Features of cognitive impairment in Parkinson's disease (review)

Background. Cognitive impairment in Parkinson's disease (PD) is characterized by significant heterogeneity of symptoms and affects the quality of life of patients and caregivers, as well as increases the financial burden on the healthcare system. As the disease progresses at later stages, cognitive impairment can become the determining factor in the clinical picture, and often doctors initiate specific treatment only at a late stage, when dementia has already developed. This determines the relevance of early diagnosis of cognitive impairment, recognition of their specificity in various forms of PD and dictates the need to search for informative biomarkers that should facilitate the identification of cognitive decline at the initial clinical stage and even in its latent phase, since the earliest possible initiation of treatment will delay the development of dementia. The objective of the review is to systematize the literature on the features of cognitive impairment in Parkinson's disease. Materials and Methods. The analysis of modern Russian and foreign scientific publications devoted to the features of cognitive impairment in Parkinson's disease, published over the past 10 years, was carried out. Scientometric databases (PubMed, eLibrary, Google Scholar) were used to search for literary sources. Results and Discussion. The article presents current concepts of the epidemiology, etiology, pathogenesis, classifications, risk factors and clinical manifestations of cognitive impairment in Parkinson's disease. Currently, this raises a number of questions, such as the lack of uniform standards for assessing cognitive impairment in Parkinson's disease, the biological basis of cognitive impairment, and the impact of affective disorders on them. It is emphasized that a multidisciplinary approach that allows comparing clinical data with the neuropsychological profile of patients and neuroimaging data seems to be the most promising for obtaining answers to open questions about the early diagnosis of cognitive impairment in Parkinson's disease. Conclusion. Despite the long history of research, many of the issues discussed remain unresolved, which requires further scientific and practical development.