FUNCTIONAL MR STUDY FOR LANGUAGE ORGANIZATION IN LEFT MEDIAL TEMPORAL LOBE EPILEPSY PATIENTS
Abstract number :
1.246
Submission category :
Year :
2003
Submission ID :
3821
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Chun Kee Chung, In Chan Song, So Hee Kim, Kee Hyun Chang Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea; Diagnostic Radiology, Seoul National University Hospital, Seoul, Republic of Korea
Functional magnetic resonance imaging (MRI) using four language tasks was used to determine difference between normal controls and left medial temporal lobe epilepsy patients.
Normal volunteers (n=12; mean age, 25 years) and left temporal lobe epilepsy patients (n=12; mean age, 26 years) were examined on a 1.5T MR unit (GE Horizon Echospeed) using a conventional head coil. All subjects had strong right-handedness on Edinburgh handedness inventory. All patients had left hippocampal sclerosis on conventional MR imaging. A single-shot GRE-EPI sequence (TR/TE/flip angle = 3000ms/50ms/90, FOV = 240 mm, matrix= 64x64, slice thickness/gap = 5mm/0mm, 20 axial slices) was used. A flow-sensitive conventional gradient echo sequence (TR/TE/flip angle = 50ms/4ms/60) was used for high-resolution anatomical images. Four different word generation paradigms were used; noun, verb, adjective and adverb. Simple 8 phrases/sentences were presented at a rate of 1 / 3 seconds during each activation period of 24 seconds. Rest periods consisted of reading pseudo-words, to say, the meaningless letters during 24 seconds. All tasks consisted of 48 phases including 3 activation and 3 rest periods. All tasks were visual-guided by LCD projector. All EPI data sets were realigned and normalized to the EPI template image included in the SPM99 package. Data sets were then smoothed with a Gaussian filter (FWHM=6mm). For group analysis, random effect model was used and the activation maps were generated with a height threshold of uncorrected p =0.05 and an extent threshold of k=100 voxels. For individual analysis, correlation coefficient analysis was performed using the reference function of a box car (p [lt]0.05).
Normal volunteers used left middle frontal, left parietal, and right medial frontal areas more actively than left medial temporal lobe epilepsy patients in all four language tasks. In comparison, left medial temporal lobe epilepsy patients used left occipital, left superior temporal, and right frontal areas more actively. However, this difference depends on the language tasks.
Left medial temporal lobe epilepsy patients had different language organization from the normal volunteers.