Regionally Specific Diffusion Tensor Imaging in Mild Cognitive Impairment and Alzheimer's Disease

  • Prof Jian Wang, Department of Neurological Research, Hebei Medical University, China
  • Prof Pei Lv, Department of Neurological Research, Hebei Medical University, China
  • Prof He Wang, Neurology Department, Heibei provincial hospital, China
  • Dr Zhi Li, Neurology Department, Heibei provincial hospital, China
  • Dr Na Li, Neurology Department, Heibei provincial hospital, China
  • Dr Zhan Sun, Neurology Department, Heibei provincial hospital, China
  • Dr Bao Zhao, Neurology Department, Heibei provincial hospital, China
  • Dr Yue Huang, Prince of Wales Medical Research Institute, Australia

Objective: To investigate regionally microstructural white matter lesions and its correlation with the cognitive function in patients with mild cognitive impairment (MCI),and mild and moderate Alzheimer’s disease(AD).
Methods: 12 patients with MCI,12 patients with mild and moderate AD,and 12 sex and age matched healthy volunteers were recruited. All subjects were tested using the mini-mental state examination (MMSE) and AD Assessment Scale-Cognitive (ADAS-Cog).Diffusion tensor imaging (DTI), fractional anisotropy (FA), and mean diffusivity (MD) of normal-appearing white matter (NAWM) in different brain regions were acquired and compared across the three groups. Furthermore, the identified significant DTI differences were correlated with cognitive function of all subjects using SPSS-Pearson analysis.
Results: Compared with the healthy controls, MCI patients demonstrated decreased FA only in the temporal lobe (p<0.05). Mild and moderate AD patients showed decreased FA in the frontal, parietal and temporal NAWM (p<0.05), and increased MD in the splenium of the corpus callosum, frontal and parietal NAWM (p<0.05). No differences were found in the anterior and posterior limbs of the internal capsule and the occipital NAWM(p>0.05). Both FA in parietal and temporal lobes and MD in the splenium of the corpus callosum NAWM and parietal lobe correlated with MMSE scores, and word recall and word recognition of ADAS-Cog(p<0.05).
Conclusion: Our results indicated that the selective impairment of microstructural white matter was responsible for sub-domain cognitive performance in patients with MCI and AD.