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Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
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Thalamus involvement in genetic frontotemporal dementia assessed using structural and diffusion MRI: a GENFI study
Sonja Soskic1, Henry F J Tregidgo1, Emily G Todd2,3
1Department of Medical Physics and Biomedical Engineering, UCL Hawkes Institute, University College London, London WC1V 6LJ, UK.
Brain Communications
|November 17, 2025
Summary
Genetic frontotemporal dementia impacts thalamic subregions, particularly the medial pulvinar. This study reveals distinct patterns in presymptomatic and symptomatic carriers across C9orf72, GRN, and MAPT mutations.
Area of Science:
- Neuroimaging
- Neurology
- Genetics
Background:
- Frontotemporal dementia (FTD) variably affects thalamic subregions.
- Genetic FTD, particularly C9orf72, GRN, and MAPT mutations, warrants detailed thalamic subregion analysis.
- Previous studies lacked fine-grained thalamic segmentation and diffusion metrics.
Purpose of the Study:
- To characterize thalamic subregional involvement in genetic FTD using advanced MRI segmentation.
- To compare volumetric and diffusion metrics (mean diffusivity) across C9orf72, GRN, and MAPT mutation carriers and non-carriers.
- To identify shared and distinct thalamic changes in presymptomatic and symptomatic genetic FTD stages.
Main Methods:
- Utilized a novel thalamus segmentation tool on 3-Tesla structural and diffusion MRI data.
- Analyzed cross-sectional MRI scans from C9orf72, GRN, and MAPT mutation carriers (presymptomatic and symptomatic) and non-carriers from the GENetic Frontotemporal dementia Initiative (GENFI).
- Employed analyses of covariance to compare thalamic subregion volumes and mean diffusivity, controlling for age, sex, and intracranial volume.
Main Results:
- Presymptomatic C9orf72 carriers showed reduced volumes and increased mean diffusivity in multiple thalamic subregions, including all pulvinar subdivisions.
- Presymptomatic GRN and MAPT carriers exhibited subtle volume increases in specific anterior/ventral subregions.
- Symptomatic carriers across all genetic groups displayed significantly reduced volumes and widespread increased mean diffusivity, most pronounced in associative and limbic regions. A shared feature was marked reduction in volume and increased diffusivity of the medial pulvinar's most medial part.
Conclusions:
- Thalamic subregional alterations are confirmed in genetic FTD.
- The medial pulvinar's medial part shows significant involvement across genetic groups at the symptomatic stage, potentially serving as a unifying biomarker.
- Advanced MRI segmentation provides a more detailed understanding of thalamic pathology in genetic FTD subtypes.
