Cognitive disorders and parkinson's disease: a literature review

Parkinson's Disease (PD) is a movement disorder characterized by tremors, rigidity, and bradykinesia, accompanied by several non-motor symptoms, with cognitive impairment as one of the most debilitating. This narrative review of literature aims to provide a general overview on the defining features, pathologic changes, and management principles of cognitive changes in PD. A literature review was conducted by searching the terms "Cognition" OR "Cognitive Decline", AND "Parkinson's Disease" in PubMed, Scopus, and Google Scholar. Mild cognitive impairment (PD-MCI) and dementia (PDD) have been well-defined with consensus criteria. Recent researches have focused on pathophysiologic changes, identifying patterns of atrophy, as well as corresponding neurochemical insults. These have been primarily targeted in the existing pharmacologic literature, with evidence for non-pharmacologic therapies still lacking. Cognitive changes in PD range from a spectrum of mild cognitive impairment (PD-MCI) to dementia (PDD). Evidence exists for clinical and pathologic mechanisms which guide current and future therapeutic principles. Current trends of research are focused on the potential of discovering preventive therapies strengthens the need for more high-level evidence in the future.