Somatosensory and magnetic evoked potentials in a postoperative paraparetic patient: case report.

Abstract

Somatosensory evoked potential (SSEP) testing is increasingly being used to test for spinal cord injuries and to monitor spinal surgery to reduce the risk of paraplegia. It is a sensory test, but it is assumed that any process severe enough to affect the motor tracts will also affect the sensory tracts and, therefore, be identified. Increasingly, however, isolated motor-tract involvement has been reported. A new technique, magnetic coil stimulation of the cortex, directly monitors the motor tracts. We report a case where the SSEP was normal although the magnetic motor-evoked potential was abnormal, supporting the hypothesis that direct testing of motor tracts may be advantageous.