Alternate numbness in the upper extremities as the initial symptom of basilar migraine: an electrophysiological evaluation using EEG power topography.

A case of basilar migraine (BM) with alternate numbness as the initial symptom is described. The patient's chief complaint was alternate numbness in the right and left upper extremities. After angiography the patient fell into a drowsy state, followed by excitation, and finally confusion. The EEG power topography showed slow alpha, theta and delta power in the right occipital area, and alternatively in the right and left parietal area. These findings suggest that the cause of BM is not only based on a vasoconstriction mechanism, but also cortical spreading depression. BM should be suspected as a cause of sensory symptoms.