title: Regional Cerebral Disease Progression in Friedreich's Ataxia: A Longitudinal Diffusion Tensor Imaging Study.
abstract: OBJECTIVE
  Imaging biomarkers of disease progression are desirable in inherited ataxias. MRI has demonstrated brain damage in Friedreich ataxia (FRDA) in form of regional atrophy of the medulla, peridentate cerebellar white matter (WM) and superior cerebellar peduncles (visible in T1-weighted images) and of change of microstructural characteristics of WM tracts of the brainstem, cerebellar peduncles, cerebellum, and supratentorial structures (visible through diffusion-weighted imaging). We explored the potential of brain MR morphometry and diffusion tensor imaging (DTI) to track the progression of neurodegeneration in FRDA.
  
  
  METHODS
  Eight patients (5F, 3M; age 13.4-41.2 years) and 8 healthy controls (2F, 6M; age 26.2-48.3 years) underwent 2 MRI examinations (mean 3.9 and 4.1 years apart, respectively) on the same 1.5T scanner. The protocol included 3D T1-weighted images and axial diffusion-weighted images (b-value 1,000 s/mm(2)) for calculating maps of fractional anisotropy, mean, axial and radial diffusivity, and mode of anisotropy. Tensor-based morphometry was used to investigate regional volume changes and tract-based spatial statistics was used to investigate microstructural changes in WM tracts.
  
  
  RESULTS
  Longitudinal analyses showed no differences in regional volume changes but a significant difference in axial diffusivity changes in cerebral and corpus callosum WM of patients as compared to controls (mean longitudinal rate of change for axial diffusivity: -.02 × 10(-3) mm(2)/s/year in patients vs. .01 × 10(-3) mm(2)/s/year in controls). No correlation with number of triplets, disease duration, and worsening of the clinical deficit was observed.
  
  
  CONCLUSIONS
  DTI can track brain microstructural changes in FRDA and can be considered a potential biomarker of disease progression.
authors.affiliation: Quantitative and Functional Neuroradiology Research Unit at Meyer Children and Careggi Hospitals of Florence, Florence, Italy.|"Mario Serio" Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Mascalchi
authors.affiliation: Medical Physics Section, Department of Biomedicine and Prevention, University of Rome "Tor Vergata,", Rome, Italy.|Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA.|Harvard Medical School, Boston, MA.
authors.forename: Nicola
authors.initials: N
authors.lastname: Toschi
authors.affiliation: Unit of Medical Physics, Pisa University Hospital "Azienda Ospedaliero-Universitaria Pisana,", Pisa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Giannelli
authors.affiliation: Neuroradiology Unit, Careggi General Hospital, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ginestroni
authors.affiliation: "San Giuseppe" Hospital, Azienda USL 11 Empoli, Empoli (Fi), Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Della Nave
authors.affiliation: Unit of Radiology, Versilia Hospital, Azienda USL 12 Viareggio, Lido di Camaiore (Lu), Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Tessa
authors.affiliation: NEUROFARBA Department, University of Florence, Florence, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Piacentini
authors.affiliation: Department of Neurological Sciences, University of Siena, Siena, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Dotti
authors.affiliation: IRCSS SDN Foundation, Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Aiello
authors.affiliation: IRCSS SDN Foundation, Naples, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Nicolai
authors.affiliation: IRCSS SDN Foundation, Naples, Italy.|University of Naples Parthenope, Naples, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Soricelli
authors.affiliation: "Il Bene" Centre for Immunological and Rare Diseases, Bellaria Hospital, IRCSS Neurologia Città di Bologna, Bologna, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Salvi
authors.affiliation: Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi,", University of Bologna, Cesena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Diciotti
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005621:Friedreich Ataxia / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009410:Nerve Degeneration / Q000000981:diagnostic imaging* / Q000473:pathology; D055815:Young Adult
keywords: Friedreich ataxia, diffusion tensor imaging, tensor-based morphometry