Urodynamic evaluation of boy with myelodysplasia and incontinence.

Twenty-two boys with myelodysplasia and incontinence were evaluated urodynamically. Three types of bladder function were noted, but each could not be correlated with any particular neuroligic level. The integrity of the external sphincter innervation was determined by electomyographic monitoring of periurethral striated muscle. Bladder sphincter dyssynergia was found in one of the boys with voluntary control, five with involuntary bladder contractions, and five with adynamic bladders who voided by Credé's method. A radiologically narrow external sphincter on voiding cystography could only be correlated with the bioelectric activity in children with dyssynergia. A narrow sphincter was also noted in three children with synergy and four with complete lower motor neuron lesions. Marked fibrosis was found to be the cause of narrowing of external sphincter area in these boys. Thus, urodynamic evaluation helped define the etiology of outlet obstruction when it was present in the boy with myelodysplasia. A classification of bladder sphincter function is proposed.