Functional Reorganization Associated with Semantic Language Processing in Temporal Lobe Epilepsy Patients after Anterior Temporal Lobectomy : A Longitudinal Functional Magnetic Resonance Image Study.
10.3340/jkns.2010.47.1.17
- Author:
Jae Hun KIM
1
;
Jong Min LEE
;
Eunjoo KANG
;
June Sic KIM
;
In Chan SONG
;
Chun Kee CHUNG
Author Information
1. Department of Biomedical Engineering, Hanyang University, Seoul, Korea. ljm@hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
fMRI;
Language;
Epilepsy;
Brain plasticity;
Hippocampus
- MeSH:
Anterior Temporal Lobectomy;
Brain;
Epilepsy;
Epilepsy, Temporal Lobe;
Hippocampus;
Humans;
Magnetic Resonance Imaging;
Magnetic Resonance Spectroscopy;
Magnetics;
Magnets;
Plastics;
Prefrontal Cortex;
Seizures;
Semantics;
Temporal Lobe
- From:Journal of Korean Neurosurgical Society
2010;47(1):17-25
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: The focus of this study is brain plasticity associated with semantic aspects of language function in patients with medial temporal lobe epilepsy (mTLE). METHODS: Using longitudinal functional magnetic resonance imaging (fMRI), patterns of brain activation were observed in twelve left and seven right unilateral mTLE patients during a word-generation task relative to a pseudo-word reading task before and after anterior temporal section surgery. RESULTS: No differences were observed in precentral activations in patients relative to normal controls (n = 12), and surgery did not alter the phonological-associated activations. The two mTLE patient groups showed left inferior prefrontal activations associated with semantic processing (word-generation > pseudo-word reading), as did control subjects. The amount of semantic-associated activation in the left inferior prefrontal region was negatively correlated with epilepsy duration in both patient groups. Following temporal resection, semantic-specific activations in inferior prefrontal region became more bilateral in left mTLE patients, but more left-lateralized in right mTLE patients. The longer the duration of epilepsy in the patients, the larger the increase in the left inferior prefrontal semantic-associated activation after surgery in both patient groups. Semantic activation of the intact hippocampus, which had been negatively correlated with seizure frequency, normalized after the epileptic side was removed. CONCLUSION: These results indicate alternation of semantic language network related to recruitment of left inferior prefrontal cortex and functional recovery of the hippocampus contralateral to the epileptogenic side, suggesting an intra- and inter-hemispheric reorganization following surgery.
