Voxel-based morphometry of temporal lobe epilepsy: An introduction and review of the literature
Version of Record online: 28 DEC 2007
© 2008 International League Against Epilepsy
Volume 49, Issue 5, pages 741–757, May 2008
How to Cite
Keller, S. S. and Roberts, N. (2008), Voxel-based morphometry of temporal lobe epilepsy: An introduction and review of the literature. Epilepsia, 49: 741–757. doi: 10.1111/j.1528-1167.2007.01485.x
- Issue online: 7 FEB 2008
- Version of Record online: 28 DEC 2007
- Accepted November 15, 2007; Online Early publication December 31, 2007.
- Voxel-based morphometry
We review the applications and results of voxel-based morphometry (VBM) studies that have reported brain changes associated with temporal lobe epilepsy (TLE). A PubMed search yielded 18 applications of VBM to study brain abnormalities in patients with TLE up to May 2007. Across studies, 26 brain regions were found to be significantly reduced in volume relative to healthy controls. There was a strong asymmetrical distribution of temporal lobe abnormalities preferentially observed ipsilateral to the seizure focus, particularly of the hippocampus (82.35% of all studies), parahippocampal gyrus (47.06%), and entorhinal (23.52%) cortex. The contralateral hippocampus was reported as abnormal in 17.65% of studies. There was a much more bilateral distribution of extratemporal lobe atrophy, preferentially affecting the thalamus (ipsilateral = 61.11%, contralateral = 50%) and parietal lobe (ipsilateral = 47.06%, contralateral = 52.94%). VBM generally reveals a distribution of brain abnormalities in patients with TLE consistent with the region-of-interest neuroimaging and postmortem literature. It is unlikely that VBM has any clinical utility given the lack of robustness for individual comparisons. However, VBM may help elucidate some unresolved important research questions such as how recurrent temporal lobe seizures affect hippocampal and extrahippocampal morphology using serial imaging acquisitions.