title: Progression of microstructural damage in spinocerebellar ataxia type 2: a longitudinal DTI study.
abstract: OBJECTIVE
  The ability of DTI to track the progression of microstructural damage in patients with inherited ataxias has not been explored so far. We performed a longitudinal DTI study in patients with spinocerebellar ataxia type 2.
  
  
  METHODS
  Ten patients with spinocerebellar ataxia type 2 and 16 healthy age-matched controls were examined twice with DTI (mean time between scans, 3.6 years [patients] and 3.3 years [controls]) on the same 1.5T MR scanner. Using tract-based spatial statistics, we analyzed changes in DTI-derived indices: mean diffusivity, axial diffusivity, radial diffusivity, fractional anisotropy, and mode of anisotropy.
  
  
  RESULTS
  At baseline, the patients with spinocerebellar ataxia type 2, as compared with controls, showed numerous WM tracts with significantly increased mean diffusivity, axial diffusivity, and radial diffusivity and decreased fractional anisotropy and mode of anisotropy in the brain stem, cerebellar peduncles, cerebellum, cerebral hemisphere WM, corpus callosum, and thalami. Longitudinal analysis revealed changes in axial diffusivity and mode of anisotropy in patients with spinocerebellar ataxia type 2 that were significantly different than those in the controls. In patients with spinocerebellar ataxia type 2, axial diffusivity was increased in WM tracts of the right cerebral hemisphere and the corpus callosum, and the mode of anisotropy was extensively decreased in hemispheric cerebral WM, corpus callosum, internal capsules, cerebral peduncles, pons and left cerebellar peduncles, and WM of the left paramedian vermis. There was no correlation between the progression of changes in DTI-derived indices and clinical deterioration.
  
  
  CONCLUSIONS
  DTI can reveal the progression of microstructural damage of WM fibers in the brains of patients with spinocerebellar ataxia type 2, and mode of anisotropy seems particularly sensitive to such changes. These results support the potential of DTI-derived indices as biomarkers of disease progression.
authors.affiliation: From the Quantitative and Functional Neuroradiology Research Unit (M.M.), Meyer Children and Careggi Hospitals of Florence, Florence, Italy "Mario Serio" Department of Experimental and Clinical Biomedical Sciences (M.M., A.B.), University of Florence, Florence, Italy m.mascalchi@dfc.unifi.it.
authors.forename: M
authors.initials: M
authors.lastname: Mascalchi
authors.affiliation: Medical Physics Section (N.T.), Department of Biomedicine and Prevention, University of Rome "Tor Vergata," Rome, Italy Department of Radiology (N.T.), Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts Harvard Medical School (N.T.), Boston, Massachusetts.
authors.forename: N
authors.initials: N
authors.lastname: Toschi
authors.affiliation: Unit of Medical Physics (M.G.), Pisa University Hospital "Azienda Ospedaliero-Universitaria Pisana," Pisa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Giannelli
authors.affiliation: Neuroradiology Unit (A.G.), Careggi General Hospital, Florence, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ginestroni
authors.affiliation: "San Giuseppe" Hospital (R.D.N.), Empoli, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Della Nave
authors.affiliation: IRCSS SDN Foundation (E.N., M.A., A.S.), Naples, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Nicolai
authors.affiliation: From the Quantitative and Functional Neuroradiology Research Unit (M.M.), Meyer Children and Careggi Hospitals of Florence, Florence, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bianchi
authors.affiliation: Unit of Radiology (C.T.), Versilia Hospital, Lido di Camaiore, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Tessa
authors.affiliation: Department of Neurological Sciences (E.S.), University of Naples Federico II, Naples, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Salvatore
authors.affiliation: IRCSS SDN Foundation (E.N., M.A., A.S.), Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Aiello
authors.affiliation: IRCSS SDN Foundation (E.N., M.A., A.S.), Naples, Italy University of Naples Parthenope (A.S.), Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Soricelli
authors.affiliation: Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi" (S.D.), University of Bologna, Cesena, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Diciotti
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*