title: Abnormal diffusion tensor in nonsymptomatic familial amyotrophic lateral sclerosis with a causative superoxide dismutase 1 mutation.
abstract: OBJECTIVE
  To determine whether diffusion abnormalities can be observed in nonsymptomatic family members with a known causative Cu/Zn superoxide dismutase mutation (asymptomatic familial amyotrophic lateral sclerosis; AFALS(+SOD1)) in a family with autosomal dominant familial amyotrophic lateral sclerosis (ALS) using diffusion tensor imaging (DTI).
  
  
  METHODS
  A total of eight AFALS(+SOD1) subjects (aged 17-43 years) were age-matched with 13 healthy controls (aged 19-45 years) without SOD1 mutations. DTI was carried out on a 1.5T scanner. The diffusion index maps derived were then normalized spatially for voxel-based analysis. region of interest (ROI)-based analysis was also carried out.
  
  
  RESULTS
  Our voxel-based and ROI-based analysis showed that AFALS(+SOD1) subjects have decreased fractional anisotropy (FA) (0.5401 vs. 0.5168, P < 0.05) and increased tensor trace (TT) (2.5854 x 10(-3) mm(2)/second vs. 2.6226 x 10(-3) mm(2)/second, P < 0.04) at the posterior limb of the internal capsule compared to the control subjects. Increased radial diffusivity (E((2,3)/2)) was detected on both sides (right = 0.5710 x 10(-3) mm(2)/second vs. 0.5943 x 10(-3) mm(2)/second, P < 0.05; left = 0.5666 x 10(-3) mm(2)/second vs. 0.5872 x 10(-3) mm(2)/second, P < 0.05). No significant change in axial diffusivity (E(1)) was detected.
  
  
  CONCLUSIONS
  Abnormal diffusivity was found at the posterior limb of the internal capsule in AFALS(+SOD1) subjects, hitherto unreported. Our results suggest that DTI may detect diffusion abnormalities in AFALS(+SOD1) subjects before symptoms develop.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong.
authors.forename: Man-Cheuk
authors.initials: MC
authors.lastname: Ng
authors.forename: Jenny Ting
authors.initials: JT
authors.lastname: Ho
authors.forename: Shu-Leong
authors.initials: SL
authors.lastname: Ho
authors.forename: Raymand
authors.initials: R
authors.lastname: Lee
authors.forename: Geng
authors.initials: G
authors.lastname: Li
authors.forename: Tat-Sun
authors.initials: TS
authors.lastname: Cheng
authors.forename: You-Qiang
authors.initials: YQ
authors.lastname: Song
authors.forename: Philip Wing-Lok
authors.initials: PW
authors.lastname: Ho
authors.forename: Gardian Chung-Yan
authors.initials: GC
authors.lastname: Fong
authors.forename: Windsor
authors.initials: W
authors.lastname: Mak
authors.forename: Koon-Ho
authors.initials: KH
authors.lastname: Chan
authors.forename: Leonard Sheung-Wai
authors.initials: LS
authors.lastname: Li
authors.forename: Keith Dip-Kei
authors.initials: KD
authors.lastname: Luk
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: David Boyer
authors.initials: DB
authors.lastname: Ramsden
authors.forename: Lilian Ling-Yee
authors.initials: LL
authors.lastname: Leong
mesh_terms: D000293:Adolescent; D000328:Adult; D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology*; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009154:Mutation; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1
chemical_list: C000606290:SOD1 protein, human; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1