Thalamic atrophy in childhood absence epilepsy.
OBJECTIVE
Patients with childhood absence epilepsy (CAE) have normal clinical magnetic resonance imaging (MRI) studies. The presence of abnormalities in corticothalamic networks has been suggested to be the functional basis of absence seizure generation. We assessed whether structural grey and white matter volume changes of these areas occurred in patients with absence seizures by using optimized voxel-based morphometry (VBM).


METHODS
We recruited 13 patients with a clinical and EEG diagnosis of CAE (mean age at examination, 17 +/- 8 years) and compared them with a consecutive series of 109 controls (mean age, 29 +/- 9 years). The 3 tesla MRI examination included a 3D T(1)-weighted sequence, which was analyzed with an optimized VBM protocol using the SPM2 package. The threshold was set at p < 0.05, corrected for multiple comparisons.


RESULTS
Compared with controls, CAE patients showed areas of grey matter decrease in both thalami and in the subcallosal gyrus. White matter decrease was found in the extranuclear subcortical area and in the white matter of the basal forebrain. Grey and white matter increase was restricted to small clusters of cortical and subcortical areas.


CONCLUSIONS
Evidence exists of subcortical grey and white matter volume reduction in CAE patients. Bilateral thalamic atrophy may be either a result of damage from seizures (as in hippocampal sclerosis) or a reflection of a primary underlying pathology as the cause of absence seizures.
Chan
Chow Huat Patrick
CH
Brain Research Institute, Neurosciences Building, Austin Health, Heidelberg West, Victoria 3081, Australia.
Briellmann
Regula S
RS
Pell
Gaby S
GS
Scheffer
Ingrid E
IE
Abbott
David F
DF
Jackson
Graeme D
GD
D000293:Adolescent; D000328:Adult; D001284:Atrophy; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology; D004292:Dominance, Cerebral; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D016548:Prosencephalon / Q000473:pathology; D013702:Temporal Lobe / Q000473:pathology; D013788:Thalamus / Q000473:pathology*