A Comparative White Matter Study with Parkinson's disease, Parkinson's Disease with Dementia and Alzheimer's Disease.
Alzheimer's disease (AD) and Parkinson's disease (PD) are among the most common neurodegenerative disorders affecting older populations. AD is characterized by impaired memory and cognitive decline while the primary symptoms of PD include resting tremor, bradykinesia and rigidity. In PD, mild cognitive changes are frequently present, which could progress to dementia (PD dementia (PDD)). PDD and AD dementias are different in pathology although the difference in microstructural changes remains unknown. To further understand these diseases, it is essential to understand the distinct mechanism of their microstructural changes. We used diffusion tensor imaging (DTI) to investigate white matter tract differences between early stage individuals with AD (n=14), PD (n=12), PDD (n=9), and healthy non-demented controls (CON) (n=13). We used whole brain tract based spatial statistics (TBSS) and a region of interest (ROI) analysis focused on the substantia nigra (SN). We found that individuals with PDD had more widespread white matter degeneration compared to PD, AD, and CON. Individuals with AD had few regional abnormalities in the anterior and posterior projections of the corpus callosum while PD and CON did not appear to have significant white matter degeneration when compared to other groups. ROI analyses showed that PDD had the highest diffusivity in the SN and were significantly different from CON. There were no significant ROI differences between CON, PD, or AD. In conclusion, global white matter microstructural deterioration is evident in individuals with PDD, and DTI may provide a means with which to tease out pathological differences between AD and PD dementias.
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA ; Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA ; Bioengineering Program, Department of Engineering, University of Kansas, Lawrence, KS, USA.
Rodrigo D
RD
Perea
Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA.
Rebecca C
RC
Rada
Department of Psychology, University of Kansas, Lawrence, KS, USA.
Jessica
J
Wilson
Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA.
Eric D
ED
Vidoni1
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA ; Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA.
Jill K
JK
Morris
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA.
Kelly E
KE
Lyons
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA.
Rajesh
R
Pahwa
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA ; Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA.
Jeffrey M
JM
Burns
Department of Neurology, University of Kansas School of Medicine, Kansas City, KS, USA ; Alzheimer's Research Disease Center, University of Kansas School of Medicine, Kansas City, KS, USA ; Bioengineering Program, Department of Engineering, University of Kansas, Lawrence, KS, USA.
Robyn A
RA
Honea
Cingulum; Corpus callosum; Corticospinal tract; Dementia; Neurodegenerative disorders