Cardiac stunning as first manifestation of multiple sclerosis: A case report reminding us not to overlook cardiovascular autonomic dysfunction in multiple sclerosis

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.

Validation of the Composite Autonomic Symptom Score 31 in the German language

Background

The Composite Autonomic Symptom Score 31 (COMPASS 31) is a validated, 31-item self-assessment questionnaire assessing autonomic symptoms in six domains, orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor function. So far, there is no validated German COMPASS 31 version. This study aimed at developing and validating a German COMPASS 31.

Methods

Two autonomic experts with command of German and English independently translated the English COMPASS 31 into German. One agreed-upon German version was translated back into English to assure conformity with the original version. Twenty patients with possible autonomic symptoms and 20 age- and gender-matched healthy persons completed the English and German COMPASS 31 in a randomized order with a 4-week interval. To evaluate reliability of the German COMPASS 31, total scores and sub-scores of the domains assessed with the German version were correlated with corresponding scores of the English version using Pearson’s or Spearman’s test. The Cronbach alpha-coefficient evaluated the internal consistency of the questions. Total- and sub-scores of both COMPASS 31 versions were compared between patients and controls by analysis of variance with post-hoc analysis (significance: p < 0.05).

Results

Total scores and sub-scores of the German and English COMPASS 31 correlated significantly (p < 0.001) and closely (correlation coefficients: 0.757–0.934). Cronbach alpha-coefficients were above 0.7 in all domains except for the secretomotor domain. In the German and English COMPASS 31, total scores were significantly higher in patients than controls.

Conclusions

The German COMPASS 31 is reliable, internally consistent, and valid to detect and quantify autonomic symptoms in patients with neurological disorders.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05764-4.

The Brain-Heart Link: A Case Report of a Critically Located Multiple Sclerosis Lesion in the Brainstem Leading to Recurrent Takotsubo Syndrome

Various central nervous system (CNS) diseases, including neurovascular and neuroinflammatory diseases, can lead to stress cardiomyopathy, also known as Takotsubo syndrome (TTS). We present a case of a 69-year-old woman with cardiovascular comorbidities, suffering from repeated episodes of TTS and respiratory failure due to a critical lesion in the brainstem, leading to a diagnosis of multiple sclerosis (MS). Despite aggressive treatment, intractable and recurrent symptoms in our patient occurred. Repeated bouts of autonomic dysfunction and respiratory failure ultimately led to installment of palliative care and the patient passing away. TTS should raise suspicion for underlying neurological diseases. Thorough questioning of previous neurological symptoms and extensive neurological workup is warranted. MS should be considered as a trigger of TTS also in elderly patients with cardiovascular risk factors.

Autonomic dysfunctions in multiple sclerosis: Challenges of clinical practice (Review)

Multiple sclerosis, demyelinating, inflammatory, degenerative, and chronic disease, raises many challenges in terms of disease management. The autonomic nervous system is affected by neuroinflammation but also contributes to its maintenance and the evolution of the disease. Multiple sclerosis interfering with parasympathetic or sympathetic modulation may influence the immune response. Less attention is paid to autonomic dysfunctions, although they produce a serious impact on the quality of life. In addition to motor disabilities, patients also have non-motor dysfunctions. Regardless of its clinical forms, patients with multiple sclerosis may have autonomous disturbances such as bladder, sexual, cardiovascular, thermoregulatory, gastrointestinal dysfunction and fatigue. These must be identified based on medical history, clinical symptoms, and specific paraclinical tests. In addition to the multitude of immunomodulatory therapeutic agents that influence the progression of the disease, the therapy of autonomic dysfunctions remains difficult to address. However, their identification and treatment lead to increased quality of patient management and avoid complications of this disease.

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.

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.

Cerebral lesion correlates of sympathetic cardiovascular activation in multiple sclerosis

Cardiovascular autonomic dysfunction is common in multiple sclerosis (MS) and contributes significantly to disability. We hypothesized that cerebral MS‐lesions in specific areas of the central autonomic network might account for imbalance of the sympathetic and parasympathetic cardiovascular modulation. Therefore, we used voxel‐based lesion symptom mapping (VLSM) to determine associations between cardiovascular autonomic dysfunction and cerebral MS‐related lesion sites. In 74 MS‐patients (mean age 37.0 ± 10.5 years), we recorded electrocardiographic RR‐intervals and systolic and diastolic blood pressure. Using trigonometric regressive spectral analysis, we assessed low (0.04–0.15 Hz) and high (0.15–0.5 Hz) frequency RR‐interval‐and blood pressure‐oscillations and determined parasympathetically mediated RR‐interval–high‐frequency modulation, mainly sympathetically mediated RR‐interval–low‐frequency modulation, sympathetically mediated blood pressure‐low‐frequency modulation, and the ratios of sympathetic and parasympathetic RR‐interval‐modulation as an index of sympathetic‐parasympathetic balance. Cerebral MS‐lesions were analyzed on imaging scans. We performed a VLSM‐analysis correlating parameters of autonomic dysfunction with cerebral MS‐lesion sites. The VLSM‐analysis showed associations between increased RR‐interval low‐frequency/high‐frequency ratios and lesions most prominently in the left insular, hippocampal, and right frontal inferior opercular region, and a smaller lesion cluster in the right middle cerebellar peduncle. Increased blood pressure‐low‐frequency powers were associated with lesions primarily in the right posterior parietal white matter and again left insular region. Our data indicate associations between a shift of cardiovascular sympathetic‐parasympathetic balance toward increased sympathetic modulation and left insular and hippocampal lesions, areas of the central autonomic network. The VLSM‐analysis further distinguished between right inferior fronto‐opercular lesions disinhibiting cardiac sympathetic activation and right posterior parietal lesions increasing sympathetic blood pressure modulation.

Brain MRI Lesions are Related to Bowel Incontinence in Multiple Sclerosis

BACKGROUND AND PURPOSE

Bowel incontinence in multiple sclerosis might be associated with specific lesion sites. This study intended to determine associations between bowel incontinence and cerebral multiple sclerosis lesions using a voxel-wise lesion symptom mapping analysis.

METHODS

We conducted a retrospective study of multiple sclerosis patients with self-reported bowel incontinence and matched controls. Lesions were manually outlined on T2-weighted MRI scans and transformed into stereotaxic space. We performed a voxel-wise subtraction analysis subtracting the lesion overlap of patients without from patients with bowel incontinence. Finally, we compared the absence or presence of bowel incontinence between patients with and without lesions in a given voxel using the Liebermeister test.

RESULTS

A total of 51 patients were included in the study. The analysis yielded associations between bowel incontinence and lesions in the supramarginal gyrus of the left secondary somatosensory cortex and another lesion cluster in the right parahippocampal gyrus and amygdala.

CONCLUSIONS

Our analysis indicates associations between bowel incontinence and lesions in the left supramarginal gyral area contributing to integrating anorectal-visceral sensation and in the right parahippocampal gyrus and amygdala contributing to generating visceral autonomic arousal states. Moreover, our results suggest left hemispheric dominance of sensory visceral integration, while limbic areas of the right hemisphere seem to contribute to the autonomic component of the defecation process. A limitation of our study is the retrospective evaluation of the bowel incontinence status based on medical records. Further research should evaluate the bowel incontinence status in multiple sclerosis patients prospectively to overcome the limitations of the current study.

Insular multiple sclerosis lesions are associated with erectile dysfunction

Erectile function (EF) is frequently compromised in men with multiple sclerosis (MS). Functional neuroimaging in healthy men identified a network of brain areas, such as the insula, visual and somatosensory association areas, cingulate gyrus, prefrontal cortex, as well as subcortical regions, contributing to EF. This study intended to determine associations between EF deterioration during MS and cerebral MS-associated lesion sites. In 31 men with MS (mean age 38.2 ± 11.2 years), we evaluated MS-related EF deterioration by comparing scores of the 5-item International Index of Erectile Function-5 questionnaire (IIEF5) at the time of study and retrospectively, 3 months prior to MS diagnosis, by calculating score differences as DeltaIIEF5 (DeltaIIEF5 score < 0 indicated EF deterioration). To assess the impact of confounding factors of EF, patient age, disease duration, disease severity, depressiveness, bladder and bowel symptoms, and total cerebral MS lesion volume were correlated with DeltaIIEF5 scores (Spearman rank correlation) and compared between patients with and without EF deterioration (t tests or Mann-Whitney U test). MS lesions were assessed on T2-weighted magnetic resonance imaging (MRI; 1.5 or 3 T). We determined the lesion overlap (prevalence of identical lesion sites among patients), subtracted lesion overlaps in patients without EF deterioration from overlaps in patients with EF deterioration, and compared DeltaIIEF5 scores voxel-wise between patients with and without lesions in a given voxel (t test; significance: p < 0.05). In 14 patients (45.2%), DeltaIIEF5 scores indicated EF deterioration. DeltaIIEF5 scores were not associated with age (ρ = 0.06; p = 0.74), disease duration (ρ = 0.26; p = 0.15), disease severity (ρ = - 0.19; p = 0.31), depressiveness (ρ = 0.07; p = 0.72), bladder symptoms (ρ = - 0.11; p = 0.57), bowel symptoms (ρ = 0.17; p = 0.37), and total lesion volume (ρ = - 0.13; p = 0.47). The voxel-wise analysis showed associations between EF deterioration and MS lesions primarily in the bilateral, and predominantly left juxtacortical insular region. In conclusion, MS lesions particularly in the left insular region, which is activated with sexual arousal, contribute to erectile dysfunction.

Fingolimod initiation in multiple sclerosis patients is associated with potential beneficial cardiovascular autonomic effects

BACKGROUND

Fingolimod slows heart rate (HR) due to vagomimetic effects and might cause additional cardiovascular autonomic changes. While the time course of HR changes is well described, the extent and course of cardiovascular autonomic changes upon fingolimod initiation has not yet been evaluated. This study, therefore, intended to assess cardiovascular autonomic changes during the first 6 h after fingolimod initiation.

METHODS

In 21 patients with relapsing-remitting multiple sclerosis (RRMS), we recorded respiration (RESP), electrocardiographic RR interval (RRI), systolic and diastolic blood pressure (BPsys, BPdia) at rest, before and 0.5, 1, 2, 3, 4, 5, and 6 h after fingolimod initiation. We calculated parameters of total autonomic modulation [RRI standard deviation (RRI-SD), RRI coefficient of variation (RRI-CV), RRI-total powers], mainly sympathetic cardiac modulation [RRI low frequency (LF) powers], sympathetic BP modulation (BPsys-LF powers), parasympathetic modulation [square root of the mean squared difference of successive RRIs (RMSSD), RRI high frequency (HF) powers], sympatho-vagal cardiac balance (RRI-LF/HF ratios), and baroreflex sensitivity (BRS). We compared parameters between the eight measurements [analysis of variance (ANOVA) or Friedman test with post-hoc analysis; significance: p < 0.05].

RESULTS

After fingolimod initiation, RESP, BPsys, and BPsys-LF powers remained unchanged while RRIs, RRI-CV, RRI-SD, RRI-total powers, RRI-LF powers, RMSSD, RRI-HF powers, and BRS increased after 1 h and rose to peak values occurring after 5, 1, 2, 2, 1, 4, 4, and 4 h, respectively. After 3 h, BPdia had decreased significantly and was lowest after 5 h. RRI-LF/HF ratios decreased to a nadir after 4 h.

CONCLUSIONS

The increases in parasympathetic and overall cardiac autonomic modulation and in BRS seen with fingolimod initiation are theoretically beneficial for the MS patient's cardiovascular system. However, long-term studies must show whether these effects persist or are attenuated (e.g. due to S1P1 receptor down-regulation upon continued fingolimod therapy).