Fifty-two men with clinical, electrodiagnostic and radiological signs supportive of chronic cauda equina or conus medullaris lesions were included. Clinical examination, including perianal sensation and penilo-cavernosus reflex testing, and neurophysiologic testing, including quantitative anal sphincter EMG and penilo-cavernosus reflex testing (on single and double electrical, and mechanical stimulation), were performed separately on each side