Corpora amylacea in the neocortex in patients with temporal lobe epilepsy and focal cortical dysplasia

Abstract

IntroductionCorpora amylacea (CoA) are present in about 60% of atrophic hippocampi resected from patients with drug resistant temporal lobe epilepsy (DRTLE). They have also been described in the lateral temporal neocortex, although less frequently. ObjectiveThe objective is to measure the presence, distribution and density of CoA in the lateral temporal lobes of patients with DRTLE and focal cortical dysplasia (FCD), also examining how CoA density may be linked to demographic and clinical traits. MethodsResected tissue from 35 patients was analysed. CoA density was assessed with a semi-quantitative scale according to the criteria established by Cherian et al. ResultsPresence of CoA in the neocortex of nine patients was associated with hippocampal sclerosis (FCD type IIIa, seven cases), dysembryoplastic neuroepithelial tumour (FCD type IIIb, one case), and cavernous angioma (FCD type IIIC, 1 case). The meningeal surface (MS) was involved in all cases, and eight cases displayed CoA in the cerebral parenchyma (white matter) and around blood vessels. CoA density on the MS showed a negative correlation with age at seizure onset (r=−0.828, P<.05) and a positive correlation with disease duration (r=0.678, P<.05) but not with postoperative clinical outcome. ConclusionsPatients with DRTLE and a primary lesion (hippocampal sclerosis, tumour, vascular malformation) associated with mild FCD were shown to have CoA deposits in the neocortex. No association was found between presence of CoA and clinical outcome 1 year after surgery.