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Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Voxelwise analysis of diffusion tensor imaging and structural MR imaging in patients with the m.3243A>G mutation in
S M Virtanen1, M M Lindroos, K Majamaa
1Medical Imaging Centre of Southwest Finland, Turku University Hospital, Finland. sami.virtanen@tyks.fi
Background And Purpose:
The m.3243A>G mutation is the most common pathogenic mutation in mtDNA; tissues with high dependence on aerobic energy metabolism, such as the brain, heart, and skeletal muscle, are most affected by the ensuing mitochondrial dysfunction. We hypothesized that the m.3243A>G mutation manifests as disturbances in white matter microstructural integrity and volumetric changes in the brain.
Materials And Methods:
DTI and structural MR imaging were performed on 15 adult patients with the m.3243A>G mutation and 14 healthy age-matched controls. Voxelwise analysis of the DTI data was performed to reveal possible differences in FA and MD values. Additionally, normalized brain tissue volumes of the subjects were measured, and voxelwise analysis of gray matter was performed to assess volumetric changes in the brain.
Results:
Among patients with m.3243A>G mutation, voxelwise analysis of the DTI data revealed significantly reduced FA in several areas located mainly in the occipital lobes, thalami, external and internal capsules, brain stem, cerebellar peduncles, and cerebellar white matter. There were no differences in MD values between the patients and the controls. Analysis of the structural MR imaging data revealed reduced total volume of gray and white matter in patients with m.3243A>G mutation, and VBM analysis identified areas of significant gray matter loss mainly in the occipital lobes and cerebellum.
Conclusions:
Our findings show that patients with m.3243A>G mutation have mild microstructural damage leading to loss of directional organization of white matter and reduced brain volumes.
Insights
The common m.3243A>G mutation in mitochondrial DNA (mtDNA) causes white matter damage and reduced brain volumes in affected individuals. This study investigated these neurological effects using advanced MRI techniques.
Area of Science:
- Neuroimaging
- Mitochondrial Genetics
- Neurology
Background:
- The m.3243A>G mutation is the most prevalent pathogenic mutation in mitochondrial DNA (mtDNA).
- This mutation leads to mitochondrial dysfunction, primarily affecting tissues with high aerobic energy demands like the brain, heart, and skeletal muscle.
Purpose of the Study:
- To investigate if the m.3243A>G mutation causes white matter microstructural changes and volumetric alterations in the brain.
- To identify specific brain regions affected by this mutation.
Main Methods:
- Diffusion Tensor Imaging (DTI) and structural Magnetic Resonance Imaging (MRI) were used.
- 15 adult patients with the m.3243A>G mutation and 14 healthy controls were analyzed.
- Voxelwise analysis assessed fractional anisotropy (FA), mean diffusivity (MD), and gray matter volumes.
Main Results:
- Patients showed significantly reduced FA in white matter regions, including the occipital lobes, thalami, and brain stem.
- No differences in MD values were observed between patients and controls.
- Reduced total gray and white matter volumes were found, with gray matter loss concentrated in the occipital lobes and cerebellum.
Conclusions:
- The m.3243A>G mutation is associated with mild white matter microstructural damage.
- This damage results in impaired directional organization of white matter and reduced overall brain volumes in affected individuals.
