title: Mild cognitive impairment and cognitive-motor relationships in newly diagnosed drug-naive patients with Parkinson's disease.
abstract: OBJECTIVE
  (1) To establish the prevalence of mild cognitive impairment (MCI) in newly diagnosed drug-naive patients with Parkinson's disease adopting recently proposed and more conservative preliminary research criteria. (2) To investigate the relation between cognitive performances, MCI and motor dysfunction.
  
  
  METHODS
  132 consecutive newly diagnosed drug-naive PD patients and 100 healthy controls (HCs) underwent a neuropsychological evaluation covering different cognitive domains. Moreover, on the basis of the Unified Parkinson's Disease Rating Scale II/III, different motor scores were calculated and patients were classified in motor subtypes. 11 patients were excluded from the analysis during clinical follow-up which was continued at least 3 years from the diagnosis; therefore, the final sample included 121 patients.
  
  
  RESULTS
  MCI prevalence was higher in PD (14.8%) patients than in HCs (7.0%). PD patients reported lower cognitive performances than HCs in several cognitive domains; HCs also outperformed cognitively preserved PD patients in tasks of episodic verbal memory and in a screening task of executive functions. MCI-PD patients presented a more severe bradykinesia score than non-MCI PD patients and patients mainly characterised by tremor had better performances in some cognitive domains, and specific cognitive-motor relationships emerged.
  
  
  CONCLUSIONS
  Although the adoption of more conservative diagnostic criteria identified a lower MCI prevalence, we found evidence that newly diagnosed drug-naive PD patients present a higher risk of MCI in comparison with HCs. Axial symptoms and bradykinesia represent risk factors for MCI in PD patients and a classification of PD patients that highlights the presence/absence of tremor, as proposed in this study, is probably better tailored for the early stages of PD than classifications proposed for more advanced PD stages.
authors.affiliation: Department of Neuroscience, University of Pisa, Pisa I56125, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Poletti
authors.forename: Daniela
authors.initials: D
authors.lastname: Frosini
authors.forename: Cristina
authors.initials: C
authors.lastname: Pagni
authors.forename: Filippo
authors.initials: F
authors.lastname: Baldacci
authors.forename: Valentina
authors.initials: V
authors.lastname: Nicoletti
authors.forename: Gloria
authors.initials: G
authors.lastname: Tognoni
authors.forename: Claudio
authors.initials: C
authors.lastname: Lucetti
authors.forename: Paolo
authors.initials: P
authors.lastname: Del Dotto
authors.forename: Roberto
authors.initials: R
authors.lastname: Ceravolo
authors.forename: Ubaldo
authors.initials: U
authors.lastname: Bonuccelli
mesh_terms: D000368:Aged; D060825:Cognitive Dysfunction / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D056344:Executive Function; D005260:Female; D006801:Humans; D018476:Hypokinesia / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D007558:Italy / Q000453:epidemiology; D008297:Male; D061212:Memory, Episodic; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D015995:Prevalence; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D014202:Tremor / Q000150:complications / Q000175:diagnosis / Q000523:psychology*