Cardiovascular regulation in epilepsy with emphasis on the interictal state

Abstract Epilepsy is associated with changes in autonomic cardioregulatory function. Ictally, autonomic disturbances may be evident with significant changes in heart rate (HR), blood pressure (BP) and respiration. However, interictal dysfunction of autonomic cardiovascular system may be subtle and it may be recognized only by delicate tools designed for that purpose. The aim of this study was to evaluate the function of the cardiovascular autonomic regulatory system in patients with epilepsy. Cardiovascular reflex tests were performed on patients with partial or idiopathic generalized epilepsies. Special attention was paid to temporal lobe epilepsy (TLE). An association of refractory and well controlled TLE and hippocampal sclerosis with altered cardioregulation was evaluated by using cardiovascular reflex tests and an analysis of spectral and non-linear analysis of heart rate variation (HRV). Cardiovascular reflexes were altered both in patients with partial and idiopathic generalized epilepsies who had been treated for epilepsy with antiepileptic drugs (AEDs), whereas patients with newly, untreated epilepsy did not differ from the control subjects. Diminished cardiovascular reflexes also seemed to be associated with carbamazepine (CBZ) treatment. Various parameters of cardiovascular reflex tests and analysis of spectral and dynamic measures of HRV were diminished in patients with TLE compared to the control subejcts. These results indicate that epilepsy, especially TLE, is associated with interictal changes of autonomic cardioregulation. Although these changes seem to be evident in patients with severe form of TLE, patients with well controlled TLE and patients without hippocampal sclerosis also have altered autonomic cardioregulatory function. These results suggest that dysfunction of the cardioregulatory system is rather associated with functional than structural changes of the inner temporal lobe in patients with TLE