Jija S. James, Presenter: Nothing to Disclose

Chandrasekharan Kesavadas MD, Abstract Co-Author: Nothing to Disclose

Bejoy Thomas MBBS, MD, Abstract Co-Author: Nothing to Disclose

Ashalatha Radhakrishnan, Abstract Co-Author: Nothing to Disclose

Tirur Raman Kapilamoorthy, Abstract Co-Author: Nothing to Disclose

To assess the in vivo structure–function relationship of language function in intractable Temporal Lobe Epilepsy (TLE) patients using functional Magnetic Resonance Imaging (fMRI) and Diffusion fiber tractography as a part of their presurgical planning.

We studied 20 patients with intractable TLE patients (11 males and 9 females; age range: 20 – 48; 16 = Right handed, 4 = Left handed) and 18 normal healthy volunteers (11 males, 7 females; age range: 15 -40; 15 = Right handed, 3 = Left handed). After proper training, the subjects were scanned using 1.5 Tesla MR Imager. We visually presented three block design language paradigms (verb generation, semantic and syntax). A total of 100 dynamics were obtained per session. fMRI data analysis was done using SPM (Statistical Parametric Mapping) software. DTI data were acquired using diffusion gradients along 30 non collinear directions. Fiber tractography of language tracts was done using Seimens Neuro 3D software.

Out of 15 right handed normal subjects, 13 showed increased language activation in left inferior frontal gyrus (BA43, BA44) and temperoparietal language areas (BA22) and 2 of them showed bilateral pattern of activations with associated structural connections. 3 left handed subjects showed increased language activation and connectivity in right hemisphere. Out of 20 TLE patients, 16 right handed TLE showed increased left-lateralised pattern of language-related activations with increased structural connectivity. Out of 4 left handed TLE patients, 3 of them showed activation of language areas in right hemisphere with significant structural connectivity and the other one showed bilateral pattern of language and associated bilateral white matter connectivity pattern.

From the results of fMRI activation studies and diffusion based tractography, we concluded that there exist a strong one to one correlation between fMRI lateralization indices and structural connectivity measures for determining language lateralization in presurgical TLE patients.

In patients especially small children who fail to perform the fMRI language tasks, the presurgical lateralisation of language function can be done using diffusion tractography.

James, J, Kesavadas, C, Thomas, B, Radhakrishnan, A, Kapilamoorthy, T, Correlation between Functional Magnetic Resonance Imaging (fMRI) and Diffusion Tensor Imaging (DTI) Reveals Language Laterality in Temporal Lobe Epilepsy Patients Compared to Normal Volunteers.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031858.html