Background Urinary dysfunction is common in Parkinson's disease (PD); however, little is known about urinary dysfunction in early and untreated PD patients.

Methods Fifty consecutive untreated PD patients (mean age, 66.7; mean disease duration, 23.6 months; and mean Hoehn & Yahr scale, 1.9) were recruited; those with other conditions that might have influenced urinary function were excluded. Patients were evaluated using a urinary questionnaire and urodynamic studies.

Results Sixty-four per cent complained of urinary symptoms (storage, 64.0%; voiding, 28.0%). Urodynamic studies showed abnormal findings in the storage phase in 84%, with detrusor overactivity (DO) and increased bladder sensation without DO in 58.0% and 12.0% of patients, respectively. In the voiding phase, detrusor underactivity, impaired urethral relaxation such as detrusor sphincter dyssynergia, and bladder outlet obstruction were present in 50.0%, 8.0% and 16% of patients, respectively. In patients with both storage and voiding phase abnormalities, DO+detrusor underactivity was the most common finding. Few patients experienced urge incontinence and/or quality-of-life impairment owing to urinary dysfunction; none had low-compliance bladder or abnormal anal-sphincter motor unit potential. These urinary symptoms and urodynamic findings were not correlated with gender, disease severity or motor symptom type.

Conclusion Urinary dysfunction, manifested primarily as storage disorders with subclinical voiding disorders and normal anal-sphincter electromyography, occurs in early and untreated PD patients. In cases with severe voiding disorder and/or abnormal anal-sphincter electromyography, other diagnoses should be considered.