Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Jan 1996
Case ReportsMonitoring of median nerve somatosensory evoked potentials during cervical spinal cord decompression.
We evaluated the intraoperative utility of monitoring median nerve somatosensory evoked potentials (SEPs) in 31 consecutively hospitalized neurosurgical patients (mean age 55.3 +/- 2.1 years) who underwent spinal cord decompression for cervical herniated disc, spondylosis, or tumor. Pre- and postoperative standard neurological examinations included evaluation of motor function, sensory responses, gait, tone, and reflexes. Evoked potentials were recorded from clavicular Erb's (N9) and contralateral cortical (N20) points. ⋯ The SEP waveform disappeared in two of the group II and in none of the group I subjects. In the two group II subjects exhibiting increases of N9-N20 latencies, increments were > 20%. These findings indicate that in patients undergoing cervical spinal cord decompression, disappearance of SEPs or increases > 20% in the N9-N20 interpeak latency are suggestive of operative conditions that place patients at risk for poor neurological outcome.