Autonomic dysfunction in reversible cerebral vasoconstriction syndromes

Abstract

BackgroundAutonomic imbalance may play an important role in the pathogenesis of reversible cerebral vasoconstriction syndromes (RCVS). This study aimed to assess the autonomic function by analyzing heart rate variability (HRV) in patients with RCVS.MethodsPatients with RCVS and age- and gender-matched controls were consecutively recruited. All patients (both ictal and remission stage) and controls underwent 24-hour ambulatory electrocardiographic (ECG) recordings. HRV measures covering time and frequency domains were used to assess autonomic functioning.ResultsThirty-nine patients with RCVS and 39 controls completed the study. Compared to the controls, RCVS patients during the ictal stage showed reductions in parasympathetic-related indices, including the root mean square of difference of consecutive interbeat intervals (RMSSD) (22.1 ± 7.0 vs. 35.2 ± 14.2, p < 0.001), the percentage of adjacent intervals that varied by more than 50 ms (pNN50) (3.7 ± 3.4 vs. 10.6 ± 8.1, p < 0.001), and high-frequency power (HF) (5.82 ± 0.73 vs. 6.77 ± 0.74; p < 0.001), and increased low-frequency/high-frequency (LF/HF) ratio (index of sympathovagal balance) (3.38 ± 1.32 vs. 2.48 ± 1.07; p =0.001). These HRV indices improved partially but remained significantly different from controls during remission.ConclusionsDecreased parasympathetic modulations and accentuated sympathetic activity might be a biological trait in patients with RCVS.

Influence of Climate on the Incidence of RCVS – A Retrospective Study From Taiwan

“…Although it is not known how weather variables, which are highly inter‐related, may influence the incidence or trigger the onset of RCVS, we hypothesized that associations between weather variables and the incidence of RCVS might be related to altered sympathetic tone. Previously, we documented sympathetic overactivity and parasympathetic hypofunction in patients with RCVS . We suspected that the sympathetic nervous system might be more excitable in cold weather in a manner that could aggravate a preexisting sympatho‐vagal imbalance and thus induce cerebral vasoconstriction.…”

“…[5][6][7][8][9][10][11][12][13] Patients with RCVS are at risk of severe complications including posterior reversible encephalopathy syndrome, ischemic stroke, and intracranial hemorrhage (including cortical subarachnoid, intracerebral, and subdural hemorrhage). [5][6][7][8][9][10]14 Sympathetic overactivity, 15 oxidative stress, 16 an impaired endothelial repair capacity, 17 and genetic predisposition 18 may contribute to the dysregulated vascular tone of cerebral arteries in RCVS, 4,19,20 though a definitive pathogenesis has not yet been delineated.…”

Blood–brain barrier breakdown in reversible cerebral vasoconstriction syndrome: Implications for pathophysiology and diagnosis

“…12,13 Clinical manifestations are valuable for making a diagnosis, but can also overlap with other disorders presenting with thunderclap headache. 1,3,5,6,[15][16][17][18] Among them, BBB breakdown can be visualized by contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) MRI. 14 Pathophysiology of RCVS has been postulated to comprise of sympathetic overactivity, dysregulation of vascular tone, and blood-brain barrier (BBB) breakdown.…”

Spectral Analyses of Heart Rate Variability by Acceleration Plethysmography for Diagnostic Support of Migraine: Clinical Research

“…Recently, spectral analyses of HRV were introduced in many areas [10,18,19]. It is supposed that the HF component of HRV reflects parasympathetic activity and the LF component represents sympathetic and parasympathetic activities [20]. In many studies, the LF/HF power ratio has been utilized as an index of sympathovagal balance [8,20].…”

“…It is supposed that the HF component of HRV reflects parasympathetic activity and the LF component represents sympathetic and parasympathetic activities [20]. In many studies, the LF/HF power ratio has been utilized as an index of sympathovagal balance [8,20]. Autonomic activities are usually influenced by the body's position.…”