Science News: Autonomic Function Tests, Heart Rate Variability, and Electrophysiological Evaluation in Patients With a Primary Episodic Headache: An Observational Study

Published May 24, 2024

Science News

Submitted by: Eman Tawfik, MD

Edited by: Rebecca O'Bryan, MD

Citation: Qavi A, Jasrotia RB, Maurya PK, et al. Autonomic function tests, heart rate variability, and electrophysiological evaluation in patients with a primary episodic headache: An observational study. J Clin Neurophysiol. 2023;40(7):625-633. doi:10.1097/WNP.0000000000000943

Summary: The basic postulated mechanism of headache involves the activation of the trigeminovascular system and sensitization of trigeminal brainstem nuclei. However, autonomic nervous system dysfunction has been reported in various headache disorders and proposed as one of the mechanisms that may trigger the headache attacks.

This cross-sectional study aimed to evaluate the parasympathetic and sympathetic autonomic functions in patients with migraine and tension-type headache. During the period from June 2018 to June 2020, the authors enrolled 100 patients in the age group of 14-50 years who have episodic migraine and episodic tension-type headache according to the International Classification of Headache Disorder third edition beta. They excluded patients with systemic illness such as DM, HTN, hypothyroidism and patients with previous cranial neuropathy, Bell palsy, facial trauma, and leprosy. The study also included 50 healthy age- and sex-matched controls.

Electrophysiological and autonomic function tests were performed in all patients during headache-free periods at least 7 days after headache to avoid the effect on ictal and postdromal sympathovagal tone. At the time of the tests, the patients were off from any prophylactic drugs for two or more weeks and were also not taking any abortive/acute treatment of headache on the day of the test. Electrophysiological tests included blink Reflex and sympathetic skin response (SSR). Parasympathetic function tests included heart rate responses to deep breathing, to Valsalva maneuver, and to standing. The sympathetic function tests included blood pressure responses to the sustained handgrip test and to standing. Based on these 5 autonomic tests, the patients were classified into normal, early, definite, severe, and atypical according to the Ewing Classification of Autonomic Failure.

Parasympathetic and sympathetic dysfunction was found in the patients group. Significant difference in blood pressure response to sustained handgrip and heart rate response to Valsalva maneuver was found in patients with migraine. Significant difference in blood pressure response to sustained handgrip and heart rate variability was found in patients with a tension-type headache. The blink reflex test and SSR were normal, but the latency of the SSR was significantly prolonged in patients compared to the controls. Patients with migraine showed a significant dysautonomia in category three of the Ewing battery for autonomic functional disability.

Comments: The study adds to our understanding of the autonomic changes that may occur in patients with episodic primary headache (migraine and tension-type headache). It included many patients and assessed both sympathetic and parasympathetic functions. However, the authors did not assess the patients during the attack which did not allow the study of the effect of treatment on autonomic dysfunction and the relation between the severity of autonomic dysfunction and headache severity. Episodic primary headache is very common worldwide. It impacts the patient’s quality of life and imposes a financial load on the health care system. Understanding the underlying mechanisms may help the physicians better treat the patients. 

Articles of Similar Interest:

1. Azam MA, Katz J, Mohabir V, Ritvo P. Individuals with tension and migraine headaches exhibit increased heart rate variability during post-stress mindfulness meditation practice but a decrease during a post-stress control condition - A randomized, controlled experiment. Int J Psychophysiol. 2016;110:66-74. doi:10.1016/j.ijpsycho.2016.10.011

2. Miglis MG. Migraine and Autonomic Dysfunction: Which Is the Horse and Which Is the Jockey?. Curr Pain Headache Rep. 2018;22(3):19. Published 2018 Feb 23. doi:10.1007/s11916-018-0671-y