Asymmetric hemispheric representation of periictal heart rate modulation is individually lateralised.

Asymmetric cortical representation of cardiac function is a matter of debate and large inter-individual variability of cortical autonomic networks and different study designs may contribute to this controversy. Lateralised seizure activity in individual patients may provide valuable insights into cortical regulation of cardiac function. We report two patients with focal epilepsy who had seizures arising from both hemispheres. In Patient 1, heart rate increased over two-fold with seizures arising from the right hemisphere, whereas heart rate increased invariably less with seizures arising from the left hemisphere. In Patient 2, heart rate increased 1.3 fold or less with seizures arising from the left hemisphere, whereas a seizure with right-sided onset was followed by bradycardia and asystole. Our findings support the notion that effects on autonomic function are lateralised, although lateralisation varies from patient to patient. This may partially explain the difficulty in determining cortical representation of cardiac autonomic function.