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Updated: Jul 7, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Brain white matter tracts degeneration in Friedreich ataxia. An in vivo MRI study using tract-based spatial
Riccardo Della Nave1, Andrea Ginestroni, Carlo Tessa
1Radiodiagnostic Section, Department of Clinical Physiopathology, University of Florence, Viale Morgagni 85, Florence, Italy.
Background And Purpose:
Neuropathological examination in Friedreich ataxia (FRDA) reveals neuronal loss in the gray matter (GM) nuclei and degeneration of the white matter (WM) tracts in the spinal cord, brainstem and cerebellum, while the cerebral hemispheres are substantially spared. Tract-based spatial statistics (TBSS) enables an unbiased whole-brain quantitative analysis of the fractional anisotropy (FA) and mean diffusivity (MD) of the brain WM tracts in vivo.
Patients And Methods:
We assessed with TBSS 14 patients with genetically confirmed FRDA and 14 age- and sex-matched healthy controls who were also examined with voxel-based morphometry (VBM) to assess regional atrophy of the GM and WM.
Results:
TBSS revealed decreased FA in the inferior and superior cerebellar peduncles and the corticospinal tracts in the medullary pyramis, in WM tracts of the right cerebellar hemisphere and in the right occipito-frontal and inferior longitudinal fasciculi. Increased MD was observed in the superior cerebellar peduncles, deep cerebellar WM, posterior limbs of the internal capsule and retrolenticular area, bilaterally, and in the WM underlying the left central sulcus. Decreased FA in the left superior cerebellar peduncle correlated with clinical severity. VBM showed small symmetric areas of loss of bulk of the peridentate WM which also correlated with clinical severity.
Conclusions:
TBSS enables in vivo demonstration of degeneration of the brainstem and cerebellar WM tracts which neuropathological examination indicates to be specifically affected in FRDA. TBSS complements VBM and might be a more sensitive tool to detect WM structural changes in degenerative diseases of the CNS.
Insights
Tract-based spatial statistics (TBSS) reveals white matter degeneration in Friedreich ataxia (FRDA) patients, particularly in the brainstem and cerebellum. This advanced imaging technique shows promise for detecting structural changes in central nervous system degenerative diseases.
Area of Science:
- Neuroimaging
- Neurology
- Genetics
Background:
- Friedreich ataxia (FRDA) is characterized by neuronal loss and white matter (WM) tract degeneration, primarily affecting the spinal cord, brainstem, and cerebellum.
- Cerebral hemispheres are largely spared in FRDA neuropathology.
- Tract-based spatial statistics (TBSS) offers in vivo, whole-brain quantitative analysis of WM integrity using fractional anisotropy (FA) and mean diffusivity (MD).
Purpose of the Study:
- To assess WM tract degeneration in FRDA patients using TBSS.
- To compare TBSS findings with voxel-based morphometry (VBM) for detecting regional atrophy.
- To correlate imaging findings with clinical severity in FRDA.
Main Methods:
- TBSS analysis was performed on 14 genetically confirmed FRDA patients and 14 healthy controls.
- Voxel-based morphometry (VBM) was used to assess gray matter (GM) and WM atrophy.
- Correlation analyses were conducted between imaging metrics and clinical severity.
Main Results:
- TBSS detected decreased FA in the cerebellar peduncles, corticospinal tracts, and cerebellar WM.
- Increased MD was observed in the superior cerebellar peduncles, internal capsule, and periventricular WM.
- Decreased FA in the left superior cerebellar peduncle and WM loss correlated with FRDA clinical severity.
Conclusions:
- TBSS effectively demonstrates in vivo WM tract degeneration in the brainstem and cerebellum in FRDA.
- TBSS complements VBM and may be a more sensitive tool for detecting WM changes in neurodegenerative diseases.
- The findings highlight the utility of advanced neuroimaging in understanding FRDA's structural impact.
