Voxel-based morphometry of temporal lobe epilepsy: an introduction and review of the literature

Epilepsia. 2008 May;49(5):741-57. doi: 10.1111/j.1528-1167.2007.01485.x. Epub 2007 Dec 28.

Abstract

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.

Publication types

  • Review

MeSH terms

  • Brain / pathology
  • Brain Mapping / methods
  • Epilepsy, Temporal Lobe / diagnosis
  • Epilepsy, Temporal Lobe / pathology*
  • Forecasting
  • Functional Laterality / physiology
  • Hippocampus / pathology
  • Humans
  • Image Processing, Computer-Assisted* / trends
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Imaging / statistics & numerical data
  • Magnetic Resonance Imaging / trends
  • Stereotaxic Techniques
  • Temporal Lobe / pathology*