Somatosensory evoked potential monitoring accurately predicts hemi-spinal cord damage: a case report.

Separate somatosensory evoked potentials (SEPs) were monitored from each lower extremity during instrumentation for a spinal fracture. The SEP disappeared from the right lower extremity after instrumentation, but not from the left lower extremity. The predicted hemi-spinal cord injury was pathologically confirmed. The merits of sequential, as opposed to simultaneous, stimulation of multiple extremities during surgical monitoring are discussed.