title: Gray matter volume deficits in spinocerebellar ataxia: an optimized voxel based morphometric study.
abstract: BACKGROUND
  Spinocerebellar ataxias (SCA) are a group of autosomal dominant ataxias with varied clinical phenotypes. However there are no unique distinguishing features on routine neuroimaging among the various genetically defined SCAs. Voxel-based morphometry (VBM) provides an automated unbiased analysis of structural MRI scans and gives a comprehensive assessment of anatomical differences throughout the brain.
  
  
  OBJECTIVE
  The aims of this study were to (i) characterize the patterns of atrophy in SCA1, SCA2 and SCA3 using optimized VBM, (ii) demonstrate the characteristic anatomical differences in these genetically distinct SCA subtypes, and (iii) assess the relationship between morphometric measures and the CAG repeat lengths and other attributes of the disease.
  
  
  METHODS
  Thirty-one genetically confirmed patients suffering from SCA (SCA1 - 12, SCA2 - 9, and SCA3 - 10) were studied. High resolution T1-weighted 3-Dimensional Magnetic Resonance Images of 31 patients were analyzed using the optimized VBM procedure.
  
  
  RESULTS
  In all the three SCAs there was a significant loss of gray matter in both cerebellar hemispheres and vermis. Vermian atrophy was more pronounced in SCA3, while SCA1 and SCA2 had significant white matter atrophy. Pontine white matter atrophy was more pronounced in SCA2. In SCA1, the severity of ataxia strongly correlated with the degree of gray matter atrophy in cerebellar hemispheres. The duration of symptoms and lengths of CAG repeats had no correlation with the degree of atrophy.
  
  
  CONCLUSIONS
  This study showed that the different subtypes of SCAs may have morphometric differences in the cerebellum, brainstem and the supratentorial structures.
authors: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore, Karnataka, India.
authors: Gaurav
authors: G
authors: Goel
authors: Pramod Kumar
authors: PK
authors: Pal
authors: Shivashankar
authors: S
authors: Ravishankar
authors: Ganesan
authors: G
authors: Venkatasubramanian
authors: Peruvumba N
authors: PN
authors: Jayakumar
authors: Nithin
authors: N
authors: Krishna
authors: Meera
authors: M
authors: Purushottam
authors: Jitender
authors: J
authors: Saini
authors: Mohammed
authors: M
authors: Faruq
authors: Mitali
authors: M
authors: Mukherji
authors: Sanjeev
authors: S
authors: Jain