title: Impairments in social cognition in early medicated and unmedicated Parkinson disease.
abstract: BACKGROUND
  Theory of mind (ToM) refers to the ability to infer others' mental states, including intentions and feelings, and is considered to be a critical part of social cognition. Earlier studies in individuals with Parkinson disease (PD) have shown ToM deficits in the more advanced stages of the disease. There is currently no evidence of social cognition deficits in patients in the early stages of PD.
  
  
  METHODS
  In this study, we compared patients with early PD (n=36) and a control group of healthy subjects (n=36). Patients were assessed with 2 ToM tasks designed to differentially detect subtle deficits in the affective and cognitive aspects of ToM. Patients were also assessed with a complete neuropsychologic battery which included classic executive tests aimed at investigating the relationship between ToM and executive functions. Performance of medicated (n=16) and unmedicated (n=20) patients was also compared.
  
  
  RESULTS
  Our results are the first to indicate that ToM is affected in the early stages of PD. As has already been reported in more advanced stages of PD, such deficits seem to be related to the cognitive aspects of this domain. In our study, these deficits were not related with performance on executive functioning, depression, or medication usage.
  
  
  CONCLUSIONS
  These results provide evidence for ToM impairments early in the course of PD. Recognition of ToM impairments in early PD is important, as these deficits may impact patients' social interactions and quality of life.
authors.affiliation: Department of Neuropsychology, Institute of Cognitive Neurology (INECO) , Favaloro University, Buenos Aires, Argentina.
authors.forename: María
authors.initials: M
authors.lastname: Roca
authors.forename: Teresa
authors.initials: T
authors.lastname: Torralva
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Gleichgerrcht
authors.forename: Anabel
authors.initials: A
authors.lastname: Chade
authors.forename: Gonzalo Gómez
authors.initials: GG
authors.lastname: Arévalo
authors.forename: Oscar
authors.initials: O
authors.lastname: Gershanik
authors.forename: Facundo
authors.initials: F
authors.lastname: Manes
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D000978:Antiparkinson Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D003071:Cognition; D018450:Disease Progression; D056344:Executive Function; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D016555:Matched-Pair Analysis; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy / Q000523:psychology*; D012016:Reference Values; D012938:Social Perception; D018709:Statistics, Nonparametric; D056345:Theory of Mind; D013997:Time Factors
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa