title: Diffusion tensor imaging and tract-based spatial statistics analysis in Friedreich's ataxia patients.
abstract: BACKGROUND
  Friedreich's ataxia (FRDA) is the most common hereditary ataxia and thinning of the cervical spinal cord is a consistent observation in Magnetic resonance imaging (MRI), although neuropathological examination in FRDA reveals neuronal loss in gray matter (GM) nuclei and degeneration of white matter (WM) tracts in the spinal cord, brainstem and cerebellum. Using diffusion-tensor (DTI) imaging and tract-based spatial statistics (TBSS) we tested the hypothesis that WM damage in FRDA is more extensive than previously described and probably involves normal-appearing WM.
  
  
  METHODS
  This transversal study included 21 genetically confirmed FRDA patients and seventeen healthy controls that underwent structural MRI of the brain on a 1.5 T scanner. We quantify the severity of ataxia using SARA scale. DTI was performed and diffusion data were analyzed using FMRIB's Diffusion Toolbox in FSL 4.1 in order to identify Fractional anisotropy (FA) decreases in specific brain regions and also the mean, radial and axial diffusivities (MD, RD, AD).
  
  
  RESULTS
  The greatest decreases in FA were in the left superior cerebellar peduncle, left posterior thalamic radiation, major forceps, left inferior fronto-occipital fasciculus and corpus callosum and had a significance level of p < 0.01. No significant correlation between FA, AD, MD and RD values and the clinical findings, SARA scores and genetic expansion was found.
  
  
  CONCLUSIONS
  DTI and TBSS techniques clearly demonstrate the extensive cerebral and cerebellar involvement in FRDA, partially explaining the clinical phenotype of the disease. Further studies are needed with larger samples to correlate clinical, genetic findings and ataxia scores.
authors: Federal University of Parana, Hospital de Clinicas, Brazil. Electronic address: simone@karuta.com.br.
authors: Simone Carreiro
authors: SC
authors: Vieira Karuta
authors: Pontificia Universidade Catolica do Parana, Genetika Laboratorio: Rua Saldanha Marinho, 1782, Bigorrilho, Curitiba, Parana 80730-180, Brazil. Electronic address: genetika@genetika.com.br.
authors: Salmo
authors: S
authors: Raskin
authors: Federal University of Parana, Hospital de Clinicas: R. Gen. Carneiro, 181, Alto da Glória, Curitiba, Parana 80060-900, Brazil. Electronic address: arnolfocarvalho@hotmal.com.
authors: Arnolfo
authors: A
authors: de Carvalho Neto
authors: Federal University of Rio de Janeiro, CDPI Clinica de Diagnostico por Imagem: Centro Medico Barra Shopping, Aveinda das Americas, 4666, terceiro andar, Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: egasparetto@gmail.com.
authors: Emerson Leandro
authors: EL
authors: Gasparetto
authors: CDPI Clinica de Diagnostico por Imagem: Centro Medico Barra Shopping, Aveinda das Americas, 4666, terceiro andar, Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: thomas.doring@gmail.com.
authors: Thomas
authors: T
authors: Doring
authors: Federal University of Parana, Hospital de Clinicas: R. Gen. Carneiro, 181, Alto da Glória, Curitiba, Parana 80060-900, Brazil. Electronic address: teiveads@mps.com.br.
authors: Helio Afonso Ghizoni
authors: HA
authors: Teive
mesh_terms: D000293:Adolescent; D000328:Adult; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005621:Friedreich Ataxia / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D055815:Young Adult
keywords: Diffusion tensor imaging; Friedreich ataxia; Gait disorders; MRI; Tract-based spatial statistics