Effects of phytocannabinoids on heart rate variability and blood pressure variability in female post-concussion syndrome patients: case series.

Cannabidiol (CBD) can exert neuroprotective effects without being intoxicating, and in combination with Δ9-tetrahydrocannabinol (THC) CBD has shown to protect against THC psychosis. Acute concussion and post-concussion syndrome (PCS) can result in autonomic dysfunction in heart rate variability (HRV), but less information is available on blood pressure variability (BPV). Furthermore, the effects of phytocannabinoids on HRV and BPV in PCS are unknown. The purpose of this study was to observe the influence of daily administration of CBD or a combination of CBD and THC on HRV and BPV parameters in four female PCS participants. Participants completed a seated 5-min rest followed by six breaths-per-minute paced breathing protocol. Data was collected prior to phytocannabinoid intake and continued over 54 to 70 days. High frequency systolic BPV parameter increased every assessment period, unless altered due to external circumstances and symptoms. HRV parameters showed less consistent and varying responses. These results suggest that CBD can help to improve the altered autonomic dysfunction in those with PCS, and that responses to the drug administration was individualized. Double blinded, randomized controlled trials with greater sample sizes are required to better understand the influences of the varying dosages on human physiology and in PCS.

Autonomic Dysfunction and Neurohormonal Disorders in Atrial Fibrillation.

Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia and eludes an efficacious cure despite an increasing prevalence and a significant association with morbidity and mortality. In addition to an array of clinical sequelae, the origins and propagation of AF are multifactorial. In recent years, the contribution from the autonomic nervous system has been an area of particular interest. This review highlights the relevant physiology of autonomic and neurohormonal contributions to AF origin and maintenance, the current state of the literature on targeted therapies, and the path forward for clinical interventions.

Gqα/G11α deficiency in dorsomedial hypothalamus leads to obesity resulting from decreased energy expenditure and impaired sympathetic nerve activity.

The G-protein subunits Gqα and G11α (Gq/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of Gq/11α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of Gq/11α (DMHGq/11KO) were generated by stereotaxic injection of adeno-associated virus (AAV)-Cre-green fluorescent protein (GFP) into the DMH of Gqαflox/flox:G11α-/- mice. Compared with control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22°C), DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT uncoupling protein 1 (Ucp1) gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6°C for 5 h) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30°C). Thus our results show that Gqα and G11α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.NEW & NOTEWORTHY This paper demonstrates that signaling within the dorsomedial hypothalamus via the G proteins Gqα and G11α, which couple cell surface receptors to the stimulation of phospholipase C, is critical for regulation of energy expenditure, thermoregulation by brown adipose tissue and the induction of white adipose tissue browning.

Impaired orthostatic heart rate recovery is associated with smaller thalamic volume: Results from The Irish Longitudinal Study on Aging (TILDA).

The thalamus is a central hub of the autonomic network and thalamic volume has been associated with high-risk phenotypes for sudden cardiac death. Heart rate response to physiological stressors (e.g., standing) and the associated recovery patterns provide reliable indicators of both autonomic function and cardiovascular risk. Here we examine if thalamic volume may be a risk marker for impaired heart rate recovery in response to orthostatic challenge. The Irish Longitudinal Study on Aging involves a nationally representative sample of older individuals aged ≥50 years. Multimodal brain magnetic resonance imaging and orthostatic heart rate recovery were available for a cross-sectional sample of 430 participants. Multivariable regression and linear mixed-effects models were adjusted for head size, age, sex, education, body mass index, blood pressure, history of cardiovascular diseases and events, cardiovascular medication, diabetes mellitus, smoking, alcohol intake, timed up-and-go (a measure of physical frailty), physical exercise and depression. Smaller thalamic volume was associated with slower heart rate recovery (-1.4 bpm per 1 cm3 thalamic volume, 95% CI -2.01 to -0.82; p < .001). In multivariable analysis, participants with smaller thalamic volumes had a mean heart rate recovery -2.7 bpm slower than participants with larger thalamic volumes (95% CI -3.89 to -1.61; p < .001). Covariates associated with smaller thalamic volume included age, history of diabetes, and heavy alcohol consumption. Thalamic volume may be an indicator of the structural integrity of the central autonomic network. It may be a clinical biomarker for stratification of individuals at risk of autonomic dysfunction, cardiovascular events, and sudden cardiac death.

Hyperoxia improves autonomic function in individuals with long-duration type 1 diabetes and macroalbuminuria.

AIM: Acute oxygen inhalation and slow deep breathing improve measures of autonomic function transiently in individuals with short-duration type 1 diabetes. Our aims were to examine these interventions and changes in autonomic function in individuals with long-duration type 1 diabetes and to explore interactions with the presence of macroalbuminuria or existing cardiovascular autonomic neuropathy. METHODS: Individuals with type 1 diabetes (n = 54) were exposed to acute oxygen inhalation, slow deep breathing and a combination of both (hereafter 'the combination'). Primary outcomes were change in baroreflex sensitivity and heart rate variability. Associations between changes in outcomes were evaluated using mixed effects models. RESULTS: Mean age ± sd was 60 ± 10 years and diabetes duration was 38 ± 14 years. Changes are presented as per cent difference from baseline with 95% confidence intervals. Acute oxygen inhalation, slow deep breathing and the combination increased baroreflex sensitivity by 21 (10, 34)%, 32 (13, 53)% and 30 (10, 54)%, respectively. Acute oxygen inhalation trended towards increasing heart rate variability 8 (-1, 17)% (P = 0.056), and slow deep breathing and the combination increased heart rate variability by 33 (18, 49)% and 44 (27, 64)% respectively. Macroalbuminuria or cardiovascular autonomic neuropathy did not modify results. CONCLUSION: Autonomic function is improved transiently in individuals with long-duration type 1 diabetes and normoalbuminuria or macroalbuminuria by acute oxygen inhalation and slow deep breathing. There is a risk of survival bias. Autonomic dysfunction might be a reversible condition, and hypoxia might represent a target of intervention.

[A study of the functions of the autonomic nervous system in socially active people in conditions of meteo-climatic maladaptation]. / Otsenka funktsii vegetativnoi nervnoi sistemy u sotsial'no aktivnykh lits v usloviiakh meteoklimaticheskoi dizadaptatsii.

AIM: To develop the algorithm of prognosis and prevention of climatic maladaptation in healthy young people with peculiarities of the autonomic nervous system (VNS) during off-season and treatment the identified disturbances with reflexotherapy. MATERIAL AND METHODS: VNS functions were assessed in load conditions in 145 people in the beginning and in the end of a rest at the Black Sea coast. The Vein's questionnaire, active orthoclinostatic test (AOT), and heart rate variability (HRV) analysis and ECG recording were used. Spielberger-Khanin test was administered to assess anxiety. Autonomic disorders caused by climatic maladaptation were treated with reflexotherapy. RESULTS: AOT has shown VNS dysfunctions in 67.7% of subjects, HRV analysis in 54.3%, and the Vein questionnaire in 96.55%. There was no significant difference between the results of AOT and HRV analysis, while the Vein questionnaire results exceeded them both (Pearson χ2, p<0.05), being 1,4 times greater than the HRV analysis result. This higher percentage is explained by the high level of subjects' trait anxiety. CONCLUSION: The practical value of the Vein questionnaire for the diagnosis, choice and assessment of treatment is confirmed.

[Vascular dysfunction in Cardiorenal Syndrome type 4].

The Cardiorenal Syndrome type 4 (CRS-4) defines a pathological condition in which a primary chronic kidney disease (CKD) leads to a chronic impairment of cardiac function. The pathophysiology of CRS-4 and the role of arterial stiffness remain only in part understood. Several uremic toxins, such as uric acid, phosphates, advanced glycation end-products, asymmetric dimethylarginine, and endothelin-1, are also vascular toxins. Their effect on the arterial wall may be direct or mediated by chronic inflammation and oxidative stress. Uremic toxins lead to endothelial dysfunction, intima-media thickening and arterial stiffening. In patients with CRS-4, the increased aortic stiffness results in an increase of cardiac workload and left ventricular hypertrophy whereas the loss of elasticity results in decreased coronary artery perfusion pressure during diastole and increased risk of myocardial infarction. Since the reduction of arterial stiffness is associated with an increased survival in patients with CKD, the understanding of the mechanisms that lead to arterial stiffening in patients with CRS4 may be useful to select potential approaches to improve their outcome. In this review we aim at discussing current understanding of the pathways that link uremic toxins, arterial stiffening and impaired cardiac function in patients with CRS-4.

Harlequin Syndrome in Acute Thalamic Hemorrhage.

Harlequin syndrome is a disorder of the autonomic nervous system. It clinically presents as a distinct line of hemifacial sympathetic denervation. We describe a case of Harlequin syndrome with co-existing central first-order Horner syndrome in the setting of a large thalamic hemorrhage with intraventricular extension.

Fatal familial insomnia and Agrypnia Excitata: Autonomic dysfunctions and pathophysiological implications.

Fatal Familial Insomnia (FFI) is a hereditary prion disease caused by a mutation at codon 178 of the prion-protein gene leading to a D178N substitution in the protein determining severe and selective atrophy of mediodorsal and anteroventral thalamic nuclei. FFI is characterized by physiological sleep loss, which polygraphically appears to be a slow wave sleep loss, autonomic and motor hyperactivation with peculiar episodes of oneiric stupor. Alteration of autonomic functions is a great burden for FFI patients consisting in sympathetic overactivation, dysregulation of its physiological responses and disruption of circadian rhythms. The cardiovascular system is the most frequently and severely affected confirming the increased sympathetic drive with preserved parasympathetic responses. Sleep loss, autonomic and motor hyperactivation define Agrypnia Excitata (AE), which is not exclusive to FFI, but it has been canonically described also in Morvan Syndrome and Delirium Tremens. These three conditions present different pathophysiological mechanisms but share the same thalamo-limbic impairment of which AE is one of the possible clinical presentations. FFI, and consequently also AE, is a model for the investigation of the essential role of the thalamus in the organization of body homeostasis, integrating both sleep and autonomic function control.

Percutaneous mastoid electrical stimulator alleviates autonomic dysfunction in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Poststroke prognosis is associated with autonomic status. The purpose of our study was to determine whether percutaneous mastoid electrical stimulator (PMES) can alleviate abnormal heart rate variability (HRV) and improve clinical outcome. METHODS: This prospective, randomized, double-blinded, placebo-controlled study enrolled a total of 140 patients with autonomic dysfunction within 3d after acute ischemic stroke. The patients were treated with PMES or sham stimulation once daily over a period of 2 weeks. HRV was primarily assessed by the fractal dimension (FD) at admission and 2 weeks. All patients were followed up for 3 months. The clinical outcome was death and major disability (modified Rankin Scale score≥ 3) at 3 months after acute ischemic stroke. RESULTS: FD of the 2-week treatment period increased in PMES groups. PMES can significantly alleviate abnormal HRV. The difference in FD of the 2-week treatment period between the PMES and sham groups was significant (1.14 ± 0.27 vs. 1.00 ± 0.23; P = 0.001). In fully adjusted models, PMES was associated with reduced 3-month mortality (adjusted odds ratio, 0.32; 95% confidence interval, 0.11-0.93; P = 0.036). No significant group differences were seen in three major disability and composite outcome (P > 0.05). CONCLUSIONS: PMES was a safe, effective, and low-cost therapy to alleviate HRV and could significantly reduce mortality in the early recovery phase after acute ischemic stroke.

Phosphodiesterase 2A as a therapeutic target to restore cardiac neurotransmission during sympathetic hyperactivity.

Elevated levels of brain natriuretic peptide (BNP) are regarded as an early compensatory response to cardiac myocyte hypertrophy, although exogenously administered BNP shows poor clinical efficacy in heart failure and hypertension. We tested whether phosphodiesterase 2A (PDE2A), which regulates the action of BNP-activated cyclic guanosine monophosphate (cGMP), was directly involved in modulating Ca2+ handling from stellate ganglia (SG) neurons and cardiac norepinephrine (NE) release in rats and humans with an enhanced sympathetic phenotype. SG were also isolated from patients with sympathetic hyperactivity and healthy donor patients. PDE2A activity of the SG was greater in both spontaneously hypertensive rats (SHRs) and patients compared with their respective controls, whereas PDE2A mRNA was only high in SHR SG. BNP significantly reduced the magnitude of the calcium transients and ICaN in normal Wistar Kyoto (WKY) SG neurons, but not in the SHRs. cGMP levels stimulated by BNP were also attenuated in SHR SG neurons. Overexpression of PDE2A in WKY neurons recapitulated the calcium phenotype seen in SHR neurons. Functionally, BNP significantly reduced [3H]-NE release in the WKY rats, but not in the SHRs. Blockade of overexpressed PDE2A with Bay 60-7550 or overexpression of catalytically inactive PDE2A reestablished the modulatory action of BNP in SHR SG neurons. This suggests that PDE2A may be a key target in modulating the action of BNP to reduce sympathetic hyperactivity.

Mechanisms underpinning sympathetic nervous activity and its modulation using transcutaneous vagus nerve stimulation.

NEW FINDINGS: What is the topic of this review? This review briefly considers what modulates sympathetic nerve activity and how it may change as we age or in pathological conditions. It then focuses on transcutaneous vagus nerve stimulation, a method of neuromodulation in autonomic cardiovascular control. What advances does it highlight? The review considers the pathways involved in eliciting the changes in autonomic balance seen with transcutaneous vagus nerve stimulation in relationship to other neuromodulatory techniques. The autonomic nervous system, consisting of the sympathetic and parasympathetic branches, is a major contributor to the maintenance of cardiovascular variables within homeostatic limits. As we age or in certain pathological conditions, the balance between the two branches changes such that sympathetic activity is more dominant, and this change in dominance is negatively correlated with prognosis in conditions such as heart failure. We have shown that non-invasive stimulation of the tragus of the ear increases parasympathetic activity and reduces sympathetic activity and that the extent of this effect is correlated with the baseline cardiovascular parameters of different subjects. The effects could be attributable to activation of the afferent branch of the vagus and, potentially, other sensory nerves in that region. This indicates that tragus stimulation may be a viable treatment in disorders where autonomic activity to the heart is compromised.

Hypothalamic Glucose Transport in Humans During Experimentally Induced Hypoglycemia-Associated Autonomic Failure.

Context: Upregulated brain glucose transport in response to recurrent hypoglycemia may contribute to the development of hypoglycemia-associated autonomic failure (HAAF) and impaired awareness of hypoglycemia. Whether recurrent hypoglycemia alters glucose transport in the hypothalamus is unknown. Objective: To test the hypothesis that hypothalamic glucose transport will increase in healthy volunteers preconditioned with recurrent hypoglycemia to induce HAAF. Setting: University medical center. Design and Participants: Thirteen healthy subjects underwent paired euglycemic and hypoglycemic preconditioning studies separated by at least 1 month. Following preconditioning, hypothalamic glucose transport was measured by magnetic resonance spectroscopy (MRS) in the afternoon on day 2 of each preconditioning protocol. Outcome Measure: The ratio of maximal transport rate to cerebral metabolic rate of glucose (Tmax/CMRglc), obtained from MRS-measured glucose in the hypothalamus as a function of plasma glucose. Results: HAAF was successfully induced based on lower epinephrine, glucagon, and cortisol during the third vs first hypoglycemic preconditioning clamp (P ≤ 0.01). Hypothalamic glucose transport was not different following recurrent euglycemia vs hypoglycemia (Tmax/CMRglc 1.62 ± 0.09 after euglycemia preconditioning and 1.75 ± 0.14 after hypoglycemia preconditioning; P was not significant). Hypothalamic glucose concentrations measured by MRS were not different following the two preconditioning protocols. Conclusions: Glucose transport kinetics in the hypothalamus of healthy humans with experimentally induced HAAF were not different from those measured without HAAF. Future studies of patients with diabetes and impaired awareness of hypoglycemia will be necessary to determine if the existence of the diabetes state is required for this adaptation to hypoglycemia to occur.

Palliative Care and Nonmotor Symptoms in Parkinson's Disease and Parkinsonism.

The term palliative care (PC) is defined as a collection of interventions and strategies that helps to improve and sustain the quality of life of patients and caregivers in situations and scenarios associated with life-threatening illness. This is usually implemented by means of early identification and treatment of relevant motor and nonmotor issues such as pain, sleep, and autonomic dysfunction, dementia, and depression. In addition, a holistic PC program also includes delivery of physical, psychosocial, and spiritual support. PC as a specific discipline, as well as a treatment strategy for long-term neurological conditions such as Parkinson's disease (PD), is relatively new, but very important as neurodegenerative disorders in the United Kingdom alone affects approximately 10 million people and there are over 130,000 people with PD. With longer life expectancy, the burden of long duration and late stage PD is even more evident, bringing in focus the need for PC. However, the concept of PC in PD is still poorly defined and although there are pockets of excellence, the strategy is poorly implemented into routine clinical practice. The variable progressive nature of the disease, the heterogeneity of clinical subtypes, and also the burden of nonmotor symptoms create challenges for effective PC delivery in PD, but recent clinical trials have started addressing PC in PD and are to be welcomed.

The Nonmotor Features of Parkinson's Disease.

Nonmotor symptoms (NMS) of Parkinson's disease (PD) were recognized by the great James Parkinson himself who mentioned symptoms such as sleep dysfunction, delirium, dementia, and dysautonomia, in his seminal 1817 essay, "An Essay on the Shaking Palsy" (Parkinson, 1817). In spite of the key impact of PD NMS on quality of life, there was little holistic research and awareness till the validation and use of comprehensive tools such as the NMS questionnaire, scale, and the revised version of the unified PD rating scale. Research studies using these tools highlighted the key impact of the burden of NMS on quality of life of PD patients and the need for NMS to be routinely assessed in clinic. We now define PD as a motor and nonmotor disorder, and the natural history includes a long prodromal phase of PD dominated by a range of NMS. The prodromal phase is the subject of much research particularly in relation to neuroprotection and identifying subjects at risk. Use of NMS tools has also validated burden grading of NMS with cutoff values, which can be used as outcome measure in clinical trials. Finally, the complex multineurotransmitter dysfunction that is seen in PD has been shown to manifest clinically as nonmotor subtypes. Recognition of such subtypes is likely to lead to the emergence of personalized and precision medicine in PD.

High and low vitamin D level is associated with cardiovascular autonomic neuropathy in people with Type 1 and Type 2 diabetes.

AIM: To investigate the possible association between vitamin D deficiency and cardiovascular autonomic neuropathy in people with diabetes. METHODS: A total of 113 people with Type 1 or Type 2 diabetes [mean (interquartile range) diabetes duration 22.0 (12-31) years, mean (sd) age 56.2 (13.0) years, 58% men] underwent vitamin D (D2 and D3) assessment, and were screened for cardiovascular autonomic neuropathy using three cardiovascular reflex tests [heart rate response to deep breathing (E/I ratio), to standing (30/15 ratio) and to the Valsalva manoeuvre] and assessment of 5-min resting heart rate and heart rate variability indices. RESULTS: We found an inverse U-shaped association between serum vitamin D level and E/I ratio, 30/15 ratio and three heart rate variability indices (P < 0.05). Vitamin D level was non-linearly associated with cardiovascular autonomic neuropathy diagnosis (P < 0.05 adjusted for age and sex). Linear regression models showed that an increase in vitamin D level from 25 to 50 nmol/l was associated with an increase of 3.9% (95% CI 0.1;7.9) in E/I ratio and 4.8% (95% CI 4.7;9.3) in 30/15 ratio. Conversely, an increase from 125 to 150 nmol/l in vitamin D level was associated with a decrease of 2.6% (95% CI -5.8;0.1) and 4.1% (95% CI -5.8;-0.5) in the respective outcome measures. CONCLUSIONS: High and low vitamin D levels were associated with cardiovascular autonomic neuropathy in people with diabetes. Future studies should explore this association and the efficacy of treating dysvitaminosis D to prevent cardiovascular autonomic neuropathy.

Trajectories of response to acupuncture for menopausal vasomotor symptoms: the Acupuncture in Menopause study.

OBJECTIVE: To examine the trajectories of responses to acupuncture treatment for menopausal vasomotor symptoms (VMS) and the characteristics of women in each trajectory. METHODS: Two hundred nine perimenopausal and postmenopausal women aged 45 to 60 years experiencing at least four VMS per day were recruited and randomized to receive up to 20 acupuncture treatments within 6 months or to a waitlist control group. The primary outcome was percent change from baseline in the mean daily VMS frequency. Finite mixture modeling was used to identify patterns of percent change in weekly VMS frequencies over the first 8 weeks. The Freeman-Holton test and analysis of variance were used to compare characteristics of women in different trajectories. RESULTS: Analyses revealed four distinct trajectories of change in VMS frequency by week 8 in the acupuncture group. A small group of women (11.6%, n = 19) had an 85% reduction in VMS. The largest group (47%, n = 79) reported a 47% reduction in VMS frequency, 37.3% (n = 65) of the sample showed only a 9.6% reduction in VMS frequency, and a very small group (4.1%, n = 7) had a 100% increase in VMS. Among women in the waitlist control group, 79.5% reported a 10% decrease in VMS frequency at week 8. Baseline number of VMS, number of acupuncture treatments in the first 8 weeks, and traditional Chinese medicine diagnosis were significantly related to trajectory group membership in the acupuncture group. CONCLUSIONS: Approximately half of the treated sample reported a decline in VMS frequency, but identifying clear predictors of clinical response to acupuncture treatment of menopausal VMS remains challenging.

Ginkgo biloba L. extract protects against chronic cerebral hypoperfusion by modulating neuroinflammation and the cholinergic system.

BACKGROUND: Ginkgo biloba extract (GBE)-a widely used nutraceutical-is reported to have diverse functions, including positive effects on memory and vasodilatory properties. Although numerous studies have assessed the neuroprotective properties of GBE in ischemia, only a few studies have investigated the neuro-pharmacological mechanisms of action of GBE in chronic cerebral hypoperfusion (CCH). PURPOSE: In the present study, we sought to determine the effects of GBE on CCH-induced neuroinflammation and cholinergic dysfunction in a rat model of bilateral common carotid artery occlusion (BCCAo). METHODS: Chronic BCCAo was induced in adult male Wistar rats to reflect the CCH conditions. On day 21 after BCCAo, the animals were treated orally with saline or GBE (5, 10, 20, and 40mg/kg) daily for 42 days. After the final treatment, brain tissues were isolated for the immunohistochemical analysis of glial markers and choline acetyltransferase (ChAT), as well as for the western blot analysis of proinflammatory cytokines, toll-like receptor (TLR)-related pathway, receptor for advanced glycation end products (RAGE), angiotensin-II (Ang-II), and phosphorylated mitogen-activated protein kinases (MAPKs). RESULTS: BCCAo increased glial proliferation in the hippocampus and white matter, whereas proliferation was significantly attenuated by GBE treatment. GBE also attenuated the BCCAo-related increases in the hippocampal expression of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6), TLR4, myeloid differentiation primary response gene 88, RAGE, Ang-II, and phosphorylated MAPKs (ERK, p38, and JNK). Furthermore, GBE treatment restored the ChAT expression in the basal forebrain following BCCAo. CONCLUSIONS: These findings suggest that GBE has specific neuroprotective effects that may be useful for the treatment of CCH. The pharmacological mechanism of GBE partly involves the modulation of inflammatory mediators and the cholinergic system.