title: Radial diffusivity in the cerebellar peduncles correlates with clinical severity in Friedreich ataxia.
abstract: Friedreich ataxia (FRDA) is a common inherited ataxia, caused by an expanded GAA repeat sequence in the Frataxin (FXN) gene. The proprioceptive system, which enters the cerebellum through the cerebellar peduncles, is a primary focus of pathology. In this study, we investigate the relationship of clinical and genetic data with diffusion-tensor imaging (DTI) indices reflecting white matter integrity of the cerebellar peduncles. Nine FRDA patients underwent DTI. After between-subject registration using tract-based spatial statistics, a white matter atlas was used for computing average values of DTI indices in the regions of interest. These were the inferior, middle and superior cerebellar peduncles (ICP, MCP, SCP). For Bonferroni correction, significance threshold was set to p < 0.0056. We found that radial diffusivity (D(⊥)) within the ICP significantly correlated with scores on the Friedreich Ataxia Rating Scale (FARS, Spearman's ρ = 0.883, p = 0.0016, all two-sided) and, at trend level, with number of trinucleotide repeats (ρ = 0.812, p = 0.008). D(⊥) in the SCP correlated with scores on the Scale for the Assessment and Rating of Ataxia (SARA, ρ = 0.867, p = 0.0025). These findings support the role of DTI, and especially D(⊥), as an informative biomarker in FRDA.
authors: Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, 1249 Boylston St, Boston, Massachusetts, 02215, USA. clemm@bwh.harvard.edu
authors: Christian
authors: C
authors: Clemm von Hohenberg
authors: Michael F
authors: MF
authors: Schocke
authors: Marlene C
authors: MC
authors: Wigand
authors: Wolfgang
authors: W
authors: Nachbauer
authors: Charles R G
authors: CR
authors: Guttmann
authors: Marek
authors: M
authors: Kubicki
authors: Martha E
authors: ME
authors: Shenton
authors: Sylvia
authors: S
authors: Boesch
authors: Karl
authors: K
authors: Egger
mesh_terms: D000293:Adolescent; D000328:Adult; D002531:Cerebellum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D005621:Friedreich Ataxia / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged
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