Function of the conus medullaris and cauda equina in the early period following spinal cord injury and the relationship to recovery of detrusor function.

A total of 26 patients with an early suprasacral spinal cord injury underwent comprehensive neurourological evaluation to determine if there was any correlation between the return of detrusor function and neural function of the sacral cord. In addition, the incidence of a subclinical sacral neural dysfunction early after spinal cord injury was assessed. Lumbosacral evoked potentials to tibial nerve stimulation were used to assess the sensory root and cord gray matter of the L5 to S2 segments, while urodynamic evaluation was performed to assess detrusor function. Of those patients with normal lumbosacral evoked potentials 82% recovered detrusor contractility as opposed to 66% with abnormal evoked potentials. Four patients (23.5%) had persistent detrusor areflexia when studied 9 to 20 months following the acute injury. The potential problems attempting to correlate the neurophysiological and urodynamic studies are multiple and are extensively discussed. Despite these potential problems the return of detrusor function correlated well with associated normal lumbosacral evoked potentials suggesting that this test can be used in the early phase following spinal cord injury to predict return of bladder function, since it is independent of the level of spinal cord excitability. Of the patients studied 38% had coexistence of an occult lumbosacral dysfunction. This rate is higher than that found in the chronic stabilized spinal cord injury population (20.5%), since the cases in our study may represent a more severe lesion.