Investigation of altered microstructure in patients with drug refractory epilepsy using diffusion tensor imaging
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The risk of refractory epilepsy can be more dangerous than the adverse effect caused by medical treatment. In this study, we employed voxel-wise analysis (VWA) and tract-based spatial statistics (TBSS) methods to measure microstructural changes using diffusion tensor imaging (DTI) in patients of drug refractory epilepsy (DRE) who had been epileptic for more than 10 years.
To examine the specific microstructural abnormalities in DRE patients and its difference from medically controlled epilepsy (MCE), we acquired DTI data of 7 DRE patients, 37 MCE patients, and 31 healthy controls (HCs) using a 3 T MRI scanner. Comparisons between epileptic patients and HCs between MCE and DRE patients were performed based on calculated diffusion anisotropic indices data using VWA and TBSS.
Compared to HCs, epileptic patients (including MCE and DRE) showed significant DTI changes in the common affected regions based on VWA, whereas TBSS found that widespread DTI changes in parts of microstructures of bilateral hemispheres were more obvious in the DRE patients than that in the MCE patients when compared with HCs. In contrast, significant reduction of fractional anisotropy values of thalamo-cortical fibers, including left superior temporal gyrus, insular cortex, pre-/post-central gyri, and thalamus, were further found in DRE patients compared with MCE.
The results of multiple diffusion anisotropic indices data provide complementary information to understand the dysfunction of thalamo-cortical pathway in DRE patients, which may be contributors to disorder of language and motor functions. Our current study may shed light on the pathophysiology of DRE.
KeywordsDrug refractory epilepsy Diffusion tensor imaging Voxel-wise analysis Tract-based spatial statistics
Compliance with ethical standards
This study was funded in part by grants from the China National Natural Science Foundation (Nos. 81471734 and 31271188), a grant from the China National 13th Five-Year Program and a grant from the Shanghai Municipal Committee of Science and Technology (No. 13DJ1400300).
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in the studies involving human participants were in accordance with the ethical standards of the Zhongshan Hospital affiliated with Fudan University Internal Review Board and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
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