Uro-Neurology | 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 > Adult Neurology > Uro-Neurology

Uro-Neurology

A. Bladder detrusor and internal sphincter

1. Parasympathetic: Acetylcholine from S2-4 via pelvic nerve constricts bladder via muscarinic receptors.
2. Sympathetic: Norepinephrine from L2-4 via hypogastric nerve constricts sphincter via -receptors. The bladder has -receptors.

B. External sphincter

Voluntary control via S2-4

C. H&P

Often a poor correlation between sx and urodynamic findings.

1. Autonomic dysreflexia: Urgent problem. In pts with spine injury (usually above T5/6). Pain, bladder distension or catheterization, bowel distension, or other stimuli can trigger acute hypertension, bradycardia, anxiety, and headache. Sit the pt. up, and treat BP promptly, e.g., with nifedipine 10 mg SL.
2. Frequency or urgency: From high fluid intake, urinary tract infection, partial outlet obstruction (prostate, diaphragm), upper or lower motor neuron lesion, psychosomatic.
3. Urinary retention: From drugs (anticholinergics, opiates, anesthetics), pain, prostate, lower motor neuron lesion, bladder-sphincter dyssynergia, obstruction.
4. Incontinence:
- a. Stress: Often a bladder suspension defect or sphincter damage.
- b. Overflow: Dribbling, small volumes, big painful bladder. Causes are those of urinary retention, above.
- c. Confusional: Varying volumes, usually shameless.

D. Upper vs. lower motor neuron lesions

Table 36. Distinguishing upper and lower motor neuron lesions.

	Upper Motor Neuron	Lower Motor Neuron
Bladder	Small, spastic, low PVR	Large, flaccid, high PVR
History	Urgency, trouble starting, wet at night	Strains to empty fully, wet or dry at night.
Bulbocavernosus	Present	Absent
Causes	Bilat. frontal lesion, cord lesion above T12	Anesthetics, neuropathy, ALS, cauda equina lesion
Treatment	Decrease bladder tone with anticholinergics or adrenergics	Increase bladder tone with cholinergics or antiadrenergics; self-catheterization

P.126

E. Rx by urodynamic finding

1. Flaccid bladder: Detrusor hyporeflexia, poor voiding. Catheterization helps. Try cholinergics, e.g., bethanechol (Urecholine) 10-50 mg bid-tid. Avoid cholinergics in COPD, PUD, CAD, hyperthyroidism.
2. Spastic bladder: Detrusor hyperreflexia, poor storage. Try anticholinergics, e.g., tolterodine (Detrol) 1 mg bid, oxybutynin (Ditropan) 5 mg bid-tid, implanted stimulator.
3. Detrusor-sphincter dyssynergia: Spinal cord lesions above the sacral level can leave just the sphincter spastic. The bladder eventually dilates, but secondarily. Treat with catheterization, anticholinergics, prazosin (an anti- ₁-adrenergic, 1 mg bid-tid), Botox.