title: Respiratory and autonomic dysfunction in children with autism spectrum disorders.
abstract: BACKGROUND
  Cardiac parasympathetic hypofunction has been reported in autism spectrum disorders (ASD). This usually is linked to respiratory dysrhythmia which has been documented in some children with ASD.
  
  
  OBJECTIVE
  This study evaluated the cardiorespiratory functions in ASD to elucidate the physiologic basis of behaviors.
  
  
  METHODS
  Nineteen children with ASD and 18 age matched controls underwent autonomic function monitoring at a defined resting state using the NeuroScope. The non-invasive real time beat-to-beat blood pressure was measured by Portapres and fed into the NeuroScope where heart rate, cardiac vagal tone and cardiac sensitivity to baroreceptor were derived from the EKG and blood pressure waveforms using the Vagosoft software; and respiratory rate and rhythm were measured simultaneously by plethysmograph. Respiration was analyzed breath by breath using our prior published methods.
  
  
  RESULTS
  Various respiratory dysrhythmias, particularly Biot's and Cheyne-Stokes respiration, were detected in children with ASD, who also exhibited greater variability in respiratory rhythm and amplitudes than controls. The respiratory dysrhythmia in children with ASD was associated with a lower cardiac vagal activity.
  
  
  CONCLUSIONS
  The Biot's breathing and Cheyne-Stokes respiration coupled with cardiac vagal hypofunction in ASD suggest a brainstem dysfunction consistent with our previous findings. The low parasympathetic activity could explain in part the chronic sensory hyperarousal state in children with ASD.
authors.affiliation: Department of Neurosciences and Neurology, New Jersey Medical School, Rutgers University, USA; New Jersey Neuroscience Institute, Sleep Medicine Center, JFK Medical Center, Seton Hall University, USA. Electronic address: mingxu@rutgers.edu.
authors.forename: Xue
authors.initials: X
authors.lastname: Ming
authors.affiliation: Pennsylvania State College of Medicine, USA.
authors.forename: Ritesh
authors.initials: R
authors.lastname: Patel
authors.affiliation: School of Arts and Sciences, Johns Hopkins University, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Kang
authors.affiliation: New Jersey Neuroscience Institute, Sleep Medicine Center, JFK Medical Center, Seton Hall University, USA.
authors.forename: Sudhansu
authors.initials: S
authors.lastname: Chokroverty
authors.affiliation: Division of Brain Sciences, Department of Medicine, Imperial College, UK; Swedish National Rett Center, Sweden; Department of Neuroscience, Breakspear Medical Group, UK.
authors.forename: Peter O
authors.initials: PO
authors.lastname: Julu
mesh_terms: D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D002639:Cheyne-Stokes Respiration / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D012119:Respiration; D012131:Respiratory Insufficiency / Q000503:physiopathology*
keywords: Autism spectrum disorders; Autonomic dysfunction; Biot’s breathing; Cheyne–Stokes respiration; Respiratory dysrhythmia