The Use of Somatosensory Evoked Potentials in Patients with Stroke

ABSTRACT.Somatosensory evoked potentials (SEPs) were recorded in 125 (n = 151) stroke patients more than 3 weeks after the onset of the disease. The correlation between sensory disturbance, N20 amplitude ratio, and the central conduction time (CCT) was then investigated. The N20 amplitude ratio was calculated by dividing the amplitude of the affected side by that of the unaffected side and presented as a percentage. The CCT represents the time interval between N20 and N13.Of 98 stroke patients with an abnormal amplitude ratio and 23 with an abnormal CCT, 91.8% and 95.7% respectively, had sensory disturbances. Conversely, 82.6% of those with sensory disturbances showed an abnormal amplitude ratio, whereas only 38.6% of those with sensory disturbances showed an abnormal CCT. There were definite correlations between sensory disturbance and either the CCT or amplitude ratio, however, there were none between the CCT and amplitude ratio. On the basis of these results, we conclude that amplitude ratio is more ef...