Stroke is a syndrome characterized by an acute onset of a neurologic deficit that persists for at least 24 hours, reflects focal involvement of the central nervous system. It is the third leading cause of adult disability and death. Twenty-two patients presented with the first attack of stroke confirmed by CT scan and 22 age and sex matched control subjects were enrolled in the present study. They underwent clinical tests (Medial Research Council scale score and Barthel index) and electrophysiological tests (Somatosensory Evoked Potentials and Sympathetic Skin Response) The results of the study revealed that twelve cases (54.55%) presented with right sided weakness and 10 (45.45%) presented with left sided weakness. Lacunar stroke was found in 7 cases (31.8%), while large vessel stroke was found in 15 cases (68.2%). Eighteen cases (81.82%) were of ischemic type and 4 cases (19.18%) were of hemorrhagic type. The tests were performed at 1st week and 3 months thereafter. The mean Medical Research Council scale at 1st week was significantly less than that after 3 months of stroke. Significantly low Medical Research Council scale was found in patients with large vessel as compared to the lacunar stroke patients both at first week and after 3 months. The mean Barthel index score after 3 months was significantly higher than that at first week. Barthel index was significantly low in patients with large vessel stroke as compared to lacunar stroke patients both at first week and after 3 months of stroke. N20 latency and Sympathetic Skin Response latency were significantly prolonged, whereas N20-P25 amplitude, amplitude ratio and Sympathetic Skin Response amplitude were significantly lower in stroke patients compared with controls. All the neurophysiological parameters were not different in patients between 1st week and 3rd month except for the Sympathetic Skin Response amplitude. The Medical Research Council score has strong correlation and N20-P25 amplitude has moderately strong correlation with the outcome Medical Research Council scale and Barthel index after 3 months. Concerning N20 latency, Sympathetic Skin Response latency and amplitude, they correlate well with the outcome Medical Research Council Scale but not with the outcome Barthel index. The amplitude ratio had no correlation with both outcome parameters. Interestingly, the N20 latency and both Sympathetic Skin Response latency and amplitude were significantly different in lacunar form large vessel stroke patients.
In conclusion, this study shows that muscle power (Medical Research Council score) is the main outcome predictor in stroke patients; meanwhile, N20-P25 amplitude is the main Somatosensory Evoked Potentials prognostic factor in stroke. Both Somatosensory Evoked Potentials (N20 latency) and Sympathetic Skin Response (latency and amplitude) can predict (even roughly) the size of cerebral infarction (whether lacunar or large vessel stroke).