title: Corpus callosal atrophy in premanifest and early Huntington's disease.
abstract: BACKGROUND
  Volumetric MRI studies have highlighted the pronounced loss of white matter in premanifest and early Huntington's Disease (HD). The current study focussed on the corpus callosum (CC) since it provides interhemispheric connections to vulnerable cortical areas.
  
  
  OBJECTIVE
  To investigate cross-sectional and longitudinal group differences in CC volume and hypothesis-driven associations with three cognitive tasks.
  
  
  METHODS
  Baseline and 24-month 3T MRI were analysed from 106 premanifest (PreHD), (59 preHD-A ≥10.8 and 47 preHD-B <10.8 years from predicted onset), 84 early HD (53 Stage 1 (HD1) and 31 Stage 2 (HD2)) and 101 control subjects from the TRACK-HD study, using a semi-automated technique for CC delineation. Between-group differences in volume and 24-month atrophy rates, and correlations with cognitive performance were investigated using regression models, adjusting for potential confounders.
  
  
  RESULTS
  PreHD-B, HD1 and HD2 had statistically significantly smaller baseline CC volumes (p < 0.001) and all groups had elevated 24-month atrophy rates compared with controls (p < 0.001). Smaller baseline CC volume was associated with impaired performance in the Circle Tracing Indirect task in early HD (p < 0.05). Positive, non-statistically significant relationships with Stroop Word Reading were shown in both gene-positive groups. There was no evidence of an association with the Trail Making B task.
  
  
  CONCLUSIONS
  We found reduced CC volume and elevated 24-month atrophy rates, even in individuals far from disease onset. Structural degeneration of interhemispheric connections may contribute to cognitive deficits, such as performance in the Circle Tracing Indirect task in HD. Examination of different image acquisitions may provide more specific information about underlying CC degeneration.
authors: UCL Institute of Neurology, University College London, UK.
authors: Helen E
authors: HE
authors: Crawford
authors: UCL Institute of Neurology, University College London, UK.
authors: Nicola Z
authors: NZ
authors: Hobbs
authors: Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK.
authors: Ruth
authors: R
authors: Keogh
authors: Departments of Psychiatry and Biostatistics (Secondary), University of Iowa, Iowa City, IA, USA.
authors: Douglas R
authors: DR
authors: Langbehn
authors: Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK.
authors: Chris
authors: C
authors: Frost
authors: Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
authors: Hans
authors: H
authors: Johnson
authors: Department of Neurology, Ulm University, Ulm, Germany.
authors: Bernhard
authors: B
authors: Landwehrmeyer
authors: Department of Neurology, University of Münster, Münster, Germany.
authors: Ralf
authors: R
authors: Reilmann
authors: Institute of Human Development, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK and Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
authors: David
authors: D
authors: Craufurd
authors: School of Psychology and Psychiatry, Monash University, VIC, Australia.
authors: Julie C
authors: JC
authors: Stout
authors: Department of Genetics and Cytogenetics, and INSERM UMR S679, APHP Hôpital de la Salpêtrière, Paris, France.
authors: Alexandra
authors: A
authors: Durr
authors: Centre for Molecular Medicine & Therapeutics, Dept. of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.
authors: Blair R
authors: BR
authors: Leavitt
authors: Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.
authors: Raymund A C
authors: RA
authors: Roos
authors: UCL Institute of Neurology, University College London, UK.
authors: Sarah J
authors: SJ
authors: Tabrizi
authors: UCL Institute of Neurology, University College London, UK.
authors: Rachael I
authors: RI
authors: Scahill
mesh_terms: D000328:Adult; D001284:Atrophy / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000473:pathology*; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D062706:Prodromal Symptoms
keywords: Huntington's disease; MRI; atrophy; corpus callosum