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

Impact of the autonomic dysfunction on the quality of life in people with NMOSD and MS: An international cross-sectional study

BACKGROUND

A substantial autonomic nervous system (ANS) dysfunction has been described in multiple sclerosis (MS) and recently, also in neuromyelitis optica spectrum disorder (NMOSD). The prevalence of ANS symptoms contributes to the chronic symptom burden in both diseases. The aim of our study was to assess ANS dysfunction in people with (pw) NMOSD and MS, using the Composite Autonomic Symptom Score-31 (COMPASS-31), and additionally, to evaluate if ANS dysfunction have impact on the quality of life of these patients.

METHODS

We conducted cross-sectional study at three national referral neurological clinics in Serbia, Croatia, and Montenegro. A total of 180 consecutive subjects, 80 pwNMOSD and 100 pwMS, followed-up at these clinics, were enrolled in the study. Subjects included in the study completed: the validated versions of the COMPASS-31 and the Multiple Sclerosis Quality of Life-54 (MSQoL-54), and the Beck Depression Inventory (BDI).

RESULTS

This study demonstrated that the total COMPASS-31 score > 0.0, implicating the presence of ANS dysfunction, was detected in almost all NMOSD and MS study participants tested (80/80, and 97/100, respectively). Our findings showed that autonomic symptom burden was statistically significantly correlated with decreased quality of life, in both NMOSD and MS cohorts. The independent predictors of the better quality of life in pwNMOSD were lower autonomic burden, particularly the absence of the orthostatic intolerance (p = 0.005), along with lower EDSS and BDI score (p ≤ 0.001). Similarly, in pwMS, independent predictors were EDSS, BDI, orthostatic intolerance, and the total COMPASS-31 (p ≤ 0.001).

CONCLUSION

Our study demonstrated that a significant proportion of persons with both NMOSD and MS have considerable dysautonomic symptom burden which is correlated with the decreased quality of life. Further investigations are warranted in order to optimize treatment interventions in MS and NMOSD.

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.

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.

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.

Understanding and managing autonomic dysfunction in persons with multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic demyelinating immune mediated disease of the central nervous system. Autonomic dysfunction (AD) is frequently present in persons with MS (pwMS) and increases with disease duration and progression.

AREAS COVERED

Cardiovascular, genitourinary, and sudomotor autonomic dysfunction in pwMS are reviewed and managing of these disorders is addressed.

EXPERT OPINION

AD in pwMS can manifest with a myriad of symptoms including cardiovascular, urogenital, and sweating disorders. These symptoms can significantly impact the quality of life of pwMS with poor tolerance of upright position, difficulties in sexual function, and low endurance of physical activity especially in warm environments. Health professionals involved in care of pwMS should possess basic knowledge of the function of the autonomic nervous system and be informed of the way disorders of the autonomic function may manifest in pwMS in order to provide the proper care.

Peripheral nervous system in multiple sclerosis-understanding the involvement via autonomic nervous system

AIM

The aim of this review is to summarize the clinical and paraclinical findings that demonstrate that multiple sclerosis (MS) affects the peripheral nervous system (PNS) as well as the central nervous system (CNS). Methods: Narrative review.

RESULTS

MS is traditionally defined as a chronic demyelinating immune-mediated disease of the CNS. However, there is emerging evidence that MS is a disease that does not solely affect the CNS but can manifest with PNS involvement as well. Several pathology studies have reported on signs of demyelination in the PNS, as well as on structural and functional involvement of the PNS in persons with MS (pwMS). From the functional aspect, several studies have shown autonomic nervous system (ANS) involvement in the form of sudomotor dysfunction measured with quantitative sudomotor axon reflex test (QSART) in different stages of MS, adding to the growing body of evidence that indicate PNS involvement in MS. In this review the clinical, pathological, neurophysiological, and imaging findings that demonstrate that MS affects the PNS as well as the CNS are summarized, with the emphasis on the ANS abnormalities.

CONCLUSION

Further large-scale research is needed in order to fully understand the frequency and importance of PNS affection in MS.

Gastrointestinal dysfunction in neuroinflammatory diseases: Multiple sclerosis, neuromyelitis optica, acute autonomic ganglionopathy and related conditions

Disorders of the nervous system can produce a variety of gastrointestinal (GI) dysfunctions. Among these, lesions in various brain structures can cause appetite loss (hypothalamus), decreased peristalsis (presumably the basal ganglia, pontine defecation center/Barrington's nucleus), decreased abdominal strain (presumably parabrachial nucleus/Kolliker-Fuse nucleus) and hiccupping and vomiting (area postrema/dorsal vagal complex). In addition, decreased peristalsis with/without loss of bowel sensation can be caused by lesions of the spinal long tracts and the intermediolateral nucleus or of the peripheral nerves and myenteric plexus. Recently, neural diseases of inflammatory etiology, particularly those affecting the PNS, are being recognized to contribute to GI dysfunction. Here, we review neuroinflammatory diseases that potentially cause GI dysfunction. Among such CNS diseases are multiple sclerosis, neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein associated disorder, and autoimmune encephalitis. Peripheral nervous system diseases impacting the gut include Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, acute sensory-autonomic neuropathy/acute motor-sensory-autonomic neuropathy, acute autonomic ganglionopathy, myasthenia gravis and acute autonomic neuropathy with paraneoplastic syndrome. Finally, collagen diseases, such as Sjogren syndrome and systemic sclerosis, and celiac disease affect both CNS and PNS. These neuro-associated GI dysfunctions may predate or present concurrently with brain, spinal cord or peripheral nerve dysfunction. Such patients may visit gastroenterologists or physicians first, before the neurological diagnosis is made. Therefore, awareness of these phenomena among general practitioners and collaboration between gastroenterologists and neurologists are highly recommended in order for their early diagnosis and optimal management, as well as for systematic documentation of their presentations and treatment.

Cardiac autonomic function in patients with early multiple sclerosis

PURPOSE

Cardiac autonomic dysfunction has been reported in patients with long-standing multiple sclerosis (MS); however, data in early disease are limited. The present study was aimed at evaluating cardiac autonomic function in patients with early MS in the context of white matter metabolic status, which could potentially affect functions of the autonomic brain centers.

METHODS

Cardiac sympathetic and baroreflex cardiovagal responses to the Valsalva maneuver, orthostatic test, and the Stroop test were evaluated in 16 early, treatment-naïve patients with relapsing-remitting MS, and in 14 healthy participants. Proton magnetic resonance spectroscopic imaging (MRSI) of the brain was performed in eight of these MS patients and in eight controls.

RESULTS

Valsalva maneuver outcomes were comparable between patients and controls. At baseline, norepinephrine levels were lower (p = 0.027) in MS patients compared to controls. The patients had higher heart rate (p = 0.034) and lower stroke volume (p = 0.008), but similar blood pressure, cardiac output and norepinephrine increments from baseline to 2 min of the orthostatic test compared to controls. MS patients and controls did not differ in responses to the Stroop test. MRSI showed lower total N-acetylaspartate/total creatine (p = 0.038) and higher myo-inositol/total creatine (p = 0.013) in MS lesions compared to non-lesional white matter.

CONCLUSION

Our results show normal cardiac sympathetic and baroreflex cardiovagal function in MS patients with relapsing-remitting MS with lesions at the post-acute/early resolving stage.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov under the Identifier: NCT03052595 and complies with the STROBE checklist for cohort, case-control, and cross-sectional studies.

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.

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.

Delayed high-grade atrioventricular block requiring pacemaker implantation in a multiple sclerosis patient treated with fingolimod

Fingolimod is a sphingosine-1-phosphate 1 (S1P1) modulator which retains lymphocytes in secondary lymphoid organs and is approved for the treatment of relapsing multiple sclerosis (MS). The decrease of heart rate and AV block are reversible side-effects of treatment initiation. We report a case of persistent high-grade atrioventricular (AV) block 450 days after start of fingolimod and permanent pacemaker requirement in late-onset relapsing multiple sclerosis (MS). We discuss emerging risk factors for cardiac conduction deficits including the recently discovered vagomimetic effects of S1P1 modulation, structural brain and spinal cord damage, ageing and comorbidities.