Relationship between bilateral temporal hypometabolism and EEG findings for mesial temporal lobe epilepsy: analysis of 18F-FDG PET using SPM.
OBJECTIVE
To investigate the clinical significance of bilateral temporal hypometabolism (BTH) for patients with mesial temporal lobe epilepsy (MTLE) by using statistical parametric mapping (SPM).


METHODS
Interictal 18F-FDG PET scans were performed for 29 patients with surgically treated MTLE. Clinical data, interictal epileptiform discharges (IEDs), ictal scalp EEG and intracarotid amobarbital test (IAT) were analyzed. To assess an 18F-FDG PET image, an SPM analysis as well as visual interpretation were applied.


RESULTS
In 9 of 29 patients, the 18F-FDG PET scan revealed BTH by the SPM analysis, while only 3 patients showed BTH by the visual assessment. When the patients were classified into the unilateral temporal hypometabolism (UTH) and BTH groups based on the SPM results, bitemporal IEDs occurred significantly more frequently in the BTH group than in the UTH group (66.7% versus 22.2%). Bilateral independent seizure onset seen on the scalp EEG and bitemporal epilepsy were present only in the BTH group. Lateralized ictal onset was present less frequently in the BTH group than in the UTH group (44.4% versus 83.3%). There was no statistically significant difference in age at onset, duration of epilepsy, generalized seizure, history of febrile convulsion and CNS infection, lateralization throughout the whole tracing, lateralization on the IAT test, and surgical outcome between the UTH and BTH groups.


CONCLUSIONS
Bilaterality of the EEG findings correlated with BTH on 18F-FDG PET by the SPM method. Our results suggest that analysis of 18F-FDG PET by using SPM may have a role in predicting those patients with bitemporal excitability or bitemporal independent epileptogenicity, and these patients should be monitored carefully.
Kim
Mi Ae
MA
Department of Neurology, Yonsei University College of Medicine, Severance Hospital, Shinchon-dong 134, Seoul 120-752, Republic of Korea.
Heo
Kyoung
K
Choo
Min Kyung
MK
Cho
Jung Hee
JH
Park
Soo Chul
SC
Lee
Jong Doo
JD
Yun
Mijin
M
Park
Hae-Jeong
HJ
Lee
Byung In
BI
D000293:Adolescent; D000328:Adult; D000654:Amobarbital; D038481:Anterior Temporal Lobectomy; D002648:Child; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008568:Memory; D049268:Positron-Emission Tomography / Q000379:methods*; D016896:Treatment Outcome
D019788:Fluorodeoxyglucose F18; D000654:Amobarbital