Post-stroke urinary incontinence with impaired awareness of the need to void: clinical and urodynamic features

To describe a clinical subtype of urinary incontinence (UI) after a stroke, i.e. with impaired awareness of the need to void (IA-UI), and to compare it to urge UI after a stroke for the risk factors and medium-term outcome.

In a consecutive sample of 315 hospitalized stroke patients who were clinically stable and able to communicate, 65 with UI were identified (27 urge UI, 38 IA-UI). All had a comprehensive clinical assessment and cerebral computed tomography (CT). Cysto-urethrometry was performed in seven patients with IA-UI.

Of the 38 patients with IA-UI, 16 were partially aware of leakage, but not of bladder fullness; the remaining 22 denied leakage. Patients with IA-UI were more functionally impaired (P=0.001), had more visible new CT lesions (24 of 38 vs 10 of 27, P=0.04) and less frontal lobe involvement (seven of 24 vs seven of 10, P=0.05) than those with urge UI. Ten of 12 patients with parietal lobe involvement denied leakage; no particular lesion pattern was found in those with partial awareness. Two patients had normal cysto-urethrometry, four showed terminal detrusor overactivity, and one had an incompetent urethral closure mechanism. In all, bladder sensation was reduced or absent. Only two of the surviving patients had regained continence after 1 year, whereas half of those with urge UI had become continent.

IA-UI after a stroke differs from urge UI in clinical and prognostic respects, and probably reflects greater brain damage. It might explain the prognostic importance of stroke-related UI. There are various urodynamic patterns. Patients with better preserved insight might benefit from early awareness training and even from additional medical treatment if bladder overactivity is present; this needs further investigation.