[Transient global amnesia (a study of 30 cases)].

The authors have studied 30 patients with transient global amnesia aged between 49 and 76 years (median age of 63 years), without focal neurologic signs that have been followed for periods varying between 6 months and 10 years. Three of the patients had recurrent attacks of transient global amnesia, and another three had a stroke, although at some distance from the amnesia attack. Association was noted with certain risk factors including high blood pressure, and angiopathic changes of the eye fundus (in 50% of the patients), dyslipidemia (in 30%), diabetes (in 10%), and essential polyglobulia (in 7%). Coagulation studies including thrombelastograms were carried out in 22 patients, and demonstrated hypercoagulability in 50% of them. Changes in the arterial wall were noted in 85% of the 14 patients in whom carotid sphygmograms were recorded. The presence of these risk factors could explain the occurrence of cerebrovascular accidents in patients with transient global amnesia. Electroencephalograms performed immediately or a short time after the amnesia attack have evidenced in 18 patients rapid-type dysrhythmia, or diffuse theta waves, predominantly located in the deep layers of the left and right temporal areas. The EEG tracings were either flat or normal in the remaining 12 patients. Of the 30 patients presenting with global transient amnesia only two had migraine in antecedents, and another six had headache during the evolution of amnesia. The neurologic examination did not reveal any abnormality in 27 of the patients. Sequelar signs of neurological deficits were noted in the remaining three patients.(ABSTRACT TRUNCATED AT 250 WORDS)