Improved Diagnosis of Cervical Spondylotic Myelopathy with Contact Heat Evoked Potentials

Abstract

The aim of this study was to reveal the sensitivity and responsiveness of contact heat evoked potentials (CHEPs) to assess cervical spondylotic myelopathy (CSM). A total of 81 patients with clinically and radiologically confirmed spinal cord compression were reviewed. All patients underwent full clinical examinations with combined recordings of segmental CHEPs and somatosensory evoked potentials (dSSEPs) compared with healthy controls. Cross-sectional area, maximal canal compression, and maximal spinal cord compression were determined based on T2-weighted MRI. CHEPs exhibited the highest sensitivity (∼ 95%) to disclose at-level impairments in CSM patients. Normally appearing rostral segments above the level of lesion were impaired in 17% of patients. Comparatively, dSSEPs were less affected (24%) and predominantly impaired at and below the level of CSM. Longitudinal evaluation revealed that CHEPs became progressively impaired in parallel with clinical deterioration. CHEPs were sensitive to CSM, revealing evidence of impaired neurophysiology at and below the radiographic level of stenosis. The changes observed above the level of CSM suggest neurophysiological deficits beyond the focally damaged area. Deteriorating CHEPs were observed in a cohort of patients with worsening neurological symptoms, indicating their responsiveness to track CSM. The present study highlights the value of incorporating CHEPs into the diagnosis and prognosis of CSM.