title: Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation.
abstract: OBJECTIVE
  To compare heart rate variability (HRV) parameters in newly diagnosed and untreated temporal lobe epilepsy (TLE) between the interictal, preictal, ictal, and postictal states.
  
  
  METHODS
  HRV parameters were extracted from single-lead electrocardiography data collected during video-electroencephalography (EEG) recordings from 14 patients with newly diagnosed TLE in a resting, awake, and supine state. HRV parameters in the time and frequency domains included low frequency (LF), high frequency (HF), standard deviation of all consecutive R wave intervals (SDNN), and square root of the mean of the sum of the squares of differences between adjacent R wave intervals (RMSSD). Cardiovagal index (CVI), cardiosympathetic index (CSI), and approximate entropy (ApEn) were also studied.
  
  
  RESULTS
  Frequency domain analysis showed significantly higher preictal, ictal, and postictal LF/HF ratio compared to the interictal state. Similarly, the LF component increased progressively and was significantly higher during the ictal state compared to interictal and preictal states. RR interval values were lower in the ictal state compared to basal and preictal states and in the postictal state compared to the preictal state. Interictal RMSSD was significantly higher compared to all other states, and ictal SDNN was significantly higher compared to all other states. Ictal CSI was significantly higher compared to preictal and interictal states, whereas preictal CVI was lower than in basal and ictal states. In addition, ictal ApEn was significantly lower than interictal and preictal ApEn. Interictal CVI was lower in left TLE compared to right TLE. In addition, in left TLE, ictal CVI was higher than interictal CVI, whereas in right TLE, CVI was lower in the preictal state compared to all other states.
  
  
  CONCLUSIONS
  Our data suggest an ictal sympathetic overdrive with partial recovery in the postictal state. Higher sympathetic tone and vagal tone imbalance may induce early autonomic dysfunction and increase cardiovascular risk in patients affected by TLE.
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.|IRCCS Neuromed Sleep Medicine Centre, Pozzilli, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Romigi
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.|IRCCS Neuromed Sleep Medicine Centre, Pozzilli, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Albanese
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Placidi
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Izzi
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.|Santa Lucia Foundation, Rome, Italy.
authors.forename: Nicola B
authors.initials: NB
authors.lastname: Mercuri
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Marchi
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Liguori
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Campagna
authors.affiliation: Department of Biomedicine and Prevention, Medical Physics Section, University of Rome "Tor Vergata,", Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Duggento
authors.affiliation: Department of Biomedicine and Prevention, Medical Physics Section, University of Rome "Tor Vergata,", Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Canichella
authors.affiliation: Department of Systems Medicine, Neurophysiopathology Unit, Sleep Medicine Centre, Tor Vergata University and Hospital, Rome, Italy.
authors.forename: Giada
authors.initials: G
authors.lastname: Ricciardo Rizzo
authors.affiliation: Department of Biomedicine and Prevention, Medical Physics Section, University of Rome "Tor Vergata,", Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Guerrisi
authors.affiliation: Department of Neuroscience, "Tor Vergata," University, Rome, Italy.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Marciani
authors.affiliation: Department of Biomedicine and Prevention, Medical Physics Section, University of Rome "Tor Vergata,", Rome, Italy.|Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, U.S.A.|Harvard Medical School, Boston, Massachusetts, U.S.A.
authors.forename: Nicola
authors.initials: N
authors.lastname: Toschi
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
keywords: Autonomic nervous system; Heart rate variability; Temporal lobe epilepsy