Background Progressive subcortical changes are known to occur in HD, but less is known about the occurrence of whole brain grey matter changes. Regional voxel-based analysis is frequently used approach in detecting structural volume loss in HD. Structural network analysis is based on the co-variation of grey matter volume and is independent of a-priori defined regions.
Objective To identify network integrity changes in grey matter whole brain structural covariance networks (SCNs) in Huntington’s disease (HD).
Methods Structural MRI scans of 30 pre-HD, 30 HD patients and 30 controls of the Track-HD study of the Leiden study site were included. SCNs were identified using a recently developed technique with independent component analysis in FSL. Group differences were studied controlling for age and gender using linear regression analysis.
Results Two of the ten identified anatomical networks showed decreased network integrity in pre-HD and HD patients compared to controls. One network included the caudate nucleus, precuneous and anterior cingulate cortex, and one other network contained the hippocampus, premotor, sensorimotor, and insular cortices. Additionally, in HD patients only, a network involving the lingual gyrus, intracalcarine, cuneal, and lateral occipital cortices showed decreased network integrity. To explore whether SCN analysis is an effective approach to examine grey matter changes, regional voxel-based analysis was additionally performed. In pre-HD, voxel-based analyses showed pronounced volume loss in the basal ganglia, but less prominent in cortical regions.
Conclusions Our study revealed changes in network integrity in different anatomical brain networks in pre-HD and HD patients. We therefore suggest that a network-based approach might be more sensitive to reveal early grey matter changes in HD, especially for premanifest gene carriers, compared to regional voxel-based methods.
- Structural MRI