Seizure outcomes in relation to the extent of resection of the perifocal fluorodeoxyglucose and flumazenil PET abnormalities in anteromedial temporal lobectomy.
BACKGROUND
The area of predominant perifocal [(18)F]fluorodeoxyglucose ((18)F-FDG) hypometabolism and reduced [(11)C]flumazenil ((11)C-FMZ) -binding on PET scans is currently considered to contain the epileptogenic zone and corresponds anatomically to the area localizing epileptogenicity in patients with temporal lobe epilepsy (TLE). The question is whether the volume of the perifocal pre-operative PET abnormalities, the extent of their resection, and the volume of the non-resected abnormalities affects the post-operative seizure outcome.


METHODS
The sample group consisted of 32 patients with mesial temporal sclerosis who underwent anteromedial temporal lobe resection for refractory TLE. All patients had pathologic perifocal findings on both of the PET modalities as well as on the whole-brain MRI. The volumetric data of the PET and MRI abnormalities within the resected temporal lobe were estimated by automated quantitative voxel-based analysis. The obtained volumetric data were investigated in relation to the outcome subgroups of patients (Engel classification) determined at the 2-year post-operative follow-up.


RESULTS
The mean volume of the pre-operative perifocal (18)F-FDG- and (11)C-FMZ PET abnormalities in the volumes of interest (VOI) of the epileptogenic temporal lobe, the mean resected volume of these PET abnormalities, the mean volume of the non-resected PET abnormalities, and the mean MRI-derived resected volume were not significantly related to the outcome subgroups and had a low prediction for individual freedom from seizures.


CONCLUSIONS
The extent of pre-surgical perifocal PET abnormalities, the extent of their resection, and the extent of non-resected abnormalities were not useful predictors of individual freedom from seizures in patients with TLE.
Department of Neurosurgery Rikshospitalet, Oslo University Hospital, Sognsvannsveien 20, 0027, Oslo, Norway. mstanisi@ous-hf.no.
Milo
M
Stanišić
PET Core Facility/PET Centre, Oslo University Hospital, Oslo, Norway.
Christopher
C
Coello
Department of Neurosurgery Rikshospitalet, Oslo University Hospital, Sognsvannsveien 20, 0027, Oslo, Norway.
Jugoslav
J
Ivanović
Department of Neurosurgery Rikshospitalet, Oslo University Hospital, Sognsvannsveien 20, 0027, Oslo, Norway.
Arild
A
Egge
Section of Nuclear Medicine & PET, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
Torsten
T
Danfors
Department of Radiology, Oslo University Hospital, Oslo, Norway.
John
J
Hald
Department of Clinical Psychology and Neuropsychology, National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.
Einar
E
Heminghyt
Department of Adult Epilepsy, National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.
Marjan Makki
MM
Mikkelsen
Department of Pathology, Oslo University Hospital, Oslo, Norway.
Bård Kronen
BK
Krossnes
Oslo Center of Biostatistics and Epidemiology, Research Support Service, Oslo University Hospital, Oslo, Norway.
Are Hugo
AH
Pripp
Clinical Neurophysiologic Laboratories, Department of Neurosurgery, Oslo University Hospital, Oslo, Norway.
Pål Gunnar
PG
Larsson
D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy / Q000009:adverse effects* / Q000379:methods; D002648:Child; D004833:Epilepsy, Temporal Lobe / Q000601:surgery*; D005260:Female; D005442:Flumazenil; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012640:Seizures / Q000601:surgery*; D013702:Temporal Lobe / Q000000981:diagnostic imaging* / Q000601:surgery
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005442:Flumazenil
11C-FMZ-PET; 18F-FDG-PET; Post-operative outcome; Temporal lobe epilepsy