Nonmotor Symptoms in Parkinson Disease: A Descriptive Review on Social Cognition Ability.

Parkinson disease (PD) is a neurodegenerative disorder characterized by motor and nonmotor symptoms. Nonmotor symptoms include cognitive deficits and impairment in emotions recognition ability associated with loss of dopaminergic neurons in the substantia nigra and with alteration in frontostriatal circuits. In this review, we analyzed the studies on social cognition ability in patients with PD. We searched on PubMed and Web of Science databases and screening references of included studied and review articles for additional citations. From initial 260 articles, only 18 met search criteria. A total of 496 patients were compared with 514 health controls, through 16 different tests that assessed some subcomponents of social cognition, such as theory of mind, decision-making, and emotional face recognition. Studies on cognitive function in patients with PD have focused on executive function. Patients with PD showed impairment in social cognition from the earliest stages of disease. This ability seems to not be significantly associated with other cognitive functions.