Hyperhomocysteinemia Association With Transient Global Amnesia: A Rare Case Report

Transient global amnesia (TGA) is an intriguing condition that classically presents with an abrupt onset of temporary complete anterograde amnesia and partial retrograde amnesia. Most individuals who experience such a form of amnesia usually have only one attack but recurrent attacks are possible. Most attacks last for a few minutes or few hours and the ability to lay down new memories may also be affected but gradually improves, leaving only a dense amnestic gap for the duration of the episode. There has been some discussion about the etiology behind TGA; however, there has yet to be a consensus with regard to any significant association.

We report the case of a 65-year-old male presenting with a sudden onset of memory loss that is typical of TGA and who was found to have elevated homocysteine levels. There has only been one other case previously reported that discussed a possible correlation between hyperhomocysteinemia and TGA. It is yet to be determined if increased homocysteine level is a significant risk factor for attacks of TGA.

Although it was first described more than half a century ago, it can still be misdiagnosed frequently as many physicians are not familiar with this condition. Furthermore, there are quite a few medical conditions that may cause sudden memory impairment, such as epilepsy and stroke, which make it difficult to distinguish them from this form of amnesia. The knowledge of these clinical identities is necessary for a high index of suspicion, which may lead to a meticulous medical evaluation as required for proper diagnosis.