Urethral sphincter abnormalities in Parkinsonism.

Urethral sphincter function was studied in 14 patients with Parkinsonism. All patients had urethral pressure profiles, sphincter electromyography and a voiding study with or without cystourethrography. Abnormalities were found in all patients, but profound abnormalities were present in four patients who had markedly increased sphincter tone and sphincter tremor and who failed to relax the sphincter when voiding. These abnormalities may be a significant cause of urinary symptoms in these patients.