Extratemporal Involvement in Temporal Lobe Epilepsy A Diffusion Tensor Imaging Study DTI

Abstract

Imaging of Temporal lobe epileptics (TLE) frequently appears normal on conventional magnetic resonance imaging (MRI) also patients suffer from multiple cognitive affection that could be related to structural defects. Modern MR Techniques are helpful in assessment of patient with seizures as Diffusion Tensor Imaging (DTI). This study aims at evaluating the presence of extratemporal involvement in TLE not visualized by conventional MRI brain using DTI, and to correlate these findings with associated cognitive dysfunction. Forty patients with TLE and 10 healthy subjects had performed conventional MRI epilepsy protocol, followed by DTI. MR tractography was performed for 14 regions of interest (ROIs) and tracts. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured and then compared quantitatively as an assessment of pertinent regions. Patients and controls underwent Wisconsin card scoring test, Benetton visual retention test and Wechsler Adult Intelligence Scale IV. All data was correlated with the clinical and advanced EEG of the patient. The patients group had significantly decreased FA values and increased ADC values in multiple tracts and ROIs ipsilateral and contralateral to the seizure focus, which was positively correlated with the cognitive function deficit in those patients. We concluded that patients with TLE had significant abnormalities in both hemispheres ipsilateral and contralateral to seizure foci that could be a cause for the cognitive function deficits in those patients.