Related Experiment Video
Updated: Apr 30, 2026
09:33
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
27.9K
Brain white matter involvement in hereditary spastic paraplegias: analysis with multiple diffusion tensor indices
G Aghakhanyan1, A Martinuzzi2, F Frijia3
1From the Institute of Life Sciences (G.A.), Scuola Superiore Sant'Anna, Pisa, ItalyNeuroradiology Unit (G.A., F.F., H.H., D.M.), Fondazione CNR/Regione Toscana G. Monasterio, Pisa, Italy.
AJNR. American Journal of Neuroradiology
|May 3, 2014
Summary
Diffusion tensor imaging reveals widespread white matter changes in pure hereditary spastic paraplegia. Radial diffusivity is a sensitive marker for myelin integrity loss, while fractional anisotropy changes suggest frontal connection disruption.
Area of Science:
- Neuroimaging
- Neurology
- Biomedical Engineering
Background:
- Hereditary spastic paraplegias (HSPs) are neurodegenerative disorders causing progressive lower limb spasticity and weakness.
- While conventional MRI is normal in pure HSP, diffusion tensor imaging (DTI) can detect white matter (WM) microstructural alterations.
- Investigating multiple DTI indices offers insight into the neurobiology of WM degeneration in pure HSP.
Purpose of the Study:
- To investigate microstructural WM alterations in pure HSP using DTI.
- To compare DTI metrics (fractional anisotropy, mean, axial, and radial diffusivity) between patients and healthy controls.
- To elucidate the neurobiologic substrate of WM degeneration in pure HSP.
Main Methods:
- Tract-based spatial statistics (TBSS) analysis of DTI data.
- Comparison of WM skeleton diffusivities between 12 pure HSP patients and 12 healthy volunteers.
- Statistical analysis controlled for age and sex, with family-wise error rate controlled via permutation tests.
Main Results:
- Widespread decreases in fractional anisotropy and increases in radial and mean diffusivity were observed in pure HSP patients (P < .05, corrected).
- No significant differences in axial diffusivity were found.
- Radial diffusivity showed the most widespread changes (51% of WM skeleton voxels), followed by fractional anisotropy (41.6%) and mean diffusivity (11.9%).
- A preferential decrease in fractional anisotropy was noted in the frontal circuitry, indicating an anteroposterior pattern.
Conclusions:
- Pure HSP is associated with multiple DTI index alterations.
- Increased radial diffusivity suggests widespread myelin integrity loss, more sensitive than fractional anisotropy changes.
- Lack of axial diffusivity changes supports myelin-related pathology.
- Decreased fractional anisotropy in the frontal circuitry may indicate subtle disruption of frontal connections.
