Abstract
About 23 million people worldwide suffer from medically refractory epilepsy. Surgery might be the best treatment option with a reasonable chance of seizure freedom. Surgical success depends on the exact definition of the epileptogenic zone (EZ). Magnetoencephalography (MEG) is one of the newer additions to the noninvasive presurgical work-up. This study gives an overview of the impact of MEG on the management of epilepsy patients, focusing on (1) the influence on presurgical evaluation, (2) the identification of patients with the greatest benefit, and (3) possible surgical outcome predictors. An extensive Medline literature search was conducted for studies published from 1990. MEG is in clinical use in the presurgical evaluation of epilepsies for the identification of the EZ and outcome prediction. In cases of failed surgery, it serves as a means to locate the remaining epileptogenic cortex. The usefulness of MEG has been reported for a wide range of localizations including challenging areas like the insula. In cases of multiple possible culprit lesions, MEG can mark the epileptogenic lesion, whereas in cases of nonlesional magnetic resonance imaging (MRI) findings, MEG can pinpoint a lesional or nonlesional epileptogenic cortex area. The role of MEG in the presurgical evaluation of epilepsy was shown with rates of modified approaches in 20–35% of cases. This holds true especially for cases with extratemporal epilepsy. The value of MEG source localization is highest in extratemporal epilepsy, in MRI-negative or multilesional cases, if other modalities yield contradictory or inconclusive results, or in cases of suspected multifocal epilepsy. There is clear evidence that MEG yields nonredundant information and influences the therapeutic course of patients. Various patient groups likely to benefit from MEG were identified. Considering the poor chances of seizure freedom with continued medical treatment, these patients should not be denied source localization, which could result in surgery with favorable outcomes.
Highlights
Epilepsy is one of the most common neurological diseases with a prevalence of about 70 million people worldwide
In temporal lobe epilepsy (TLE), MEG spike yield depends on the location of the epileptogenic zone (EZ)
The value of MEG source localization is highest in extratemporal epilepsy, in magnetic resonance imaging (MRI)-negative or multilesional cases, if other modalities yield contradictory or inconclusive results, or in cases of suspected multifocal epilepsy
Summary
Epilepsy is one of the most common neurological diseases with a prevalence of about 70 million people worldwide. Surgical success depends on the exact definition of the epileptogenic zone (EZ) and its surgical accessibility [26]. The former is achieved via multiple noninvasive diagnostic tools including video-electroencephalographic (EEG) monitoring, magnetic resonance imaging (MRI), [18 F]fluorodeoxyglucosepositron emission tomography (FDGPET), single-photon emission computed tomography (SPECT), and neuropsychological testing. Outcome strongly depends on the type of surgery and its location, with a chance of seizure freedom after 1 year of 66% for temporal lobe epilepsy, 46% for parietal and occipital lobe epilepsy, but only 27% in frontal lobe epilepsy [37]. Surgery might be the best treatment option with a reasonable chance of seizure freedom. An extensive Medline literature search was conducted for studies published from 1990
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
