Parkinson’s Disease: Clinical Profile and Social Cognition

Social cognition is defined as a set of cognitive and emotional abilities which people use predominantly in social situations. Thus, it may be described as the array of mental processes involved in perceiving, remembering and processing information about social interactions. These processes enable us to understand oneself and others, control oneself and interact with others. A wide array of abilities is involved in social cognition, such as cognitive and affective Theory of Mind (ToM), empathy, and emotion regulation. Human social interaction relies on the ability to recognise and identify social cues as well as emotional cues such as facial expressions and prosody. Social cognition deficits have been tied to poor social competence, interpersonal functioning and communication. Parkinson’s disease (PD) is a progressive neurodegenerative disease associated mainly with the degeneration of dopamine neurons in the substantia nigra pars compacta. The pattern of degeneration starts from the dorsal striatum and then extends further to ventral parts when the disease progresses. In recent years a gradual modification of the definition of PD has been established, from a classical movement disorder to a multi-system neurodegenerative disease. Similarly the focus has shifted from motor symptoms to include a range of disabling non-motor symptoms such as sleep disturbances, cognitive decline, neuropsychiatric symptoms and autonomic dysfunction. Although highly disabling and impactful on quality of life, non-motor symptoms have only recently become the focus of medical treatment. Some studies have pointed out the existence of impairments of some social cognitive abilities in patients with PD. These studies have examined the relationship between dopaminergic pathways, social cognitive skills and cognitive decline with a particular emphasis on executive functioning. The results, although still not fully consistent, point to a dysfunction of some social cognitive skills. Given the impact of social cognition on the quality of life of patients with PD and possible implications in the course of treatment, the aim of the present work is to examine evidence on impairment of social cognition in patients with PD.