Parietal and prerolandic somatosensory evoked responses in carotid artery reversible ischemic attacks (RIA).

Somatosensory potentials evoked by median nerve stimulation were recorded bilaterally from the prerolandic and parietal scalp in 36 patients with reversible ischemic attacks in one carotid artery distribution. Responses recorded from the affected and unaffected hemisphere were compared. SEP abnormalities were observed over the affected hemisphere in 22 subjects (61.1%), irrespective of number and/or duration of episodes, and appeared selectively correlated to their clinical features. SEP studies proved to be more sensitive than conventional EEG recordings and are suitable for evaluation of the functional impairment of specific cerebral areas following transient cerebral ischemia. The occurrence of SEP abnormalities in RIA may represent an unfavourable sign, being more frequent in patients with evidence of internal carotid artery disease.