Neuromagetic activations in medial temporal lobe during verbal memory tasks in patients with temporal lobe epilepsy.

• Main Authors: Hsien-Wei Ko, 柯賢薇
• Other Authors: Yung-Yang Lin
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/28965394173037027668

碩士 === 國立陽明大學 === 腦科學研究所 === 101 === Purpose: This study aimed to determine the hemispheric laterality of medial temporal activations during Chinese verbal memory encoding and recognition in patients with temporal lobe epilepsy (TLE). Methods: We recorded magnetoencephalographic (MEG) responses during memory tasks for Chinese nouns in 14 adult TLE patients and 13 age-matched healthy participants. The patients were divided into three groups according to the findings on magnetic resonance imagings and video/EEG recordings. Group 1 included 5 patients with left hippocampal sclerosis (HS). Group 2 included 4 patients with right HS. Group 3 consisted of 5 patients with a cavernoma in the right temporal lobe. Each participant silently viewed 120 words during encoding session, and reported during recognition session whether individual words had been viewed previously in encoding session (target) by lifting the right index finger. The neuromagnetic activations in response to memory tasks were analyzed with equivalent current dipole (ECD) modeling. We compared the number of ECD between hemispheres and between subject groups. Key findings: In the control participants, the encoding activation was significantly larger in the left than the right medial temporal region, whereas the recognition activation was similar in both hemispheres. In patients with left HS, the left medial temporal responses to memory tasks were reduced. Significance: Our results showed a dominant involvement of left medial temporal region in Chinese memory encoding in right-handed healthy participants. In contrast, bilateral medial temporal areas contributed to memory recognition process. The encoding activation in the left temporal lobe region was significantly reduced in patients with left HS.