ABSTRACT
The pre-operative assessment and surgical management of patients with dual pathology is challenging. We describe a patient with drug-resistant focal epilepsy with hippocampal sclerosis and extensive periventricular nodular heterotopia in the same hemisphere. The semiology, scalp EEG, and imaging were divergent, but the presence of focal interictal and ictal epileptic discharges of the putative ictal onset zone resulted in successful localization of the epileptogenic zone. A less aggressive resection was performed based on intracranial EEG recording. The patient has been seizure-free for three years since resection. Electroclinical hypotheses and challenges in defining the epileptogenic network are discussed.
Subject(s)
Cerebral Ventricles/pathology , Drug Resistant Epilepsy , Epilepsies, Partial , Hippocampus/pathology , Nervous System Malformations/pathology , Adult , Drug Resistant Epilepsy/pathology , Drug Resistant Epilepsy/physiopathology , Drug Resistant Epilepsy/surgery , Epilepsies, Partial/pathology , Epilepsies, Partial/physiopathology , Epilepsies, Partial/surgery , Female , Humans , Sclerosis/pathologyABSTRACT
Surface electroencephalogram (EEG) recording remains the gold standard for noninvasive assessment of electrical brain activity. It is the most efficient way to diagnose and classify epilepsy syndromes as well as define the localization of the epileptogenic zone. The EEG is useful for management decisions and for establishing prognosis in some types of epilepsy. Electroencephalography is an evolving field in which new methods are being introduced. The Canadian Society of Clinical Neurophysiologists convened an expert panel to develop new national minimal guidelines. A comprehensive evidence review was conducted. This document is organized into 10 sections, including indications, recommendations for trained personnel, EEG yield, paediatric and neonatal EEGs, laboratory minimal standards, requisitions, reports, storage, safety measures, and quality assurance.
