The impact of maturation of brainstem inhibition on enuresis: a startle eye blink modification study with 2-year followup

Abstract

Purpose: Previous research reveals that children with enuresis show reduced prepulse inhibition, which is supposed to reflect dysfunction in a brainstem nucleus involved in the voiding circuitry cyclus. The main aim of this study was to investigate whether maturation of the brainstem, indexed by a marked increase in percent prepulse inhibition during a period of 2 years, co-occurs with children becoming dry at night.

Materials and methods: Electromyography recorded startle eye blink during modified Ornitz automatic attention task was used to measure brainstem function. For this followup study we randomly contacted 60 children with enuresis (30 with and 30 without attention deficit-hyperactivity disorder) and 25 normally developing controls from a baseline sample. Performance at baseline and at 2-year followup in 25 children with enuresis and attention deficit-hyperactivity disorder and 24 children with enuresis without attention deficit-hyperactivity disorder was compared to 25 controls.

Results: At short lead intervals a significant difference between enuresis groups and the control group was found at baseline, whereas no significant differences were found at 2-year followup. In the enuresis groups there was a significant increase in percent prepulse inhibition between baseline and 2-year followup. Percent prepulse inhibition increase did not differ between children with different 2-year followup enuresis status, or baseline incontinence or attention deficit-hyperactivity disorder symptoms.

Conclusions: Brainstem maturation was detected in children with enuresis but was not associated with children becoming dry. Patients with and without enuresis at followup did not demonstrate a significant difference in percent prepulse inhibition increase. These data suggest that immaturity of the brainstem may be a mechanism involved in the pathogenesis of enuresis but not in its persistence.