An 8-year study of people with multiple sclerosis in Isfahan, Iran: Association between environmental air pollutants and severity of disease

Impact of air pollution on the clinical exacerbation of central demyelinating disease: A 10-year data from the Northern Thailand MS and NMOSD registry

BACKGROUND

Particulate matter (PM) 2.5 (PM2.5) and PM10 are implicated in neurological diseases, yet their impact on central demyelinating diseases like multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) remains unclear. This study aimed to determine the association between the levels of PM2.5 and PM10 and the exacerbation of MS and NMOSD.

METHODS

Patients with clinical exacerbations of MS and NMOSD in the Northern Thailand Registry from 2013 to 2022 were enrolled. Eligible patients were categorized based on air pollution exposure (defined as PM2.5 > 15 μg/m3 and PM10 > 45 μg/m3) or no air pollution exposure. Outcomes assessed included clinical characteristics, Expanded Disability Status Scale (EDSS), and functional outcomes.

RESULTS

We analyzed 126 exacerbations in the PM2.5 database (mean age: 44.9±14.9 years, 114 NMOSD, 49 first exacerbations) and 135 exacerbations with the PM10 database (mean age: 44.9±14.9 years, 121 NMOSD, 54 first exacerbations), with the highest incidence four months post-peak air pollution. The PM2.5 exposure group had higher severity, showing increased rates of unfavorable EDSS at exacerbation and 90 days (56.3% vs. 23.6%, P < 0.001 and 47.9% vs. 16.4%, P < 0.001, respectively). Gadolinium enhancement in PM2.5 exposure was significantly higher (56.3% vs. 36.4%, P = 0.03). The PM2.5 exposure group also had a higher rate of second-line therapy with plasma exchange (21.1% vs. 7.3%, P = 0.03). PM2.5 exposure, not PM10, was associated with unfavorable EDSS at any time point, active radiological activity, risk of plasma exchange, and prolonged hospitalization.

CONCLUSION

Environmental pollution, especially PM2.5, significantly impacts MS and NMOSD patients, influencing disease severity, causing permanent disability, and prolonging hospitalization. A national policy on pollution control is imperative, and further data on long-term exposure, together with other pollutants, is still required.

Cancer and mortality risks among people with multiple sclerosis: A population-based study in Isfahan, Iran

BACKGROUND

Multiple sclerosis (MS) and cancer present substantial global health challenges. Understanding cancer patterns among people with MS (PwMS) is crucial due to potential variations across demographics and geographic regions. Isfahan province in Iran, known for its high MS incidence ratio, offers a significant population for comprehensive studies on MS. In this study, we aim to investigate the association between risk of cancer and MS.

METHOD

Data on PwMS were collected utilizing the National Multiple Sclerosis Registry System of Iran (NMSRI), with diagnoses confirmed using McDonald criteria by neurologists specialized in MS. Cancer incidence was investigated using the Iranian National Population-Based Cancer Registry (INPCR) data, collected following international protocols. Descriptive statistics and regression analyses were employed to assess factors associated with cancer and mortality risks among PwMS. Survival analysis was conducted using Kaplan-Meier curves.

RESULTS

Out of 10,049 PwMS, 123 were diagnosed with cancer, with an mean age at the time of cancer diagnosis being 40.41 years and a mean MS duration of 6.76 years. The majority had relapsing-remitting MS (81.2%), and Interferon-β was the most common disease-modifying therapy (DMT) (42.4%). Cancer incidence was 125.6 per 100,000 person-years, peaking at ages 60-64 (677.9 per 100,000 person-years). Receiving monoclonal antibody medications and older age were significantly associated with higher cancer risk (OR:1.542 (1.009-2.357), OR:1.033 (1.015-1.051), respectively). Female breast cancer had the highest incidence ratio among PwMS (40.17 per 100,000 person-years), followed by thyroid (18.38 per 100,000 person-years) and digestive system cancers (17.36 per 100,000 person-years). Breast cancer was the predominant cancer in women, while digestive system cancers were most common among men. Being male and having longer MS duration were linked to higher cancer mortality risk (HR: 2.683, 1.087, respectively).

CONCLUSION

Cancer incidence among 10,049 people with multiple sclerosis was significant, especially in older individuals, with breast cancer being the most common. Male gender and longer MS duration were linked to higher cancer mortality risk.

Geospatial analysis of environmental atmospheric risk factors in neurodegenerative diseases: a systematic review update

Following up the previously published systematic review on the same topic and realizing that new studies and evidence had emerged on the matter, we conducted an update on the same research terms. With the objective of updating the information relating environmental risk factors on neurodegenerative diseases and the geographic approaches used to address them, we searched PubMed, Web of Science and Scopus for all scientific studies considering the following three domains: neurodegenerative disease, environmental atmospheric factor and geographical analysis, using the same keywords as in the previously published systematic review. From February 2020 to February 2023, 35 papers were included versus 34 in the previous period, with dementia (including Alzheimer's disease) being the most focused disease (60.0%) in this update, opposed to multiple sclerosis on the last review (55.9%). Also, environmental pollutants such as PM2.5 and NO2 have gained prominence, being represented in 65.7% and 42.9% of the new studies, opposed to 9.8% and 12.2% in the previous review, compared to environmental factors such as sun exposure (5.7% in the update vs 15.9% in the original). The mostly used geographic approach remained the patient's residence (82.9% in the update vs 21.2% in the original and 62.3% in total), and remote sensing was used in 45.7% of the new studies versus 19.7% in the original review, with 42.0% of studies using it globally, being the second most common approach, usually to compute the environmental variable. This review has been registered in PROSPERO with the number CRD42020196188.

Environmental factors related to multiple sclerosis progression

Multiple Sclerosis (MS) is a complex neurological disease which prevalence is increasing worldwide. The impact of environmental factors on MS susceptibility has already been defined and highlighted in many previous reports, particularly vitamin D or ultraviolet B light exposure, Epstein-Barr virus (EBV) infection, obesity, and smoking. There is increasing evidence that environmental and lifestyle factors are not only important in triggering MS but are also implicated in MS progression. Low sun exposure and vitamin D deficiency exhibit a strong relationship with disease progression in both animal and human studies. The gestational period seems also to impact long-term disease progression as January's babies had a higher risk of requiring walking assistance than those born in other months. The implication of EBV in neurodegeneration and MS progression was also suggested even though its specific targets and mechanisms are still unclear. Cigarette smoking is correlated with faster clinical progression. The association of obesity and smoking seems to be associated with a faster progression and an increased rate of brain atrophy. Although the effect of air pollution on MS pathogenesis remains not fully understood, exposure to polluted air can stimulate several mechanisms that might contribute to MS severity. People with MS with active disease have an altered microbiota compared to patients in the remission phase. Cardiovascular comorbidities, epilepsy, and depression are also associated with a more severe disability accrual. Knowledge about MS modifiable risk factors of progression need to be incorporated into everyday clinical practice in order to ameliorate disease outcomes.

Prevalence and incidence of multiple sclerosis in Isfahan, Iran between 1996 and 2021: A population-based study

BACKGROUND

There has been no recent comprehensive epidemiological study on a large and stable population of multiple sclerosis (MS) in Isfahan. Therefore, we conducted this study to estimate the incidence and prevalence of MS in Isfahan province from 1996 to 2021.

METHOD

In this population-based study, we utilized the dataset from the Vice-Chancellor's Office of Isfahan University of Medical Sciences, which registers all people diagnosed with MS (PDWM) in Isfahan province, excluding those residing in Kashan city. We measured crude incidence and prevalence of MS, separated by sex, and based on age of MS onset, as well as changes in age of MS onset during observation.

RESULTS

A total of 9,909 PDWM were included in our study. The incidence during the time period of 1996-2000 was 5.4/100,000 (1.1/100,000 per year), which subsequently increased to 14.1 (2.8/100,000 per years) and 31.1 per 100,000 (6.2/100,000 per year) during 2001-2005 and 2006-2010, respectively. There was a further increase to 70.9/100,000 (14.2/100,000 per year) in 2011-2015, but it remained stable at 71.8/100,000 (12/100,000 per year) during the period of 2016-2021. In 2016, the age-standardized incidence rates of pediatric-onset, adult-onset, and late-onset MS were 1.8/100,000, 31.4/100,000, and 17.5/100,000, respectively. The prevalence of MS in 2021 was 183.9/100,000. The female/male new case ratio was 4.5 during 1996-2000, decreasing to 4.0, 3.9, 3.9, and 2.9 in the subsequent four five-year periods. The mean age of RRMS onset was 26.3 ± 8.1 between 1990 and 1999, 28.5 ± 8.3 during 2000-2009, and increased to 32.8 ± 9.6 in 2010-2019.

CONCLUSION

This study shows that Isfahan has one of the highest incidence rate and prevalence ratio of MS in the region. We observed an increase in the incidence rate during the first decade, followed by stability in the last two five- and six-year periods. Further studies are needed to identify the reasons behind the change in incidence of MS in Iran.

Particulate matter exposure and neurodegenerative diseases: A comprehensive update on toxicity and mechanisms

Exposure to particulate matter (PM) has been associated with a range of health impacts, including neurological abnormalities that affect neurodevelopment, neuroplasticity, and behavior. Recently, there has been growing interest in investigating the possible relationship between PM exposure and the onset and progression of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. However, the precise mechanism by which PM affects neurodegeneration is still unclear, even though several epidemiological and animal model studies have provided mechanistic insights. This article presents a review of the current research on the neurotoxicity of PM and its impact on neurodegenerative diseases. This review summarizes findings from epidemiological and animal model studies collected through searches in Google Scholar, PubMed, Web of Science, and Scopus. This review paper also discusses the reported effects of PM exposure on the central nervous system and highlights research gaps and future directions. The information presented in this review may inform public health policies aimed at reducing PM exposure and may contribute to the development of new treatments for neurodegenerative diseases. Further mechanistic and therapeutic research will be needed to fully understand the relationship between PM exposure and neurodegenerative diseases.

Epidemiologic and clinical characteristics of neuromyelitis optica spectrum disorder patients, A seven years follow-up study from Iran

BACKGROUND

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare neuroinflammatory disease characterized by recurrent relapses. The most common signs are myelitis and optic neuritis. It can also present by cerebral or brain stem syndromes. There are still many challenges in its diagnosis and treatment, and long-term follow-up studies are needed to see the disease course over time.

METHODS

We established an electronic registration system of NMOSD patients starting from October 2015 in Kashani hospital, Isfahan, Iran. Every suspected patient was documented and included in the follow-up system to survey their disease course. Anti-aquaporine 4 (AQP4) antibody checked for all by cell-based assay method. All information such as demographic and clinical data and laboratory and MRI findings were documented. Participants were followed up for any relapses, new paraclinical tests and drug changes. This study is based on the definite NMOSD cases (according to the 2015 criteria) characteristics and clinical course during 7 years of registration.

RESULTS

The study included 173 NMOSD cases and 56 ones were seropositive for AQP4 Ab. Their mean age was 40.02±11.11 years (45.78 in the seropositive group). The mean age at disease onset was about 30.16 years. The mean time of follow-up by our registration system is 55.84 ± 18.94 months (54.82 months in seropositive ones). The annual relapse rate is estimated as 0.47±0.36. Long extended transvers myelitis (LETM) was present in the baseline MRI of 77 patients (44.5%), while 32 of them did not show any related clinical symptoms. 124 patients revealed an abnormality in the first brain MRI. 27 individuals suffer hypothyroidism as the most common comorbid disease. The disease seems to be more prevalent in the west and southwest areas of Isfahan province.

CONCLUSION

The mean age of onset is higher than Multiple Sclerosis (MS) patients, but there are notable pediatric cases too. It should also be noticed that cervical LETM can be asymptomatic at first. Brain MRI abnormalities are frequently observed. The disease is more prevalent in the geographical areas where showing high MS prevalence.

Air Pollution and Its Adverse Effects on the Central Nervous System

Air pollution is recognized as a significant public health problem and is associated with illnesses of the central nervous system (CNS) as well as neuroinflammation and neuropathology. Air pollution may cause chronic brain inflammation, white matter abnormalities, and microglia activation, which increases the risk of autism spectrum disorders, neurodegenerative disorders, stroke, and multiple sclerosis (MS). Methods: A literature review was done on "PubMed, EMBASE and Web of Science" on the relationship of air pollution with MS and stroke, using the keywords "air pollution" OR "pollution"; "ambient air pollution," "particulate matter, ozone, black carbon" AND "stroke" OR "cerebrovascular diseases," "multiple sclerosis," "neuroinflammation," or "neurodegeneration." Results: We first identified 128 articles and their related websites, of which 44 articles were further selected for analysis mainly based on study relevance, study quality and reliability, and date of publication. Further studies on air pollution and its adverse effects on the CNS are needed. The findings of such studies will support the development of appropriate preventive measures in the future.

Multiple Sclerosis in Mongolia; the First Study Exploring Predictors of Disability and Depression in Mongolian MS Patients

Mongolia is located at 45° north latitude in the center of the Asian continent, and about 80% of the territory is at 1000 m above sea level. Epidemiologically, multiple sclerosis (MS) has not been investigated in Mongolia, although there have been a few MS case reports. We investigated the characteristics of MS in Mongolia for the first time, focusing on the association between MS-related parameters and depression levels. We initiated cross-sectional analyses, using data from 27 MS patients aged 20 to 60 years in Ulaanbaatar, Mongolia. The patients completed a questionnaire on their lifestyles and clinical information. We classified the MS patients on the basis of disability levels using the expanded disability status scale (EDSS) scores: 11.1% mild disability and 88.9% moderate to severe disability (median EDSS score, 5.5). We also classified the patients on the basis of depression levels using the 9-item patient health questionnaire (PHQ-9) scores: 44.4% mild depression, 40.7% moderate depression, and 14.8% severe depression (mean PHQ-9's score, 9.96 ± 5.05). We used multivariate logistical regression analyses to identify predictors of EDSS or PHQ-9 scores. Disability levels were associated with vision and balance problems. Depression levels were associated with corticosteroid treatment; no patients were treated with disease-modifying drugs (DMDs). The odds ratios for disease onset age and treatment duration were associated with EDSS scores. In conclusion, MS onset age and treatment duration were independent predicting factors influencing the level of disability. Appropriate DMD treatment would lower the disability and depression levels.

social determinants of health in multiple sclerosis

Social determinants of health are the conditions in which people are born, grow, live, work and age. These circumstances are the non-medical factors that influence health outcomes. Evidence indicates that health behaviours, comorbidities and disease-modifying therapies all contribute to multiple sclerosis (MS) outcomes; however, our knowledge of the effects of social determinants — that is, the ‘risks of risks’ — on health has not yet changed our approach to MS. Assessing and addressing social determinants of health could fundamentally improve health and health care in MS; this approach has already been successful in improving outcomes in other chronic diseases. In this narrative Review, we identify and discuss the body of evidence supporting an effect of many social determinants of health, including racial background, employment and social support, on MS outcomes. It must be noted that many of the published studies were subject to bias, and screening tools and/or practical interventions that address these social determinants are, for the most part, lacking. The existing work does not fully explore the potential bidirectional and complex relationships between social determinants of health and MS, and the interpretation of findings is complicated by the interactions and intersections among many of the identified determinants. On the basis of the reviewed literature, we consider that, if effective interventions targeting social determinants of health were available, they could have substantial effects on MS outcomes. Therefore, funding for and focused design of studies to evaluate and address social determinants of health are urgently needed.

Here, the authors discuss the potential effects of social determinants of health on multiple sclerosis risk and outcomes. They suggest that addressing these determinants of health could substantially improve the lives of individuals with multiple sclerosis and call for more research.

Addressing an individual’s social determinants of health — that is, the conditions under which they are born, grow, live, work and age — could provide opportunities to reduce the burden of living with multiple sclerosis (MS).

Individual factors that may influence MS-related outcomes include sex, gender and sexuality, race and ethnicity, education and employment, socioeconomic status, and domestic abuse.

Societal infrastructures, including access to food, health care and social support, can also affect MS-related outcomes.

Awareness of the specific circumstances of a patient with MS might help neurologists deliver better care.

Social determinants of health are not static and can change according to wider sociopolitical contexts, as highlighted by the COVID-19 pandemic.

Rigorous studies of interventions to ameliorate the effects of poor social determinants on people with MS are urgently needed.

Toxic Air Pollutants and Their Effect on Multiple Sclerosis: A Review Study

Toxic air pollutants are one of the main factors that have the effect of synergism to increase the incidence of multiple sclerosis (MS). This review aims to investigate the effects of toxic air pollutants on the occurrence of multiple sclerosis (MS). A narrative review of the literature was done from 2000 to 2022 based on various databases such as Google Scholar, Web of Science, Springer, PubMed, and Science Direct. In this study, according to the databases, three hundred and sixty articles were retrieved. Of these, 28 studies were screened after review and 14 full-text articles entered into the analysis process. Finally, 9 articles were selected in this study. According to the finding of this study, toxic air pollutants including polycyclic aromatic hydrocarbons (PAHs), heavy metals (HM), volatile organic compounds (VOCs), particulate matter (PM), and gases are the main agents that cause the development and spread of chronic diseases such as respiratory and cardiovascular diseases, chronic obstructive pulmonary disease (COPD), and multiple sclerosis. The result of this study showed that the main sources of emission of toxic air pollutants include industries, cars, power plants, and the excessive consumption of fossil fuels. In general, the inhalation of high concentration of toxic air pollutants can increase the risk of chronic diseases and multiple sclerosis.

Ambient air pollution and multiple sclerosis: a systematic review

OBJECTIVES

Some studies have shown that environmental risk factors, including air pollution, might be related to the incidence or recurrence of multiple sclerosis (MS). This systematic review was conducted to investigate the relation between air pollution and MS.

METHODS

A systematic search was conducted in PubMed, Scopus, Science Direct, Embase, and Web of Science; until January 2020 with no restrictions. The search strategy was conducted with air pollution key words such as CO, PM_2.5, PM₁₀, SO₂, and NO₂, for exposure and the key word "Multiple sclerosis" as the outcome.

RESULTS

Eventually, after applying the inclusion and exclusion criteria, 17 articles were included. The methodologies and outcomes reported were heterogeneous and different metrics had been used in the results; therefore conducting a meta-analysis was not possible. Eight studies had analyzed the relation between particulate matter (PM) and the prevalence or relapse of MS and had observed a significant relation. NO₂ and NOx were associated with recurrence or prevalence of MS in three studies. But, in three cohort studies, no association was observed between air pollution and recurrence or occurrence of MS.

CONCLUSIONS

The results of this systematic review show that outdoor air pollution, especially PM and nitrogen oxides might be related to the prevalence or relapse of MS.

Association between ambient air pollution and multiple sclerosis: a systemic review and meta-analysis

Recently, increasing attention has been paid to the effects of air pollutants on autoimmune diseases. The results of relationship between ambient air pollution and multiple sclerosis (MS) showed a variety of differences. Thus, the purpose of this study is to further clarify and quantify the relationship between ambient air pollutants and MS through meta-analysis. Through electronic literature search, literature related to our research topic was collected in Cochrane Library, Embase, and PubMed till August 18, 2020, according to certain criteria. Pooled risk estimate and 95% confidence intervals (95%CI) were calculated by random-effect model analysis. After removing copies, browsing titles and abstracts, and reading full text, 6 studies were finally included. The results showed that only particulate matter (PM) with aerodynamic diameter ≤ 10 (PM₁₀) was related to MS (pooled HR = 1.058, 95% CI = 1.050-1.066), and no correlation was found between PM with aerodynamic diameter < 2.5 (PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), benzene (C₆H₆), major road < 50 m, and MS. There was no publication bias, and the heterogeneity analysis results were stable. PM₁₀ is correlated with the disease MS, while other pollution is not connected with MS. Therefore, it is important for MS patients to take personal protection against particulate pollution and avoid exposure to higher levels of PM.

Role of environmental factors in multiple sclerosis

INTRODUCTION

Environmental factors play a significant role in the pathogenesis and progression of multiple sclerosis (MS), either acting alone or by interacting with other environmental or genetic factors. This cumulative exposure to external risk factors is highly complex and highly variable between individuals.

AREAS COVERED

We narratively review the current evidence on the role of environment-specific risk factors in MS onset and progression, as well as the effect of gene-environment interactions and the timing of exposure We have reviewed the latest literature, by Ovid Medline, retrieving the most recently published systematic reviews and/or meta-analyses and more recent studies not previously included in meta-analyses or systematic reviews.

EXPERT OPINION

There is some good evidence supporting the impact of some environmental risk factors in increasing the risk of developing MS. Tobacco smoking, low vitamin D levels and/or low sun exposure, Epstein Barr Virus (EBV) seropositivity and a history of infectious mononucleosis may increase the risk of developing MS. Additionally, there is some evidence that gene-smoking, gene-EBV, and smoking-EBV interactions additively affect the risk of MS onset. However, the evidence for a role of other environmental factors in MS progression is limited. Finally, there is some evidence that tobacco smoking, insufficient vitamin D levels and/or sun exposure have impacts on MS phenotypes and various markers of disease activity including relapse, disability progression and MRI findings. Clearly the effect of environmental factors on MS disease course is an area that requires significantly more research.

Air pollution and multiple sclerosis: a comprehensive review

Multiple sclerosis (MS) is an inflammatory, autoimmune demyelinating disorder of the central nervous system (CNS), leading to progressive functional impairments, and many intrinsic and acquired factors are believed to be associated with its development and relapse. In terms of environmental factors, air pollution has gained much attention during recent decades, as chronic exposure to ambient air pollution seems to increase the level of some pro-inflammatory markers in the human brain, which can lead to neuroinflammation, neurodegeneration, and blood-brain barrier (BBB) breakdown. These events may also be associated with the risk of MS development and relapse. In this review, we aimed to summarize recent findings around the impact of air pollutants, including particulate matter (PM10, PM2.5, and ultra-fine particles), gaseous pollutants (carbon monoxide [CO], nitrogen oxides [NO_x], sulfur dioxide [SO₂], and ozone [O₃]), and heavy metals, on MS development and relapse.

Air pollution and multiple sclerosis: a comprehensive review

Multiple sclerosis (MS) is an inflammatory, autoimmune demyelinating disorder of the central nervous system (CNS), leading to progressive functional impairments, and many intrinsic and acquired factors are believed to be associated with its development and relapse. In terms of environmental factors, air pollution has gained much attention during recent decades, as chronic exposure to ambient air pollution seems to increase the level of some pro-inflammatory markers in the human brain, which can lead to neuroinflammation, neurodegeneration, and blood-brain barrier (BBB) breakdown. These events may also be associated with the risk of MS development and relapse. In this review, we aimed to summarize recent findings around the impact of air pollutants, including particulate matter (PM10, PM2.5, and ultra-fine particles), gaseous pollutants (carbon monoxide [CO], nitrogen oxides [NO_x], sulfur dioxide [SO₂], and ozone [O₃]), and heavy metals, on MS development and relapse.

The Air We Breathe: Air Pollution as a Prevalent Proinflammatory Stimulus Contributing to Neurodegeneration

Air pollution is regarded as an important risk factor for many diseases that affect a large proportion of the human population. To date, accumulating reports have noted that particulate matter (PM) is closely associated with the course of cardiopulmonary disorders. As the incidence of Alzheimer’s disease (AD), Parkinson’s disease (PD), and autoimmune disorders have risen and as the world’s population is aging, there is an increasing interest in environmental health hazards, mainly air pollution, which has been slightly overlooked as one of many plausible detrimental stimuli contributing to neurodegenerative disease onset and progression. Epidemiological studies have indicated a noticeable association between exposure to PM and neurotoxicity, which has been gradually confirmed by in vivo and in vitro studies. After entering the body directly through the olfactory epithelium or indirectly by passing through the respiratory system into the circulatory system, air pollutants are subsequently able to reach the brain. Among the potential mechanisms underlying particle-induced detrimental effects in the periphery and the central nervous system (CNS), increased oxidative stress, inflammation, mitochondrial dysfunction, microglial activation, disturbance of protein homeostasis, and ultimately, neuronal death are often postulated and concomitantly coincide with the main pathomechanisms of neurodegenerative processes. Other complementary mechanisms by which PM could mediate neurotoxicity and contribute to neurodegeneration remain unconfirmed. Furthermore, the question of how strong and proven air pollutants are as substantial adverse factors for neurodegenerative disease etiologies remains unsolved. This review highlights research advances regarding the issue of PM with an emphasis on neurodegeneration markers, symptoms, and mechanisms by which air pollutants could mediate damage in the CNS. Poor air quality and insufficient knowledge regarding its toxicity justify conducting scientific investigations to understand the biological impact of PM in the context of various types of neurodegeneration.

Use of geographical information systems in multiple sclerosis research: A systematic scoping review

INTRODUCTION

Geographical information system (GIS) and spatial analysis have an emerging role in the understanding and management of health-related outcomes. However, there is a knowledge gap about the extent to which GIS has supported multiple Sclerosis (MS) research. Therefore, this review aimed to explore the types of GIS applications and the complexity of their visualisation in MS research.

METHODS

A systematic scoping review was conducted based on York's five-stage framework. PubMed, Scopus and Web of Science were searched for relevant studies published between 2000 and 2020 using a comprehensive search strategy based on the main concepts related to GIS and MS. Grounded, inductive analysis was conducted to organize studies into meaningful application areas. Further, we developed a tool to assess the visualisation complexity of the selected papers.

RESULTS

Of 3,723 identified unique citations, 42 papers met our inclusion criteria for the final review. One or more of the following types of GIS applications were reported by these studies: (a) thematic mapping (37 papers); (b) spatial cluster detection (16 papers); (c) risk factors detection (16 papers); and (d) health access and planning (two papers). In the majority of studies (88%), the score of visualisation complexity was relatively low: three or less from the range of zero to six.

CONCLUSIONS

Although the number of studies using GIS techniques has dramatically increased in the last decade, the use of GIS in the areas of MS access and planning is still under-researched. Additionally, the capacity of GIS in visualising complex nature of MS care system is not yet fully investigated.

Temporal trends of incidence and prevalence of multiple sclerosis in Razavi Khorasan Province, Northeast Iran

OBJECTIVES

The prevalence of multiple sclerosis (MS) in the Persian Gulf countries has been significantly increasing during the past decades. This study was conducted for investigating the prevalence and incidence of MS in Northeast Iran (Khorasan Razavi province).

METHODS

This cross-sectional study was conducted during 1 January 1988 and 23 September 2018. All patients with a clinically definite diagnosis of MS according to the McDonald criteria (2005) and MRI along with the medical diagnosis, recorded in the Khorasan MS society, were considered for calculation of crude and age-standardized prevalence, and incidence rates of MS. The periodic incidence rates were calculated based on the year of onset of MS. Also, we calculated gender ratios for prevalence and incidence rates.

RESULTS

The mean age-standardized prevalence and incidence rates of MS in the Khorasan Razavi were 8.69 (95% CI 8.05-9.41) per 100,000 (3.99 (95% CI 3.39-4.74) for males, 13.49 (95% CI 12.37-14.76) for females). Age-standardized prevalence was 48.87 (95% CI 48.37-49.35) per 100,000 (22.47 (95% CI 22.01-22.93) for males, 75.65 (95% CI 74.80-76.51) for females). Also, the mean incidence and prevalence for Mashhad County as capital of province were 11.38 and 59.09 per 100,000 populations, respectively. The female/male ratio was 3.33 for all age groups.

CONCLUSION

Our results showed that this region is a high-risk area for MS like central region of Iran. Our results revealed that the prevalence and incidence of MS in the study area have increased during the recent decades with a sharp slope.

Association between air pollution and Multiple Sclerosis: A systematic review

Air pollution is a major public health threat. The present study is the first systematic review (SR) to determine the association of exposure to air pollution and Multiple Sclerosis (MS) Progression. A Literature search was carried out using relevant keywords within several international databases. A comprehensive literature search was carried out systematically and yielded 24 eligible studies concerning the relationship of exposure to air pollution including criteria air pollutants such as particulate matter, NOx and SOx, CO₂, traffic noise, etc. and MS disease. The results of the included studies reveal that there was a significant relationship between exposure to air pollution and MS development and progression. Although the effect of air pollution in the pathogenesis of MS is notfully known, according to the results of the included studies exposure to polluted air can stimulate several mechanisms that act as risk factors for developing MS and for having disease relapses or neurological disability. The major potential mechanism is Dysimmune inflammatory responses subsequent oxidative stress (OS), which leads to neuroinflammation and breakdown of the normal balance between immunity and self-tolerance. Air pollutants induce and sustain chemical reactions that produce reactive oxygen species (ROSs) and nitrogen reactive species (RNSs) which can initiate inflammatory cascades via the redox-sensitive mitogen-activated protein kinase (MAPK) and NF-κB that recruit and activate neutrophils, monocytes, and dendritic cells that stimulate the adaptive immune responses such as Th1 and Th17 inflammatory responses. The uncontrolled inflammatory responses following these events cause cell death and the release of self-antigens capable of stimulating the production of auto-aggressive T-cells via enhancing antigen presentation and facilitate entry of these cells to the central nervous system. Thus, oxidative stress is the culprit in the systemic inflammation and immune imbalance development and progression, powerful risk factors in MS.

Geospatial Analysis of Environmental Atmospheric Risk Factors in Neurodegenerative Diseases: A Systematic Review

Despite the vast evidence on the environmental influence in neurodegenerative diseases, those considering a geospatial approach are scarce. We conducted a systematic review to identify studies concerning environmental atmospheric risk factors for neurodegenerative diseases that have used geospatial analysis/tools. PubMed, Web of Science, and Scopus were searched for all scientific studies that included a neurodegenerative disease, an environmental atmospheric factor, and a geographical analysis. Of the 34 included papers, approximately 60% were related to multiple sclerosis (MS), hence being the most studied neurodegenerative disease in the context of this study. Sun exposure (n = 13) followed by the most common exhaustion gases (n = 10 for nitrogen dioxide (NO₂) and n = 5 for carbon monoxide (CO)) were the most studied atmospheric factors. Only one study used a geospatial interpolation model, although 13 studies used remote sensing data to compute atmospheric factors. In 20% of papers, we found an inverse correlation between sun exposure and multiple sclerosis. No consensus was reached in the analysis of nitrogen dioxide and Parkinson’s disease, but it was related to dementia and amyotrophic lateral sclerosis. This systematic review (number CRD42020196188 in PROSPERO’s database) provides an insight into the available evidence regarding the geospatial influence of environmental factors on neurodegenerative diseases.

Prevalence and incidence of multiple sclerosis in Ardabil, Northwest of Iran

BACKGROUND

Multiple sclerosis (MS) epidemiology is studies in many populations; however, studying populations with unique characteristics could provide opportunities to deepen the understanding of the underlying reason of the disease. In this regard, we aimed to study the epidemiology of MS in Ardabil, a province in northwest Iran, where the majority are of Iranian Azerbaijanis.

METHOD

A retrospective population-based study was conducted from 2008 to 2018 in Ardabil, based on the data of Iran's Ministry Of Health. Collected information includes sex, age, age at disease onset, education and type of MS. We used t-test to compare means and chi-square test to analyze the association among variables.

RESULTS

The total number of patients was 760 with 533 (70.13%) females and 227 (29.87%) males. The crude prevalence was 59.37 per 100,000 in 2018 (95% CI: 55.31, 63.73). The crude incidence rate was 7.65 per 100,000 in 2018 (95% CI: 6.28, 9.32). The most frequent educational level was high school diploma (38.36%). The relapsing-remitting (RR) form was the most frequent type of MS (48.16%). The F/M ratio was 2.92:1 and the mean onset age was 33.14 (95% CI: 31.56, 34.72) in 2018, significantly higher in males (P value= 0.01).

CONCLUSION

Ardabil is a medium risk zone of MS. The different ethnicity of its population, climate and environmental features, may explain the factors modulating the risk of MS in similar areas and present windows of opportunity to understand the causes of MS.

Evidence of an increased prevalence of multiple sclerosis: a population-based study of Tehran registry during 1999-2018

BACKGROUND

The epidemiological characteristics of multiple sclerosis (MS) have been investigated in various studies, which have revealed that the prevalence of MS varies across countries. The present study was conducted to investigate the longitudinal prevalence of MS in Tehran, Iran.

METHODS

The present population-based study was conducted in Tehran, the capital of Iran from 1999 to 2018 based on the annual report data provided by the Iranian MS Society (IMSS) registry system. The age-standardized and crude prevalence were estimated using population data presented by the Statistical Centre of Iran.

RESULTS

A total of 21,580 MS cases were registered and included in the analysis. Among the participant patients, 24.99% (5393) and 75.01% (16,187) of cases were male and female, respectively. The mean age of MS onset was 28.8 years (S.D: 8.7). The age-standardized prevalence (ASP) of MS increased from 73.7 (95%CI: 72.1-75.2) per 100,000 people in 2006 to 137.6 (95% CI: 135.7-139.5) per 100,000 people in 2018. The ASP of MS in 2018 was estimated to be 67.9 (95%CI: 66.0-69.8) and 207.3 (95%CI: 204.0-210.7) per 100,000 people among males and females, respectively. The age-standardized female-to-male ratio of MS ranged from 3.7 (in 2010) to 2.06 (in 2017).

CONCLUSION

The findings of this study suggested that the prevalence of MS in Tehran province is relatively high, and the occurrence of the disease is more common in the age groups under 40 years as compared with older-aged groups. In line with reports provided for various regions of the world, the prevalence of MS was higher among women. Similarly, the findings of this study revealed that the female-to-male ratio was 2.14 in 2018.

Internet of Things and Enhanced Living Environments: Measuring and Mapping Air Quality Using Cyber-physical Systems and Mobile Computing Technologies

This paper presents a real-time air quality monitoring system based on Internet of Things. Air quality is particularly relevant for enhanced living environments and well-being. The Environmental Protection Agency and the World Health Organization have acknowledged the material impact of air quality on public health and defined standards and policies to regulate and improve air quality. However, there is a significant need for cost-effective methods to monitor and control air quality which provide modularity, scalability, portability, easy installation and configuration features, and mobile computing technologies integration. The proposed method allows the measuring and mapping of air quality levels considering the spatial-temporal information. This system incorporates a cyber-physical system for data collection and mobile computing software for data consulting. Moreover, this method provides a cost-effective and efficient solution for air quality supervision and can be installed in vehicles to monitor air quality while travelling. The results obtained confirm the implementation of the system and present a relevant contribution to enhanced living environments in smart cities. This supervision solution provides real-time identification of unhealthy behaviours and supports the planning of possible interventions to increase air quality.

Environmental and genetic risk factors for MS: an integrated review

Recent findings have provided a molecular basis for the combined contributions of multifaceted risk factors for the onset of multiple sclerosis (MS). MS appears to start as a chronic dysregulation of immune homeostasis resulting from complex interactions between genetic predispositions, infectious exposures, and factors that lead to pro-inflammatory states, including smoking, obesity, and low sun exposure. This is supported by the discovery of gene-environment (GxE) interactions and epigenetic alterations triggered by environmental exposures in individuals with particular genetic make-ups. It is notable that several of these pro-inflammatory factors have not emerged as strong prognostic indicators. Biological processes at play during the relapsing phase of the disease may result from initial inflammatory-mediated injury, while risk factors for the later phase of MS, which is weighted toward neurodegeneration, are not yet well defined. This integrated review of current evidence guides recommendations for clinical practice and highlights research gaps.

Air Pollution, Multiple Sclerosis and its Relevance to Mexico City

Long-term exposure to air pollution has been linked with the development of neurodegenerative diseases. The proposed mechanisms include neuroinflammation and brain oxidative stress. Multiple sclerosis (MS) is a neurodegenerative disease with an auto-immune physiopathology and some studies have associated it with long-term exposure to airborne particulate matter. In this opinion we discuss the current body of knowledge regarding air pollution and the risk of MS as well as MS relapses. Also, its relevance in the case of Mexico City is discussed.