A comparative analysis of cognitive profiles and white-matter alterations using voxel-based diffusion tensor imaging between patients with Parkinson's disease dementia and dementia with Lewy bodies
- Ji E Lee1,
- Hae-Jeong Park2,3,
- BoSuk Park1,
- Sook K Song1,
- Young H Sohn1,
- Jong Doo Lee2,3,
- Phil Hyu Lee1,3
- 1Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
- 2Department of Diagnostic Radiology, Nuclear Medicine and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea
- 3BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
- Correspondence to Dr Phil Hyu Lee, Department of Neurology, Yonsei University Medical College, 250 Seongsanno, Seodaemun-gu, Seoul, 120-752, South Korea;
- Received 28 May 2009
- Revised 26 August 2009
- Accepted 24 September 2009
- Published Online First 14 October 2009
Background Despite clinical and neuropsychological similarities between Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB), recent studies have demonstrated that structural and pathological changes are more severe in DLB than in PDD.
Methods 19 patients with probable PDD and 18 patients with probable DLB who had a similar overall severity of dementia and demographic characteristics were examined by a standardised neuropsychological test and voxel-based analysis of fractional anisotropy (FA) using diffusion tensor imaging (DTI).
Results The patients with DLB performed significantly worse in visual recognition memory, semantic fluency and ideomotor praxis than those with PDD (p<0.05). Compared with controls, the FA value in patients with PDD was significantly lower in bilateral frontal, left temporal and left parietal white matter. In patients with DLB, the pattern of FA reduction was similar to that of patients with PDD; however, white-matter abnormalities were more severe and extended into bilateral insular, bilateral posterior cingular and bilateral visual association regions. In a direct comparison between PDD and DLB, the FA value in patients with DLB was significantly decreased in bilateral posterior temporal, posterior cingular and bilateral visual association fibres extending into occipital areas.
Conclusions Despite global similarities in cognitive performance and white-matter pathology between DLB and PDD patients, those with DLB had more severely impaired frontal and temporal area-associated cognitive subsets, and more severe white-matter pathology in temporal and visual association fibres. These data suggest that differences in the underlying nature of PDD and DLB may exist with global similarities in their cognitive performance and white-matter pathology.
Funding This research was supported by a grant (M10862020005-08N6202-00410) from Bio-technology Development Program funded by the Ministry of Education, Science and Technology, the Republic of Korea.
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was provided by the the Institutional Review Board of Yonsei University Severance Hospital.
Provenance and peer review Not commissioned; externally peer reviewed.