Abstract
BACKGROUND AND PURPOSE: Automated volumetry of the hippocampus is considered useful to assist the diagnosis of hippocampal sclerosis in temporal lobe epilepsy. However, voxel-based morphometry is rarely used for individual subjects because of high rates of false-positives. We investigated whether an approach with high dimensional warping to the template and nonparametric statistics would be useful to detect hippocampal atrophy in patients with hippocampal sclerosis.
MATERIALS AND METHODS: We performed single-subject voxel-based morphometry with nonparametric statistics within the framework of Statistical Parametric Mapping to compare MRI from 26 well-characterized patients with temporal lobe epilepsy individually against a group of 110 healthy controls. The following statistical threshold was used: P < .05 corrected for multiple comparisons with family-wise error over the region of interest right and left hippocampus.
RESULTS: The sensitivity for the detection of atrophy related to hippocampal sclerosis was 0.92 (95% CI, 0.67–0.99) for the right hippocampus and 0.60 (0.31–0.83) for the left, and the specificity for volume changes was 0.98 (0.93–0.99). All clusters of decreased hippocampal volumes were correctly lateralized to the seizure focus. Hippocampal volume decrease was in accordance with neuronal cell loss on histology reports.
CONCLUSIONS: Nonparametric voxel-based morphometry is sensitive and specific for hippocampal atrophy in patients with mesial temporal lobe epilepsy and may be useful in clinical practice.
ABBREVIATIONS:
- TLE
- temporal lobe epilepsy
- VBM
- voxel-based morphometry
- TIV
- total intracranial volume
- ILAE
- International League Against Epilepsy
- DARTEL
- Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra
- MAP
- Morphometric Analysis Program
- ROC
- Receiver operating characteristic curves
- AUC
- area under the curve
- SnPM
- Statistical non Parametric Mapping
- HS
- hippocampal sclerosis
- FLAIR
- fluid attenuated inversion recovery
- EEG
- electroencephalography
- © 2020 by American Journal of Neuroradiology
Indicates open access to non-subscribers at www.ajnr.org