title: Autonomic dysfunction according to disease progression in Parkinson's disease.
abstract: BACKGROUND
  Although autonomic dysfunction is common in patients with Parkinson's disease (PD), few data are available regarding its pattern and quantitative severity with increasing Hoehn and Yahr (H&Y) stage. We conducted autonomic function tests to quantify autonomic dysfunction in PD patients and to elucidate its possible relationship with disease progression.
  
  
  METHODS
  We performed autonomic function tests including Valsalva ratio, heart rate response to deep breathing, quantitative sudomotor axon reflex test, and head-up tilt test in 66 patients with PD. We compared clinical characteristics and results of autonomic function tests between stages, and correlated the proportion of abnormal patients in each test with their H&Y stage. In addition, logistic regression analyses were conducted to examine the contribution of increasing H&Y stage to impairments of each domain of the autonomic nervous system.
  
  
  RESULTS
  We found that PD patients with higher disease stage tended to have impairments in cardiovagal and sudomotor domains of the autonomic nervous system. Cardiovagal function was the domain most influenced by disease progression. Our findings also demonstrated that the pattern of sudomotor impairment in PD was similar to that in patients with peripheral autonomic neuropathy.
  
  
  CONCLUSIONS
  Our study demonstrates that autonomic dysfunction is not only common in early stage PD but it increases in severity with increasing disease stage. Given that the patterns of sudomotor impairments in PD are similar to those in peripheral neuropathy, our data support a previous hypothesis that pathophysiology of PD involves both the central and peripheral nervous systems.
authors.affiliation: Department of Neurology, Korea University Medical Center, Korea University College of Medicine, #126-1, Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, Republic of Korea.
authors.forename: Jung Bin
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Department of Neurology, Korea University Medical Center, Korea University College of Medicine, #126-1, Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, Republic of Korea.
authors.forename: Byung-Jo
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Korea University Medical Center, Korea University College of Medicine, #126-1, Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, Republic of Korea.
authors.forename: Seong-Beom
authors.initials: SB
authors.lastname: Koh
authors.affiliation: Department of Neurology, Korea University Medical Center, Korea University College of Medicine, #126-1, Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, Republic of Korea. Electronic address: neuro_kim@naver.com.
authors.forename: Kun-Woo
authors.initials: KW
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology*; D012720:Severity of Illness Index
keywords: Autonomic dysfunction; Hoehn & Yahr stage; Parkinson’s disease; Severity