The structural connectivity of the recurrent transient global amnesia

Abstract

One of recent interesting hypotheses of transient global amnesia (TGA) pathophysiology is the preexisting vulnerability of the memory network in patients with TGA. To verify the hypothesis that patients with recurrent amnestic attacks may have more disrupted structural connectivity than patients of a single TGA event, we compared the brain imaging of patients with repeated episodes of TGA with those who experienced a single attack. Seven patients who were having recurrent TGA and 14 age- and sex-matched control subjects who had only a single episode of TGA participated in the study. Diffusion tensor images from both groups were assessed and analyzed using tract-based spatial statistics. The fractional anisotropy and mean diffusivity values were not reduced in any lesion within the memory pathway of recurrent patient group when compared with those of single event group. No disruptions in the structural connectivity of the memory pathway were observed in patients with recurrent TGA attacks, refuting the hypothesis that recurrent TGA patients present predisposing weakness of the memory network. The stability of structural connectivity suggests that repeated hippocampal lesions associated with TGA do not affect the microstructure of the brain.