Dendritic pathology, spine loss and synaptic reorganization in human cortex from epilepsy patients

Laura Rossini, D. De Santis, R.R. Mauceri, C. Tesoriero, M. Bentivoglio, E. Maderna, A. Maiorana, F. Deleo, M. de Curtis, G. Tringali, M. Cossu, G. Tumminelli, M. Bramerio, R. Spreafico, L. Tassi and R. Garbelli

doi:10.1093/brain/awaa387

Selezionato dal Lettore: Renato Simonetti - Azienda Ospedaliero-Universitaria di Ferrara

Motivation: The study of the neuropathological aspect of the epileptogenic zone is of fundamental interest to analyse the intrinsic organization of the epileptogenic network and to derive relevant information to understand both the pathophysiology of epilepsies and the mechanisms of epileptogenesis.

Authors evaluated postsurgical neocortical areas from 28 subjects admitted to neurosurgery for drug-resistant epilepsy; non-epileptic control tissue was obtained from autopsies performed in adult subjects without history of seizures or neurological diseases. The aim of the study is to determine whether epilepsy per se does determine structural alterations in patients with a long-lasting history of epilepsy and high seizure frequency or not.

The study showed that severe rearrangement of both neuronal morphology and synaptic networks in the core of the type II focal cortical dysplasias (particularly type IIb), but not in the surrounding perilesional tissue. The study also demonstrates that, except for type II focal cortical dysplasias, neurons and dendritic spines are structurally normal in highly epileptogenic neocortices. These findings substantiate the hypothesis that seizures per

se do not promote structural alteration of the neocortex even in patients with a longlasting history of epilepsy and high seizure rate.