Electrocardiographic changes at the onset of epileptic seizures.
OBJECTIVE
We studied heart-rate (HR) changes at the transition from the preictal to the ictal state in patients with focal epilepsies to gain some insight into the mechanisms involved in the neuronal regulation of cardiovascular function.


METHODS
We assessed ECG changes during 145 seizures recorded with scalp EEG in 58 patients who underwent video-EEG monitoring. Consecutive RR intervals were analyzed with a newly developed mathematical method for a total of 90 s.


RESULTS
Ictal-onset tachycardia occurred in 86.9% of all seizures, whereas bradycardia was documented only in 1.4%. The incidence as well as the amount of ictal HR increase was significantly more pronounced in patients with mesial temporal lobe epilepsy (TLE) as compared with those with non-lesional TLE or extratemporal epilepsy. Moreover, right hemispheric seizures were associated with ictal-onset tachycardia. On average, ictal HR increase preceded EEG seizure onset by 13.7 s in TLE patients and 8.2 s in patients with extratemporal epilepsy. This difference was significant. Ictal HR changes could be classified according to their temporal evolution into two different patterns. These two patterns differed significantly between the temporal lobe and the extratemporal epilepsy patient group.


CONCLUSIONS
Epileptic discharges directly influence areas of the central autonomic network, thus regulating HR and rhythm. Such changes occur before ictal discharges appear on surface electrodes. Our newly developed method may be of potential use for clinical applications such as automatic seizure-detection systems. Moreover, our method might help to clarify further the basic mechanisms of interactions between heart and brain.
Leutmezer
Fritz
F
Neurologische Universitätsklinik Wien, Vienna, Austria.
Schernthaner
Christiana
C
Lurger
Stefanie
S
Pötzelberger
Klaus
K
Baumgartner
Christoph
C
D001341:Autonomic Nervous System / Q000503:physiopathology*; D001919:Bradycardia / Q000175:diagnosis* / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D004569:Electroencephalography / Q000706:statistics & numerical data; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000503:physiopathology*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology; D007839:Functional Laterality / Q000502:physiology; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008433:Mathematics; D008955:Models, Cardiovascular; D008959:Models, Neurological; D009434:Neural Pathways / Q000503:physiopathology; D012189:Retrospective Studies; D013610:Tachycardia / Q000175:diagnosis* / Q000503:physiopathology; D014743:Videotape Recording