Autonomic Dysfunction after Mild Traumatic Brain Injury

Abstract

A mild traumatic brain injury (mTBI) is a complex pathophysiologic process that has a systemic effect on the body aside from solely an impairment in cognitive function. Dysfunction of the autonomic nervous system (ANS) has been found to induce abnormalities in organ systems throughout the body, and may contribute to cardiovascular dysregulation and increased mortality. Autonomic dysfunction, also known as dysautonomia, has been studied in moderate and severe TBI, and has emerged as a major contributing factor in the symptomatology in mTBI as well. Analysis of the ANS has been studied through changes in heart rate variability (HRV), pupillary dynamics, eye pressure, and arterial pulse wave in those with mild TBI. Graded exercise testing has been studied as both a method of diagnosis and as a means of recovery in those with mild TBI, especially in those with persistent symptoms. Given the studies showing persistence of autonomic dysfunction after symptomatic resolution of concussions, further research is needed to establish return to play protocols

Symptoms of Autonomic Dysfunction Among Those With Persistent Posttraumatic Headache Attributed to Mild Traumatic Brain Injury: A Comparison to Migraine and Healthy Controls

“…Although not specifically studies of PTH, prior studies have identified symptoms of dysautonomia among those with TBI . Studies of autonomic dysfunction following mTBI have assessed heart rate variability, pupillary light reflex, arterial pulse wave, and graded exercise testing .…”

“…Although not specifically studies of PTH, prior studies have identified symptoms of dysautonomia among those with TBI. 22,28,46 Studies of autonomic dysfunction following mTBI have assessed heart rate variability, 19 pupillary light reflex, arterial pulse wave, and graded exercise testing. 26,27,35 One such study showed head-upright tilt table abnormalities similar to postural orthostatic tachycardia syndrome (POTS) in youth with persistent post-concussion syndrome.…”

“…Investigations that deeply phenotype individuals with PTH and compare the PTH phenotype to migraine might lead to identification of features that are more representative of PTH compared to migraine. Based on our clinical observations and published literature demonstrating evidence for autonomic dysfunction following mild traumatic brain injury (mTBI) and in those with migraine, we hypothesized that PTH is often accompanied by autonomic symptoms such as orthostatic intolerance, and that symptoms of autonomic dysfunction are more severe among those with PTH compared to those with migraine …”

“…Based on our clinical observations and published literature demonstrating evidence for autonomic dysfunction following mild traumatic brain injury (mTBI) and in those with migraine, we hypothesized that PTH is often accompanied by autonomic symptoms such as orthostatic intolerance, and that symptoms of autonomic dysfunction are more severe among those with PTH compared to those with migraine. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The objective of this study was to compare symptoms of autonomic dysfunction between individuals with persistent posttraumatic headaches (PPTH) attributed to mTBI vs those with migraine vs healthy controls using the Composite Autonomic Symptom Score 31 (COMPASS-31) questionnaire. [38][39][40] We also interrogated correlations between COMPASS-31 scores and headache characteristics (headache days per month and years with headache) to investigate the association between headache burden and autonomic dysfunction in the PPTH and migraine groups and correlations between lifetime number of TBIs and COMPASS-31 scores among those with PPTH.…”

American‐Style Football and Cardiovascular Health

“…As a primary example, the association between pathologic central nervous system processes as a consequence of repetitive head trauma and cardiovascular pathology is a compelling but speculative realm in need of testing. To date, among ASF athletes, the acute and long‐term effects of postconcussive autonomic dysregulation80 and sympathetic nervous system overstimulation on cardiovascular parameters have not been explored. A second intriguing unknown worthy of study is the impact of NSAID use on both cardiovascular and renal physiology.…”