title: Static and dynamic autonomic response with increasing nausea perception.
abstract: BACKGROUND
  Nausea is a commonly occurring symptom typified by epigastric discomfort with urge to vomit. The relationship between autonomic nervous system (ANS) outflow and increasing nausea perception is not fully understood.
  
  
  METHODS
  Our study employed a nauseogenic visual stimulus (horizontally translating stripes) while 17 female subjects freely rated transitions in nausea level and autonomic outflow was measured (heart rate, HR; heart rate variability, HRV; skin conductance response, SCR; respiratory rate). We also adopted a recent approach to continuous high-frequency (HF) HRV estimation to evaluate dynamic cardiovagal modulation.
  
  
  RESULTS
  HR increased from baseline for all increasing nausea transitions, especially transition to strong nausea (15.0 +/- 11.4 bpm), but decreased (-6.6 +/- 4.6 bpm) once the visual stimulus ceased. SCR also increased for all increasing nausea transitions, especially transition to strong nausea (1.76 +/- 1.68 microS), but continued to increase (0.52 +/- 0.65 microS) once visual stimulation ceased. LF/HF HRV increased following transition to moderate (1.54 +/- 2.11 a.u.) and strong (2.57 +/- 3.49 a.u.) nausea, suggesting a sympathetic shift in sympathovagal balance. However, dynamic HF HRV suggested that bursts of cardiovagal modulation precede transitions to higher nausea, perhaps influencing subjects to rate higher levels of nausea. No significant change in respiration rate was found.
  
  
  CONCLUSIONS
  Our results suggest that increasing nausea perception is associated with both increased sympathetic and decreased parasympathetic ANS modulation. These findings corroborate past ANS studies of nausea, applying perception-linked analyses and dynamic estimation of cardiovagal modulation in response to nausea.
authors.affiliation: Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149 Thirteenth St., #2301, Charlestown, MA 02129, USA.
authors.forename: Lauren T
authors.initials: LT
authors.lastname: LaCount
authors.forename: Riccardo
authors.initials: R
authors.lastname: Barbieri
authors.forename: Kyungmo
authors.initials: K
authors.lastname: Park
authors.forename: Jieun
authors.initials: J
authors.lastname: Kim
authors.forename: Emery N
authors.initials: EN
authors.lastname: Brown
authors.forename: Braden
authors.initials: B
authors.lastname: Kuo
authors.forename: Vitaly
authors.initials: V
authors.lastname: Napadow
mesh_terms: D000328:Adult; D000465:Algorithms; D001341:Autonomic Nervous System / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response; D006339:Heart Rate; D006801:Humans; D009325:Nausea / Q000503:physiopathology*; D010275:Parasympathetic Nervous System / Q000502:physiology*; D056152:Respiratory Rate; D013026:Space Flight; D055815:Young Adult