The distribution of the transient global amnesia in the province of Ferrara, Italy, a clue to the pathogenesis?

The pathophysiology of transient global amnesia (TGA) is uncertain. In the province of Ferrara (Fe-province) the cases of TGA correspond to the resident outpatients diagnosed as TGA in the ER of the University Hospital of Ferrara. Thanks to this, a retrospective survey identified 35 (14 men, 21 women) first-ever TGA cases in the resident population of the Fe-province in 2018 giving a crude incidence rate of 10.10/100,000 (95% CI 7.00 - 14.00), 8,40 (95% CI 4.60 - 14.10) for men and 11.60 (95% CI 7.20-17.80) for women, a non significant gender difference. The monthly cases of TGA followed the Poisson distribution (goodness-of-fit test: chi-square = 2.557, 5 degrees of freedom , p>0.70). The incidence of TGA in the Fe-province was higher in the highest level of urbanization (21.40/100,000 95% CI 13.10 - 33.00) than in the lowest one (4.20/100,000 95% CI 1.92-8.00). The incident cases of TGA incresed with the level of urbanization (chi-square trend test = 19.940, p < 0.001) and the population density level (chi-square trend test = 46.684, p< 0.001). Since urbanization is likely involved in stress-related disorders, these findings support the hypothesis of the involvement of stress in TGA.