Multimodal Neurophysiology Research Articles

FV 6 Characterization of spinothalamic tract lesions using multi-modal neurophysiology

FV 6 Characterization of spinothalamic tract lesions using multi-modal neurophysiology

Application of neurophysiology in electrical cervical spinal cord stimulation for persistent vegetative state

Objective To investigate the correlation between the overall scores of multimodal neurophysiological methods [electroencephalography (EEG), brainstem auditory evoked potential (BAEP), somatosensory evoked potential (SEP)] and therapeutic effect of cervical spinal cord stimulation (cSCS) in patients with persistent vegetative state (PVS) resulting from non-traumatic brain injury. Methods A retrospective analysis was conducted on the clinical data, neurophysiological scores and 1-year outcomes of 48 PVS patients who underwent treatment of cSCS (study group) at Department of Neurosurgery, Daqing Oilfield General Hospital from January 2010 to February 2017. The results were compared with the clinical data and outcomes of 50 patients undergoing conservative resuscitating treatment (control group) during the same period. We investigated the relationship between multimodal neurophysiological scores and therapeutic effect of cSCS treatment by Spearman rank correlation analysis in the study group. Results In the study group, 18 cases (37.5%) were resuscitated from PVS, 11 cases (22.9%) reported obvious therapeutic effect. In the control group, 3 cases (6.0%) were resuscitated from PVS, 4 cases (8.0%) had obvious therapetuic effect at 1 year post treatment. The treatment effect was significantly different between study group (R=0.6077) and control group (R=0.3966) by Ridit analysis (P<0.05). The cSCS treatment demonstrated better therapeutic effect than conservative resuscitating treatment. The Spearman rank correlation analysis showed that there was a positive correlation between the cSCS efficacy and neurophysiological scores (rs=0.854, P<0.05), i. e., higher overall neurophysiological scores indicated better therapeutic effect of cSCS. Conclusions (1) The cSCS awakening technology could promote neurological rehabilitation, improve the awakening ratio in PVS patients and facilitate early wake-up of PVS patients. (2) There is a positive correlation between multimodal neurophysiological scores and therapeutic effect of cSCS treatment. Multimodal neurophysiological scores play an important role in helping doctor choose cSCS awakening technology in clinical practice. Key words: Persistent vegetative state; Electrophysiology; Cervical spinal cord stimulation; Multimodal neurophysiology

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

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.