PURPOSE: We investigated whether recording the perineal sympathetic skin response, which reflects the sympathetic function of the thoracolumbar spinal cord, represents a reliable and accurate diagnostic tool for assessing bladder neck competence and incompetence.
MATERIALS AND METHODS: We compared the sympathetic skin response recorded from the hand, foot and perineal skin with urodynamic findings in 90 patients with neurogenic bladder dysfunction, including 66 with spinal cord injury and 24 with cauda equina lesions.
RESULTS: Video urodynamics revealed an incompetent bladder neck in 11 of 32 patients (34%) with complete and 7 of 34 (21%) with incomplete spinal cord injury but in only 1 of 24 (4%) with the conus-cauda equina syndrome. This association significantly correlated with the lesion level at T10 to L2 in 12 of 26 cases (46%) as well as with the loss of perineal but preserved hand and foot sympathetic skin response in 13 of 18 (72%).
CONCLUSIONS: Recording the perineal sympathetic skin response in addition to that of the hand and foot represents a sensitive diagnostic tool for assessing sympathetic nerve function within the thoracolumbar spinal cord. It is of diagnostic value for evaluating neurogenic bladder neck incompetence in spinal cord injured patients.