title: A longitudinal diffusion tensor imaging study in symptomatic Huntington's disease.
abstract: OBJECTIVE
  The striatum and its projections are thought to be the earliest sites of Huntington's disease (HD) pathology. This study aimed to investigate progression of striatal pathology in symptomatic HD using diffusion tensor imaging.
  
  
  METHODS
  Diffusion weighted images were acquired in 18 HD patients and in 17 healthy controls twice, 1 year apart. Mean diffusivity (MD) was calculated in the caudate, putamen, thalamus and corpus callosum, and compared between groups. In addition, caudate width was measured using T1 high resolution images and correlated with caudate MD. Correlation analyses were also performed in HD between caudate/putamen MD and clinical measures.
  
  
  RESULTS
  MD was significantly higher in the caudate and putamen bilaterally for patients compared with controls at both time points although there were no significant MD differences in the thalamus or corpus callosum. For both groups, MD did not change significantly in any region from baseline to year 1. There was a significant negative correlation between caudate width and MD in patients at baseline but no correlation between these parameters in controls. There was also a significant negative correlation between Mini-Mental State Examination scores and caudate MD and putamen MD at both time points in HD.
  
  
  CONCLUSIONS
  It appears that microstructural changes influence cognitive status in HD. Although MD was significantly higher in HD compared with controls at both time points, there were no longitudinal changes in either group. This finding does not rule out the possibility that MD could be a sensitive biomarker for detecting early change in preclinical HD.
authors.affiliation: School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, Victoria, Australia.
authors.forename: Anusha
authors.initials: A
authors.lastname: Sritharan
authors.forename: Gary F
authors.initials: GF
authors.lastname: Egan
authors.forename: Leigh
authors.initials: L
authors.lastname: Johnston
authors.forename: Malcolm
authors.initials: M
authors.lastname: Horne
authors.forename: John L
authors.initials: JL
authors.lastname: Bradshaw
authors.forename: India
authors.initials: I
authors.lastname: Bohanna
authors.forename: Hamed
authors.initials: H
authors.lastname: Asadi
authors.forename: Ross
authors.initials: R
authors.lastname: Cunnington
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Churchyard
authors.forename: Phyllis
authors.initials: P
authors.lastname: Chua
authors.forename: Maree
authors.initials: M
authors.lastname: Farrow
authors.forename: Nellie
authors.initials: N
authors.lastname: Georgiou-Karistianis
mesh_terms: D000328:Adult; D002421:Caudate Nucleus / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology; D003342:Corpus Striatum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis* / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000175:diagnosis / Q000473:pathology; D009460:Neurologic Examination; D011699:Putamen / Q000473:pathology; D012016:Reference Values; D013223:Statistics as Topic; D013788:Thalamus / Q000473:pathology