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Intracranial video-EEG monitoring in presurgical evaluation of patients with refractory epilepsy
- Department of Neurosurgery and Oncology of Central Nervous System, Barlicki University Hospital, Medical University of Lodz, Lodz, Poland
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Abstract
Reviewing our experience in intracranial video-EEG monitoring in the presurgical evaluation of patients with refractory epilepsy.
MethodsWe report on 62 out of 202 (31%) patients with refractory epilepsy, who underwent a long term video-EEG monitoring (LTM). The epileptogenic zone (EZ) was localised either based on the results of LTM or after intracranial EEG recordings from depth, subdural or foramen ovale electrodes. The decision on the location of the electrodes was based upon semiology of the seizures, EEG findings and the lesions visualised in MRI brain scan. Intraoperative corticography was carried out before and right after the resection of the seizure onset zone.
ResultsThe video-EEG monitoring could localise EZ in 43 (69%) cases based. The remaining patients underwent invasive diagnostics: 10 (53%) had intracerebral depth electrodes, 6 (31%) depth and subdural and 3 (16%) foramen ovale electrodes. Intracranial video EEG recordings showed seizure focus in all the patients. Ten of them had EZ in mesial temporal structures, 4 in accessory motor area, 3 at the base of the frontal lobe and 2 in parietal lobe. There was one case of an asymptomatic intracerebral haematoma at the electrode. All patients were subsequently operated on. In 15 (79%) cases the seizures subsided (follow-up from 2 to 5 years), in 4 (21%) they decreased.
ConclusionsThe intracranial EEG is required in all patients with normal MRI (so-called nonlesional cases) in whom EZ is suspected to be located in the hippocampus, insula or in the basal parts of the frontal lobe.
Abstract
Reviewing our experience in intracranial video-EEG monitoring in the presurgical evaluation of patients with refractory epilepsy.
MethodsWe report on 62 out of 202 (31%) patients with refractory epilepsy, who underwent a long term video-EEG monitoring (LTM). The epileptogenic zone (EZ) was localised either based on the results of LTM or after intracranial EEG recordings from depth, subdural or foramen ovale electrodes. The decision on the location of the electrodes was based upon semiology of the seizures, EEG findings and the lesions visualised in MRI brain scan. Intraoperative corticography was carried out before and right after the resection of the seizure onset zone.
ResultsThe video-EEG monitoring could localise EZ in 43 (69%) cases based. The remaining patients underwent invasive diagnostics: 10 (53%) had intracerebral depth electrodes, 6 (31%) depth and subdural and 3 (16%) foramen ovale electrodes. Intracranial video EEG recordings showed seizure focus in all the patients. Ten of them had EZ in mesial temporal structures, 4 in accessory motor area, 3 at the base of the frontal lobe and 2 in parietal lobe. There was one case of an asymptomatic intracerebral haematoma at the electrode. All patients were subsequently operated on. In 15 (79%) cases the seizures subsided (follow-up from 2 to 5 years), in 4 (21%) they decreased.
ConclusionsThe intracranial EEG is required in all patients with normal MRI (so-called nonlesional cases) in whom EZ is suspected to be located in the hippocampus, insula or in the basal parts of the frontal lobe.
Keywords
Refractory epilepsy, Presurgical evaluation, Depth electrodes, Streoelectroencephalography, Electrocorticography
Title
Intracranial video-EEG monitoring in presurgical evaluation of patients with refractory epilepsy
Journal
Neurologia i Neurochirurgia Polska
Issue
Pages
201-207
Page views
300
Article views/downloads
595
DOI
10.1016/j.pjnns.2017.02.002
Bibliographic record
Neurol Neurochir Pol 2017;51(3):201-207.
Keywords
Refractory epilepsy
Presurgical evaluation
Depth electrodes
Streoelectroencephalography
Electrocorticography
Authors
Marlena Hupalo
Rafal Wojcik
Dariusz J. Jaskolski