Cortical and subcortical brain alterations in Juvenile Absence Epilepsy

Abstract

Despite the common assumption that genetic generalized epilepsies are characterized by a macroscopically normal brain on magnetic resonance imaging, subtle structural brain alterations have been detected by advanced neuroimaging techniques in Childhood Absence Epilepsy syndrome. We applied quantitative structural MRI analysis to a group of adolescents and adults with Juvenile Absence Epilepsy (JAE) in order to investigate micro-structural brain changes using different brain measures. We examined grey matter volumes, cortical thickness, surface areas, and subcortical volumes in 24 patients with JAE compared to 24 healthy controls; whole-brain voxel-based morphometry (VBM) and Freesurfer analyses were used. When compared to healthy controls, patients revealed both grey matter volume and surface area reduction in bilateral frontal regions, anterior cingulate, and right mesial-temporal lobe. Correlation analysis with disease duration showed that longer disease was correlated with reduced surface area in right pre- and post-central gyrus. A possible effect of valproate treatment on brain structures was excluded. Our results indicate that subtle structural brain changes are detectable in JAE and are mainly located in anterior nodes of regions known to be crucial for awareness, attention and memory.

Evaluation of cortical thickness and brain volume on 3 Tesla magnetic resonance imaging in children with frontal lobe epilepsy

“…Anatomopathological and radiological studies in patients with different epilepsy syndromes have revealed the presence of mild abnormalities in the layering and cellularity of gray and white matter tissue, and decreases in gray matter volume including the frontal lobes [22,23]. Tondelli et al studied cortical and subcortical alterations in juvenile absence epilepsy, and found gray matter volume and surface area reductions in bilateral frontal regions, the anterior cingulate, and the right mesial temporal lobe [24]. In another study, Widjaja et al used 3T MRI to evaluate cortical thickness in 29 children with new onset epilepsy, and found significant cortical thinning in the right cingulate, medial temporal, and left frontal cortices [17].…”

Grey matter volume in healthy and epileptic beagles using voxel-based morphometry – a pilot study

“…Current VBM study revealed statistically significant reduced GMV in the frontal gyrus in epileptic dogs which is consistent with several previous studies made in human medicine. Reduced GMV was seen in some parts of the frontal lobe in patients with temporal lobe epilepsy (TLE) [ 46 – 50 ], juvenile myoclonic epilepsy (JME) [ 51 ], juvenile absence epilepsy (JAE) [ 52 ] and generalized tonic-clonic seizures (GTCS) [ 53 ] as well as frontal lobe epilepsy (FLE) [ 54 ]. Furthermore, statistically significant reduced GMV in several areas of the cortex of temporal and a few regions of parietal lobe in epileptic and IE Beagles and mildly statistically significant reduced GMV in the cortex of temporal lobe in SE Beagles was detected in the current study.…”

“…Reduced GMV in cortices of temporal and parietal lobes are known in humans with TLE [ 48 , 55 ]. Decreased GMV in areas of temporal lobe in TLE patients [ 45 , 46 , 56 ], in FLE patients [ 54 ] and patients with JAE [ 52 ] were also displayed in humans, while others found decreased GMV in parietal regions in brains of JME [ 57 ] or TLE patients [ 47 , 49 , 58 ]. Our study also revealed a statistically significant loss of GMV in occipital gyrus in SE and epileptic Beagles.…”

Cognitive Function in Genetic Generalized Epilepsies: Insights From Neuropsychology and Neuroimaging

“…While one study identified smaller thalamic volumes in CAE compared to controls, it did not detect a significant association between the latter and IQ measures (146). In JAE, reductions of gray matter volume and surface area were detected in the frontal, cingulate, and mesiotemporal locations, but formal correlations with cognitive measures were not available (155).…”