Bilateral cornu ammonis 3-dominant mechanism of visual working memory impairment in right temporal lobe epilepsy and hippocampal sclerosis.

Hippocampal sclerosis in temporal lobe epilepsy is linked to cognitive impairment. This study investigates its exacerbating role in visual working memory deficits in right temporal lobe epilepsy and the involvement of contralateral hippocampal subregions. We enrolled 103 patients with right temporal lobe epilepsy (57 with right hippocampal sclerosis and 46 without hippocampal sclerosis) and 36 healthy controls who underwent high-resolution MRI and neuropsychological assessment. Patients with hippocampal sclerosis showed more severe visual working memory impairment, widespread grey matter atrophy and significant volume loss in bilateral cornu ammonis 3 and right dentate gyrus. Contralateral cornu ammonis 3 atrophy correlated with poorer visual working memory performance. Hippocampal sclerosis in right temporal lobe epilepsy is linked to severe visual working memory deficits and extensive bilateral hippocampal atrophy. These findings establish hippocampal sclerosis as a key biomarker and underscore the role of bilateral hippocampal network disruption, with contralateral cornu ammonis 3 integrity influencing cognitive outcomes.