MR Imaging in Spinocerebellar Ataxias: A Systematic Review

Area of Science:

• Neuroimaging
• Neurodegenerative Diseases
• Biomarker Discovery

Background:

• Polyglutamine expansion spinocerebellar ataxias (SCAs) are progressive neurodegenerative diseases lacking effective treatments.
• Magnetic Resonance (MR) imaging is a promising surrogate biomarker for SCAs, but findings are inconsistent.
• Understanding quantitative MR imaging findings is crucial for tracking disease progression and evaluating potential therapies.

Purpose of the Study:

• To review quantitative central nervous system MR imaging findings in patients with polyglutamine expansion SCAs.
• To correlate MR imaging data with established clinical and molecular disease markers.
• To assess the utility of MR imaging as a biomarker for SCAs.

Main Methods:

• Systematic literature search of MEDLINE, LILACS, and Cochrane databases (1995-2016).
• Inclusion of studies utilizing quantitative MR imaging techniques (volumetry, MR spectroscopy, diffusion tensor imaging).
• Extraction of data on participants, imaging methods, and results comparing SCAs with controls.

Main Results:

• Eighteen studies met inclusion criteria, focusing on various SCA subtypes, with a strong emphasis on SCA3.
• Significant atrophy was observed in multiple brain regions in SCA3 patients, including the cerebellum, brainstem, and thalamus.
• Diffusion Tensor Imaging (DTI) and MR spectroscopy showed abnormalities in cross-sectional SCA3 studies; findings require replication across different cohorts.

Conclusions:

• Further cross-sectional and prospective studies using volumetric analysis, MR spectroscopy, and DTI are essential for SCAs.
• Future research should focus on the properties of MR imaging as preclinical biomarkers in presymptomatic individuals.
• Quantitative MR imaging holds potential for monitoring disease progression and therapeutic response in SCAs.