Histopathological characterization of cerebral small vessel disease in epilepsy patients with temporal lobe epilepsy submitted to surgery - a case-control study.

Abstract

Cerebrovascular disease (CVD) is a major contributor to epilepsy. However, patients with epilepsy also have a significantly increased risk of stroke. The way epilepsy contributes to the increased risk of stroke is still uncertain and is ill characterized in neuropathological studies. A neuropathological characterization of cerebral small vessel disease (cSVD) in patients with chronic epilepsy was performed. Thirty-three patients with refractory epilepsy and hippocampal sclerosis (HS) submitted to epilepsy surgery from a reference centre were selected between 2010 and 2020 and compared to 19 autopsy controls. Five randomly selected arterioles from each patient were analysed using a previously validated scale for cerebral small vessel disease (cSVD). The presence of CVD disease imaging markers in pre-surgical brain MRI was studied. There were no differences in age (43,8 vs 41,6; p=0,547) or gender distribution (female gender 60,6% vs 52,6%; p=0,575) between groups. Most CVD findings in brain MRI were mild. Patients had a mean time between the epilepsy onset and surgery of 26±14,7 years and were medicated with a median number of 3 antiseizure medication (ASMs) [inter-quartile range 2-3]. Patients had higher median scores in arteriolosclerosis (3 vs 1; p<0,0001), microhemorrhages (4 vs 1; p<0,0001) and total score value (12 vs 8,9; p=0,031) in comparison with controls. No correlation was found between age, number of years until surgery, number of ASMs or cumulative defined daily dosage of ASM. The present study provided evidence supporting the increased burden of cSVD in the neuropathological samples of patients with chronic epilepsy.