O209 Improved diagnosis of cervical myelopathy through multi-modal neurophysiological assessments

Abstract

Listen

Translate article

Objectives To investigate the sensitivity and responsiveness of multi-modal neurophysiology to assess cervical spondylotic myelopathy (CSM). Methods Patients were recruited from the outpatient clinic and MRI scans were performed to verify the diagnosis. A neurological examination and a set of multi-modal neurophysiological assessments including contact heat and cold stimulation (CHEPs and CEPs), pinprick stimulation and dermatomal somatosensory evoked potentials (dSSEPs) were performed to determine neuronal damage. In a cross-sectional design, clinical, neurophysiological and neuroimaging findings were correlated and sensitivity to detect subclinical functional alterations was tested. A small subset of patients was followed longitudinally in order to investigate the responsiveness of CHEPs over time. Results Impaired cortical responses were found in dermatomes above, at and below the radiological level of lesion. CHEPs displayed a high diagnostic accuracy to discriminate between patients and age-matched healthy controls in cervical dermatomes. CHEPs exhibited a superior sensitivity to detect morphological impairment (about 95%), whereas dSSEPs only reached a sensitivity of about 24%. Clinical pinprick examination also emerged to be reliable (72.9%). Dissociation of pinprick responses and temperature sensation could be objectively documented in one case. CEPs generally paralleled the CHEPs results, being a viable alternative to contact heat stimulation in patients not tolerating the noxious heat stimuli. Discussion Multi-modal neurophysiological assessments are of high diagnostic yield in the study of spinal cord impairment related to CSM. The thermal and mechanical stimuli applied specifically activated peripheral Adelta nociceptors and ascended through the spinothalamic tract. Central myelopathic changes often affect the anterior and antero-lateral aspects of the cord where the spinothalamic projections are located, rendering them vulnerable to damage. The extent of the myelopathy can be further localized through a multisegmental approach. Conclusions Using multi-modal neurophysiology, subtle alterations in neuronal function can be disclosed, and the clinical diagnosis and follow-up of patients suffering from cervical myelopathy can be improved, leading to a better management of the debiliating clinical sequelae of the condition. Significance CHEPs are sensitive to track neurological impairment in CSM.