Per Borghammer, March 2017

Up to 80% of PD patients eventually become demented, but the reasons are incompletely understood. At later disease stages, most PD patients display so called Lewy pathology in cortical neurons, but the presence of Lewy pathology correlates poorly with clinical dementia. Several studies have shown that the presence of Alzheimer-type pathology in the brains of PD patients shows a clearer association with clinical dementia.

New PET radio-ligands with affinity for pathological tau-protein (main constituent of neuro-fibrillary tangles in Alzheimer’s disease) have recently been invented (Figure 2). Using these ligands, we are currently studying whether the presence of pathological tau-protein in the brains of PD patients is a better predictor of future cognitive decline. If this is shown to be the case, tau-PET scans could be used for clinical trials to monitor effects of neuroprotective treatments aimed at clearing the pathological tau-protein from the brains of PD patients.

Figure 2. The accumulation of pathological tau-protein is evidenced by yellow-red colours in a patient with early Alzheimer’s disease. (Image courtesy of Peter Parbo and professor David Brooks.)