Cardiovascular autonomic function and baroreflex sensitivity in drug-resistant temporal lobe epilepsy

S B Athira; Pravati Pal; Pradeep P Nair; Nivedita Nanda; Rajeswari Aghoram

doi:10.1016/j.yebeh.2022.109013

Cardiovascular autonomic function and baroreflex sensitivity in drug-resistant temporal lobe epilepsy

Epilepsy Behav. 2023 Jan:138:109013. doi: 10.1016/j.yebeh.2022.109013. Epub 2022 Dec 14.

Authors

S B Athira¹, Pravati Pal², Pradeep P Nair³, Nivedita Nanda⁴, Rajeswari Aghoram⁵

Affiliations

¹ Department of Physiology, JPMER, Puducherry 605006, India. Electronic address: sreeharigowri@gmail.com.
² Department of Physiology, JPMER, Puducherry 605006, India. Electronic address: drpravatipal@gmail.com.
³ Department of Neurology, JPMER, Puducherry 605006, India. Electronic address: drpradeeppnair17@gmail.com.
⁴ Department of Biochemistry, JPMER, Puducherry 605006, India. Electronic address: drnnivedita@gmail.com.
⁵ Department of Neurology, JPMER, Puducherry 605006, India. Electronic address: rajeswari.a@gmail.com.

PMID: 36525923
DOI: 10.1016/j.yebeh.2022.109013

Abstract

Objective: Temporal lobe epilepsy (TLE) is often associated with autonomic manifestations. Sudden unexpected death in epilepsy (SUDEP) is a leading cause of mortality in epilepsy. Cardiac disturbances and autonomic dysfunction are the potential mechanisms behind SUDEP. Though heart rate variability (HRV) and autonomic function tests are well studied in drug-resistant temporal lobe epilepsy, there is a paucity of data on baroreflex sensitivity (BRS), a better marker of cardiac mortality in this population. We aimed to study the interictal cardiac autonomic function and BRS in people living with drug-resistant temporal lobe epilepsy compared to healthy controls.

Materials and methods: Thirty drug-resistant temporal lobe epilepsy (TLE) individuals and thirty healthy volunteers were recruited. Heart rate variability at rest, heart rate and blood pressure (BP) at rest, during deep breathing, postural change, BP response to isometric handgrip exercise, and baroreflex sensitivity were recorded in all study participants. The results were analyzed and compared between the two groups.

Results: Compared to controls, the resting heart rate, HRV, parasympathetic reactivity test, and BRS significantly differed in people living with drug-resistant TLE. Time-domain indices including SDNN (p < 0.001), RMSSD (p < 0.001), NN50 (p < 0.001), and pNN50 (p < 0.001) were significantly reduced in the patients compared to controls. In frequency-domain indices, the total power was reduced (p < 0.001) in drug-resistant TLE. The parasympathetic reactivity such as changes in heart rate during deep breathing (E: I) (p < 0.02) and postural change (30:15) (p < 0.005) were significantly reduced in the patients. Baroreflex sensitivity was also significantly reduced in the drug-resistant TLE group (p < 0.001).

Conclusion: The present study findings are suggestive of parasympathetic dysfunction in drug-resistant TLE. Reduced HRV and BRS may increase the risk of SUDEP in people living with epilepsy.

Keywords: Autonomic dysfunction; Baroreflex sensitivity; Heart rate variability; SUDEP.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Autonomic Nervous System
Baroreflex / physiology
Blood Pressure / physiology
Drug Resistant Epilepsy*
Epilepsy, Temporal Lobe* / complications
Hand Strength
Heart Rate / physiology
Humans
Sudden Unexpected Death in Epilepsy*