Urinary function in patients with corticobasal degeneration; comparison with normal subjects

Corticobasal degeneration (CBD) is a rare neurodegenerative disorder affecting cerebral cortex and basal ganglia, both of which are crucial for regulating the lower urinary tract function. However, urinary function of this disorder has not been fully delineated. We investigated urinary function in patients with CBD.

A questionnaire for storage and voiding urinary symptoms was performed in all 10 patients with CBD (four men, six women; mean age, 67.3 years; mean duration of disease, 3.9 years) and 11 age-matched control subjects (four men and seven women; mean age, 73.0 years). Urodynamic studies were performed in six of the patients and all control subjects, including electromyography (EMG)-cystometry and analysis of motor unit potentials of the external sphincter.

As compared to the control subjects (27%), patients with CBD had more common urinary symptoms (80%, P < 0.05). The urinary symptoms appeared 1-3 years after the onset of the disease, and were more common in patients with longer disease duration (>5 years) and in patients with forced grasp reflex. Nocturnal frequency was the most common and tended to be the initial urinary symptom (seven), followed by urinary incontinence (six), urinary urgency (six), diurnal frequency (five), and difficulty in voiding (five). None was in a state of urinary retention. While, one asymptomatic patient showed normal urodynamic finding, all five symptomatic patients showed various abnormalities, including decreased bladder capacity (four), detrusor overactivity (DO) (three), which was noted only in one of the control subjects, detrusor hypocontractility on voiding (three), and low compliance detrusor (one). None of the patients had post-void residuals, detrusor-sphincter dyssynergia, or neurogenic motor unit potentials of the external sphincter muscles.

Although the number of our patients was small, the present study suggests that urinary dysfunction is a common feature in patients with CBD. Since decreased bladder capacity and DO were common in the symptomatic patients, lesions in the supranuclear parasympathetic system are mainly responsible for their dysfunction.