title: Autonomic Dysfunction in Patients with Mild to Moderate Alzheimer's Disease.
abstract: BACKGROUND
  Autonomic function has received little attention in Alzheimer's disease (AD). AD pathology has an impact on brain regions which are important for central autonomic control, but it is unclear if AD is associated with disturbance of autonomic function.
  
  
  OBJECTIVE
  To investigate autonomic function using standardized techniques in patients with AD and healthy age-matched controls.
  
  
  METHODS
  Thirty-three patients with mild to moderate AD and 30 age- and gender-matched healthy controls, without symptoms of autonomic dysfunction, underwent standardized autonomic testing with deep breathing, Valsalva maneuver, head-up tilt, and isometric handgrip test. Brachial pressure curve and electrocardiogram were recorded for off-line analysis of blood pressure and beat-to-beat heart rate (HR).
  
  
  RESULTS
  AD patients had impaired blood pressure responses to Vasalva maneuver (p < 0.0001) and HR response to isometric contraction (p = 0.0001). A modified composite autonomic scoring scale showed greater degree of autonomic impairment in patients compared to controls (patient: 2.1 ± 1.6; controls: 0.9 ± 1.1, p = 0.001). HR response to deep breathing and Valsalva ratio were similar in the two groups.
  
  
  CONCLUSIONS
  We identified autonomic impairment ranging from mild to severe in patients with mild to moderate AD, who did not report autonomic symptoms. Autonomic impairment was mainly related to impairment of sympathetic function and evident by impaired blood pressure response to the Vasalva maneuver. The clinical implications of this finding are that AD may be associated with autonomic disturbances, but patients with AD may rarely report symptoms of autonomic dysfunction. Future research should systematically evaluate symptoms of autonomic function and characterize risk factors associated with autonomic dysfunction.
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Christina
authors.initials: C
authors.lastname: Jensen-Dahm
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Gunhild
authors.initials: G
authors.lastname: Waldemar
authors.affiliation: Danish Pain Research Center, Department of Neurology, Aarhus University Hospital, Denmark.
authors.forename: Troels
authors.initials: T
authors.lastname: Staehelin Jensen
authors.affiliation: Department of Clinical Neurophysiology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Lasse
authors.initials: L
authors.lastname: Malmqvist
authors.affiliation: Department of Clinical Neurophysiology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Michelle Mai
authors.initials: MM
authors.lastname: Moeller
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Birgitte Bo
authors.initials: BB
authors.lastname: Andersen
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Høgh
authors.affiliation: Department of Clinical Neurophysiology, Rigshospitalet, University of Copenhagen, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Ballegaard
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D001916:Brachial Artery / Q000503:physiopathology; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008609:Mental Status Schedule; D012720:Severity of Illness Index; D014636:Valsalva Maneuver / Q000502:physiology
keywords: Alzheimer’s disease; Valsalva maneuver; autonomic function; orthostatic hypotension; tilt test