Table e-4: Overview of VBM studies of adult TLE
Study / Patients / VBM details / Main findings(15) / 26 mTLE, 17 cTLE / Optimized VBM,
right and left TLE combined; customised template / Controls vs. mTLE patients
GMC ↓ in ipsilateral hippocampus and parahippocampus; ipsi- and contralateral cerebellum
GMV ↓ in addition to ipsilateral hippocampus: ipsilateral parahippocampal gyrus, enterorhinal cortex, posterior cingulate, neocortical regions in the ipspilateral temporal, occipital and parietal lobes, ipsilateral thalamus
Controls vs. cTLE patients: No differences
(13) / 40 left mTLE
36 right mTLE
with evidence for unilateral hippocampal sclerosis / Standard VBM
Optimized VBM
Both customised and SPM99 default templates / GMC ↓ in ipsilateral hippocampus, right prefrontal cortex, posterior cingulate gyrus, midbrain in right and left mTLE, GMC ↓ in the inferior occipital cortex and superior cerebellum only in right mTLE
GMC ↓ in ipsilateral hippocampus, right thalamus, occipitoparietal cortex in both groups
GMV ↓ in bilateral hippocampi, lenticular nuclei, thalami, cerebellum, ipsilateral ventral temporal lobe (including fusiform gyrus)
(12) / 40 left mTLE
36 right mTLE
with evidence for unilateral hippocampal sclerosis / Standard VBM
SPM99 default template / GMC ↓ s. above. GMC ↑ in ipsilateral parahippocampal, cerebellar, pericallosal regions in right and left mTLE. GMC ↑ bilaterally in the TL (fusiform, inferior temporal gyrus) in left mTLE, ipsilaterally in right TLE
(14) / 22 left mTLE
21 right mTLE / Standard VBM + modulation
SPM2 default template / GMV ↓ in the ipsilateral hippocampus and parahippocampal gyrus, left and right cerebellum, bilateral thalamus, ipsilateral caudate in both left and right mTLE.
GMV ↓ in right temporal isocortex, right temporo-occipital region, left and right middle frontal gyri, left parieto-occipital region in right-sided mTLE patients.
GMV ↓ left insula, left and right cingulate gyri, frontal opercula, parieto-occipital regions, contralateral caudate in left-sided mTLE patients
No GMV ↑
(21) / 45 left mTLE
40 right mTLE / VBM by means of INSECT / GMC ↓ in the ipsilateral hippocampus, bilaterally in the cingulum and thalamus, GM ↓ also in various frontal lobe areas in both right and left mTLE. Patients with left mTLE showed GMC ↓ also in the left insula and right hippocampus
(10) / 10 left mTLE
10 left cTLE / Standard VBM
Customised template / Controls vs. mTLE patients
GMC ↑ in the left temporoposterior region
Controls vs. cTLE patients
No significant abnormalities
Legend: CTLE…cryptogenic = MRI-negative temporal lobe epilepsy, mTLE = mesial temporal lobe epilepsy, GMC ↓ … reduction in gray matter concentration, referring to unmodulated data. GMV ↓ …reduction in gray matter volume, referring to modulated data. SPM …statistical parametric mapping; INSECT is an automatic algorithm based on a neural network classifier, that labels each voxel based on the MRI signal (21)