Short-latency somatosensory-evoked potential in patients with central nervous system space-occupying lesions: a study of 261 cases

Abstract

INTRODUCTION: Short-latency somatosensory-evoked potential (SSEP) is an electrophysiological technique to study the dorsal column–medial lemniscal sensory system. Its application in central nervous system spaceoccupying lesions (CNS SOLs) has sparsely been published. METHODS: A total of 261 patients with CNS SOLs underwent SSEP before neurosurgeries. Anatomical locations of the lesions, histopathological diagnoses and prognosis were tried to correlate with the SSEP variables. RESULTS: The spinal SOLs, especially nerve sheath tumours, was associated with significant abnormalities in various variables including the central conduction time. Other anatomical sites and histopathologies did not correlate with the SSEP findings. Also SSEP did not reflect clinical prognosis. CONCLUSION: Short-latency somatosensory-evoked potential is probably not a sensitive test for CNS SOLs except spinal cord lesions. This is probably due to anatomy of the somatosensory pathway. The fact that SSEP has different sensitivities to various tumours may reflect that sensory neurons have heterogenous susceptibilities to different pathologies.