The settings where the TGA episode usually occurs include immersion in water, temperature change, painful experiences (e.g., renal pain ), physical activity, emotional stress (e.g., increased work load ), sexual intercourse, driving and traveling, medical procedures, Valsalva-associated maneuvers, and other activities as walks, house works, meetings, etc. But the memory of the period of the amnesic episode is never recovered. The episode lasts some hours and then the memory is recovered gradually. A characteristic feature of TGA is the repetitive comments or questions that are repeated using the same words and making the same comments to the answers that they receive. Witnesses of TGA episode usually report a sudden expressive or behavioral change in the patient. Patients usually are aware of their disease state, but they are unable to identify the nature of their memory deficits and they overestimate their memory ability. During amnesic episode, patients maintain their attention, and they are able to perform complex tasks as gardening or driving. But those inferences were not helpful enough to make them orientate in time. This difference between spatial and temporal disorientation may be reflecting their ability to use contextual information and previous semantic knowledge to make inferences about where they are. In a study with 17 TGA patients, there were no significant differences in spatial orientation with the control group, while the temporal orientation was severely affected during the amnesic episode, and it was recovered after a week. This makes them disoriented in space and specifically in time, but they do not produce confabulations (false memories which are taken by the patient as true to fill the gaps in memory). And finally, based on new insights from the hippocampal function research, some inconsistencies derived from the memory systems perspective will be analyzed.ĭuring TGA, patients show severe anterograde amnesia, which makes them unable to create new memories and to have the sense of present. This includes both, the analysis of the ability of the TGA patients to recall knowledge acquired before the TGA (retrograde amnesia) and to learn new knowledge during the amnesic episode (anterograde amnesia).

Then, the preserved and impaired memory pattern of TGA patients will be discussed considering the classical memory systems model. The chapter starts with a review of basic characteristics of TGA including diagnostic criteria, etiology, and differential diagnosis. This perspective leads to some inconsistencies and unresolved issues that will be confronted having a more precise and updated description of the function of the hippocampus.

These consequences are going to be framed in a classical memory systems perspective, which considers that the hippocampus is engaged in declarative and explicit memory but not in non-declarative and implicit memory. As it has been shown that TGA is related with a transitory deficit of the hippocampus function, in this chapter the cognitive consequences of this deficit will be discussed.

Cognitive neuroscience is the scientific field that studies the neural bases of the cognitive processes as memory and learning. The main goal of this chapter is to provide a neurocognitive perspective of the deficits and preserved abilities of this type of amnesia. Transient global amnesia (TGA) is a neuropsychological syndrome, which shows a severe, sudden, and transitory loss of the ability to create new memories and, to some degree, to recover past events.

Global amnesia event