Neurocutaneous Syndromes | The Massachusetts General Hospital Handbook of Neurology

Authors: Flaherty, Alice W.; Rost, Natalia S.

Title: Massachusetts General Hospital Handbook of Neurology, The, 2nd Edition

> Table of Contents > Child Neurology > Neurocutaneous Syndromes

Neurocutaneous Syndromes

Table 41. Distinguishing NF1 and NF2.

	Neurofibromatosis Type I	Neurofibromatosis Type II
Incidence	1/3000	1/30,000
Onset of sx	Early childhood	Adolescence or adulthood
First sx	Caf -au-lait spots, freckling	8th nerve problems
Acoustic tumors	Almost never bilateral	Hallmark of NF2
Typical tumors	Neurofibromas, astrocytomas	Schwannomas, meningiomas
Nontumor sx	Macrocephaly, low IQ, bone dz	Retinal dz, juvenile cataracts
Typical spine sx	Scoliosis, syringomyelia	Intradural tumors, syringomyelia
Screening MRIs?	Less useful	To catch schwannomas early
Malignancy risk	NFS, leukemia, pheo	No
Inheritance	Chromosome 17, dominant	Chromosome 22, dominant
Severity	Wide variation within a family	Consistent within a family

A. Neurofibromatosis Type I

(von Recklinghausen's dz):

H&P: Family history of NF1; caf -au-lait spots, neurofibromas, axillary or inguinal freckling, optic glioma, iris (Lisch) nodules, typical osseous lesion (thoracic scoliosis, anterolateral tibia bowing, pseudoarthrosis, sphenoid wing dysplasia).
Tests: MRIs for symptoms; screening MRIs less useful.
Rx: Surgery for symptomatic lesions.

B. Neurofibromatosis Type II

H&P: Acoustic schwannomas (usually bilateral, and before age 30), caf -au-lait spots, posterior lens opacities, family history of NF2.
P.147

No Lisch nodules; not associated with seizures, mental retardation, or macrocephaly.
Tests: Screening MRI can detect acoustic tumors early.
Rx: Resect acoustic schwannomas before they cause deafness.

C. Tuberous sclerosis

Autosomal dominant gene on either chromosome 9 or 11, very variable expression. Many spontaneous mutations.

H&P: Characteristic triad of seizures, retardation, and facial adenofibromas (misnamed adenoma sebaceum). See also hypomelanotic macules, shagreen patches (connective tissue hamartomas). Family history. Heart, pulmonary, and kidney tumors are often silent.
Tests: MRI of head shows focal cortical dysplasias (tubers) and subependymal nodules. Renal, cardiac, and pulmonary screening.
Rx: Steroids or vigabatrin for infantile spasms, ACDs for seizures; resect intraventricular tumors causing hydrocephalus.

D. Sturge-Weber syndrome (encephalotrigeminal angiomatosis)

Chromosome 3 defect, causes vascular port-wine nevus on face (usually in V1 distribution), contralateral hemiparesis and field cut, ipsilateral glaucoma, seizures, retardation.

E. Incontinentia pigmenti (Bloch-Sulzberger syndrome) and hypomelanosis of Ito

Erythema/bolus lesions only in girl (X-linked dominant) and hypopigmented lesions, respectively. Both in dermatome distribution and associated with seizures, microcephaly, and mental retardation.

F. Von Hippel-Lindau dz

Dominant gene defect on chromosome 3. Not really a neurocutaneous disorder, but we had to stick it somewhere.

H&P: Sx of hemangioblastomas, usually in posterior fossa, in second to fourth decade. Also see retinal hemangiomas, renal cell carcinomas, pheochromocytomas.
Rx: Early surgery for cerebral or spinal cord tumors, laser or cryosurgery for retinal tumors, frequent screening exams.