Primary and secondary nocturnal enuresis: similarities in presentation

To determine the differences or similarities in the clinical presentation between patients with primary and secondary nocturnal enuresis.

A total of 170 patients with nocturnal enuresis were assessed at a busy tertiary care pediatric voiding dysfunction clinic at the University of Oklahoma Health Sciences Center. Patients with primary nocturnal enuresis (PNE) were compared with patients with secondary nocturnal enuresis (SNE) for a variety of clinical features, including gender, age when first voiding on their own, age on presentation, infrequent voiding, frequent voiding, urgency, daytime wetting, nocturia, urinary tract infection, constipation, vesicoureteral reflux, attention-deficit/hyperactivity disorder, uroflow results, and ultrasound evidence of a postvoid residual.

The only significant difference between the patients with PNE and those with SNE was in the prevalence of constipation. Constipation was significantly associated with PNE (74.59% vs 57.54%; odds ratio: 2.17; 95% confidence interval: 1.07-4.41). When adjusted for a history of constipation, the age at which a child began to void on his or her own became statistically significant. Patients with SNE started to void on their own at 2.13 years (SD: 0.61), an average of 0.22 years earlier than those with PNE, who started to void on their own at 2.35 years.

PNE and SNE likely share a common pathogenesis. Symptoms of daytime voiding dysfunction are common in patients with PNE and SNE. Daytime voiding habits might influence how the central nervous system responds at night to a full or contracting bladder.