Transient global amnesia and its aeromedical implications.

Introduction: Transient global amnesia (TGA) is an episode of severe anterograde amnesia of sudden onset, characteristically lasting 4 to 6 h. Patients become disorientated in time and place, but not in person. Automated motor tasks are preserved; however, the retention of new information is impaired, with clear implications to a pilot's fitness to fly. This study examines the United Kingdom Civil Aviation Authority (UK CAA) experience of pilots with TGA and compares it to the medical literature.

Methods: The UK CAA medical records database was searched for subjects who had reported a history of TGA between the years 1990 and 2010. Subject age and gender, the frequency and duration of episodes, the follow-up period, precipitants, and associated features were recorded. A literature search for papers with similar information was undertaken.

Results: The UK CAA database showed 29 subjects who had held a UK CAA medical certificate with a history of TGA. There were 28 male individuals and 1 female. The mean age was 59 yr. The mean follow-up period was 3.4 yr. The average duration of an episode was 2.8 h. Activity, stress, or exposure to cold water were reported as possible precipitants by 16 subjects (55%). There were 6 subjects (21%) who had a history of migraine and 10 (34%) who had a history of hypertension. From the literature, 10 papers were reviewed and compared to our study group.

Discussion: The aeromedical implications of TGA, including its etiology, associations, misdiagnosis, and recurrence risk are considered. A policy for the certification of pilots following TGA is proposed.