Neurophysiological study of primary nocturnal enuresis

The purpose of this study was to investigate nervous system involvement in primary nocturnal enuresis by using electrophysiological techniques. Nineteen boys with primary nocturnal enuresis and 25 boys without uroneurological abnormalities were included. Data about their psychomotor development, micturition, and defecation were obtained by interviewing the boys and their parents. The penile sensory threshold for electrical stimuli was determined. Single and averaged bulbocavernosus reflex (BCR), and averaged pudendal somatosensory evoked potentials (PSEP) to electrical stimulation, were recorded. The only statistically significant difference found in enuretic children was longer latencies of averaged BCR to single electrical stimulation (P = 0.03). No significant BCR latency differences to stimulation with double electrical pulses and no PSEP latency differences were found. By using electrophysiological techniques, differences between the enuretic and control group of boys were demonstrated. Our results can be interpreted as indicating hypoexcitability of sphincter nuclei. Along with the reported hyperexcitability of bladder motor nuclei, a minor dysfunction in the neurocontrol of the lower urinary tract, in at least a subgroup of enuretic children, can be postulated.