Seasonal variations in the occurrence of transient global amnesia (TGA)

Transient global amnesia (TGA) is a rare, benign condition characterised by a sudden deficit of anterograde and retrograde memory that usually lasts for a few hours and is not accompanied by other focal neurological symptoms or signs. Its aetiology is still unclear. Various events or activities may trigger TGA. Evidence of seasonal variations in the appearance of TGA is inconsistent.

We retrospectively analysed the medical history of 114 adult patients with diagnosed TGA, hospitalised at two neurology departments in Wrocław from 2008 to 2014. We reviewed risk factors, trigger points, and occurrence in each month of the year in our patient population.

Over this seven-year period, 114 patients were diagnosed with TGA. The annual occurrence ranged from 13 to 22 hospitalisations. The mean age of the patients was 64 years. There were 36 TGA events in men and 78 in women. TGA occurred most frequently in spring (36%) and summer (30%), with the incidence peaking during March.

Our findings suggest that there is a relationship between the season of the year and the probability of TGA.