Somatosensory evoked potentials in the evaluation of motor rehabilitation efficacy in patients with ischaemic stroke

Introduction. The quality of rehabilitation measures used during early functional recovery can be assessed by registering somatosensory evoked potentials (SSEP). In many patients, SSEP are either not recorded, or the results are poorly reproducible. To overcome these difficulties, we proposed to modify the method of recording SSEP in patients post ischaemic stroke.

The aim of the study was to evaluate changes in SSEP after patients with ischaemic stroke underwent motor rehabilitation in the early recovery period. 

Materials and methods. We examined 36 patients with acute ischaemic stroke in the middle cerebral artery territory. The severity of neurological deficits and the functional state of the nervous system were assessed using international clinical scales, based on electrophysiological and neuroimaging studies. The motor rehabilitation consisted of 10 sessions. SSEP were measured before and after the full motor rehabilitation course. We calculated the standard values for SSEP. 

Results. Before rehabilitation, SSEP were not detected in the ipsilateral hemisphere in 40% of patients. After a course of rehabilitation, SSEP were detected in the majority (83%) of patients, but the values showed significant inter-individual variation, and in such patients, SSEP cannot be used as an indicator of rehabilitation effectiveness. In the group of patients whose SSEP could be reliably recorded and the main components P and N were measurable, we found that the average component latency in the ipsilateral hemisphere was N = 48 ± 15 msec and P = 55 ± 16 msec. These values are significantly higher than in the healthy population. The amplitude parameters corresponded to the published normal values. No statistically significant changes in the latency of components N and P were observed after the course of rehabilitation.

Conclusion. Using a method for measuring SSEP with spatiotemporal separation will significantly expand the range of patients whose condition, as well as the effectiveness of the rehabilitation procedures aimed at restoring lost motor function caused by ischaemic brain damage, can be monitored over time.