Dataset Information

Extratemporal damage in temporal lobe epilepsy: magnetization transfer adds information to volumetric MR imaging.

ABSTRACT:

Background and purpose

MTS is characterized by gliosis and atrophy of the hippocampus and related limbic structures. However, the damage is not limited to those structures with atrophy and has been reported in extratemporal regions. Because volumetric studies are nonspecific, the pathophysiology of the brain damage remains to be solved. MTI is an MR imaging technique more sensitive to subtle neuropathologic changes than conventional MR imaging. Here we combined MTI with VBM analysis to evaluate extratemporal damage in patients with TLE.

Materials and methods

We studied 23 healthy controls and 21 patients with TLE with mean ages, respectively, of 37.6 ± 10.9 and 38.6 ± 9.02 years. All subjects had a full clinical follow-up and MR imaging. We processed the images with VBM for volumetric analysis of WM and GM, as well as with voxel-based analysis of MTR for macromolecular integrity analysis.

Results

In addition to MTR decrease in the temporal lobes, we found a significant decrease in GM and WM volumes. In the WM, the MTR decrease was correlated to volume loss detected by VBM, indicating that brain atrophy may explain part of the MTR decrease. We also found areas in which the MTR decrease was not associated with volume loss, suggesting an additional pathophysiologic process other than neuronal loss and atrophy underlying the MTR changes.

Conclusions

Our results support the hypothesis that there are widespread lesions in the brain, including the corpus callosum and the frontal lobe, affecting both GM and WM.

SUBMITTER: Diniz PR

PROVIDER: S-EPMC7965985 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:PurposeTo determine the ability of fully automated volumetric magnetic resonance (MR) imaging to depict hippocampal atrophy (HA) and to help correctly lateralize the seizure focus in patients with temporal lobe epilepsy (TLE).Materials and methodsThis study was conducted with institutional review board approval and in compliance with HIPAA regulations. Volumetric MR imaging data were analyzed for 34 patients with TLE and 116 control subjects. Structural volumes were calculated by using U.S. Food and Drug Administration-cleared software for automated quantitative MR imaging analysis (NeuroQuant). Results of quantitative MR imaging were compared with visual detection of atrophy, and, when available, with histologic specimens. Receiver operating characteristic analyses were performed to determine the optimal sensitivity and specificity of quantitative MR imaging for detecting HA and asymmetry. A linear classifier with cross validation was used to estimate the ability of quantitative MR imaging to help lateralize the seizure focus.ResultsQuantitative MR imaging-derived hippocampal asymmetries discriminated patients with TLE from control subjects with high sensitivity (86.7%-89.5%) and specificity (92.2%-94.1%). When a linear classifier was used to discriminate left versus right TLE, hippocampal asymmetry achieved 94% classification accuracy. Volumetric asymmetries of other subcortical structures did not improve classification. Compared with invasive video electroencephalographic recordings, lateralization accuracy was 88% with quantitative MR imaging and 85% with visual inspection of volumetric MR imaging studies but only 76% with visual inspection of clinical MR imaging studies.ConclusionQuantitative MR imaging can depict the presence and laterality of HA in TLE with accuracy rates that may exceed those achieved with visual inspection of clinical MR imaging studies. Thus, quantitative MR imaging may enhance standard visual analysis, providing a useful and viable means for translating volumetric analysis into clinical practice.