Volume Changes of Frontal Lobe and Hippocampus in Juvenile Myoclonic Epilepsy

BACKGROUND: In order to investigate the structural abnormalities in juvenile myoclonic epilepsy (JME), the volumes of the hippocampus and frontal lobe were measured. METHODS: Nineteen JME patients and 19 age- and sex-matched normal controls underwent a 1.6 mm thick brain SPGR MRI. The volumes of the frontal lobe and hippocampus were measured with a volume of interest method. The differences of volumes between JME and normal groups were compared. The volumes were also compared between the early and late onset groups, and between the short and long seizure duration groups. The correlations between the volumes of the frontal lobe, hippocampus, or mid-sagittal area of the corpus callosum, and the age of seizure onset or the duration of disease were tested. RESULTS: The cerebral volume was not found to be different between the JME and normal groups (p=0.521). The left hippocampus was significantly smaller in the JME group (p=0.032) while the left frontal lobe was significantly larger in the JME group (p=0.004). The area of the rostral body of corpus callosum showed a significant positive correlation with the age of onset (r=0.561, p=0.012). The right frontal lobe volume showed a significant negative correlation with the duration of disease (r=-0.511, p=0.025). CONCLUSIONS: These results imply that JME has volume changes in the frontal lobe and hippocampus. The volume reduction of the right frontal lobe in patients with a longer disease duration may suggest a progressive nature of JME. The smaller rostral body of the corpus callosum in patients with earlier seizure onset may suggest an ontogenic abnormality of JME.

Distribution of Cerebral Gray and White Matters in Juvenile Myoclonic Epilepsy: Voxel Based Morphometry

BACKGROUND: The brain MRI findings of juvenile myoclonic epilepsy (JME) usually appears normal upon visual inspection. The purpose of this study is to analyze the distributions of gray matter (GM) and white matter (WM) features with voxel based morphometry (VBM). METHODS: Nineteen JME patients and 19 age and sex matched normal subjects underwent a volumetric MRI study. The MRIs were spatially normalized to our T1 template and segmented into GM, WM and CSF. The spatially normalized and segmented images were smoothed. The smoothed images of GM and WM were analyzed with t-tests. Statistical nonparametric mapping (SnPM) was also used without the assumption of normality. RESULTS: At the level of uncorrected p<0.05, there were brain regions with significantly decreased or increased GM and WM distributions in JME patients compared to those of the normal controls. GM decreased in the left dorsolateral-prefrontal lobe (p=0.005), both medial prefrontal lobes (p=0.01), both medial orbito-frontal lobes (p=0.005), and left middle inferior temporal gyrus (p=0.005) while GM increased in both putamina (right: p=0.005, left: p=0.01), right caudate nucleus (p=0.005), right antero-superior temporal gyrus (p=0.005), both medial parietal lobes (p=0.005), and both medial occipital lobes (p=0.005). WM decreased in the right internal capsule (p=0.005), left internal capsule (p=0.05), and left temporal stem (p=0.05) whereas WM increased in the right temporal stem (p=0.05) and both occipital areas (p=0.001). CONCLUSIONS: JME patients appear to have abnormal distributions of GM and WM in their brains. However, it is not determined whether this finding is an ontogenical abnormality or seizure related problem.

Measurement of Corpus Callosal Area in Juvenile Myoclonic Epilepsy Using High Resolution Magnetic Resonance Imaging / 대한간질학회지

BACKGROUND: To investigate the change of corpus callosal area in juvenile myoclonic epilepsy (JME), the mid-sagittal areas of corpus callosum and its seven sub-regions were measured in JME patients and normal subjects. METHODS: Nineteen JME patients (22.6+/-5.0 year-old, 6 males, 13 females) and 19 normal controls (22.9+/-7.3 year-old, 6 males, 13 females) underwent 1.6 mm thickness whole brain SPGR MRI. Exact mid-sagittal image was obtained with image reconstruction and geometric correction. According to Witelson's work, the area of corpus callosum was divided into 7 sub-regions (a1 to a7 from anterior to posterior) with a semi-automated method. In each sub-region, the pixel number was counted according to ROI definition. The whole cerebral volume was measured. The mid-sagittal cerebral area was measured by tracing inner surface of skull and basal cortical surface of the cerebrum except for corpus callosum and cerebellum. The difference of corpus callosum areas between JME patients and normal controls were tested by t-test and ANCOVA. RESULTS: There was no difference in sex [chi-square(1)=1.00, chi square] and age (p=0.941, Mann-Whitney U test). The areas of rostrum (p0.25, t-test). CONCLUSION: Rostrum and rostral body are significantly smaller in JME patients, which suggests frontal lobe abnormality in JME. This finding is consistent with previous studies reported structural and functional abnormalities of frontal lobe in JME.