Journal of the International Neuropsychological Society

Brief Communication

White Matter Microstructural Integrity and Executive Function in Parkinson's Disease

Catherine Gallaghera1a2 c1, Brian Bella1a2, Barbara Bendlina3, Matthew Palottia1a2, Ozioma Okonkwoa3, Aparna Sodhia3, Rachel Wonga1a2, Laura Buyan-Denta2, Sterling Johnsona1a3, Auriel Wilettea3, Sandra Hardinga3, Nancy Ninmana2, Erik Kastmana3 and Andrew Alexandera4a5

a1 William S. Middleton Memorial VA Hospital, Madison, Wisconsin

a2 Department of Neurology, University of Wisconsin School of Medicine and Public Health (UWSMPH), Madison, Wisconsin

a3 Department of Medicine and Alzheimer's Disease Research Center, UWSMPH, Madison, Wisconsin

a4 Waisman Center Laboratory for Brain Imaging and Behavior, Madison, Wisconsin

a5 Department of Medical Physics, UWSMPH, Madison, Wisconsin

Abstract

Recent studies suggest that white matter abnormalities contribute to both motor and non-motor symptoms of Parkinson's disease. The present study was designed to investigate the degree to which diffusion tensor magnetic resonance imaging (DTI) indices are related to executive function in Parkinson's patients. We used tract-based spatial statistics to compare DTI data from 15 patients to 15 healthy, age- and education-matched controls. We then extracted mean values of fractional anisotropy (FA) and mean diffusivity (MD) within an a priori frontal mask. Executive function composite Z scores were regressed against these DTI indices, age, and total intracranial volume. In Parkinson's patients, FA was related to executive composite scores, and both indices were related to Stroop interference scores. We conclude that white matter microstructural abnormalities contribute to cognitive deficits in Parkinson's disease. Further work is needed to determine whether these white matter changes reflect the pathological process or a clinically important comorbidity. (JINS, 2013, 19, 1–6)

(Received May 21 2012)

(Revised September 27 2012)

(Accepted September 28 2012)

(Online publication January 15 2013)

Keywords

  • idiopathic Parkinson disease;
  • diffusion magnetic resonance imaging;
  • executive function;
  • cognition;
  • aging

Correspondence

c1 Correspondence and reprint requests to: Catherine Gallagher, 7211 MFCB, 1685 Highland Avenue, Madison, WI 53705-2281. E-mail: gallagher@neurology.wisc.edu