Lack of evidence for arterial ischemia in transient global amnesia.

Abstract

Lesions in diffusion-weighted imaging (DWI-L) have been commonly described in transient global amnesia (TGA). We investigated a possible relationship between brain ischemia and TGA. Twenty-eight patients underwent transcranial and carotid Doppler ultrasonography (including microembolus detection) and MRI within 24 hours of TGA onset (including DWI, perfusion-weighted imaging and angio-MRI). MRI was repeated at 48 to 96 hours (21 patients) and 30 days (18 patients). Punctate DWI-L were observed in 16 patients (57%) and were not attributable to perfusion abnormalities, arterial stenoses or underlying cardioembolic disease. MRIs performed between 12 and 72 hours showed the highest frequency of DWI-L (88%; P<0.001). No pathological findings were observed at 30 days. These results suggest that TGA is not related to cerebral arterial ischemia.