title: Rightward dominance in temporal high-frequency electrical asymmetry corresponds to higher resting heart rate and lower baroreflex sensitivity in a heterogeneous population.
abstract: OBJECTIVE
  Explore potential use of a temporal lobe electrical asymmetry score to discriminate between sympathetic and parasympathetic tendencies in autonomic cardiovascular regulation.
  
  
  METHODS
  131 individuals (82 women, mean age 43.1, range 13-83) with diverse clinical conditions completed inventories for depressive (CES-D or BDI-II) and insomnia-related (ISI) symptomatology, and underwent five-minute recordings of heart rate and blood pressure, allowing calculation of heart rate variability and baroreflex sensitivity (BRS), followed by one-minute, two-channel, eyes-closed scalp recordings of brain electrical activity. A temporal lobe high-frequency (23-36 Hz) electrical asymmetry score was calculated for each subject by subtracting the average amplitude in the left temporal region from amplitude in the right temporal region, and dividing by the lesser of the two.
  
  
  RESULTS
  Depressive and insomnia-related symptomatology exceeding clinical threshold levels were reported by 48% and 50% of subjects, respectively. Using a cutoff value of 5% or greater to define temporal high-frequency asymmetry, subjects with leftward compared to rightward asymmetry were more likely to report use of a sedative-hypnotic medication (42% vs. 22%, P = 0.02). Among subjects with asymmetry of 5% or greater to 30% or greater, those with rightward compared to leftward temporal high-frequency asymmetry had higher resting heart rate (≥5% asymmetry, 72.3 vs. 63.8, P = 0.004; ≥10%, 71.5 vs. 63.0, P = 0.01; ≥20%, 72.2 vs. 64.2, P = 0.05; ≥30%, 71.4 vs. 64.6, P = 0.05). Subjects with larger degrees of rightward compared to leftward temporal high-frequency asymmetry had lower baroreflex sensitivity (≥40% asymmetry, 10.6 vs. 16.4, P = 0.03; ≥50% asymmetry, 10.4 vs. 16.7, P = 0.05).
  
  
  CONCLUSIONS
  In a heterogeneous population, individuals with rightward compared to leftward temporal high-frequency electrical asymmetry had higher resting heart rate and lower BRS. Two-channel recording of brain electrical activity from bilateral temporal regions appears to hold promise for further investigation as a means to assess cortical activity associated with autonomic cardiovascular regulation.
authors.affiliation: Department of Neurology, Wake Forest School of Medicine (WFSM) Winston-Salem, North Carolina.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Tegeler
authors.affiliation: Hypertension and Vascular Research Center, Department of Obstetrics and Gynecology, WFSM Winston-Salem, North Carolina.
authors.forename: Hossam A
authors.initials: HA
authors.lastname: Shaltout
authors.affiliation: Department of Neurology, Wake Forest School of Medicine (WFSM) Winston-Salem, North Carolina.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Tegeler
authors.affiliation: Brain State Technologies, LLC Scottsdale, Arizona.
authors.forename: Lee
authors.initials: L
authors.lastname: Gerdes
authors.affiliation: Brain State Technologies, LLC Scottsdale, Arizona.
authors.forename: Sung W
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D003863:Depression / Q000175:diagnosis / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009482:Neurophysiology / Q000379:methods; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000503:physiopathology; D013702:Temporal Lobe / Q000503:physiopathology*
keywords: Autonomic nervous system; RDoC; heart rate variability; hemispheric asymmetry; neurotechnology; temporal lobe