Use of sacral reflex latency measurements in the evaluation of neural function of spinal cord injury patients: a comparison of neuro-urophysiological testing and urodynamic investigations.

Complete suprasacral spinal cord injury is followed by great changes in the neural control and function of the lower urinary tract. In the literature there is some controversy about the relationship between detrusor function and results of neurophysiological tests of sacral root conduction after the spinal shock phase. Therefore, we studied this relationship in a group of 73 patients with clinical as well as neurophysiological documented complete suprasacral spinal cord injury, and compared sacral reflex latency measurements (bulbocavernosus and urethro-anal reflexes) with detrusor function, documented by urodynamic investigation. A high incidence of sacral reflex latency abnormalities was found. Comparison of sacral reflex latencies with detrusor reflex activity showed a statistical significant correlation. No such relationship could be found between urodynamic characteristics of the detrusor in patients with detrusor hyperreflexia and sacral reflex latency measurements. We conclude that sacral reflex latency measurements can give an indication about the existence of reflex detrusor activity. On the other hand, these neurophysiological measurements do not provide a reliable indication of the detrusor function after complete spinal cord injury.