Seizure‐like discharges recorded in human dysplastic neocortex maintained in vitro
- Donatella Mattia, MD,
- André Olivier, MD, PhD and
- Massimo Avoli, MD, PhD
- From the Montreal Neurological Institute, the Department of Neurology and Neurosurgery, and the Department of Physiology, McGill University, Montreal, PQ, Canada.
- Address correspondence and reprint requests to Dr. Massimo Avoli, Montreal Neurological Institute, 3801 University, Montreal, QC, Canada H3A 2B4.
Abstract
Application of the convulsant drug 4-aminopyridine (50 to 100 μM) induced spontaneous seizure-like discharges (duration = 76.3 ± 46.8 sec, mean ± SD; interval of occurrence = 225.2 ± 87.9 sec) in slices of neocortex obtained from patients with a diagnosis of focal neuronal migration disorders during neurosurgical procedures for relief of drug-resistant seizures. Similar epileptiform discharges could also be elicited in these slices by single-shock stimuli delivered in the underlying white matter or within the gray matter. By contrast, neocortical slices obtained from patients suffering from temporal lobe epilepsy (which is characterized by Ammon's horn sclerosis but relatively normal neocortex) did not generate any epileptiform activity during 4-aminopyridine application. Thus, our study is the first to provide experimental evidence for the intrinsic epileptogenicity that characterizes neuronal migration disorders.
- Copyright 1995 by the American Academy of Neurology
