Central nervous system involvement in nocturnal enuresis: Evidence of general neuromotor delay and specific brainstem dysfunction

Purpose: To assess the involvement of central nervous system factors in the etiology of childhood nocturnal enuresis, an ongoing study of the fine neurology and neurophysiology has been instituted. Materials and Methods: A total of 22 patients 8 to 14 years old were subcategorized sporadic and familial groups. Patients underwent a number of examinations, including a complete family pedigree; blood samples for linkage analyses; pediatric examination; urinalysis; uroflowmetry with pelvic floor electromyography; 24-hour flow charts; parental micturition questionnaire; child behavior checklist; intelligence test; standardized child psychiatric interview; acoustic, visual and event related late evoked potentials; Zurich Neuromotor Test Battery and the startle-blink paradigm. In this preliminary report only the results of the Zurich Neuromotor Test Battery and startle-blink paradigm are reported. Results: In the Zurich Neuromotor Test Battery patients with enuresis had a longer timed performance but did not have more associated movements than the controls. In the startle-blink modulation paradigm inhibition of the electromyograph amplitudes was greatest following prestimulation with an interval of 120 milliseconds. This inhibition is known to be reduced among patients with enuresis compared to nonwetting children. The results indicated a general developmental (neuromotor) delay, in addition to specific dysfunction of the brain stem in patients with enuresis. The pre-pulse inhibition, as well as inhibition of bladder emptying at sleep, are regulated by brainstem centers in close anatomical proximity to the pontine micturition center and by analogous mechanisms. Conclusions: Reduced pre-pulse inhibition may represent a genetically transmitted trait indicative of nocturnal enuresis.