Study of cardiac autonomic function in drug‐naïve, newly diagnosed epilepsy patients

Abstract

Background. Epilepsy is associated with ictal autonomic dysfunction which may extend into the inter-ictal period. Antiepileptic drugs have often been blamed for cardiac autonomic dysfunction in epilepsy patients. In this study we have investigated cardiac autonomic parameters in order to evaluate autonomic functions of drug-naïve epilepsy patients. Method. Twenty drugnaïve patients (15 males and 5 females) with epilepsy, and an equal number of age and gender matched controls, were evaluated for short-term resting heart rate variability and conventional cardiovascular autonomic measurements. Results. The mean age of patients was 29.30 ± 9.80 yrs (17-55 yrs), mean age at seizure onset was 19.70 ± 9.15 yrs (3-40 yrs) and mean length of time since last seizure was 5.60 ± 7.00 days (1-30 days). While there was no difference in the resting heart rate or conventional autonomic test parameters, time domain heart rate variability measurements showed a decreased percentage of R-R intervals of less than 50 ms and root mean square of R-R intervals in patients, when compared to controls. Frequency domain parameters showed a decreased total power (patients: 1,796.58 ± 1,052.45 ms 2 ; controls: 2,934.23 ± 1,767.06 ms 2 , p = 0.008). Parameters indicative of decreased vagal tone, i.e. decreased high frequency power and increased low to high frequency ratio (patients: 1.69 ± 0.94; controls: 1.14 ± 0.64, p = 0.045), were observed among patients compared to controls. Conclusion. Subtle but definite cardiac autonomic dysfunction, especially in vagal tone, was identified in drug-naïve, new-onset epilepsy patients. Seizures can cause long-term and often progressive cardiac autonomic dysfunction which may be independent of concomitant antiepileptic drugs.

Autonomic function in reflex and non-reflex epilepsy - an exploratory study

“…Evrengul et al (3) showed increase in the sympathetic control of the heart rate in newly diagnosed GTCS. From this center in another study, subtle cardiac autonomic dysfunction especially reduced vagal tone in patients with GTCS (22). Devinsky et al (2) found abnormal BP changes for autonomic tests in patients with CPS, which might indicate impaired baroreflex functions.…”

Heart rate variability measurement in epilepsy: How can we move from research to clinical practice?

“…In adults with generalized epilepsy, the overall evidence indicates that HRV is also abnormal. Findings indicating an interictal shift toward sympathetic dominance have been reported for adult patients with juvenile myoclonic epilepsy and epilepsy with generalized tonic–clonic seizures; however, the degree of derangement tends to be milder than that observed with TLE. One study of a relatively small cohort of patients with drug‐naive genetic generalized epilepsy did not find statistically significant differences in HRV when compared to controls …”

Epilepsy: Indian perspective

“…[65] In another study at this center on drug-naïve new-onset 20 patients with epilepsy, subtle but definite cardiac autonomic dysfunction, especially in vagal tone, was identified. [66] Practice of yoga might have a role as an adjuvant therapy in the management of autonomic dysfunction in patients with refractory epilepsy. [67]…”