Objective: To identify areas of regional volume loss in structural brain images relating to poorer visual function and risk of dementia in Parkinson’s Disease (PD).

Background: Dementia affects 50% of people with PD within 10 years of diagnosis. No robust measures to identify patients at high risk exist. We have previously shown that visuo-perceptual deficits are linked with cognitive involvement in PD1. Conventional techniques to measure cortical atrophy are insensitive in PD. We examined visuo-perceptual measures alongside a newly described technique for measuring cortical volumes, namely Geodesical Information Flows (GIF). We relate these scores to risk of dementia in PD. Using these techniques, we expected PD patients at high risk of dementia to have poorer vision scores and atrophy within occipital and posterior parietal regions.

Method: In our study 109 PD patients and 37 age-matched controls were included. Participants underwent detailed neuropsychology, visuo-perceptual measures (e.g., cats and dogs task1), assessment of PD (MDS-UPDRS), and T1 structural MRI scans. Risk of cognitive involvement was calculated using a clinical algorithm (combining age at onset, MMSE, education, motor score, gender, depression)2. GIF analysis parcellated T1 images tissue segmentation techniques employing probabilistic features3, creating regions of interest to investigate whether cortical atrophy differs between high and low dementia risk PD patients and healthy controls.

Results: Age did not differ between PD patients (64.3±7.8 years) and controls (66.1±9.4 years). 52 people with PD were assigned as low risk, based on a median split of the risk score2, and 57 were high risk. Average disease duration was 4.1±2.5 years and did not differ between high and low risk patients. There was no difference in gender, motor, sleep or olfaction scores or levodopa dose between patients that were high versus low-risk for developing dementia. Region atrophy measures from GIF analysis, focusing on posterior parietal and occipital regions, in PD patients at high and low risk of dementia as well as those who had good and poor visual function will be presented.

Conclusion: Visual testing including visuo-perception and atrophy measures via GIF analysis may have potential to identify patients at risk of dementia in PD. This is important for future stratification of patients at risk of dementia onto tailored treatment programs.

References: 1. Weil, R.S, Schwarzkopf D.S., … et al. (2018). Assessing cognitive dysfunction in Parkinson’s disease: An online tool to detect visuo-perceptual deficits. Movement Disorders, 33, 544-553. DOI: 10.1002/mds.27311 2. Liu, G., Locascio, J. J., Corvol, J.-C., Boot, B., Liao, Z., Page, K., … et al. (2017). Prediction of cognition in Parkinson’s disease with a clinical-genetic score: a longitudinal analysis of nine cohorts. The Lancet Neurology, 16, 620–629. DOI:10.1016/S1474-4422(17)30122-9. 3. Cardoso, M. J., Modat, M., Wolz, R., Melbourne, A., Cash, D., … et al. (2015). Geodesic Information Flows: Spatially-Variant Graphs and Their Application to Segmentation and Fusion. IEEE Transactions on Medical Imaging, 34, 1976-1988. DOI: 10.1109/TMI.2015.2418298

« Back to 2019 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/using-brain-atrophy-and-visual-dysfunction-to-predict-dementia-in-parkinsons-disease/