Abstracts

Rationale: Imaging studies in Juvenile myoclonic epilepsy (JME) had shown abnormalities of thalamus and frontal cortex. However, alterations in white matter structures have not been well studied. The purpose of this study was to systematically investigate the morphological changes in the brain white matter using diffusion tensor imaging and to correlate these changes with theseizure control and disease duration. Methods: The study included 37(M:F=18:19; age=22.57± 5.53 years) patients with JME and 19 (M:F=11:8; age 24.5±4.2 years) matched controls. There were 21 patients with adequate seizure control and 16 with uncontrolled seizures. All subjects underwent MRI using standard protocol which included T1-3D TFE images with 1 mm thickness and DTI with 15 gradient directions and b value of 1000. TBSS [Tract based spatial statistics] analysis was performed to compare between the patients and controls. Further statistical comparisons were made between the DTI metrics of the corpus callosum and anterior thalamic radiation to confirm the changes observed using TBSS. Results: Significant changes in the FA and RD were observed in the cerebral WM affecting primarily the Corpus callosum, fronto-parietal WM, internal capsule, external capsule, brainstem and cerebellar WM in the JME patients (P<0.05) after adjusting for age, gender and ICV. Corpus callosum and anterior thalamic radiation WM indices were significantly different in the JME patients when compared to the controls. Further comparison subgroup analysis in patients with uncontrolled seizures revealed widespread WM changes while patients with controlled seizures showed no significant degenerative changes in the WM. FA of the corpus callosum and left anterior limb of internal capsule showed negative correlation with disease duration while MD and RD of the corpus callosum correlated positively with the disease duration. Conclusions: The limitations were small sample size, lack of drug naïve subjects and small number of control subjects. This study confirms the presence of cerebral, cerebellar and brainstem WM and further raises the possibility of reversible nature of these WM changes with control of seizures.