Transient global amnesia: a review emphasizing pathogenic aspects

The transitory memory disturbance known as transient global amnesia (TGA) r emains an enigma from a pathogenic point of view. In spite of its typical b enign prognosis, TGA is a frightening experience for patients and their rel atives. Moreover, a TGA episode usually leads to extensive investigation of patients in search of organic alterations that might be responsible for th e event. Finally, TGA generates queries about therapeutic choices. In this review, we critically re-evaluate the evidence in support of and against th e three main pathogenic hypotheses (i.e. ischemia, seizure discharge, and m igraine), and we conclude that none of these appears completely convincing. Given the good prognosis and the lack of association with organic and inst rumental abnormalities, we advance the hypothesis that TGA may be related t o psychological disturbances causing transient alteration in brain metaboli sm and, consequently, amnesia. Our conclusion has relevant consequences in the evaluation of patients with TGA.