Biomarkers for cognitive impairment in Parkinson disease

In advanced stages of Parkinson’s disease, cognitive impairment, including dementia, is a common symptom. Pathologically it correlates with the presence of biomarkers such as protein aggregates, including cortical Lewy bodies and also neurofibrillary tangles and amyloid plaques. However, more biomarkers are needed to predict cognitive impairment in advanced Parkinson’s disease and to monitor responses of patients to therapeutic intervention. A few clinical assessments, together with structural and functional neuroimaging, have been employed to identify such biomarkers, and candidate proteins in the cerebrospinal fluid or blood are being targeted. Interesting results are also expected from high throughput genomic, proteomic and metabolomic screening. Current findings and perspectives on the application of these strategies and techniques, as well as future advancements, are discussed within this article.