Interictal cerebral metabolism in partial epilepsies of neocortical origin

Abstract

We performed interictal [18F]fluorodeoxyglucose positron emission tomography (FDG PET) in 24 patients with partial epilepsy of neocortical origin. Two-thirds of patients had regions of hypometabolism. The zone of intracranially recorded electrographic ictal onset was always located in a region of hypometabolism, in those with hypometabolism. Hypometabolic regions in partial epilepsies of neocortical origin were usually associated with structural imaging abnormalities. Regional hypometabolism occasionally occurred without localizing ictal scalp EEG and cerebral magnetic resonance imaging findings, however. FDG PET may be useful in directing placement of intracranial electrodes for presurgical evaluation of refractory neocortical seizures.

Multimodality imaging in the surgical treatment of children with nonlesional epilepsy

“…22,23 Although FDG-PET has been shown to be useful in temporal lobe epilepsy, 24 its diagnostic value in nonlesional neocortical epilepsy is less clear. 25,26 We used SPM analysis in an attempt to eliminate some of the subjectivity required with visual analysis and to control for differences in expertise and experience between readers. 27 Using SPM analysis of FDG-PET, the lobar concordance rate with iEEG was lower for FDG-PET than the other modalities.…”

Painful Focal Sensory Seizure Arising from the Primary Somatosensory Cortex

“…The etiology of the seizures in the present patient still remains unsolved especially as to whether it was inflammatory or not. In patients with focal seizure, brain SPECTand PET often reveal regional abnormalities, and the regional CBFin the focus increases ictally and decreases interictally (15)(16)(17).…”

Positron Emission Tomography Studies of Cerebral Blood Flow and Glucose Metabolism

“…The area of reduced metabolism in frontal lobe epilepsy may be much larger than the pathological abnormality, as it is in TLE. By contrast, however, the hypometabolic area may be restricted to the underlying lesion (44,45).…”

“…It has been the general experience that the epileptic focus is contained within the hypometabolic area, if one exists (20,44,46,57). Quantitative analysis of "FDG PET scans was found to enhance sensitivity and accuracy of determination over visual assessment (48).…”