Clinical uro-neurophysiological investigation in multiple sclerosis

Subjective complaints of urinary dysfunction are common in multiple sclerosis patients. Uro-neurophysiological investigation, namely somatosensory evoked potentials (SEP) to stimulation of tibial and pudendal nerves, sacral reflex measurements and external anal sphincter electromyography (EMG) were employed in a group of 21 patients with mild to moderate multiple sclerosis and urinary symptoms. Tibial SEP showed abnormality in 86% and pudendal SEP in 48% of patients. Sacral reflexes were abnormal in 33% and external anal sphincter EMG showed abnormalities in 42% of patients (54% of women and 13% of men). Even in multiple sclerosis patients with urinary complaints tibial SEP seem to be more useful in evaluating nervous system dysfunction than pudendal SEP. On the other hand, abnormal pudendal SEP acconmpanied by normal tibial SEP may strengthen the suspicion of a conus lesion, the presence of which is some patients seems to be the cause of otherwise unexplained abnormalities of external anal sphincter EMG and sacral reflexes.