title: Ictal heart rate increase precedes EEG discharge in drug-resistant mesial temporal lobe seizures.
abstract: OBJECTIVE
  Heart rate (HR) changes, mainly tachycardia, are often observed during seizures originating from the temporal lobe. The aim of this study was to analyze the role of ictal HR changes in localizing both mesial and lateral temporal lobe epilepsy (TLE) in a group of 68 patients. The influence of the gender and the side of epilepsy on HR modulation was also evaluated.
  
  
  METHODS
  Ictal HR was recorded during prolonged Video-EEG monitoring performed in 68 patients affected by drug-resistant TLE during a non-invasive pre-surgical protocol. According to the electro-clinical correlation, obtained by video-EEG monitoring, one hundred-thirteen seizures (n=113) and one hundred-forty-four auras (n=144) were identified and included in the study. Furthermore, the electro-clinical correlation allowed the classification of all the epileptic events (seizures and auras) as having mesial or lateral origin, based on the temporal lobe seizure onset zone. Ictal HR was calculated with respect to the R-R waves, and assessed from 15 sec (s) before (T(- 15)) to 15 s after (T(+15)) the time of EEG seizure onset (T(0)).
  
  
  RESULTS
  We observed a high incidence (92%) of ictal HR increase in TLE seizures. When the ictal EEG indicated a seizure onset from the mesial temporal structures, the onset of ictal HR increase preceded by about 5 s the EEG ictal onset (SD+/-18.4), whereas the onset of HR increase coincided with the onset of EEG discharges (SD+/-14.8) when the ictal EEG indicated the onset of seizures from the lateral temporal structures. No significant differences were found between male and female patients; and between right and left TLE.
  
  
  CONCLUSIONS
  Our findings show that ictal HR increase, preceding the onset of the EEG discharge, is associated with ictal EEG seizure pattern defining temporal lobe seizures originating from the mesial temporal lobe structures; this association suggests that the HR changes may be coupled to the functional impairment of neural circuits involved in sympathetic cardiovascular regulation, in the mesial temporal lobe structures. Further studies investigating the relationship between intracranial EEG monitoring and ECG recording are worthwhile, to confirm our results and to give further indications on the pathogenesis of ictal HR abnormalities.
authors.affiliation: Epilepsy Surgery Unit, IRCCS NEUROMED, Pozzilli (IS), Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Di Gennaro
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Quarato
authors.forename: Fabio
authors.initials: F
authors.lastname: Sebastiano
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Esposito
authors.forename: Paolo
authors.initials: P
authors.lastname: Onorati
authors.forename: Liliana G
authors.initials: LG
authors.lastname: Grammaldo
authors.forename: Giulio N
authors.initials: GN
authors.lastname: Meldolesi
authors.forename: Addolorata
authors.initials: A
authors.lastname: Mascia
authors.forename: Carolina
authors.initials: C
authors.lastname: Falco
authors.forename: Ciriaco
authors.initials: C
authors.lastname: Scoppetta
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Eusebi
authors.forename: Mario
authors.initials: M
authors.lastname: Manfredi
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Cantore
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D001931:Brain Mapping; D004351:Drug Resistance; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy* / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000927:Anticonvulsants