Interictal patterns of cerebral glucose metabolism, perfusion, and magnetic field in mesial temporal lobe epilepsy.
OBJECTIVE
To characterize the epileptogenic condition of patients with mesial temporal lobe epilepsy, the interictal patterns of glucose metabolism, perfusion, and magnetic field in the temporal lobe were evaluated by using [18F]fluorodeoxyglucose-positron emission tomography, [99mTc]-ethylcysteinate dimer-single photon emission computed tomography, and magnetoencephalography (MEG).


METHODS
Twenty-one patients with mesial temporal lobe epilepsy related to hippocampal sclerosis were studied. The ictal-onset area was located by continuous video-EEG monitoring. Quantitative analysis of glucose metabolism and perfusion in the temporal lobe was performed, and the cerebral magnetic field was evaluated to measure the equivalent current dipole (MEG-ECD).


RESULTS
Although hypometabolism and hypoperfusion in the temporal lobe were lateralized with the ictal-onset area in 16 (76.2%) and in 11 (52.4%) respectively, they were localized in diverse ways without any coupling. MEG-ECD was distributed in diverse ways unrelated to the ictal-onset area: ipsilateral medial temporal origin in five (23.8%), ipsilateral lateral temporal origin in two (9.5%), ipsilateral mixed (medial and lateral) temporal origin in six (28.6%), bilateral temporal origin in four (19.0%), and contralateral temporal origin in two (9.5%).


CONCLUSIONS
MEG-ECD was distributed in varied ways with the disorder and uncoupling of glucose metabolism and perfusion in the temporal lobe. These results may help resolve the clinical controversy over the possibility that the cortical irritative area generating the interictal epileptic discharge is distinct from the ictal-onset area, and also may have some functional implications in identifying different brain compartments in the generation of metabolic signals.
Sakamoto
Shinichi
S
Departments of Neurosurgery, Neurology and Pediatrics, Osaka City University Graduate School of Medicine, Osaka, Japan. s-sakamoto@med.osaka-cu.ac.jp
Tsuyuguchi
Naohiro
N
Takami
Toshihiro
T
Morino
Michiharu
M
Goto
Takeo
T
Hattori
Hideji
H
Tsutada
Tsuyoshi
T
Haque
Moududul
M
Sunada
Ichiro
I
Shimogawara
Masahiro
M
Hara
Mitsuhiro
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000378:metabolism*; D002648:Child; D003952:Diagnostic Imaging / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008875:Middle Aged
D005947:Glucose