[18F]FDG-PET and whole-scalp MEG localization of epileptogenic cortex.
OBJECTIVE
To evaluate combined [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and 122-channel whole-scalp magnetoencephalography (MEG) in lateralizing the epileptogenic cortex in patients whose routine presurgical evaluations gave discordant results about the location of the epileptic focus.


METHODS
Nine patients (five women, four men) aged 13-40 years were studied. Subdural EEG (SEEG) was recorded from eight patients. Six patients were operated on.


RESULTS
In seven of nine patients, PET and MEG agreed in localizing the epileptogenic cortex. When PET and MEG were in congruence, SEEG agreed with the findings. In five of six operated-on patients, PET and MEG results were congruent, and the outcome of the operation was successful. Two patients had discordant PET and MEG results. In one patient, PET showed bitemporal hypometabolism, whereas MEG showed epileptiform activity in the right parietal lobe. The surgical outcome of the palliative temporal lobectomy was poor. Another patient had unilateral temporal hypometabolism in PET and bitemporal activity in MEG. She was not operated on.


CONCLUSIONS
In most patients, PET and MEG were congruent in locating the epileptogenic cortex. Thus the combination of these techniques may provide useful support for the localization of the seizure onset and reduce the need for invasive procedures.
Department of Neurology, University of Turku, Finland.
S
S
Lamusuo
N
N
Forss
H M
HM
Ruottinen
J
J
Bergman
J P
JP
Mäkelä
E
E
Mervaala
O
O
Solin
J K
JK
Rinne
U
U
Ruotsalainen
A
A
Ylinen
M
M
Vapalahti
R
R
Hari
J O
JO
Rinne
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000706:statistics & numerical data; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D013355:Subdural Space; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome
D019788:Fluorodeoxyglucose F18