Effects of Systolic Blood Pressure on Brain Integrity in Multiple Sclerosis

The Role of Extracellular Vesicles and Microparticles in Central Nervous System Disorders: Mechanisms, Biomarkers, and Therapeutic Potential

Microscopic, membranous vesicles known as extracellular vesicles (EVs) have been proposed to play a role in the mechanisms underlying central nervous system (CNS) diseases. EVs are secreted by a variety of cells, including myeloid, endothelial, microglial, oligodendroglial, and mesenchymal stem cells (MSCs). Body fluids such as plasma, urine, and cerebrospinal fluid (CSF) contain microparticles (MPs). The detection of MPs in CSF may indicate genetic or environmental susceptibility to conditions such as schizophrenia, schizoaffective disorder, and bipolar disorder. MPs of different origins can exhibit changes in specific biomarkers at various stages of the disease, aiding in the diagnosis and monitoring of neurological conditions. However, understanding the role and clinical applications of MPs is complicated by challenges such as their isolation and dual roles within the CNS. In this review, we discuss the history, characteristics, and roles of MPs in CNS diseases. We also provide practical insights for future research and highlight the challenges that obscure the therapeutic potential of MPs.

Investigating the Interplay between Cardiovascular and Neurodegenerative Disease

Neurological diseases, including neurodegenerative diseases (NDDs), are the primary cause of disability worldwide and the second leading cause of death. The chronic nature of these conditions and the lack of disease-modifying therapies highlight the urgent need for developing effective therapies. To accomplish this, effective models of NDDs are required to increase our understanding of underlying pathophysiology and for evaluating treatment efficacy. Traditionally, models of NDDs have focused on the central nervous system (CNS). However, evidence points to a relationship between systemic factors and the development of NDDs. Cardiovascular disease and related risk factors have been shown to modify the cerebral vasculature and the risk of developing Alzheimer's disease. These findings, combined with reports of changes to vascular density and blood-brain barrier integrity in other NDDs, such as Huntington's disease and Parkinson's disease, suggest that cardiovascular health may be predictive of brain function. To evaluate this, we explore evidence for disruptions to the circulatory system in murine models of NDDs, evidence of disruptions to the CNS in cardiovascular disease models and summarize models combining cardiovascular disruption with models of NDDs. In this study, we aim to increase our understanding of cardiovascular disease and neurodegeneration interactions across multiple disease states and evaluate the utility of combining model systems.

Comorbid Conditions and Physical Function in Adults With Multiple Sclerosis

OBJECTIVE

We examined the total number of comorbid conditions as a correlate of physical function in persons with multiple sclerosis (MS). We further identified the presence of common comorbid conditions and examined physical function outcomes based on presence or absence of the comorbid conditions in persons with MS.

DESIGN

Cross-sectional, comparative study.

SETTING

University-based laboratory.

PARTICIPANTS

Two hundred seven persons with MS (N=207) completed the study.

MAIN OUTCOME MEASURES

Participants provided demographic, clinical, and comorbidity information. Participants then completed the 6-minute walk (6MW), timed 25-foot walk (T25FW), timed Up and Go (TUG), and short physical performance battery (SPPB).

INTERVENTIONS

Not applicable.

RESULTS

The number of comorbid conditions was associated with 6MW, T25FW, TUG, and SPPB scores (all P≤.001). Persons with MS who had hypertension performed worse on the 6MW, T25FW, TUG, and SPPB than persons without hypertension. Persons who had osteoarthritis performed worse on the 6MW, T25FW, and SPPB than persons without osteoarthritis.

CONCLUSIONS

The results demonstrate that persons who report more comorbid conditions have worse physical function, and this may largely be associated with hypertension or osteoarthritis. There are opportunities for the design of behavioral interventions that target physical activity and/or diet for improving physical function via comorbid conditions in persons with MS.

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.

Vascular dysfunction in multiple sclerosis: Scoping review of current evidence for informing future research directions

BACKGROUND

The research involving vascular comorbidity in people with multiple sclerosis (MS) could be advanced through investigations applying measurements of vascular function such as pulse wave velocity or flow mediated dilation as mechanistic endpoints in the study of physical comorbidity management in MS across the lifespan. We conducted a scoping review of research on vascular function parameters and outcomes in MS and developed a research agenda for future inquiry.

METHODS

We searched PubMed from inception through February 2023 for articles involving relevant central and peripheral vascular function data or correlates of vascular function (arterial stiffness, endothelial function, blood pressure parameters, etc.) in conjunction with relevant outcomes (walking function, cognition, etc.) in MS. Studies were limited to English-language and primary research articles.

RESULTS

Our search and subsequent screening identified 10 relevant articles. Four papers focused on arterial stiffness and reported pulse wave velocity and arterial compliance in MS compared with controls. Two papers focused on endothelial function and reported flow-mediated dilation in MS compared with controls. There was evidence that arterial stiffness and endothelial function were associated with cognition and disease progression in MS, respectively. One paper reported that physical activity was associated with arterial stiffness in MS. There was one protocol paper examining the effect of a home-based exercise program on markers of subclinical atherosclerosis; however, the results are unpublished, and there was no literature beyond this surrounding the impact of lifestyle behavior (e.g., diet) or exercise interventions on vascular function.

CONCLUSION

There is emerging evidence for vascular dysfunction in MS, and this is associated with cognition and disease progression; we know very little about approaches for managing vascular dysfunction in MS. To that end, we offer an agenda for research on measurements and outcomes of vascular function in relation to MS and disease attributes, along with proposed mechanisms and lifestyle changes that could aid in managing vascular dysfunction.

Blood pressure and cognition in older adults with multiple sclerosis: preliminary examination

BACKGROUND

Comorbid conditions, particularly vascular comorbidity, are common in MS and may hasten the CNS damage and disease manifestations. We undertook a preliminary examination of the association between blood pressure (BP) and cognitive function in samples of older adults with MS and healthy controls.

METHODS

Older adults with MS (n = 29) and healthy controls (n = 29) completed the Brief International Cognitive Assessment for MS (BICAMS) battery and underwent assessment of BP. The data were analyzed using the Baron and Kenny approach for examining blood pressure as an explanatory variable for group differences in cognition.

RESULTS

The MS group, as expected, had significantly lower California Verbal Learning Test-II (CVLT-II) z-scores from the BICAMS and higher diastolic BP (DBP) than healthy controls. DBP had statistically significant correlations with CVLT-II z-scores in the overall sample (r =  - .42) and MS subsample (r =  - .51), but not healthy controls(r =  - .29); the correlation was not attenuated when controlling for age and disability status in the MS subsample (pr =  - .48). Group initially explained 6% of the variance in z-scores from the CVLT-II (β =  - 0.24). The inclusion of DBP accounted for an additional 14% of the variance in z-scores from the CVLT-II, and DBP(β =  - 0.39), but not group (β =  - 0.13), was a significant correlate of CVLT-II z-scores; the results were unchanged when controlling for anxiety and depression scores.

CONCLUSION

Our results provide preliminary, cross-sectional support for future population-based research examining DBP, hypertension, and verbal memory in older adults with MS.

Dietary Patterns and Metabolic Disorders in Polish Adults with Multiple Sclerosis

Diet plays a major role in the aetiopathogenesis of many neurological diseases and may exacerbate their symptoms by inducing the occurrence of metabolic disorders. The results of research on the role of diet in the course of multiple sclerosis (MS) are ambiguous, and there is still no consensus concerning dietary recommendations for patients with MS. The aim of this study was to analyse the dietary patterns (DPs) of patients with MS and to assess the relationships between these DPs and the metabolic disorders. The study participants were comprised of 330 patients aged 41.9 ± 10.8 years. A survey questionnaire was used to collect data related to diet, lifestyle and health. The DPs were identified using a principal component analysis (PCA). Three DPs were identified: Traditional Polish, Prudent and Fast Food & Convenience Food. An analysis of the odds ratios adjusted for age, gender, smoking and education showed that a patient’s adherence to the Traditional Polish and the Fast Food & Convenience Food DPs increased the likelihood of abdominal obesity and low HDL-cholesterol concentration. Conversely, adherence to the Prudent DP was not significantly associated with any metabolic disorder. The results of this study confirmed that an unhealthy diet in patients with MS is connected with the presence of some metabolic risk factors. There is also an urgent need to educate patients with MS on healthy eating, because the appropriate modifications to their diet may improve their metabolic profile and clinical outcomes.

Association of blood pressure with brain structure in youth with and without bipolar disorder

BACKGROUND

We previously found that blood pressure (BP) is elevated, and associated with poorer neurocognition, in youth with bipolar disorder (BD). While higher BP is associated with smaller brain structure in adults, studies have not examined this topic in BD or youth.

METHODS

Participants were 154 youth, ages 13-20 (n = 81 BD, n = 73 HC). Structural magnetic resonance imaging and diastolic (DBP), and systolic (SBP) pressure were obtained. Region of interest (ROI; anterior cingulate cortex [ACC], insular cortex, hippocampus) and vertex-wise analyses controlling for age, sex, body-mass-index, and intracranial volume investigated BP-neurostructural associations; a group-by-BP interaction was also assessed.

RESULTS

In ROI analyses, higher DBP in the overall sample was associated with smaller insular cortex area (β=-0.18 p = 0.007) and was associated with smaller ACC area to a significantly greater extent in HC vs. BD (β=-0.14 p = 0.015). In vertex-wise analyses, higher DBP and SBP were associated with smaller area and volume in the insular cortex, frontal, parietal, and temporal regions in the overall sample. Additionally, higher SBP was associated with greater thickness in temporal and parietal regions. Finally, higher SBP was associated with smaller area and volume in frontal, parietal, and temporal regions to a significantly greater extent in BD vs. HC.

LIMITATIONS

Cross-sectional design, single assessment of BP.

CONCLUSION

BP is associated with brain structure in youth, with variability related to structural phenotype (volume vs. thickness) and psychiatric diagnosis (BD vs. HC). Future studies evaluating temporality of these findings, and the association of BP changes on brain structure in youth, are warranted.

Smoking, cardiovascular risk factors and LRP2 gene variation: Associations with disease severity, cognitive function and brain structure in primary progressive multiple sclerosis

BACKGROUND

Smoking, cardiovascular risk factors, and genetic factors can have adverse effects in MS.

OBJECTIVE

To determine if smoking after disease onset, cardiovascular risk factors, and genetic variants influence primary progressive MS (PPMS).

METHOD

In this cross-sectional study, smoking habits, Framingham Risk Score (FRS), genetic variants, including the low-density lipoprotein receptor-related protein 2 (LRP2) SNP rs12988804 and MRI were collected in 60 PPMS trial participants. Disability and cognition were assessed with the Age-Related Multiple Sclerosis Severity (ARMSS) score, the Progressive-Onset MS Multiple Sclerosis Severity Score, and the Brief International Cognitive Assessment for MS.

RESULTS

Smoking after PPMS onset was significantly associated with higher ARMSS (95% CI 0.8-2.4, p = 0.00016) statistically significant after Bonferroni correction. Lower magnetization transfer ratio in lesions was also significantly associated with smoking after onset of PPMS after correction (95% CI -0.9--4.4, p = 0.0035). Pack-years in people who smoked after onset was likewise significantly associated with higher ARMSS score (b = 0.06 95% CI 0.02-0.09, p = 0.0021) as well as lower Symbol Digit Modalities Test scores (b = -0.40; 95% CI -0.66--0.13, p = 0.0037), both statistically significant after Bonferroni correction. The LRP2 risk allele was associated with decreased performance on the California Verbal Learning Test 2 after correction (CC vs. CT+TT 95% CI -14.2--3.4, p = 0.0018).

CONCLUSION

If validated, these findings suggest that intervention regarding smoking may be beneficial in PPMS. If confirmed, assessment of the LRP2 gene variant may aid in the understanding of underlying pathological mechanisms in PPMS.

Characterizing relapsing remitting multiple sclerosis patients burdened with hypertension, hyperlipidemia, and asthma

BACKGROUND

Hypertension, hyperlipidemia, and asthma are common in multiple sclerosis (MS) patients and adversely impact physical and mental health independent of sociodemographic and clinical attributes. Characterizing MS patients with these comorbidities is necessary for informing comorbidity screening and managed care in vulnerable patient subgroups; however, there is sparse data currently available.

METHODS

We conducted cross-sectional analyses of 2,012 relapsing remitting (RR) MS patients. Separate multivariable logistic regression models were conducted for the presence of hypertension, hyperlipidemia, and asthma. Independent variables included age, sex, race, MS duration, body mass index classification, insurance payer, smoking status, median income by residence ZIP code, disease modifying therapies, and the other comorbidities.

RESULTS

Hypertension was more common in RRMS patients who were older, obese/severely obese, had hyperlipidemia, were asthmatics, living in neighborhoods with the lowest income, and who were Black Americans. RRMS patients with hyperlipidemia were more likely to be male, older, overweight/obese/severely obese, hypertensive, asthmatics, and White American. Asthmatic RRMS patients were more likely to be female, obese, hypertensive, and living in neighborhood of medium/low income, and less likely to be on interferons or glatiramer acetate.

CONCLUSION

We identified factors independently associated with common comorbidity burden in RRMS patients, which will inform risk-stratification efforts aimed at mitigating the adverse impact of these conditions in MS patients. Our results are consistent with what is known about the determinants of hypertension, hyperlipidemia, and asthma in the non-MS patient population, and therefore disparities that exist in screening and management in the general U.S. population may likely exist in U.S. MS patients. It is also possible that there may be unique differences in specific MS patient subgroups, which warrants further investigation and detailed characterization.

Cerebrovascular disease, multiple sclerosis, or both? Case report and review of the challenging distinction between two potentially synergistic syndromes

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White matter changes (WMC) are frequently observed in clinical practice, particularly in the context of cognitive dysfunction.

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Determining the cause of WMC has practical implications, because treatment and prognosis depend on the underlying disease process.

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Multiple Sclerosis (MS) can be confused with Small Vessel Cerebrovascular Disease (SVCVD), leading to a wrong diagnosis.

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MS patients may have coexisting cardiovascular risk factors and signs of cerebrovascular disease, further undermining white matter tracts.

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Careful review of neuroimaging and past medical history is recommended in young individuals with presumptive diagnosis of vascular dementia to rule out MS.

White matter changes (WMC) are frequently observed in clinical practice, but their clinical relevance is often obscured by radiology reports that do not clearly convey a likely diagnosis. In this regard, two attitudes contribute to diagnostic confusion: a tendency to dismiss findings as trivial (i.e., using vague characterizations such as “non-specific” or “normal for age”), and a gratuitous dilatation of the differential diagnosis (i.e., routinely adding rare diseases to the list, such as vasculitis). Very often, the finding of WMC presents physicians with a very practical problem, which is to determine whether the underlying etiology is an autoimmune demyelinating disease such as multiple sclerosis (MS), or a vasculopathy such as small vessel cerebrovascular disease (SVCVD). The implications of this distinction are great, because the treatment and prognosis of these two syndromes are very different. Here, we describe the challenging case of a relatively young woman with dementia due to a combination of MS and cerebrovascular disease.

The prevalence of hypertension in multiple sclerosis based on 37 million electronic health records from the United States

BACKGROUND AND PURPOSE

Hypertension (HTN) is a common comorbidity in multiple sclerosis (MS), and it significantly contributes to adverse outcomes. Unfortunately, the distribution of HTN in persons with MS has not been well characterized, and prior estimates have primarily relied on modest sample sizes. The objective of this study was to robustly describe the distribution of HTN in the MS population in comparison to the non-MS population with considerations for age, sex, and race. To date, this is the largest investigation of its kind.

METHODS

We conducted a cross-sectional study of 37 million unique electronic health records available in the IBM Explorys Enterprise Performance Management: Explore database (Explorys) spanning the United States. This resource has previously been validated for use in MS. We evaluated the prevalence of HTN in MS (N = 122 660) and non-MS (N = 37 075 350) cohorts, stratifying by age, sex, and race.

RESULTS

The prevalence of HTN was significantly greater among those with MS than among those without MS across age, sex, and race subpopulations, even after adjusting for age and sex. HTN was 25% more common in MS. In both MS and non-MS cohorts, the prevalence of HTN progressively increased with age and was higher in Black Americans and in males.

DISCUSSION

This study demonstrated that HTN is significantly more common in the MS population compared to the non-MS population, irrespective of sex and race. Because HTN is the leading global risk factor for disability and death, these results emphasize the need for aggressive screening for, and management of, HTN in the MS population.

Dietary factors in experimental autoimmune encephalomyelitis and multiple sclerosis: A comprehensive review

BACKGROUND

Dietary intervention in multiple sclerosis carries potential therapeutic implications. While studies utilizing animal models of multiple sclerosis (MS) have demonstrated intriguing findings, well-designed clinical trials are few in number.

OBJECTIVE

The objective of this study is to review the animal model and clinical literature regarding dietary factors in experimental autoimmune encephalitis (EAE) and MS.

METHODS

This manuscript provides a comprehensive review of current animal model and clinical knowledge related to dietary factors in MS.

RESULTS

While there is currently little data for any specific diet in MS, there is growing evidence that certain dietary factors may influence the disease.

CONCLUSIONS

Definitive information regarding dietary factors as a modifiable risk factor in MS will require larger randomized clinical trials.

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.

Vascular aspects of multiple sclerosis: emphasis on perfusion and cardiovascular comorbidities

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system. Over the last two decades, more favorable MS long-term outcomes have contributed toward increase in prevalence of the aged MS population. Emergence of age-associated pathology, such as cardiovascular diseases, may interact with the MS pathophysiology and further contribute to disease progression. Areas covered: This review summarizes the cardiovascular involvement in MS pathology, its disease activity, and progression. The cardiovascular health, the presence of various cardiovascular diseases, and their effect on MS cognitive performance are further explored. In similar fashion, the emerging evidence of a higher incidence of extracranial arterial pathology and its association with brain MS pathology are discussed. Finally, the authors outline the methodologies behind specific perfusion magnetic resonance imaging (MRI) and ultrasound Doppler techniques, which allow measurement of disease-specific and age-specific vascular changes in the aging population and MS patients. Expert opinion: Cardiovascular pathology significantly contributes to worse clinical and MRI-derived disease outcomes in MS. Global and regional cerebral hypoperfusion may be associated with poorer physical and cognitive performance. Prevention, improved detection, and treatment of the cardiovascular-based pathology may improve the overall long-term health of MS patients.