Abstracts

Epilepsy patients frequently do not have identifiable white or gray matter lesions detectable using standard MRI imaging with established seizure protocol. Diffusion Tensor Imaging (DTI) sequences have been reported to reveal micro-structural white matter changes that may point to a surgically resectable lesion and may allow, if congruent with other findings, surgical intervention. We evaluated the correlation of DTI measures with the EEG and clinical findings in an epilepsy population., 28 adult patients with a confirmed diagnosis of epilepsy had complete MRI seizure protocol and DTI sequences performed using a 1.5 Tesla Siemens scanner. Fractional anisotropy (FA) and mean diffusivity (MD) were calculated and correlated with clinical and electroencephalographic findings.
Manually defined ROI[apos]s were blindly placed on DTI images in 3 temporal lobe sites and 5 frontal sites in 6 of the subjects with unilateral focal temporal EEG changes and no regional MRI.abnormalities in the EEG sites., The cohort consisted of: 21 females, 7 males, mean age 36.7( range 18-70), age of onset 22.14, (3-65), and duration of epilepsy 14.76, ( 1-40 years)
: 13 with generalized tonic clonic, 10 with complex partial, and 5 simple partial. : 14 Partial Idiopathic Epilepsy, 9 Generalized Idiopathic Epilepsy, 1 JME, and 4 unknown.
: 23 Idiopathic, 2 cavernoma, 2 cystic lesions, 1 post encephalitic, 1 glioma, 1 Schizencephaly, and 1 hippocampal atrophy
: 10 Left temporal , 3 Right Temporal, 1 bilateral occipital, and 1 left parieto-occipital.
: 3 Left Temporal, and 2 Right Temporal
20 monotherapy, 6 polytherapy, 2 none. 10 PHT (Dilantin), 4 CBZ (Tegretol), 2 LAMO, 5 LVTM, 5 Oxcarbazapine, 3 phenobarbital
: 12 normal, 15 abnormal.
The FA values were ipsilaterally lower in right sided EEG focus when compared to the contra-lateral side. Also, as expected, the MD values were higher in the right side. The left sided focii did not show any difference in either measurement., A population of 28 adults studied with standard MRI seizure protocols had additional DTI sequences added with minimal scan prolongation or discomfort to the patients. This pilot study in progress revealed DTI localizing findings in subjects with right temporal lobe EEG changes only.This observation on a small number of subjects will be further evaluated and the utility of FA/MD DTI measures further ascertained., (Supported by in part supported by RO 1 (2006) Dr. Kelvin Lim--Department of Psychiatry.)