High connectivity between reduced cortical thickness and disrupted white matter tracts in longstanding type 1 diabetes

  1. Elizabeth R. Seaquist (seaqu001{at}
  1. Medical Scientist Training Program 1, Division of Endocrinology and Diabetes
  2. Department of Medicine2, and
  3. Department of Psychiatry3, University of Minnesota Medical School. Minneapolis, Minnesota


Objective: Previous studies have observed disruptions in brain white and gray matter structure in individuals with type 1 diabetes, and these structural differences have been associated with neurocognitive testing deficiencies. This study investigated the relationship between cerebral cortical thickness reductions and white matter microstructural integrity loss in a group of patients with type 1 diabetes and healthy controls using diffusion tensor imaging (DTI).

Research design and methods: 25 subjects with type 1 diabetes for at least 15 years and 25 age- and sex-matched control subjects underwent structural T1 and proton-density and DTI imaging on a 3.0 Tesla scanner. Fractional anisotropy measurements were made on major cerebral white matter tracts, and DTI tractography was performed to indentify cortical regions with high connectivity to these tracts.

Results: Posterior white matter tracts with reduced fractional anisotropy (optic radiations, posterior corona radiata and the splenium region of the corpus callosum) were found to have high connectivity with a number of posterior cortical regions, including the cuneus, precuneus, fusiform and posterior parietal cortical regions. A significant reduction in cortical thickness in the diabetes group was observed in the regions with high connectivity to the optic radiations and posterior corona radiata tracts (p<0.05).

Conclusions: The direct relationship between white and gray matter structural pathology has not been previously demonstrated in subjects with longstanding type 1 diabetes. The relationship between posterior white matter microstructural integrity disruption and lower cortical thickness demonstrated using a novel DTI connectivity technique suggests a common or interrelated pathophysiological mechanism in type 1 diabetes.

  • Received April 30, 2010.
  • Accepted October 16, 2010.