Autonomic dysfunction in multiple sclerosis is related to disease activity and progression of disability

Current understanding of cardiovascular autonomic dysfunction in multiple sclerosis

Autoimmune diseases, including multiple sclerosis (MS), are proven to increase the likelihood of developing cardiovascular disease (CVD) due to a robust systemic immune response and inflammation. MS can lead to cardiovascular abnormalities that are related to autonomic nervous system dysfunction by causing inflammatory lesions surrounding tracts of the autonomic nervous system in the brain and spinal cord. CVD in MS patients can affect an already damaged brain, thus worsening the disease course by causing brain atrophy and white matter disease. Currently, the true prevalence of cardiovascular dysfunction and associated death rates in patients with MS are mostly unknown and inconsistent. Treating vascular risk factors is recommended to improve the management of this disease. This review provides an updated summary of CVD prevalence in patients with MS, emphasizing the need for more preclinical studies using animal models to understand the pathogenesis of MS better. However, no distinct studies exist that explore the temporal effects and etiopathogenesis of immune/inflammatory cells on cardiac damage and dysfunction associated with MS, particularly in the cardiac myocardium. To this end, a thorough investigation into the clinical presentation and underlying mechanisms of CVD must be conducted in patients with MS and preclinical animal models. Additionally, clinicians should monitor for cardiovascular complications while prescribing medications to MS patients, as some MS drugs cause severe CVD.

Inverse association between arterial stiffness and perceived fatigue independent of disability status and BMI in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated, neurodegenerative disease of the central nervous system. Fatigue represents one of the most prevalent and limiting symptoms of MS, and is associated with vascular dysfunction, notably increased arterial stiffness.

OBJECTIVE

This study examined the relationship between arterial stiffness and perceived fatigue in persons with MS.

METHODS

The sample of 52 persons with MS (71.2% Female; Age: 46.7 ± 12.3 yrs.) completed arterial stiffness and fatigue assessments as baseline for an exercise training intervention. Applanation tonometry measured arterial stiffness, pulsatility and waveform characteristics, and yielded the following outcomes: carotid-femoral pulse wave velocity (cfPWV), carotid pulse-pressure (cPP), and aortic augmentation pressure (AP). Perceived fatigue was measured using the Fatigue Severity Scale (FSS).

RESULTS

The mean (SD) scores for cfPWV, cPP, and AP were 7.0 ± 1.8 m/s, 35.7 ± 8.8 mmHg, 8.2 ± 6.2 mmHg, respectively. The mean (SD) FSS score was 4.6 ± 1.4 and indicated elevated fatigue. There were statistically significant (p < .05) inverse correlations between cfPWV (r = -.32), cPP (r = -.37) and AP (r = -.32) with FSS scores, and the correlations remained significant even after controlling for disability, body mass index, age, and sex.

CONCLUSION

Our results indicate a consistent pattern of inverse relationships between arterial stiffness, pulsatility, and waveforms with fatigue independent of disability, body mass index, age, and sex in MS. This could be explained by lower sympathetic activation linking higher arterial stiffness, pulsatility and augmentation pressure with lower fatigue in persons with MS.

Health, Wellness, and the Effect of Comorbidities on the Multiple Sclerosis Disease Course: Tackling the Modifiable

Multiple sclerosis (MS) is a disease of the central nervous system characterized by inflammatory demyelination and neurodegeneration. Numerous disease-modifying therapies for MS exist but are only partially effective, making it essential to optimize all factors that may influence the course of the disease. This includes conscientious management of both mental and physical comorbidities, as well as a comprehensive strategy for promoting wellness in patients with MS. Thoughtful engagement of those living with MS through shared decision making and involvement of a multidisciplinary team that includes primary care, relevant specialists, psychology, and rehabilitation is likely to lead to better outcomes.

Anaesthetic management of people with multiple sclerosis

There is a lack of published guidelines on the management of patients with multiple sclerosis (MS) undergoing procedures that require anaesthesia and respective advice is largely based on retrospective studies or case reports. The aim of this paper is to provide recommendations for anaesthetists and neurologists for the management of patients with MS requiring anaesthesia. This review covers issues related to the anaesthetic management of patients with MS, with a focus on preoperative assessment, choice of anaesthetic techniques and agents, side-effects of drugs used during anaesthesia and their potential impact on the disease evolution, drug interactions that may occur, and the need to use monitoring devices. A systematic PubMed research was performed to retrieve relevant articles.

Stroke risk in multiple sclerosis: a critical appraisal of the literature

Observational studies suggest that the occurrence of stroke on multiple sclerosis (MS) patients is higher compared to the general population. MS is a heterogeneous disease that involves an interplay of genetic, environmental and immune factors. The occurrence of stroke is subject to a wide range of both modifiable and non-modifiable, short- and long-term risk factors. Both MS and stroke share common risk factors. The immune mechanisms that underlie stroke are similar to neurodegenerative diseases and are attributed to neuroinflammation. The inflammation in autoimmune diseases may, therefore, predispose to an increased risk for stroke or potentiate the effect of conventional stroke risk factors. There are, however, additional determinants that contribute to a higher risk and incidence of stroke in MS. Due to the challenges that are associated with their differential diagnosis, the objective is to present an overview of the factors that may contribute to increased susceptibility or occurrence of stroke in MSpatients by performing a review of the available to date literature. As both MS and stroke can individually detrimentally affect the quality of life of afflicted patients, the identification of factors that contribute to an increased risk for stroke in MS is crucial for the prompt implementation of preventative therapeutic measures to limit the additive burden that stroke imposes.

Autonomic nervous system disorders in multiple sclerosis

Multiple sclerosis (MS) is a chronic progressive demyelinating disease of the central nervous system (CNS), which also affects the autonomic nervous system (ANS). Manifestations of MS in the ANS include urological, sexual, gastrointestinal, cardiovascular, and thermoregulatory disorders as well as increased fatigue. These problems are common yet are often underestimated due to the non-specificity of the symptoms and the limited evaluation of the ANS in the usual clinical practice. Most of these symptoms seem to be related to localized lesions in the CNS. However, the mechanisms by which these disorders are caused in MS have not been fully investigated, thus preventing any focused etiological treatment. The most common disorders of the ANS in MS represent a challenge for clinicians due to the variability of the clinical picture and our minimal data on their diagnosis and treatment. Early diagnosis and initiation of individualized treatment regimens, often in need of multiple approaches, seem to yield the best results in managing ANS dysfunction in MS patients.

The Heart–Brain Interplay in Multiple Sclerosis from Pathophysiology to Clinical Practice: A Narrative Review

Multiple sclerosis (MS) is a chronic neurological disorder characterized by inflammation in the central nervous system (CNS) that leads to neurodegeneration. The clinical course is highly variable, but its prevalence is rising worldwide, partly thanks to novel disease-modifying therapies. Additionally, the lifespan of people with MS is increasing, and for this reason, it is fundamental to have a multidisciplinary approach to MS. MS may be associated with cardiovascular diseases (CVD), but there is scarce attention on this issue. In particular, CNS is essential in regulating the autonomic system and heart activity. Moreover, cardiovascular risk factors show a higher prevalence in MS patients. On the other hand, conditions like Takotsubo syndrome are rare complications of MS. The parallelism between MS and myocarditis is also interesting. Finally, cardiac toxicity represents a not infrequent adverse reaction to MS drugs. This narrative review aims to provide an overview of cardiovascular complications in MS and their management to prompt further clinical and pre-clinical research on this topic.

How to explore and explain autonomic changes in multiple sclerosis

Autonomic dysfunction (AD) in people with MS (pwMS) is a frequent finding. This narrative review will present an overview of central neural mechanisms involved in the control of cardiovascular and thermoregulatory systems, and methods of autonomic nervous system testing will be discussed thereafter. Since the need for standardization of autonomic nervous system (ANS) testing, we will focus on the standard battery of tests (blood pressure and heart rate response to Valsalva maneuver and head-up tilt, and heart rate response to deep breathing test plus one of the tests for sudomotor function), which can detect ANS pathology in the majority of pwMS. The review will briefly discuss the other types of AD in pwMS and the use of appropriate tests. While performing ANS testing in pwMS one has to consider the multiple sclerosis phenotypes, disease duration, and its activity, the degree of clinical disability of patients included in the study, and the disease-modifying therapies taken, as these factors may have a great influence on the results of ANS testing. In other words, detailed patient characteristics presentation and patient stratification are beneficial when reporting results of ANS testing in pwMS.

Adrenoceptors as potential target for add-on immunomodulatory therapy in multiple sclerosis

This review summarizes recent findings related to the role of the sympathetic nervous system (SNS) in pathogenesis of multiple sclerosis (MS) and its commonly used experimental model - experimental autoimmune encephalomyelitis (EAE). They indicate that noradrenaline, the key end-point mediator of the SNS, acting through β-adrenoceptor, has a contributory role in the early stages of MS/EAE development. This stage is characterized by the SNS hyperactivity (increased release of noradrenaline) reflecting the net effect of different factors, such as the disease-associated inflammation, stress, vitamin D hypovitaminosis, Epstein-Barr virus infection and dysbiosis. Thus, the administration of propranolol, a non-selective β-adrenoceptor blocker, readily crossing the blood-brain barrier, to experimental rats before the autoimmune challenge and in the early (preclinical/prodromal) phase of the disease mitigates EAE severity. This phenomenon has been ascribed to the alleviation of neuroinflammation (due to attenuation of primarily microglial activation/proinflammatory functions) and the diminution of the magnitude of the primary CD4+ T-cell autoimmune response (the effect associated with impaired autoantigen uptake by antigen presenting cells and their migration into draining lymph nodes). The former is partly related to breaking of the catecholamine-dependent self-amplifying microglial feed-forward loop and the positive feedback loop between microglia and the SNS, leading to down-regulation of the SNS hyperactivity and its enhancing influence on microglial activation/proinflammatory functions and the magnitude of autoimmune response. The effects of propranolol are shown to be more prominent in male EAE animals, the phenomenon important as males (like men) are likely to develop clinically more severe disease. Thus, these findings could serve as a firm scientific background for formulation of a new sex-specific immune-intervention strategy for the early phases of MS (characterized by the SNS hyperactivity) exploiting anti-(neuro)inflammatory and immunomodulatory properties of propranolol and other relatively cheap and safe adrenergic drugs with similar therapeutic profile.

Multiple sclerosis-related heat sensitivity linked to absence of DMT prescription and subjective hand impairment but not autonomic or corticospinal dysfunction

OBJECTIVES

Heat sensitivity (HS) describes a temporary worsening of multiple sclerosis (MS) symptoms with increased body temperature. The pathophysiology may relate to central nervous system conduction deficits and autonomic dysfunction. We conducted deep clinical phenotyping of a cohort of persons with MS to identify predictors of HS.

METHODS

We recruited 59 MS participants with HS or No HS. Participants self-reported symptom severity (Hospital Anxiety and Depression Scale, Multiple Sclerosis Impact Scale, and fatigue visual analog scale) and underwent maximal exercise and transcranial magnetic stimulation testing to characterize autonomic and corticospinal function. We examined associations with HS using binomial logistic regression.

RESULTS

People with HS (36/59) had significantly greater disability, depression, fatigue, and physical and psychological functional effects of MS. They also had significantly lower corticospinal excitability but not conduction. After controlling for disease-modifying therapy (DMT), disability, and disease type, self-reported difficulty using hands in everyday tasks was significantly associated with a large increase in the odds of HS. Autonomic and corticospinal dysfunction were not associated with HS. Lack of DMT use alone was also associated with a large increase in the odds of HS.

DISCUSSION

Following a comprehensive assessment of plausible contributors to HS, HS was most strongly associated with lack of a DMT prescription and self-reported hand dysfunction. Surprisingly, objective measurement of autonomic and corticospinal integrity did not contribute to HS.

Heart rate variability and fatigue in MS: two parallel pathways representing disseminated inflammatory processes?

BACKGROUND

Fatigue is a disabling symptom of multiple sclerosis. Its biological causes are still poorly understood. Several years ago, we proposed that fatigue might be the subjective representation of inflammatory processes. An important step for a straight-forward evaluation of our model would be to show that the level of fatigue is associated with vagal activation. The heart rate is under partial control of the vagus nerve. Using power spectrum analysis allows to separate, at least partly, sympathetic and parasympathetic impact on heart rate variability.

METHODS

This narrative review summarizes the evidence for heart rate variability changes in MS patients, their relationship with fatigue and disease course. To do this, we conducted a literature search, including 45 articles relevant to the topic treated in this review.

RESULTS

We illustrate that (1) inflammation leads to a change in cardiac behavior during acute and chronic phases, both in animals and in humans; (2) MS patients show changes of heart rate variability (HRV) that resemble those during acute and chronic inflammation due to multiple causes; (3) existing evidence favors a set of specific predictions about fatigue and parallel HRV changes; and (4) that MS-related brainstem lesions or neurological impairments do not completely explain HRV changes, leaving enough place for an explanatory relation between HRV and fatigue.

DISCUSSION

We discuss the results of this review in relation to our model of fatigue and propose several observational and experimental studies that could be conducted to gain a better insight into whether fatigue and HRV can be interpreted as a common pathway, both reflecting activated autoimmune processes in MS patients.

S1P receptor modulators and the cardiovascular autonomic nervous system in multiple sclerosis: a narrative review

Sphingosine 1-phosphate (S1P) receptor (S1PR) modulators have a complex mechanism of action, which are among the most efficient therapeutic options in multiple sclerosis (MS) and represent a promising approach for other immune-mediated diseases. The S1P signaling pathway involves the activation of five extracellular S1PR subtypes (S1PR1-S1PR5) that are ubiquitous and have a wide range of effects. Besides the immunomodulatory beneficial outcome in MS, S1P signaling regulates the cardiovascular function via S1PR1-S1PR3 subtypes, which reside on cardiac myocytes, endothelial, and vascular smooth muscle cells. In our review, we describe the mechanisms and clinical effects of S1PR modulators on the cardiovascular system. In the past, mostly short-term effects of S1PR modulators on the cardiovascular system have been studied, while data on long-term effects still need to be investigated. Immediate effects detected after treatment initiation are due to parasympathetic overactivation. In contrast, long-term effects may arise from a shift of the autonomic regulation toward sympathetic predominance along with S1PR1 downregulation. A mild increase in blood pressure has been reported in long-term studies, as well as decreased baroreflex sensitivity. In most studies, sustained hypertension was found to represent a significant adverse event related to treatment. The shift in the autonomic control and blood pressure values could not be just a consequence of disease progression but also related to S1PR modulation. Reduced cardiac autonomic activation and decreased heart rate variability during the long-term treatment with S1PR modulators may increase the risk for subsequent cardiac events. For second-generation S1PR modulators, this observation has to be confirmed in further studies with longer follow-ups. The periodic surveillance of cardiovascular function and detection of any cardiac autonomic dysfunction can help predict cardiac outcomes not only after the first dose but also throughout treatment.

PLAIN LANGUAGE SUMMARY

What is the cardiovascular effect of S1P receptor modulator therapy in multiple sclerosis? Sphingosine 1-phosphate (S1P) receptor (S1PR) modulators are among the most efficient therapies for multiple sclerosis. As small molecules, they are not only acting on the immune but on cardiovascular and nervous systems as well. Short-term effects of S1PR modulators on the cardiovascular system have already been extensively described, while long-term effects are less known. Our review describes the mechanisms of action and the short- and long-term effects of these therapeutic agents on the cardiovascular system in different clinical trials. We systematically reviewed the literature that had been published by January 2022. One hundred seven articles were initially identified by title and abstract using targeted keywords, and thirty-nine articles with relevance to cardiovascular effects of S1PR therapy in multiple sclerosis patients were thereafter considered, including their references for further accurate clarification. Studies on fingolimod, the first S1PR modulator approved for treating multiple sclerosis, primarily support the safety profile of this therapeutic class. The second-generation therapeutic agents along with a different treatment initiation approach helped mitigate several of the cardiovascular adverse effects that had previously been observed at the start of treatment. The heart rate may decrease when initiating S1PR modulators and, less commonly, the atrioventricular conduction may be prolonged, requiring cardiac monitoring for the first 6 h of medication. Continuous therapy with S1PR modulators can increase blood pressure values; therefore, the presence of arterial hypertension should be checked during long-term treatment. Periodic surveillance of the cardiovascular and autonomic functions can help predict cardiac outcomes and prevent possible adverse events in S1PR modulators treatment. Further studies with longer follow-ups are needed, especially for the second-generation of S1PR modulators, to confirm the safety profile of this therapeutic class.

Blood pressure variability is altered in secondary progressive multiple sclerosis but not in patients with a clinically isolated syndrome

OBJECTIVES

To investigate differences in beat-to-beat systolic blood pressure variability (SBPV) in people with secondary progressive MS (pwSPMS), clinically isolated syndrome (pwCIS) and healthy controls (HC).

METHODS

This retrospective case-control study included 46 pwSPMS, 46 pwCIS and 44 HC. A semi-automated software made with MATLAB R2019b (The MathWorks, Inc.) was used for the evaluation of SBPV. The frequency domain characteristics observed were the power spectrum in the LF and HF bands and the LF/HF ratio. Data is expressed in absolute power (mmHg²) of LF and HF and ratio (LF/HF) during both supine and tilt-up phases of testing.

RESULTS

There were no significant differences in mean systolic (sBP) or diastolic blood pressure (dBP) values during supine and tilt-up phases of testing between groups. During the supine phase of testing LF and LF/HF were significantly lower in the SPMS group (4.17±5.38 and 3.52±2.34, respectively) compared to the CIS (5.42±3.59, p = 0.015 and 5.92±4.63, p = 0.029, respectively) and HC group (6.03±4.55, p = 0.011 and 6.52 ± 5.09, p = 0.010, respectively), while during the tilt-up phase, LF was significantly lower compared to both the CIS and HC group, and HF was significantly lower only compared to the CIS group.

CONCLUSION

SBPV is altered in pwSPMS compared to pwCIS and normal controls. Further research in the field of MS related dysautonomia is warranted not only because of its relevance to comorbidities and MS symptoms, but also because of its likely involvement in the pathophysiology of MS.

The pathophysiology of motor fatigue and fatigability in multiple sclerosis

Multiple Sclerosis (MS) is a heterogeneous immune mediated disease of the central nervous system (CNS). Fatigue is one of the most common and disabling symptom of MS. It interferes with daily activities on the level of cognition and motor endurance. Motor fatigue can either result from lesions in cortical networks or motor pathways (“primary fatigue”) or it may be a consequence of detraining with subsequent adaptions of muscle and autonomic function. Programmed exercise interventions are used frequently to increase physical fitness in MS-patients. Studies investigating the effects of training on aerobic capacity, objective endurance and perceived fatigability have yielded heterogenous results, most likely due to the heterogeneity of interventions and patients, but probably also due to the non-uniform pathophysiology of fatigability among MS-patients. The aim of this review is to summarize the current knowledge on the pathophysiology of motor fatigability with special reference to the basic exercise physiology that underlies our understanding of both pathogenesis and treatment interventions.

Short- and long-term effects of siponimod on autonomic nervous system in secondary progressive multiple sclerosis

OBJECTIVES

The aim of this study was to investigate the short- and long-term effects of siponimod on autonomic nervous system (ANS) function, in people with secondary progressive multiple sclerosis (pwSPMS) METHODS: The following ANS tests were performed in 26 pwSPMS: a 10 min supine resting position, Valsalva maneuver, deep breathing test and a 10 min tilt-up table test. Heart rate variability (HRV) was performed for the 10 min in supine resting position (M0) and for a 3 h period after siponimod treatment initiation (M0_s1-6). All ANS tests were repeated after at least 6 months of treatment with siponimod (M6).

RESULTS

In all 6 intervals after siponimod ingestion (M0_s1-6), standard deviation of NN intervals (SDNN) was higher compared to M0. After 6 months of continuous treatment with siponimod, SDNN was significantly lower compared to M0. At M6, Valsalva ratio and respiratory sinus arrhythmia were lower compared to M0 values (1.510±0.338 vs 1.864±0.456, p=0.003 and 7.969±2.865 vs 13.091±4.687, p<0.001, respectively). Cardiovagal index was significantly higher at M6 compared to M0 (1 (range 0-2) vs 0 (range 0-1), p=0.008, respectively). Active Magnetic Resonance Imaging (MRI) one year prior to starting siponimod was a positive predictor of M6 SDNN and Adrenergic Index (AI) at M0 was a negative predictor of M6 SDNN.

CONCLUSION

This study has shown an inverse relationship in short- versus long-term effects of siponimod on ANS function. A shift towards parasympathetic predominance was observed during the first three hours after ingestion, while after 6 or more months of continuous treatment with siponimod, a shift towards sympathetic predominance was observed.

Continuous monitoring with wearables in multiple sclerosis reveals an association of cardiac autonomic dysfunction with disease severity

Background

Dysfunction of the autonomic nervous system is common in multiple sclerosis patients, and probably present years before diagnosis, but its role in the disease is poorly understood.

Objectives

To study the autonomic nervous system in patients with multiple sclerosis using cardiac autonomic regulation measured with a wearable.

Methods

In a two-week study, we present a method to standardize the measurement of heart rate variability using a wearable sensor that allows the investigation of circadian trends. Using this method, we investigate the relationship of cardiac autonomic dysfunction with clinical hallmarks and subjective burden of fatigue and autonomic symptoms.

Results

In 55 patients with multiple sclerosis and 24 healthy age- and gender-matched controls, we assessed the cumulative circadian heart-rate variability trend of two weeks. The trend analysis revealed an effect of inflammation (P = 0.0490, SMD = -0.5466) and progressive neurodegeneration (P = 0.0016, SMD = 1.1491) on cardiac autonomic function. No association with subjective symptoms could be found.

Conclusions

Trend-based heart rate variability measured with a wearable provides the opportunity for unobtrusive long-term assessment of autonomic functions in patients with multiple sclerosis. It revealed a general dysregulation in patients with multiple sclerosis.

Thermal dysregulation in patients with multiple sclerosis during SARS-CoV-2 infection. The potential therapeutic role of exercise

Thermoregulation is a homeostatic mechanism that is disrupted in some neurological diseases. Patients with multiple sclerosis (MS) are susceptible to increases in body temperature, especially with more severe neurological signs. This condition can become intolerable when these patients suffer febrile infections such as coronavirus disease-2019 (COVID-19). We review the mechanisms of hyperthermia in patients with MS, and they may encounter when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Finally, the thermoregulatory role and relevant adaptation to regular physical exercise are summarized.

Peripheral nervous system electrodiagnostic abnormalities in predominantly Hispanic Multiple Sclerosis patients

BACKGROUND

Peripheral nervous system (PNS) abnormalities in Multiple Sclerosis (MS) have been reported in case reports and small case series over the past several decades. Little is known, however, about the prevalence of electrodiagnostic abnormalities in patients with MS, including not only demyelinating neuropathies such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) but also axonal peripheral neuropathy and sympathetic dysfunction.

METHODS

This is an observational, cross-sectional study with the objective of identifying the prevalence of the electrodiagnostic abnormalities in predominantly Hispanic MS patients in Miami, Florida. Electrodiagnostic data including nerve conduction study (NCS), electromyography (EMG) and sympathetic skin response (SSR) information was prospectively collected in 18 patients (16 females; 43.7±15.2 years) with a diagnosis of MS compared to 18 healthy (16 females; 39.9±11 years), age- and height-matched controls. The study was offered to all-comers in the MS Clinic over a period of 3 months, regardless of clinical suspicion for an underlying neuropathic process, in an effort to estimate the prevalence of abnormalities. Demographic data including age, sex, race/ethnicity was evaluated in addition to MS-specific characteristics including MS subtype, duration of disease, duration of therapy, clinical symptoms and laboratory data.

RESULTS

There were no significant differences in baseline characteristics of patients and controls for age (p=0.4) and height (164.0±6.4 vs 162.3±4.6 centimeters; p=0.3). The mean disease duration was 106±27 months (median 107 months; range 5-336 months). The mean Expanded Disability Status Scale (EDSS) was 2.4±1.87 (median: 2.5; range 1.0-6.5). The ethnicity of patients (15 Hispanic, 3 non-Hispanic) and controls (13 Hispanic, 5 non-Hispanic; p=0.56) was similar. The frequency of electrophysiological axonal polyneuropathy (PN) was 77.8% (14/18 patients), and 85.6% of these patients had clinical sensory symptoms. Interestingly, 1 patient had previously unrecognized CIDP. All 18 patients displayed prolonged SSR latencies consistent with autonomic dysfunction. Thirteen patients (72.2%) reported autonomic symptoms such as bladder abnormalities and blood pressure fluctuations.

CONCLUSION

The prevalence of electrodiagnostic abnormalities, especially axonal polyneuropathy, in the MS population may be higher than traditionally considered. The relationship between axonal polyneuropathy and central axonopathy in the context of neurodegeneration in MS should be further explored. Analytic studies may identify common symptomatic and pathophysiologic etiologies to further understanding and potentially guide treatment of MS subtypes with PNS involvement.

Unveiling the relationship between autonomic involvement, fatigue, and cognitive dysfunction in early relapsing-remitting multiple sclerosis

BACKGROUND

Fatigue is a common, yet disabling, symptom in patients with multiple sclerosis (PwMS). Fatigue has shown to be associated with self-reported autonomic nervous system (ANS) symptoms, particularly for cognitive fatigue; however, the question whether ANS involvement is related to cognitive impairment has never been addressed. We performed a study to unveil the complex relationship between fatigue, ANS symptoms, and cognitive impairment.

METHODS

We prospectively recruited early PwMS that were tested with Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), Modified Fatigue Impact Scale (MFIS) and Composite Autonomic Symptoms Scale-31 (COMPASS-31) scale. We performed a comparison between fatigued and non-fatigued patients and between cognitive unimpaired and impaired patients. We evaluated the association of COMPASS-31, MFIS, BDI, STAI, and BICAMS scores, and the analysis was repeated for each scale's sub-scores. A multivariable analysis was performed to elucidate predictors of fatigue.

RESULTS

Forty-four patients were recruited. Fatigued patients had higher COMPASS-31 total, orthostatic intolerance, secretomotor, and pupillomotor scores. No differences in fatigue and ANS symptoms were found between cognitive impaired and unimpaired patients. MFIS total score correlated with STAI state (p = 0.002) and trait (p < 0.001), BDI (p < 0.001), COMPASS-31 total (p < 0.001), orthostatic intolerance (p < 0.001), pupillomotor scores (p = 0.006). Multivariable analysis showed that BDI (p < 0.001) and COMPASS-31 (p = 0.021) predicted MFIS score. Sub-scores analysis showed that orthostatic intolerance has a relevant role in fatigue.

CONCLUSION

ANS symptoms are closely related with fatigue. Orthostatic intolerance may have a predominant role. Cognitive impairment seems not to be associated with ANS symptoms.

Cardiac Autonomic Dysfunction in Myasthenia Gravis and Relapsing-Remitting Multiple Sclerosis-A Pilot Study

This study assessed cardiac autonomic response to head-up tilt test (HUTT) in 23 myasthenia gravis (MG) and 23 relapsing-remitting multiple sclerosis (RRMS) patients compared to 30 healthy controls (HC). Task Force® Monitor was used to evaluate cardiac inotropy parameters, baroreflex sensitivity (BRS), heart rate (HRV), and blood pressure variability (BPV) during HUTT. MG patients were characterized by reduced BRS (p < 0.05), post-HUTT decrease in high-frequency component (p < 0.05) and increase in sympathovagal ratio of HRV (p < 0.05) when compared to controls indicating parasympathetic deficiency with a shift of sympathovagal balance toward sympathetic predominance. Compared to HC, MG patients also showed lower cardiac inotropy parameters, specifically, left ventricular work index (LVWI) during supine rest (p < 0.05) as well as LVWI and cardiac index values in response to orthostatic stress (p < 0.01 and p < 0.05, respectively). Compared to controls, RRMS patients were characterized by lower HRV delta power spectral density (p < 0.05) and delta low-frequency HRV (p < 0.05) in response to HUTT suggesting combined sympathetic and parasympathetic dysfunction. There were no differences in cardiac autonomic parameters between MG and MS patients (p > 0.05). Our study highlights the possibility of cardiac and autonomic dysfunction in patients with MG and RRMS which should be considered in the pharmacological and rehabilitation approach to managing these conditions.

Frequency and characteristics of dysautonomic symptoms in multiple sclerosis: a cross-sectional double-center study with the validated Italian version of the Composite Autonomic Symptom Score-31

BACKGROUND

Dysautonomic symptoms (DS) are frequent but often underrecognized in multiple sclerosis (MS) patients, despite the relevant impact on quality of life and physical performance.

OBJECTIVES

To assess frequency and characteristics of DS in our MS population compared with healthy controls (HC). To investigate the relationship between DS and disease characteristics (MS subtype, disease duration, Expanded Disability Status Scale (EDSS), clinical and/or radiological activity, disability progression).

PATIENTS AND METHODS

Cross-sectional study includes 324 MS patients (mean age 44.9 ± 10.7 years; 66% female) and 190 HC (mean age 40.60 ± 12.83 years; 63% female). DS were assessed using the Italian validated version of the Composite Autonomic Symptom Score-31 (COMPASS-31). Possible confounding factors were considered.

RESULTS

More than 94% of enrolled MS patients reported alterations in ≥ 2 domains of the COMPASS-31 scale (score > 0) and significantly higher COMPASS-31 total and single domain median scores compared with HC, independently from possible confounding factors (orthostatic intolerance: p = 0.001; vasomotor: p = 0.017; secretomotor: p = 0.040; gastrointestinal: p = 0.047; bladder: p < 0.001; pupillomotor: p < 0.001; COMPASS-31 total score: p < 0.001). COMPASS-31 total, secretomotor, gastrointestinal, and bladder domain scores showed weak to moderate correlation with disease duration (Rho = 0.19, p < 0.001; Rho = 0.18, p = 0.01; Rho = 0.25, p = 0.030; Rho = 0.28, p < 0.001, respectively). A moderate correlation between EDSS score, COMPASS-31 total, and bladder domain scores (Rho = 0.32, p < 0.001 and Rho = 0.48, p < 0.001, respectively) was observed. Progressive subtypes showed higher COMPASS-31 total (p = 0.025), gastrointestinal (p = 0.07), and bladder (p < 0.001) domain scores vs relapsing-remitting patients.

CONCLUSIONS

Our findings confirm that MS-related DS are frequent and tend to increase paralleling disease duration and clinical worsening, reaching the highest clinical impact in progressive subtypes.

Cardiovascular safety of mirabegron in individuals treated for spinal cord injury- or multiple sclerosis-induced neurogenic detrusor overactivity

PURPOSE

To analyze cardiovascular safety of mirabegron in patients with spinal cord injury (SCI)- and multiple sclerosis (MS)-induced neurogenic detrusor overactivity (NDO) in a prospective, randomized, double-blind, placebo-controlled study.

METHODS

Seventy-eight patients were enrolled into the study, and 66 of them were included into the final analysis. In 49 (74.2%), NDO developed due to suprasacral SCI, 17 (25.8%) suffered from NDO due to MS. Eleven patients were previously treated for hypertension and one for arrhythmia. All study participants received placebo for 2 weeks run-in period. Subsequently, eligible subjects were randomized for 4 weeks of active treatment with mirabegron 50 mg once daily (Group A; n = 32) or placebo (Group B; n = 34). Data from resting electrocardiography (ECG), 24-h ECG and blood pressure monitoring, and echocardiographic examination, were used for cardiovascular safety assessment. All reported variables were evaluated at time of randomization and at the end of the study. Longitudinal changes of variables within the groups and differences between the groups were assessed using nonparametric Kruskal-Wallis test, and p ≤ 0.05 was considered statistically significant.

RESULTS

No statistically significant longitudinal changes were found in safety variables, except for prolongation of QT interval in placebo group (p = 0.0328) recorded by resting ECG. No significant difference between the Groups A and B, in any of the variables, was observed. A single cardiovascular study drug-related adverse event was recorded in a patient with cervical SCI (3.13%).

CONCLUSIONS

Our results suggest that mirabegron can be safely used in the treatment of patients with SCI- and MS-induced NDO.

Evidence of Autonomic Dysfunction in Patients with Relapsing-Remitting Multiple Sclerosis: Heart Rate Variability and Cardiovascular Parameters

This study was aimed at evaluation of autonomic dysfunction in patients with multiple sclerosis (MS) by means of time- and frequency-domain parameters of heart rate variability (HRV) and conventional cardiovascular tests (deep breathing (DB) and active orthostatic test (AOT)). The study group enrolled 32 patients with the relapsing-remitting MS (17 m, 15 f, aged 29 ± 4.9 years, disease duration 4.2 ± 2.7 years, EDSS scores less than 3.0 and 26 subjects in good health (HC, 15 m, 11 f, aged 30.1 ± 2.7 years). In the MS group, at rest the variability of heart rate was decreased in comparison to the HC group seen by time- (SDNN, RMSSD, pNN50, CV, p < 0.01) and frequency-domain (TP, HF, LF, p < 0.05) parameters, what was indicative of the general decrease of the autonomic neurogenic control of the heart rate, both sympathetic and parasympathetic. The functional tests (DB and AOT) showed reduced cardiovascular reactivity in the MS group. Additionally, the cardio-respiratory synchronization was impaired in the MS group at rest and DB. The severity of HRV deficit in the MS group correlated with the activity of MS. In conclusion, the comprehensive assessment of time- and frequency-domain HRV parameters studied with functional tests provides better insight to understanding autonomic dysfunction in subjects with relapsing-remitting MS.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Cardiac Autonomic Modulation Is Different in Terms of Clinical Variant of Multiple Sclerosis

This study evaluates whether the cardiac autonomic response to head-up tilt test (HUTT) differs between patients with relapsing-remitting multiple sclerosis (RRMS) and those with progressive MS (PMS) as compared to healthy controls (HC). Baroreflex sensitivity, cardiac parameters, heart rate (HRV) and blood pressure variability (BPV) were compared between 28 RRMS, 21PMS and 25 HC during HUTT. At rest, PMS patients had higher values of the sympathovagal ratio, a low-frequency band HRV (LFnu-RRI) and lower values of parasympathetic parameters (HFnu-RRI, HF-RRI) compared to RRMS and HC. Resting values of cardiac parameters were significantly lower in RRMS compared to PMS patients. No intergroup differences were observed for post-tilt cardiac and autonomic parameters, except for delta HF-RRI with lower values in the PMS group. The MS variant corrected for age, sex and Expanded Disability Status Scale (EDSS) score was an independent predictor of changes in the sympathovagal ratio as measured by HRV. Furthermore, a higher overall EDDS score was related to a higher sympathovagal ratio, lower parasympathetic parameters at rest, and decrease post-tilt changes of the sympathovagal ratio of sBP BPV. Autonomic imbalance is markedly altered in the MS patient group compared to control changes were most pronounced in the progressive variant of MS disease. The MS variant appeared to have a potential influence on cardiac autonomic imbalance at rest.

Adrenergic hyperactivity: a missing link between multiple sclerosis and cardiovascular comorbidities?

The aim of the study is to investigate differences in non-standard adrenergic baroreflex sensitivity (BRS) indices in patients with different phenotypes of multiple sclerosis (pwMS) and healthy controls (HC). Retrospective analysis of types of systolic blood pressure (BP) curves during Valsalva maneuver (VM) [balanced (BAR), augmented (AAR) and suppressed (SAR) autonomic responses] and adrenergic baroreflex sensitivity (BRSa) measured with BRSa₁, α-BRSa and β-BRSa in patients with clinically isolated syndrome (CIS), relapsing remitting multiple sclerosis (RRMS), progressive multiple sclerosis (PMS) and HC. We also investigated correlations between BRSa_1, α-BRSa, β-BRSa and resting catecholamine levels. pwMS had higher α-BRSa compared to HC (p = 0.02). There was no difference in BRSa₁, s and β-BRSa between patients with CIS, RRMS and PMS. There was no association between pwMS and HC, and the type of sBP curve [χ2 = 4.332, p = 0.114]. pwMS and BAR or AAR had higher supine systolic and diastolic BP compared to pwMS and SAR. There was a significant correlation between α-BRSa and upright systolic BP (r_p =0.194, p = 0.017), α-BRSa and norepinephrine (r_s =0.228, p = 0.021), and BRSa₁ and epinephrine (r_s = 0.226, p = 0.040). pwMS and HC exhibit different alpha-adrenergic response to Valsalva maneuver. These results may explain the connection between MS and increased cardiovascular risk.

Clinical and MRI correlates of autonomic dysfunction in neuromyelitis optica spectrum disorder

BACKGROUND

The aim of this study was to investigate the relationship of autonomic dysfunction and clinical findings in patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

For the assessment of autonomic dysfunction, heart rate variability (HRV) and blood pressure (BP) measurement to deep breathing, Valsalva maneuver or head tilt-table test, with quantitative sudomotor axon reflex test (QSART) were used and interpreted in the form of the composite autonomic scoring scale (CASS). Clinical and radiological correlates with autonomic profiles were analyzed.

RESULTS

A total of 27 patients (mean age, 44.4 ± 12.26 years; female: male=22:5) were enrolled in this study and 74.1% of them showed autonomic dysfunction, involving the adrenergic, cardiovagal, or sudomotor domains. Eighteen patients were during remission, in whom, demographics and MRI findings were associated with an index or a total score of CASS. The presence of cervical cord lesion showed the association with cardiovagal index (B = 0.750, S.E. 0.242, 95% CI 0.237-1.263, p = 0.007), male gender with sudomotor index (B = 1.600, S.E. 0.653, 95% CI 0.199-3.001, p = 0.028) and the involvement of brain and/or spinal cord with a total CASS score (B = 1.500, S.E. 0.655, 95% CI 0.096-2.904, p = 0.038). In multivariable analysis, delayed pressure recovery time showed a significant positive association with EDSS score (B = 0.103, S.E. 0.031, 95% CI 0.037-0.168, p = 0.004).

DISCUSSION

Cardiovascular and sudomotor autonomic dysfunction are common in NMOSD. Several clinical and MRI characteristics of patients may warrant the investigation of autonomic dysfunction and its proper management.

The association between the adrenergic hyperactivity and blood pressure values in people with multiple sclerosis

OBJECTIVES

To evaluate the evolution of adrenergic baroreflex sensitivity (BRSa) over 2-year follow-up and to investigate the effect of baseline BRSa indices on blood pressure values after 2 years in people with multiple sclerosis (pwMS).

METHODS

The following data were analysed at baseline and after 2 years: BRSa measured with BRSa1, α-BRSa and β-BRSa, supine and tilted levels of epinephrine and norepinephrine, supine and tilted systolic and diastolic blood pressure levels.

RESULTS

Compared to baseline values, there was no change in α-BRSa (6.96 ± 2.56 vs. 6.64 ± 2.24, p = 0.379) at month 24. α-BRSa at month 24 positively correlated with tilted levels of norepinephrine at month 24 (r_p = 0.357, p = 0.005). Univariable linear regression analysis revealed that α-BRSa at baseline predicts the value of tilted systolic and diastolic blood pressure at month 24 (B = 2.724, 95% CI 1.357-4.091, p < 0.001 and B = 1.489, 95% CI 0.459-2.519, p = 0.005).

CONCLUSION

This study provides further evidence for possible role of α-BRSa as a marker of adrenergic hyperactivity in pwMS. These results may explain increased risk for cardiovascular diseases in pwMS.

Impaired heart rate recovery after sub-maximal physical exercise in people with multiple sclerosis

BACKGROUND

Heart Rate Recovery (HRR) after a physical exercise has been poorly investigated in people with multiple sclerosis (PwMS).

OBJECTIVE

To evaluate the kinetics of HRR and its autonomic modulation in PwMS and to elucidate the interplay between HRR and subjective fatigue.

METHODS

ECG was digitally acquired during rest (5 min), submaximal exercise (4 min at 10 W of upper limb cycling) and recovery (3 min) in 17 PwMS (EDSS: 5.9 ± 1.2, mean±standard deviation) and 17 healthy control (HC) subjects. Short-term (first 30 s) and long-term (up to180 s) validated indices of HRR were calculated. The time course of the parasympathetic index of heart rate variability RMSSD (Root Mean Square of Successive Differences) was computed every 30 s of recovery. Subjective fatigue was evaluated by the Borg scale applied to breathing and upper limbs.

RESULTS

In comparison with HC, the short-term HRR indices were significantly slower (P < 0.05) in PwMS, whereas the long-term ones did not. The time course of RMSSD was significantly different in PwMS (P < 0.05). HRR and HRV indexes did not correlate with fatigue perception and baseline HRV values.

CONCLUSION

The cardiac parasympathetic reactivation from a submaximal exercise was blunted in PwMS, thereby slowing the short-term phase of HRR. This may contribute to the higher cardiovascular risk in PwMS, but the mechanism needs further investigation. The parasympathetic impairment during post-exercise HR reactivation cannot be predicted by baseline HRV values and may therefore be revealed only by an appropriate provocative low-intensity physical test.

Cardiac Autonomic Dysfunction in Multiple Sclerosis: A Systematic Review of Current Knowledge and Impact of Immunotherapies

Cardiac autonomic dysfunction (CAD) has been reported in patients with multiple sclerosis (MS). This systematic review summarizes the evidence for the types and prevalence of CAD in MS patients, as well as its association with MS type, disease characteristics, fatigue and immunotherapies used to treat MS. The analysis revealed that CAD is correlated with pathophysiological processes of MS, can trigger serious cardiovascular complications that may reduce life expectancy, and may have implications for treatment with immunotherapies, especially fingolimod. Numerous mainly small case-control or cohort studies have reported various measures of CAD (particularly heart rate variation) in MS patients, showing higher rates of abnormality versus controls. A smaller number of studies have reported on cardiac autonomic symptoms in MS, including orthostatic intolerance/dizziness in around 50% of patients. CAD also appears to be associated with disease duration and to be more common in progressive than relapsing-remitting MS. However, although a substantial evidence base suggests that assessing CAD in people with MS may be important, standardised methods to evaluate CAD in these patients have not yet been established. In addition, no studies have yet looked at whether treating CAD can reduce the burden of MS symptoms, disease activity or the rate of progression.

Fatigue in Multiple Sclerosis is related to relapses, autonomic dysfunctions and introversion: A quasi-experimental study

BACKGROUND

Fatigue in Multiple Sclerosis (MS) might be partially due to inflammatory processes. If so, relapses should increase the fatigue level.

METHODS

Two groups of MS patients participated in this study. One suffered from a relapse and was treated by Methylprednisolone. The other group experienced a deterioration of their neurological condition but no relapse and received neurological rehabilitation. We assessed fatigue before admission, at admission and after discharge (t1, t2, t3). Furthermore, autonomic dysfunctions, depressive mood, apathy and extraversion were assessed at admission. Changes in fatigue were analysed with ANCOVAs and fatigue levels were analysed with regression analyses using clinical data and scores for depressive mood, apathy, extraversion and autonomic dysfunctions.

RESULTS

Only patients suffering from a relapse showed a significant increment in fatigue from t1 to t2. Regression analyses revealed that autonomic dysfunctions and introversion best explained the fatigue level.

CONCLUSIONS

This study shows that a relapse is accompanied by an increase in MS-related fatigue. Moreover, autonomic dysfunctions and introversion, more than depression and apathy, play a major role in the explanation of MS-related fatigue. This finding represents additional evidence for the relationship between inflammation, vagal afferent signaling, autonomic dysfunctions, introversion and the feeling of MS-related fatigue.

Longitudinal assessment of autonomic nervous system in patients with first demyelinating event suggestive of multiple sclerosis

BACKGROUND AND PURPOSE

As a high proportion of people with clinically isolated syndrome (pwCIS) exhibit sympathetic adrenergic and sudomotor dysfunction, the aim of this study was to investigate the evolution of autonomic nervous system (ANS) abnormalities in pwCIS over a 2-year follow-up.

METHODS

This was a prospective cohort study in which 121 pwCIS were enrolled and followed for 2 years. After 2-year follow-up, data were available for 84 pwCIS. ANS symptoms were evaluated with the Composite Autonomic System Score-31 (COMPASS-31) and results of the ANS tests were expressed using the Composite Autonomic Scoring Scale (CASS) at baseline and visit at month 24. Symptomatic dysautonomia was defined if the patient had a COMPASS-31 value above the median of the whole cohort at baseline evaluation (COMPASS-31 > 6.79) and CASS score >0.

RESULTS

Complete CASS data at baseline and month 24 were available for 62 patients; in 24 (38.7%) patients there was worsening, in 16 (25.8%) there was improvement and in 22 (35.5%) there was no change in CASS score. In 90% of pwCIS (72 of 80) there was no change in parasympathetic nervous system tests, whereas 47.3% (35 of 74) had either worsening or improvement in sympathetic adrenergic and 28.6% (20 of 70) had either worsening or improvement in sudomotor function. A multivariable regression model identified the total number of T2 lesions as an independent predictor for worsening of symptomatic dysautonomia. No predictors for worsening or improving of CASS score were identified.

CONCLUSION

A substantial proportion of pwCIS experienced worsening of ANS abnormalities during the 2-year follow-up and magnetic resonance imaging parameters seemed to predict these abnormalities.

Neurodegenerative Interplay of Cardiovascular Autonomic Dysregulation and the Retina in Early Multiple Sclerosis

Introduction: Autonomic nervous system (ANS) symptoms are prevalent in multiple sclerosis (MS) as is neurodegeneration. Our aim was to explore the occurrence of ANS symptoms and retinal neurodegeneration in a newly diagnosed MS population with tools available in a clinical setting.

Methods: Forty-three MS patients and 44 healthy controls took part in the study. We employed a bedside cardiovascular ANS test battery together with classical pupillometry, optical coherence tomography (OCT) evaluation of retinal neurodegeneration in eyes without previous optic neuritis (MSNON) and patients' self-report forms on fatigue, orthostatic and ANS symptoms.

Results: Half of the patients presented with ANS symptoms and a high level of fatigue. There was a significant difference in ganglion cell layer thickness (mean GCIPL) evaluated by OCT in MSNON compared to healthy control eyes. We found a negative linearity of mean GCIPL on group level with increasing disease duration. Three patients fulfilled the criteria of postural orthostatic tachycardia syndrome (POTS).

Conclusion: Our results demonstrate retinal neurodegeneration in MSNON, a high frequency of fatigue and a high prevalence of ANS symptoms in newly diagnosed patients. Whether neurodegeneration precedes ANS dysfunction or vice versa is still open to debate, but as unveiled by the presence of POTS in this MS population, differences in stress-response regulation add to the understanding of variation in onset-time of ANS dysfunction in early MS.

Capturing fatigue parameters: The impact of vagal processing in multiple sclerosis related cognitive fatigue

BACKGROUND

Causes of fatigue in Multiple Sclerosis remain elusive. Recently, we developed a model linking cognitive fatigue to inflammatory processes based on a neuroinflammatory reflex-arc instantiated by the vagus nerve. The relation between experienced autonomic dysfunctions, based on vagal processing, and cognitive fatigue is well-known, but an examination of the association of objectively measured vagal activity and cognitive fatigue is missing. An attempt was made to collect behavioral and physiological evidence that can be associated with experienced autonomic dysfunctions and fatigue in Multiple Sclerosis patients.

METHODS

Behavioral performance (response bias) and autonomic functioning (Heart rate variability and Skin conductance level) during an acoustic vigilance task were investigated in 53 Multiple Sclerosis patients. We assessed trait fatigue (independent from task), and time-on-task related increase of fatigue. Regression analysis was used to predict the fatigue status with physiological and behavioral scores.

RESULTS

Response bias, indicating a reduced responsiveness, and high and very low frequency components of Heart rate variability, indicating an increased parasympathetic activity, contribute to the regression of trait fatigue. Reduced Heart rate variability (SDNN) and increased parasympathetic activity (pNN50) remained in the regression model predicting time-on-task fatigue.

CONCLUSION

Cognitive fatigue in MS is related to parasympathetic activity and reduced responsiveness, supporting our model representing fatigue as inflammatory processes in the brain. Standardized subjective and objective autonomous dysfunction measures might be considered as additional assessments in MS.

Immune and autonomic nervous system interactions in multiple sclerosis: clinical implications

Multiple sclerosis is characterized by a wide spectrum of clinical manifestations, among which dysfunction of the autonomic nervous system represents an important cause of multiple sclerosis-related disability. The aim of this review is to provide an overview of autonomic dysfunction in people with multiple sclerosis, and to discuss the interactions between the immune and autonomic nervous systems and the effects of these interactions on various aspects of multiple sclerosis. Autonomic dysfunction in people with multiple sclerosis can be demonstrated clinically and on a molecular level. Clinically, it can be demonstrated by measuring autonomic symptoms with the Composite Autonomic Symptom Score (COMPASS-31), and neurophysiologically, with different autonomic nervous system tests. Both symptomatic and objectively determined autonomic dysfunction can be associated with increased risk of multiple sclerosis disease activity. Further supporting these clinical observations are molecular changes in immune cells. Changes in the sympathetic autonomic system, such as different expression of dopaminergic and adrenergic receptors on immune cells, or modulation of the cholinergic anti-inflammatory pathway over different subunits of the nicotinic acetylcholine receptor in the peripheral immune system, may mediate different effects on multiple sclerosis disease activity.

Autonomic dysfunction in people with neuromyelitis optica spectrum disorders

Aims:

To determine the difference in autonomic symptom burden measured with the Composite Autonomic System Score-31 (COMPASS-31) and presence of objective dysautonomia in people with neuromyelitis optica spectrum disorders (pwNMOSD) compared to people with multiple sclerosis (pwMS).

Design/Methods:

Twenty pwNMOSD and 20 pwMS, matched for age, sex, and disease duration, were enrolled. All patients completed the COMPASS-31. The quantification of cardiovascular autonomic dysfunction (CAD) was made using the two indices of the Composite Autonomic Scoring Scale (CASS): adrenergic index (AI) and cardiovagal index (CI).

Results:

In all pwNMOSD, COMPASS-31 was >0. Sympathetic dysfunction was present in 8 (40%), parasympathetic dysfunction in 10 (50%), and orthostatic hypotension in 6 (30%) pwNMOSD. This group of patients had higher frequency and level on the pupillomotor domain of the COMPASS-31 compared to pwMS ( p = 0.048 and p = 0.006, respectively). A binary logistic regression model showed that drop in diastolic blood pressure (dBP) during tilt-table test and normal function of autonomic nervous system, defined as AI = 0 and CI = 0, were independent predictors of pwNMOSD ( p = 0.042 and p = 0.029, respectively). If CAD was present, it was significantly worse in pwNMOSD compared to pwMS ( p = 0.003).

Conclusion:

Significant proportion of pwNMOSD experience dysautonomia, which seems to be different from dysautonomia observed in pwMS.

Traditional risk factors may not explain increased incidence of myocardial infarction in MS

Objective

To compare the risk of incident acute myocardial infarction (AMI) in the multiple sclerosis (MS) population and a matched population without MS, controlling for traditional vascular risk factors.

Methods

We conducted a retrospective matched cohort study using population-based administrative (health claims) data in 2 Canadian provinces, British Columbia and Manitoba. We identified incident MS cases using a validated case definition. For each case, we identified up to 5 controls without MS matched on age, sex, and region. We compared the incidence of AMI between cohorts using incidence rate ratios (IRR). We used Cox proportional hazards regression to compare the hazard of AMI between cohorts adjusting for sociodemographic factors, diabetes, hypertension, and hyperlipidemia. We pooled the provincial findings using meta-analysis.

Results

We identified 14,565 persons with MS and 72,825 matched controls. The crude incidence of AMI per 100,000 population was 146.2 (95% confidence interval [CI] 129.0–163.5) in the MS population and 128.8 (95% CI 121.8–135.8) in the matched population. After age standardization, the incidence of AMI was higher in the MS population than in the matched population (IRR 1.18; 95% CI 1.03–1.36). After adjustment, the hazard of AMI was 60% higher in the MS population than in the matched population (hazard ratio 1.63; 95% CI 1.43–1.87).

Conclusion

The risk of AMI is elevated in MS, and this risk may not be accounted for by traditional vascular risk factors.

[Ejaculation disorders in multiple sclerosis: Prospective study of 44 patients]

INTRODUCTION

To analyze in a descriptive way the ejaculation disorders during MS and to study the correlations between dysejaculations, other sexual, urinary and anorectal disorders.

MATERIAL

Prospective, monocentric, non-interventional study. Ejaculation disorders were assessed by Premature Ejaculation Profile (PEP) scores, intravaginal latency, and the Male Sexual Health Questionnaire - Ejaculation (MSHQ-Ej). The sexual disorders were evaluated by the International Index of Erectile Function (IIEF15) and the Sclerosis Intimacy and Sexuality Questionnaire-19 (MSISQ).

RESULTS

Forty-four men of mean age 46.8 (±10.3) years, with an average EDSS of 5.0 (±1.5) were included. According to the MSHQ-Ej score, ejaculation disorders were present in 28 out of 44 patients included (64%); 26/44 (59%) had an orgasm disorder, 23/44 (52%) a delay in ejaculation, 26/44 (59%) a decrease in ejaculation flow, 24/44 (55%) decreased ejaculated volume, 18/44 (41%) decreased ejaculation frequency, 15/44 (33%) ejaculatory pain and 11 34 (25%) showed systematic non ejaculation. The PEP score showed premature ejaculation in 14 patients (32%). The intra-vaginal latency time was less than 1minute in 6 patients (13.6%). There was a statistically significant correlation between ejaculation disorders and erectile dysfunction (P<0.05, correlation coefficient at 0.53) but no statistically significant correlation between ejaculation disorders and urinary or ano-rectal disorders.

CONCLUSIONS

Dysejaculation was present in 64% of MS. These disorders were mainly characterized by a decrease in the volume of the ejaculation, the strength of ejaculation and the delay in ejaculation.

LEVEL OF EVIDENCE

4.

Autonomic symptom burden can predict disease activity in early multiple sclerosis

BACKGROUND

We aimed to evaluate the role of autonomic nervous system (ANS) abnormalities on disease activity (relapses and new MRI lesions) and disease progression in people with clinically isolated syndrome (pwCIS).

METHODS

Out of 121 consecutive pwCIS, data on disease activity and progression after 2.9 (1.4-4.1) years of follow-up, was available for 94 pwCIS. Baseline characteristics included MRI parameters, Composite Autonomic System Score-31 (COMPASS-31), Composite Autonomic Scoring Scale, and supine and standing levels of epinephrine and norepinephrine.

RESULTS

Univariable logistic regression analysis revealed three predictors for occurrence of new relapse, COMPASS-31 > 7.32, total number of T2 lesions > 3 and decreasing supine level of epinephrine. The Kaplan-Meier survival analysis showed that patients with COMPASS-31 > 7.32 have statistically significant lower probability that they will be relapse free (p = 0.013). It has also showed that the relative risk reduction for occurrence of new relapse in participants with COMPASS < 7.32 was 46%. The multivariable regression model confirmed that COMPASS-31 > 7.32 and total number of T2 lesions > 3 increase the likelihood and the increasing supine level of epinephrine reduces the likelihood for a relapse. Finally, results of the Cox regression analysis showed, that after controlling for age, sex, total number of T2 lesions > 3 and supine level of epinephrine, the hazard for occurrence of new relapse for participants with COMPASS-31 > 7.32 is 2.7 times that of participants with COMPASS-31 < 7.32.

CONCLUSION

This study provides evidence that ANS is an important contributor to development of disease activity in pwCIS.

Role of the End-Point Mediators of Sympathoadrenal and Sympathoneural Stress Axes in the Pathogenesis of Experimental Autoimmune Encephalomyelitis and Multiple Sclerosis

The role of stress effector systems in the initiation and progression of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the most commonly used experimental model of MS, has strongly been suggested. To corroborate this notion, alterations in activity of the sympathoadrenal and sympathoneural axes of sympathoadrenal system (a major communication pathway between the central nervous system and the immune system), mirrored in altered release of their end-point mediators (adrenaline and noradrenaline, respectively), are shown to precede (in MS) and/or occur during development of MS and EAE in response to immune cell activation (in early phase of disease) and disease-related damage of sympathoadrenal system neurons and their projections (in late phase of disease). To add to the complexity, innate immunity cells and T-lymphocytes synthesize noradrenaline that may be implicated in a local autocrine/paracrine self-amplifying feed-forward loop to enhance myeloid-cell synthesis of proinflammatory cytokines and inflammatory injury. Furthermore, experimental manipulations targeting noradrenaline/adrenaline action are shown to influence clinical outcome of EAE, in a disease phase-specific manner. This is partly related to the fact that virtually all types of cells involved in the instigation and progression of autoimmune inflammation and target tissue damage in EAE/MS express functional adrenoceptors. Although catecholamines exert majority of immunomodulatory effects through β₂-adrenoceptor, a role for α-adrenoceptors in EAE pathogenesis has also been indicated. In this review, we summarize all aforementioned aspects of immunopathogenetic action of catecholamines in EAE/MS as possibly important for designing new strategies targeting their action to prevent/mitigate autoimmune neuroinflammation and tissue damage.

Impact of the Autonomic Nervous System on the Skeleton

It is from the discovery of leptin and the central nervous system as a regulator of bone remodeling that the presence of autonomic nerves within the skeleton transitioned from a mere histological observation to the mechanism whereby neurons of the central nervous system communicate with cells of the bone microenvironment and regulate bone homeostasis. This shift in paradigm sparked new preclinical and clinical investigations aimed at defining the contribution of sympathetic, parasympathetic, and sensory nerves to the process of bone development, bone mass accrual, bone remodeling, and cancer metastasis. The aim of this article is to review the data that led to the current understanding of the interactions between the autonomic and skeletal systems and to present a critical appraisal of the literature, bringing forth a schema that can put into physiological and clinical context the main genetic and pharmacological observations pointing to the existence of an autonomic control of skeletal homeostasis. The different types of nerves found in the skeleton, their functional interactions with bone cells, their impact on bone development, bone mass accrual and remodeling, and the possible clinical or pathophysiological relevance of these findings are discussed.

Burn injury and multiple sclerosis: A retrospective case-control study

OBJECTIVES

The purpose of this study was to determine whether having a previous diagnosis of multiple sclerosis (MS) changed acute care needs in burn-injured patients.

METHODS

This was a retrospective case-control study that included adult (aged ≥18years) patients with an acute burn injury. Control patients were matched with eleven patients with a history of MS at a 4:1 ratio. Outcomes included fluid resuscitation volumes, temperature, heart rate, mean arterial pressure, in-hospital complications, and hospital length of stay (LOS).

RESULTS

There were fifty-five patients included and of those, eleven had a documented history of MS. Fluid resuscitation volumes, temperature, heart rate, and mean arterial pressure were similar between groups during the resuscitation period (p>0.05). LOS was similar between both groups (12, IQR: 2-17 vs. median 16, IQR: 12-21; p=0.090). However, when normalized to % TBSA burn, patients with MS had a significantly higher median LOS/% TBSA burned (1.2, IQR: 0.7-2.0 vs. 2.1, IQR: 1.1-7.1; p=0.031).

CONCLUSIONS

Patients with concurrent burn injuries and MS have a significantly longer LOS/% TBSA burn suggesting that more time is required to heal their wounds. Surprisingly, there were no other significant differences in the after the burn acute phase between these two cohorts.

Progressive multiple sclerosis patients have a higher burden of autonomic dysfunction compared to relapsing remitting phenotype

OBJECTIVE

To determine autonomic dysfunction (AD) differences in patients with relapsing remitting multiple sclerosis (pwRRMS) and progressive MS (pwPMS).

METHODS

Composite autonomic scoring scale (CASS) and heart rate variability (HRV) were performed in 40 pwRRMS and 30 pwPMS.

RESULTS

pwPMS had a significantly higher sudomotor index and total CASS score compared to pwRRMS (p < 0.001 and p < 0.001, respectively). Disease duration positively correlated with sudomotor index and total CASS (r_s = 0.409, p < 0.001 and r_s = 0.472, p < 0.001, respectively), while the Expanded Disability Status Scale (EDSS) positively correlated with sudomotor index and total CASS (r_s = 0.411, p < 0.001 and r_s = 0.402, p = 0.001, respectively) in all patients. Type of multiple sclerosis (pwRRMS or pwPMS) corrected for age, sex and disease duration, was a statistically significant predictor of CASS value (B = 1.215, p = 0.019). Compared to pwRRMS, pwPMS had a significantly lower standard deviation of NN intervals (SDNN), low frequency (LF), and high frequency (HF), during both the supine and tilt-up phases (all p-values <0.006). pwPMS had a significantly lower LF/HF (p = 0.008) during tilt-up.

CONCLUSION

There is a significant difference in autonomic function in pwRRMS and pwPMS; with pwPMS having a higher burden of AD, which is particularly evident for sweating dysfunction.

SIGNIFICANCE

Further research is needed to establish whether parasympathetic and sudomotor dysfunction may serve as markers of progressive MS.

Depression and Age at First Neurology Appointment Associated with Receipt of Behavioral Medicine Services Within 1 Year in a Multiple Sclerosis Population

BACKGROUND

Patients with multiple sclerosis (MS) newly seen by a neurologist may benefit from early psychological intervention owing to the reciprocal relationship between stress and disease progression. However, it is uncertain what factors contribute to patients' receiving these services.

METHODS

Logistic regression analysis of prospectively gathered data evaluated how demographic and disease characteristics and emotional/physical health factors contributed to referral to receive behavioral medicine (BM) services within 1 year of their first neurology appointment at the Mellen Center for Multiple Sclerosis at the Cleveland Clinic. Survival analyses then evaluated whether this resulted in earlier receipt of services.

RESULTS

Although many factors were associated with receiving BM services during univariate analyses (age, race, marital status, years since MS onset, depression, stress, and quality of life), when considering multivariable interactions, only two variables remained significant: age (odds ratio [OR] = 0.86, 95% confidence interval [CI], 0.80-0.92) and depression (OR = 1.56, 95% CI, 1.39-1.75). Survival analyses did not show differences in time to BM services for stratifications of age or depression scores.

CONCLUSIONS

Younger patients and patients with more severe depression were more likely to receive BM services within 1 year of their first neurology appointment. Future research will focus on evaluating whether these are also the patients in greatest need of services or whether they are simply more open to receiving them.