Unilateral or bilateral punctate hippocampal hyperintensities on DW-MRI: seizures, amnesia, or both?

Abstract

The presence of small hippocampal hyperintense lesions on diffusion-weighted (DW) MRI can respond to different etiologies and represents a challenge where clinical judgment is imperative, since therapeutic approach may be quite different.We here report three patients with similar neuroradiological findings, i.e., hyperintense punctate hippocampal lesions on diffusion-weighted MRI sequences, yet of different origin. The first one presented with isolated amnesia (transient global amnesia), the second one with amnesia and seizures, and the third one with seizures.Thus, hippocampal punctate lesions appear after transient global amnesia, but the same pattern may be present after seizures, either focal-onset or generalized seizures. This peculiar radiological MRI pattern could indicate a pathogenic link between transient global amnesia (TGA) and seizures which should be further studied.

Simultaneous transient global amnesia and Takotsubo syndrome after death of a relative: a case report

“…Cortisol secretion can be increased during a TGA [11]. Cerebral MRI patterns may indicate that seizures trigger the development of a TGA [12]. Recently, cytotoxic edema of the hippocampus has been related to the pathogenesis of a TGA [13].…”