title: Clinical phenotype of drug-naïve Parkinson's disease based on nonmotor symptoms.
abstract: BACKGROUND
  Nonmotor symptoms in Parkinson's disease (PD) are heterogeneous and can result in a variety of symptoms at various disease stages. The objective of the present study was to identify clinically meaningful nonmotor symptoms and to assess the relationship between changes in nonmotor symptoms and cognition and motor symptoms.
  
  
  METHODS
  A total of 159 patients who had drug-naïve PD participated in this study. Nonmotor symptoms (Nonmotor Symptoms Scale), PD status (Unified Parkinson's Disease Rating Scale), depression (Geriatric Depression Scale or Montgomery-Asberg Depression Scale) and health-related quality of life (39-item Parkinson's Disease Questionnaire) were assessed. An exploratory factor analysis was performed to establish a nonmotor symptom factor, which was analyzed to evaluate whether the results were associated with the clinical severity measures.
  
  
  RESULTS
  Exploratory factor analysis revealed one factor comprised of sleep/fatigue, attention/memory and mood/cognition. The modified Hoehn and Yahr Stage, Unified Parkinson's Disease Rating Scale Part III, Montgomery-Asberg Depression Scale and the 39-item Parkinson's Disease Questionnaire Summary Index were independently associated with the sleep/fatigue, attention/memory and mood/cognition domains. The presence of these domains was associated with advanced Parkinson's disease or depressed mood.
  
  
  CONCLUSIONS
  This study shows that motor impairment and depressed mood in PD are related to sleep/fatigue, attention/memory and mood/cognition. Sleep/fatigue, attention/memory and mood/cognition also had a major impact on health-related quality of life. It is appropriate to identify patients with severe motor symptoms and depressed mood in order to signify the need to consider more detailed care and further assessment.
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea.
authors.forename: Hye Mi
authors.initials: HM
authors.lastname: Lee
authors.affiliation: Department of Information Statistics, Kangwon National University College of Natural Sciences, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do 200-701, Republic of Korea.
authors.forename: Seung-Soo
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea.
authors.forename: Minjik
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Kang
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea.
authors.forename: Woo-Keun
authors.initials: WK
authors.lastname: Seo
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Neurology and Parkinson's disease Centre, Korea University College of Medicine at Guro Hospital, 148 Gurodong-Road, Guro-Ku, Seoul 152-703, Republic of Korea. Electronic address: parkinson@korea.ac.kr.
authors.forename: Seong-Beom
authors.initials: SB
authors.lastname: Koh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology; D003863:Depression / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D003866:Depressive Disorder / Q000150:complications*; D005221:Fatigue / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology*; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life / Q000523:psychology*; D056910:Republic of Korea; D012720:Severity of Illness Index; D012890:Sleep; D011795:Surveys and Questionnaires
keywords: Attention; Exploratory factor analysis; Mood; Nonmotor symptoms; Parkinson’s disease; Sleep