Correlation between sensory loss, functional disability and short-latency somatosensory evoked potentials in strokes

Short-latency somatosensory evoked potentials (SEPs) were reviewed for their correlation with the clinical features and functional deficit of 64 patients with supratentorial deep or superficial ischemic strokes. Abnormal SEPs correlated with lesions of proprioceptive pathways and with clinical sensory impairment. 87% of patients with abnormal SEPs had sensory loss and 88% of those with normal SEPs had normal sensation. The reliability of the SEPs made them useful in an objective demonstration of an abnormality in sensory system function. However, they are not sensitive enough to be used as a method of prognostication because 1) the SEPs abnormalities depend on the involvement of their generators and therefore may be normal in some thalamic or cortical lesions associated with severe disability, 2) 48.4% of the patients studied had normal sensation, and 3) in the group with absent SEPs, the functional disability was poorer than in the group with normal SEPs, not in relation to the type of the sensory loss but to the volume and location of the infarcted area.