycobacterium tuberculosis direct test. Australas J Dermatol. 2004;45(2):94. Erratum in: Australas J Dermatol. 2005;46(3):209. (This report demonstrates a possible link between Mycobacterium and Melkersson-Rosenthal syndrome.) and Melkersson-Rosenthal syndrome.)  [PMID: 15068454]

Dutt SN, Mirza S, Irving RM, Donaldson I. Total decompression of facial nerve for Melkersson-Rosenthal syndrome. J Laryngol Otol. 2000;114(11):870. (This study describes a successful case of a surgical decompression of the facial nerve in a 27-year-old woman with Melkersson-Rosenthal syndrome and reviews the literature pertaining to facial nerve decompression for this syndrome.) [PMID: 11144840]

Glickman LT, Gruss JS, Birt BD, Kohli-Dang N. The surgical management of Melkersson-Rosenthal syndrome. Plast Reconstr Surg. 1992;89(5):815. (This article reports on 14 patients with Melkersson-Rosenthal syndrome and provides an algorithm that guides the surgeon with regard to both the medical and surgical treatment of the patient with this syndrome.) [PMID: 1561252]

Graham MD, Kemink JL. Total facial nerve decompression in recurrent facial paralysis and Melkersson-Rosenthal syndrome: a preliminary report. Am J Otol. 1986;7(1):34. (This preliminary report describes two patientsone with unilateral Melkersson-Rosenthal syndrome and the other with a bilateral recurrent idiopathic facial paralysiswho were treated with combined transmastoid and middle cranial fossa total facial nerve exposure, decompression, and slitting of the fibrous nerve sheath.) [PMID: 3946579]

Gerressen M, Ghassemi A, Stockbrink G, Riediger D, Zadeh MD. Melkersson-Rosenthal syndrome: case report of a 30-year misdiagnosis. J Oral Maxillofac Surg. 2005;63(7):1035. (Report of a case and review of the literature of patients with Melkersson-Rosenthal syndrome.) [PMID: 16003636]

Pigozzi B, Fortina AB, Peserico A. Successful treatment of Melkersson-Rosenthal syndrome with lymecycline. Eur J Dermatol. 2004;14(3):166. (This report documents the successful treatment of a patient with Melkersson-Rosenthal syndrome with the tetracycline-like drug lymecycline.) [PMID: 15246942]

Sciubba JJ, Said-Al-Naief N. Orofacial granulomatosis: presentation, pathology and management of 13 cases. J Oral Pathol Med. 2003;32(10):576. (A large series of patients with Melkersson-Rosenthal syndrome.) [PMID: 14632932]

Lyme Disease

General Considerations

Lyme disease is a multisystem infection induced by the tick-borne strain of the Borrelia burgdorferi spirochete. The occurrence of acute facial palsy in association with Lyme disease is well recognized. Unilateral or bilateral facial palsy may occur in up to 11% of patients with Lyme disease. The ratio of unilateral to bilateral involvement is 3:1.

Clinical Findings

Symptoms and Signs

Although most patients with facial palsy associated with Lyme disease note an antecedent rash adjacent to the site of a tick bite, others do not; the palsy may be the presenting sign of the illness. The interval between the onset of the rash and facial palsy is less than 2 months. Facial palsy may occur in association with other neurologic deficits produced by meningoencephalitis and radiculoneuritis.

After a tick bite and a 1- to 4-week incubation period, skin lesions develop in approximately 50% of infected individuals in association with flu-like symptoms. Less than half of patients suspected to have Lyme disease can recall a previous tick bite. Within weeks to months after the initial infection, constitutional, neurologic, and cardiac manifestations, including ipsilateral or bilateral facial palsy, may appear. Arthritic symptoms typically follow.

Laboratory Findings

If Lyme disease is suspected, diagnostic testing should include serologic testing with ELISA (Enzyme-Linked Immunosorbent Assay) to search for IgG and IgM antibodies. By some reports, serologic evidence of Lyme disease has been found in up to 20% of patients diagnosed with Bell's palsy.

Treatment

Early antibiotic treatment is thought to enhance symptomatic improvement and prevent long-term sequelae. A 3-week course of tetracycline, doxycycline, or amoxicillin (for adults) or penicillin (for children) is recommended, with erythromycin administered as an alternative choice. Success in over 90% of patients has been reported with this treatment. Adequate antibiosis provides high rates of recovery of facial function with a generally good prognosis for facial nerve recovery. Residual dysfunction was more likely in patients with bilateral involvement.

Bagger-Sjoback D, Remahl S, Ericsson M. Long-term outcome of facial palsy in neuroborreliosis. Otol Neurotol. 2005;26(4):790. (This study shows that not all children with neuroborreliosis-related facial palsy recover with 100% normal function.) [PMID: 16015186]

Burgdorfer W, Barbour AG, Hayes S, Benach J, Grunwaldt E, David J. Lyme disease: a tickborne spirochetosis? Science. 1982;216:1317. (This classic paper is the first that links the newly discovered spirochete in the etiology of Lyme disease.) [PMID: 7043737]

Clark JR, Carlson RD, Pachner AR, Sasaki CT, Steere AC. Facial paralysis in Lyme disease. Laryngoscope. 1985;95(11):1341. (This paper reviews the clinical course, distinguishing features, and outcome of 124 patients with facial palsies. The authors believe that antibiotics should be given to patients with this facial palsy to treat any other concurrent manifestations of the illness and to prevent subsequent complications.) [PMID: 4058212]

Jonsson L, Stiernstedt G, Thomander L. Tick-borne Borrelia infection in patients with Bell's palsy. Arch Otolaryngol Head Neck Surg. 1987;113:303. (This classic study evaluates 94 patients diagnosed as having Bell's palsy for evidence of Lyme disease infection.) [PMID: 3814376]

Kalish RA, Kaplan RF, Taylor E, Jones-Woodward L, Workman K, Steere AC. Evaluation of study patients with Lyme disease: 1020-year follow-up. J Infect Dis. 2001;183(3):453. (This classic article describes the long-term impact of Lyme disease in 84 patients from the Lyme, Connecticut, region who had erythema migrans, facial palsy, or Lyme arthritis 20 years previously.) [PMID: 11133377]

Peltomaa M, McHugh G, Steere AC. The VlsE (IR6) peptide ELISA in the serodiagnosis of Lyme facial paralysis. Otol Neurotol. 2004;25(5):838. (This study demonstrates the usefulness of ELISA in the diagnosis of Lyme diseaseassociated facial paralysis.) [PMID: 15354020]

Skogman BH, Croner S, Odkvist L. Acute facial palsy in childrena 2-year follow-up study with focus on Lyme neuroborreliosis. Int J Pediatr Otorhinolaryngol. 2003;67(6):597. (This study is a long-term examination of children with facial palsy from Lyme neuroborreliosis, demonstrating that one fifth of children with an acute facial palsy get a permanent dysfunction of the facial nerve. Other neurologic symptoms or health problems do not accompany the sequelae of the facial palsy.) [PMID: 12745151]

Taylor RS, Simpson IN. Review of treatment options for Lyme borreliosis. J Chemother. 2005;17(Suppl 2):3. (This review outlines contemporary treatment algorithms for patients with Lyme borreliosis.) [PMID: 16315580]

Acute Otitis Media & Mastoiditis

Clinical Findings

If the history or physical examination suggests evidence of prior or existing otitis media or if there is a history of otologic surgery, an otogenic etiology for a facial palsy should be suspected (Figure 6810). Concomitant symptoms of hearing loss, otorrhea, and vestibular symptoms are highly suggestive of an otogenic etiology. Facial palsy due to acute suppurative otitis media (ASOM) is typically seen in children who appear toxic and manifest otoscopic findings of middle ear empyema. The palsy is often progressive over a 2- to 3-day interval. In such cases, there is often a history of recent episodes of otitis media that have been partially treated. In cases of prolonged palsy, radiographic evaluation of the temporal bone may rarely disclose coalescence of infection in the mastoid. Facial palsy associated with ASOM is generally the result of toxic neuritis and can be adequately treated with wide myringotomy and systemic antibiotics.

Figure 6810.

Unsuspected right facial palsy in a child who was found 2 weeks later to have a complete facial paralysis in association with right-sided otitis media, underscoring the subtle nature of facial paralysis in young children.

Treatment

Cortical mastoidectomy is required when antibiotics and myringotomy fail to render the patient afebrile after 24 hours or when facial paralysis persists beyond 1 week. The surgical objective is to drain the empyema; extended nerve decompression is unnecessary except in cases of prolonged dysfunction.

Agrawal S, Husein M, MacRae D. Complications of otitis media: an evolving state. J Otolaryngol. 2005;34(Suppl 1):S33. (This review discusses the intracranial and extracranial complications of acute and chronic otitis media, including the clinical presentation, work-up, and management of the individual complications such as facial paralysis.) [PMID: 16089238]

Gaio E, Marioni G, de Filippis C, Tregnaghi A, Caltran S, Staffieri A. Facial nerve paralysis secondary to acute otitis media in infants and children. J Paediatr Child Health. 2004;40(8):483. (This study reviews the authors' experience with facial nerve paralysis secondary to otitis media and outlines the indications for surgical intervention.) [PMID: 15265194]

Goldstein NA, Casselbrant ML, Bluestone CD, Kurs-Lasky M. Intratemporal complications of acute otitis media in infants and children. Otolaryngol Head Neck Surg. 1998;119(5):444. (This review of 100 children with an intratemporal complication of acute otitis media includes 22 children who presented with facial paralysis; complete in 5 [22.7%] and incomplete in 17 [77.3%].) [PMID: 9807067]

Kvestad E, Kvaerner KJ, Mair IW. Otologic facial palsy: etiology, onset, and symptom duration. Ann Otol Rhinol Laryngol. 2002;111(7 Pt 1):598. (This 10-year retrospective review showed that facial palsy was a complication of acute otitis media in 56%, of acute mastoiditis in 17%, of secretory otitis media in 17%, and of chronic otitis media in 11%; total remission was achieved in all patients.) [PMID: 12126015]

Chronic Otitis Media

Chronic suppurative otitis media (CSOM), manifesting mucosal inflammation or cholesteatoma, may produce an associated facial palsy (Figure 6811; also see Figure 6810). Facial nerve dysfunction associated with CSOM reflects a toxic neuritis, external compression, or intraneural compression from edema or abscess.

Figure 6811.

Chronic suppurative otitis media manifesting as an associated facial palsy.

Facial palsy associated with this disorder should be addressed surgically as soon as possible. Surgical removal of irreversible disease in the middle ear and mastoid, as well as decompression of the involved segment of the nerve without slitting the sheath, is advised. Long-standing paralysis (but less than 2 years in duration) requires sectioning of attenuated tympanic or mastoid segments of the nerve followed by grafting.

Agrawal S, Husein M, MacRae D. Complications of otitis media: an evolving state. J Otolaryngol. 2005;34(Suppl 1):S33. (This review discusses the intracranial and extracranial complications of acute and chronic otitis media, including the clinical presentation, work-up, and management of the individual complications such as facial paralysis.) [PMID: 16089238]

Ikeda M, Nakazato H, Onoda K, Hirai R, Kida A. Facial nerve paralysis caused by middle ear cholesteatoma and effects of surgical intervention. Acta Otolaryngol. 2006;126(1):95. (This study demonstrates that in patients with advanced and facial paralysis, the outcome of facial paralysis was good; however, poor outcomes were observed in patients with petrosal cholesteatoma and in those who underwent surgical decompression more than 2 months after the onset of paralysis.) [PMID: 16308261]

Omran A, De Denato G, Piccirillo E, Leone O, Sanna M. Petrous bone cholesteatoma: management and outcomes. Laryngoscope. 2006;116(4):619. (This review of 94 patients with petrous cholesteatoma demonstrates the high incidence of facial nerve palsy in this presentation.) [PMID: 16585869]

Osma U, Cureoglu S, Hosoglu S. The complications of chronic otitis media: report of 93 cases. J Laryngol Otol. 2000;114(2):97. (The aim of this study was to investigate the incidence, mortality, and morbidity of complications due to chronic otitis media in 93 patients.) [PMID: 10748823]

Yetiser S, Tosun F, Kazkayasi M. Facial nerve paralysis due to chronic otitis media. Otol Neurotol. 2002;23(4):580. (This study demonstrated that a middle ear cholesteatoma was present in the majority of patients with facial paralysis caused by chronic otitis media.) [PMID: 12170164]

Necrotizing (Malignant) Otitis Externa

Clinical Findings

Infection by Pseudomonas aeruginosa is the primary offending agent in necrotizing infection of the external auditory canal and temporal bone. These infections are observed in patients with diabetes mellitus or in others who are immunocompromised. Patients typically present with symptoms of otorrhea and progressive, disabling otalgia. The pathognomonic signs are otoscopic evidence of ear canal inflammation or a breech of the external canal skin at the bony-cartilaginous junction. The breech is filled with granulation tissue. Facial palsy is ominous and reflects skull base extension of the osteomyelitic process along vascular channels. The diagnosis is based on the clinical presentation in association with radioisotope gallium and technetium scanning that demonstrates osteomyelitis of the temporal bone.

Treatment

Treatment of necrotizing otitis externa requires aggressive management with intravenously administered antipseudomonal antibiotics, which should be maintained for 812 weeks to facilitate sequestration of the infection. Oral fluoroquinolones (ciprofloxacin) are also becoming increasingly popular for treatment of malignant otitis externa after an initial treatment with intravenous antibiotics for early disease. Aggressive debridement of granulation tissue within the ear canal is key to promoting the replacement of necrotic bone with viable tissue. Because necrotizing otitis externa is associated with extensive ischemia of the skull base, the operative debridement of the tympanic bone, the mastoid, and the skull base is indicated only when medical treatment fails to produce improvement. Radioisotope scanning can be helpful while following the progress of the infection and helps to determine the length of the course of intravenous therapy that is required. Hyperbaric oxygen has also been used as an adjuvant therapy in some cases with success, although recent meta-analyses have failed to find it significantly adds to the rate of cure.

Benecke JE Jr. Management of osteomyelitis of the skull base. Laryngoscope. 1989;99(12):1220. (This classic paper reviews 13 patients with skull base osteomyelitis treated over a 4-year period and describes a now commonly used method of staging and monitoring this malady using gallium and technetium scanning techniques.) [PMID: 2601534]

Chandler JR. Malignant otitis externa. Laryngoscope. 1968;78:1257. (This classic article describes the clinical presentation and treatment of malignant external otitis.) [PMID: 4970362]

Phillips JS, Jones SE. Hyperbaric oxygen as an adjuvant treatment for malignant otitis externa. Cochrane Database Syst Rev. 2005;2:CD004617. (This meta-analysis shows no added benefit of hyperbaric oxygen therapy for malignant otitis externa). [PMID: 15846724]

Rubin Grandis J, Branstetter BF 4th, Yu VL. The changing face of malignant (necrotizing) external otitis: clinical, radiological, and anatomic correlations. Lancet Infect Dis. 2004;4(1):34. (This review outlines contemporary management of malignant otitis externa.) [PMID: 14720566]

Sreepada GS, Kwartler JA. Skull base osteomyelitis secondary to malignant otitis externa. Curr Opin Otolaryngol Head Neck Surg. 2003;11(5):316. (This review summarizes the diagnosis and treatment of patients with skull base osteomyelitis.) [PMID: 14502060]

Weber PC, Seabold JE, Graham SM, Hoffmann HH, Simonson TM, Thompson BH. Evaluation of temporal and facial osteomyelitis by simultaneous In-WBC/Tc-99m-MDP bone SPECT scintigraphy and computed tomography scan. Otolaryngol Head Neck Surg. 1995;113(1):36. (The results from this study suggest that dual In-WBC/Tc-99m MDP bone SPECT scintigraphy provides an accurate imaging modality for diagnosis and follow-up of temporal and facial osteomyelitis when existing clinical or postoperative bone changes make it difficult to detect active osteomyelitis by CT scan.) [PMID: 7603719]

Childhood Facial Palsy

General Considerations

The evaluation of a facial palsy in a child should be guided by the fact that although Bell's palsy is the most common cause of childhood facial palsies, it accounts for a substantially smaller proportion of palsies relative to adults. For instance, a clinically or radiographically identified etiology can be found in 20% of adult palsies initially diagnosed as Bell's palsy; this incidence may reach as high as 72% in childhood palsies. Patients under the age of 18 years with facial palsy are most likely to have an etiology of Bell's palsy (42%), trauma (21%), infection (13%), congenital causes (8%), and neoplasms (2%).

Clinical Findings

The onset of facial palsy in childhood is frequently obscured by the excellent tone of aponeurotic tissues and skin and, therefore, the excellent static suspension of central and lower portions of the face. Consequently, childhood facial nerve disorders are often referred to as "asymmetric crying facies" (see Figure 688).

Treatment

The treatment for childhood facial palsies generally follows that for adults, with the appropriate adjustment in medication strength and dosing schedules.

Carr MM, Ross DA, Zuker RM. Cranial nerve defects in congenital facial palsy. J Otolaryngol. 1997;26(2):80. (This paper evaluates the cranial nerve defects in 29 children with congenital facial palsy presenting for reanimation.) [PMID: 9106081]

Evans AK, Licameli G, Brietzke S, Whittemore K, Kenna M. Pediatric facial nerve paralysis: patients, management and outcomes. Int J Pediatr Otorhinolaryngol. 2005;69(11):1521. Epub 2005 June 27. (This retrospective review of 35 cases of facial palsy in children demonstrated that infectious causes were the most likely etiology, followed by trauma, iatrogenic, congenital, Bell/idiopathic, relapsing, and neoplastic.) [PMID: 15985298]

Gaio E, Marioni G, de Filippis C, Tregnaghi A, Caltran S, Staffieri A. Facial nerve paralysis secondary to acute otitis media in infants and children. J Paediatr Child Health. 2004;40(8):483. (This series and review of the literature demonstrate that facial paralysis is an uncommon complication of otitis media and recommends antibiotic therapy and myringotomy as first-line interventions, with surgery reserved for cases of acute or coalescent mastoiditis, suppurative complications, and lack of clinical regression.) [PMID: 15265194]

May M, Fria RJ, Blumenthal F et al. Facial paralysis in children: differential diagnosis. Otolaryngol Head Neck Surg. 1981;89:841. (The differential diagnosis in 170 patients with facial paralysis between birth and 18 years of age is reviewed in this classic article, and symptoms and signs associated with each diagnosis are presented.) [PMID: 6799919]

Saito H, Takeda T, Kishimoto S. Neonatal facial nerve defect. Acta Otolaryngol Suppl. 1994;510:77. (This important study reports on the findings from 42 temporal bones with facial nerve, and includes 9 temporal bones in which the facial nerve disappeared midway through the course of the temporal bone.) [PMID: 8128879]

Singhi P, Jain V. Bell's palsy in children. Semin Pediatr Neurol. 2003;10(4):289. (This review outlines the presentation and management of Bell's palsy in children.) [PMID: 14992461]

Perinatal Facial Palsy

Traumatic Perinatal Facial Palsy

Intrauterine trauma to the facial nerve may occur as a consequence of compression from the maternal sacrum. Prolonged labor and forceps delivery may produce facial nerve trauma. The extratemporal facial nerve is at risk because the absence of an overlying mastoid tip places the vertical segment of the nerve at risk for injury. A traumatic cause of the facial nerve dysfunction is suggested by hemotympanum, periauricular ecchymosis, and the progressive decline of facial nerve responsiveness to an applied stimulus.

The assessment of perinatal facial nerve dysfunction relies heavily on electrodiagnosis. Electromyographic evidence of preserved or declining neuromuscular activity is most diagnostic. In the absence of such activity, muscle biopsy may be required to determine whether a congenital palsy exists.

A review of the etiologic basis for facial palsy in 95 newborns indicated that a traumatic etiology was suspected in 74 cases (78%), as suggested by signs of periauricular injury or electrical testing (evoked and spontaneous electromyography). There was excellent recovery in 41 of 45 children with perinatal trauma. Occasional cases of poor recovery, however, suggest the need for a radiographic and electrodiagnostic evaluation to detect an unfavorable prognosis for spontaneous recovery. In such cases, surgical exploration and decompression of the nerve may be critical for effective reanimation.

May M, Fria RJ, Blumenthal F et al. Facial paralysis in children: differential diagnosis. Otolaryngol Head Neck Surg. 1981;89:841. (The differential diagnosis in 170 patients with facial paralysis between birth and 18 years of age is reviewed in this classic article, and symptoms and signs associated with each diagnosis are presented.) [PMID: 6799919]

Renault F. Facial electromyography in newborn and young infants with congenital facial weakness. Dev Med Child Neurol. 2001;43(6):421. (This study highlights the importance of electrophysiologic measures for diagnosing and treating children with facial paralysis.) [PMID: 11409833]

Sapin SO, Miller AA, Bass HN. Neonatal asymmetric crying facies: a new look at an old problem. Clin Pediatr (Phila). 2005;44(2):109. (This article describes asymmetric facies as a means of diagnosing newborn facial paralysis and describes the use of ultrasound to aid in diagnosis.) [PMID: 15735828]

Congenital Perinatal Facial Palsy

Newborn facial palsy unrelated to trauma accounts for a smaller proportion of cases than does traumatic facial palsy. Both syndromic and nonsyndromic forms of congenital facial palsy occur. The palsy may be complete or incomplete, unilateral or bilateral, and isolated to particular branches. Associated craniofacial malformations, often those involving first and second branchial arch derivatives, are common. Microtia and facial clefts are most frequently noted. Palsies isolated to a single branch, particularly the marginal mandibularis, indicate the need for a cardiac evaluation in light of a high rate of concurrent cardiac conductive and anatomic anomalies.

Otologic, electrodiagnostic, and radiologic evaluations are performed, as necessary, to determine the etiology. A congenital neuromuscular etiology is suggested by a concomitant defect (or defects) involving other cranial nerves and the absence of evidence of electrical responsiveness to evoked and spontaneous electromyographic evaluation.

The Mbius syndrome encompasses a wide spectrum of anomalies due to dysgenesis at the level of the brainstem with resultant neuromuscular deficits peripherally. The bilateral absence of facial and abducens nerve function, as well as other cranial neuropathies, may occur. The auditory brainstem response is often abnormal and is a helpful adjunct in diagnosis.

The prognosis for effective facial animation with congenital facial palsies is poor. However, resting tone may provide adequate eye coverage and oral competence even into adulthood. Facial motor rehabilitative procedures and reconstructive procedures to effect better symmetry may be indicated later in life.

Abramson DL, Cohen MM Jr, Mulliken JB. Mbius syndrome: classification and grading system. Plast Reconstr Surg. 1998;102(4):961. (This paper retrospectively analyzes 27 patients with Mbius syndrome using a newly developed grading system termed the CLUFT, which permits categorization and comparison of patients with Mbius for phenotypic and management outcome studies.) [PMID: 9734409]

Jemec B, Grobbelaar AO, Harrison DH. The abnormal nucleus as a cause of congenital facial palsy. Arch Dis Child. 2000;83(3):256. (This study documents that developmental abnormalities of the facial nucleus itself constitute an important, and previously ignored, cause of monosymptomatic unilateral congenital facial palsy.) [PMID: 10952650]

Saito H, Takeda T, Kishimoto S. Neonatal facial nerve defect. Acta Otolaryngol Suppl. 1994;510:77. (This study reports on the pathologic findings in temporal bones with congenital anomalies of the facial nerve. Some of the nerve fibers suggested regeneration after necrotic lesions induced during the perinatal period.) [PMID: 8128879]

Sudarshan A, Goldie WD. The spectrum of congenital facial diplegia (Mbius syndrome). Pediatr Neurol. 1985;1(3):180. (This manuscript reviews Mbius syndrome, congenital facial diplegia with associated anomalies, and includes six cases that manifest a very broad spectrum of associated neurologic anomalies.) [PMID: 3880403]

Toelle SP, Boltshauser E. Long-term outcome in children with congenital unilateral facial nerve palsy. Neuropediatrics. 2001;32(3):130. (This study follows the long-term outcome of 12 children with congenital unilateral facial nerve palsies and note a poor long-term functional prognosis.) [PMID: 11521208]

Verzijl HT, van der Zwaag B, Lammens M, ten Donkelaar HJ, Padberg GW. The neuropathology of hereditary congenital facial palsy vs Mbius syndrome. Neurology. 2005;64(4):649. (This study demonstrates that neuropathologic findings confirm clinical observations that hereditary congenital facial palsy and Mbius syndrome are two different entities with a different pathogenesis.) [PMID: 15728286]

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