Dissociation of urethral and anal sphincter activity in neurogenic bladder dysfunction

In 53 patients with suspected neurogenic bladder dysfunction carbon dioxide cystometry was done in combination with urethral and anal sphincter electromyography. Complete dissociation between the reflex activity of the 2 sphincters was found in 25 per cent of the patients and only 58 per cent of the patients had identical reflex activity. It is concluded that anal sphincter electromyography is highly unreliable in the diagnosis of urethral sphincter dysfunction.