Abnormal Diffusion Tensor in Nonsymptomatic Familial Amyotrophic Lateral Sclerosis With a Causative Superoxide Dismutase 1 Mutation

J Magn Reson Imaging. 2008 Jan;27(1):8-13. doi: 10.1002/jmri.21217.

Abstract

Purpose: 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).

Materials and 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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Amyotrophic Lateral Sclerosis / enzymology
  • Amyotrophic Lateral Sclerosis / genetics*
  • Amyotrophic Lateral Sclerosis / pathology*
  • Anisotropy
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Mutation*
  • Statistics, Nonparametric
  • Superoxide Dismutase / genetics*
  • Superoxide Dismutase-1

Substances

  • SOD1 protein, human
  • Superoxide Dismutase
  • Superoxide Dismutase-1