Somatosensory evoked potentials in patients with thalamic lesions

Summary Somatosensory evoked potentials (SEPs) were recorded in 20 patients with thalamic lesions confirmed by CT (10 with infarction, 10 with haemorrhage). The changes in SEP configuration are discussed in their relationship to clinical symptoms. Four types of SEP abnormality produced by thalamic lesion are distinguished: (1) FF type, (2) N20/P23 dissociation type, (3) N18/N20 false shift type, and (4) reduced early component type. It was shown that clinically similar lesions might produce different SEP patterns.