title: Pulmonary function in patients with Huntington's disease.
abstract: BACKGROUND
  Huntington's disease (HD) is a neurodegenerative disorder characterized by progressive motor, cognitive and psychiatric disturbances. Chest muscle rigidity, respiratory muscle weakness, difficulty in clearing airway secretions and swallowing abnormalities have been described in patients with neurodegenerative disorders including HD. However limited information is available regarding respiratory function in HD patients. The purpose of this study was to investigate pulmonary function of patients with HD in comparison to healthy volunteers, and its association with motor severity.
  
  
  METHODS
  Pulmonary function measures were taken from 18 (11 male, 7 female) manifest HD patients (53 ± 10 years), and 18 (10 male, 8 female) healthy volunteers (52 ± 11 years) with similar anthropometric and life-style characteristics to the recruited HD patients. Motor severity was quantified by the Unified Huntington's Disease Rating Scale-Total Motor Score (UHDRS-TMS). Maximum respiratory pressure was measured on 3 separate days with a week interval to assess test-retest reliability.
  
  
  RESULTS
  The test-retest reliability of maximum inspiratory and expiratory pressure measurements was acceptable for both HD patient and control groups (ICC ≥0.92), but the values over 3 days were more variable in the HD group (CV < 11.1%) than in the control group (CV < 7.6%). The HD group showed lower respiratory pressure, forced vital capacity, peak expiratory flow and maximum voluntary ventilation than the control group (p < 0.05). Forced vital capacity, maximum voluntary ventilation and maximum respiratory pressures were negatively (r = -0.57; -0.71) correlated with the UHDRS-TMS (p < 0.05).
  
  
  CONCLUSIONS
  Pulmonary function is decreased in manifest HD patients, and the magnitude of the decrease is associated with motor severity.
authors.affiliation: School of Medical Sciences Edith Cowan University, 270 Joondalup Drive, Joondalup, 6027, WA, Australia. a.reyes@ecu.edu.au.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Reyes
authors.forename: Travis
authors.initials: T
authors.lastname: Cruickshank
authors.forename: Mel
authors.initials: M
authors.lastname: Ziman
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nosaka
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D011597:Psychomotor Performance; D012016:Reference Values; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index; D013147:Spirometry / Q000379:methods*; D014797:Vital Capacity