Resection extent versus postoperative outcomes of seizure and memory in mesial temporal lobe epilepsy.
OBJECTIVE
To investigate the effects of the resection of hippocampus and temporal neocortex on postsurgical seizure and memory outcomes in mesial temporal lobe epilepsy (mTLE) patients.


METHODS
Sixty-eight mTLE patients underwent pre- and postsurgical brain magnetic resonance imaging (MRI). The patients were divided into seizure-free group (SF, N=54) and non-seizure-free group (NSF, N=14). The resection length of hippocampus was determined by the difference between presurgical and postsurgical hippocampus lengths in MRIs. The lengths of resected temporal gyri were measured on three-dimensional MRI reconstruction. Among SF group, 37 patients performed pre- and postsurgical neuropsychological tests. The postsurgical memory decline (PMD) was calculated by subtracting postsurgical memory score from presurgical one in verbal and visual memory tests.


RESULTS
The resection length of hippocampus in SF was significantly longer than in NSF (32.7 +/- 7.7 mm versus 25.1 +/- 7.3 mm, t-test, p=0.002), regardless of intersubject difference in the extent of hippocampal sclerosis (logistic regression, p=0.003) while the resection lengths of the lateral temporal gyri were not different between SF and NSF. Overall postsurgical change of verbal or visual memory was not significant. However, regression analysis showed a significant correlation between the resection length of inferior or basal temporal gyrus and verbal PMD (p<0.001) in left TLE patients with seizure-free outcome.


CONCLUSIONS
More resection of hippocampus may predict a better postsurgical seizure-free outcome. The larger resection of inferior or basal temporal gyrus seems to be related to a postsurgical verbal memory decline in left TLE patients.
Joo
Eun Yeon
EY
Department of Neurology, Samsung Medical Center and Center for Clinical Medicine, SBRI, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-Gu, Seoul 135-710, Korea.
Han
Hyun Jung
HJ
Lee
Eun Kyung
EK
Choi
Sujung
S
Jin
Ju Hee
JH
Kim
Jee Hyun
JH
Tae
Woo Suk
WS
Seo
Dae Won
DW
Hong
Seung-Chyul
SC
Lee
Munhyang
M
Hong
Seung Bong
SB
D000293:Adolescent; D000328:Adult; D000465:Algorithms; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011184:Postoperative Period; D011612:Psychosurgery / Q000009:adverse effects* / Q000379:methods; D015203:Reproducibility of Results; D012640:Seizures / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome