<abstract xmlns="http://www.w3.org/1999/xhtml"><sec><h3>Background</h3>Epilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65 million people worldwide suffer from epilepsy; 20–40% of them are refractory to medication therapy. Early detection of disease is crucial in the management of patients with epilepsy. Correct localization of the ictal onset zone is associated with a better surgical outcome. The modern non-invasive techniques used for structural-functional localization of the seizure focus includes electroencephalography (EEG) monitoring, magnetic resonance imaging (MRI), single photon emission tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT). PET/CT can predict surgical outcome in patients with refractory epilepsy. The aim of the article is to review the current role of routinely used tracer 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) as well as non routinely used 18F-Flumazenil (18F-FMZ) tracers PET/CT in patients with refractory epilepsy.</sec><sec><h3>Conclusions</h3>Functional information delivered by PET and the morphologic information delivered by CT or MRI are essential in presurgical evaluation of epilepsy. Nowadays 18F-FDG PET/CT is a routinely performed imaging modality in localization of the ictal onset zone in patients with refractory epilepsy who are unresponsive to medication therapy. Unfortunately, 18F-FDG is not an ideal PET tracer regarding the management of patients with epilepsy: areas of glucose hypometabolism do not correlate precisely with the proven degree of change within hippocampal sclerosis, as observed by histopathology or MRI. Benzodiazepine-receptor imaging is a promising alternative in nuclear medicine imaging of epileptogenic focus. The use of 11C-FMZ in clinical practice has been limited by its short half-life and necessitating an on-site cyclotron for production. Therefore, 18F-FMZ might be established as one of the tracers of choice for patients with refractory epilepsy because of better sensitivity and anatomical resolution.</sec></abstract>

BackgroundEpilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65 million people worldwide suffer from epilepsy; 20–40% of them are refractory to medication therapy. Early detection of disease is crucial in the management of patients with epilepsy. Correct localization of the ictal onset zone is associated with a better surgical outcome. The modern non-invasive techniques used for structural-functional localization of the seizure focus includes electroencephalography (EEG) monitoring, magnetic resonance imaging (MRI), single photon emission tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT). PET/CT can predict surgical outcome in patients with refractory epilepsy. The aim of the article is to review the current role of routinely used tracer 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) as well as non routinely used 18F-Flumazenil (18F-FMZ) tracers PET/CT in patients with refractory epilepsy.ConclusionsFunctional information delivered by PET and the morphologic information delivered by CT or MRI are essential in presurgical evaluation of epilepsy. Nowadays 18F-FDG PET/CT is a routinely performed imaging modality in localization of the ictal onset zone in patients with refractory epilepsy who are unresponsive to medication therapy. Unfortunately, 18F-FDG is not an ideal PET tracer regarding the management of patients with epilepsy: areas of glucose hypometabolism do not correlate precisely with the proven degree of change within hippocampal sclerosis, as observed by histopathology or MRI. Benzodiazepine-receptor imaging is a promising alternative in nuclear medicine imaging of epileptogenic focus. The use of 11C-FMZ in clinical practice has been limited by its short half-life and necessitating an on-site cyclotron for production. Therefore, 18F-FMZ might be established as one of the tracers of choice for patients with refractory epilepsy because of better sensitivity and anatomical resolution.

18F-fluorodeoxyglucose and 18F-flumazenil positron emission tomography in patients with refractory epilepsy

Nuclear Medicine Research Department, Iason, Graz, Austria

Department of Nuclear Medicine, Palacký University Olomouc, Czech Republic

Department of Neurology, Klinikum Wels-Grieskirchen, Wels, Austria

Institute of Nuclear Medicine, Kepler Universitätsklinikum, Neuromed Campus, Linz, Austria

Radiology and Oncology

F-fluorodeoxyglucose and F-flumazenil positron emission tomography in patients with refractory epilepsy

BackgroundEpilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65...

PET scan	Findings on PET scan
¹⁸F-FDG interictal	Decreased metabolism
¹⁸F-FDG ictal	Increased and decreased metabolism (complex pattern)
¹⁸F-FDG postictal	Increased and decreased metabolism (complex pattern)
Serotonin receptor (e.g. ¹⁸F-Mefway)	Reduced binding
Dopamine receptor (e.g. ¹⁸F-Fallypride)	Reduced binding
¹⁸F-Flumazenil (GABA receptor)	Decreased binding
¹5O-H₂O interictal	Reduced perfusion
¹5O-H₂O ictal	Increased perfusion

¹⁸F-fluorodeoxyglucose and ¹⁸F-flumazenil positron emission tomography in patients with refractory epilepsy

Article Category: Review Article

Published Online: Jul 19, 2016

Page range: 247 - 253

Received: Feb 23, 2016

Accepted: Apr 29, 2016

DOI: https://doi.org/10.1515/raon-2016-0032

Keywords
epilepsy, nuclear medicine, PET/CT, F-FDG, F-Flumazenil

© 2016 Radiol Oncol

This content is free.

Figure 1

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Some PET tracers used for imaging of epileptic focus and PET scan findings