Prevalence survey of multiple sclerosis in the Australian Capital Territory

The prevalence of multiple sclerosis (MS) in Oceania, a systematic review, and meta-analysis

BACKGROUND

Oceania is a continent, covering more than 8 million km2, with a population of more than 44 million people. In different countries landing in Oceania, various prevalence of MS has been reported, so we designed this systematic review and meta-analysis to estimate the pooled prevalence of MS in Oceania.

METHODS

We systematically searched PubMed, Scopus, EMBASE, Web of Science, and Google Scholar. We also searched references of included studies, and conference abstracts. The search was done on January 1, 2023, by two independent researchers. We extracted the name of the first author, country, publication year, prevalence period, number of study participants, total female and male population, disease duration, type of MS, mean duration of the disease, mean age at disease onset, mean Expanded Disability Status Scale (EDSS), and total female and male patients with MS.

RESULTS

A literature search revealed 81,044 records; after deleting duplicates, 38,260 records remained. One hundred and six full texts were evaluated, and finally, seventeen studies remained for systematic review. Most studies were done in Newcastle; eight studies were done in 1961, 8 in 1981, 2 in 1996, and 2 in 2001. In all other years, only one study was done. The pooled prevalence of MS in 1961 in Oceania was estimated as 19.85/100,000 (I2=70.3%, p=0.001). The pooled prevalence of MS in 1981 in Oceania was estimated as 39.07/100,000 (I2 =88%, p=0.001).

CONCLUSIONS

The result of this systematic review and meta-analysis shows that the prevalence of MS has increased dramatically during the timespan in Oceania.

Three Dimensional Brain Parameters of Multiple Sclerosis (MS) Patients

BACKGROUND & OBJECTIVES

MS is not only a demyelinating disease of central nervous system, but it also affects cortical and deep gray matter (GM). Furthermore, it causes axonal damage in the brain and spinal cord through inflammation and axonal degeneration. It is mostly seen between the ages of 20 and 40 and prevalence of the disease is higher among females than males. In the present study, we measured different parameters in the brains of patients with multiple sclerosis (MS) and healthy controls in both genders to determine the amount of brain atrophy quantitatively in MS patients.

METHODS

We used T2-weighted MRI scans of 40 MS patients (25 females + 15 males) with clinically definite relapsing-remitting multiple sclerosis that was determined according to Poser criteria in multiple parts of the brain, and we compared these data with those of sex-matched healthy controls in the same numbers.

RESULTS

Wideness of the lateral and third ventricles and the volumes of cerebral sulci in MS patients were significantly increased compared to both male and female controls. Brain width, corpus callosum area and the total brain/cerebellum + brain stem volumes of MS patients were decreased considerably.

INTERPRETATION & CONCLUSIONS

The present measurements indicated that MS caused parenchymal destruction in the cortex, axonal degeneration and myelin loss in the white matter of the brain. Consequently, the current observations correlate well with worsening disability in MS patients.

Epidemiological study of multiple sclerosis in Illawarra region

BACKGROUND

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease which causes significant disabilities. Latest MS epidemiological data in Australia reveals rising prevalence. No epidemiological study of MS has been conducted so far in the Illawarra region.

AIM

To calculate prevalence and incidence of MS in the Illawarra and compare with other regions', states' and national prevalence data.

METHOD

Data of MS patients in the Illawarra were collected from hospital medical records, ambulatory care units and hospital pharmacy. Prevalence was calculated for alive MS patients on June 30, 2018 expressed per 100 000 population. Yearly adjusted incidence rate was calculated for 10 years (2009-2019), expressed as cases per 100 000 population-years.

RESULTS

Estimated MS prevalence in the Illawarra was 116.6 per 100 000 population with yearly incidence (2009-2019) of 5.06 cases per 100 000 population-years (female to male, 3:1). Relapsing-remitting MS (RRMS) was the most common type (277/397 ~ 69.7%) with primary progressive MS (PPMS) in 52/397 ~ 13%, and secondary progressive MS (SPMS) in 45/397 ~ 11.3% (unknown in 23). Commonest age at diagnosis ranged between 30-39 years for all types with RRMS and PPMS between 30-39 years and 40-49 years respectively. The most commonly recorded treatment was natalizumab (103 patients) followed by fingolimod (82 patients) and interferon (58 patients).

CONCLUSION

The calculated MS prevalence in the Illawarra is higher than NSW and Australian average MS prevalence. Further epidemiological studies focusing on MS risk factors and other factors bearing on MS prevalence in the Illawarra are required. This article is protected by copyright. All rights reserved.

Multiple sclerosis epidemiology in Asia and Oceania; A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is an inflammatory demyelinating CNS disease and the most common neurological immune-mediated disorder. Due to its progressive format, it affects patients' quality of life (QoL) significantly. This study aimed to evaluate epidemiologic parameters of MS in the Asia and Oceania continents.

METHODS

A comprehensive literature search on October 1st, 2020, was performed in PubMed, Scopus, and Web of Science to retrieve original population-based studies on MS epidemiology in the Asian and Oceanian countries, published between January 1st, 1985 and October 1st, 2020. The designed search strategy was repeated for each country, and the relevant referenced articles were added to our database. A random-effect model was used to combine the epidemiological estimates, and subgroup analysis was also performed by continent, region, and country, when possible. Meta-regression analysis was done to evaluate the effects of Human Developmental Index (HDI), latitude, and study period on the epidemiologic parameters.

RESULTS

A total of 3,109 publications were found, of which 89 articles met the eligibility criteria and were included for data extraction. These articles provided data on prevalence, incidence, and mean age at disease onset in 18 countries in Asia and Oceania, including Iran, Turkey, Cyprus, Kuwait, Saudi Arabia, Qatar, UAE, Jordan, Israel, India, Malaysia, China, Hong Kong, Taiwan, Republic of Korea, Japan, Australia, and New Zealand. The pooled total prevalence, incidence, and mean age of onset in Asia and Oceania were 37.89/100000 (95% CI: 35.65 - 40.142), 2.40/100000 (95% CI: 2.22 - 2.58), and 28.21 (95% CI: 27.55 - 28.88), respectively. MS prevalence and incidence in the female gender (68.7/100000 and 4.42/100000, respectively) were infinitely higher than in the male gender (24.52/100000 and 2.06/100000, respectively). Our subgroup analysis showed that MS was much more prevalent in Australia and West Asia among the studied area. The meta-regression showed that the total incidence decreased with an increase in the HDI, and the total prevalence in Asia increased with increasing latitude gradients. Also, the study period had a positive effect on the total prevalence and incidence in Asia and Oceania.

CONCLUSION

MS prevalence and incidence have increased in recent decades. This study highlights the need for further studies to elucidate MS's geographical and temporal variations' exact etiologies.

A novel method for calculating prevalence of multiple sclerosis in Australia

Objectives:

The purpose of this study was to determine the prevalence of multiple sclerosis (MS) in Australia in 2010 using a novel method based on Australia-wide prescription data for MS-specific disease modifying agents. The results obtained were validated against two other prevalence estimates.

Methods:

We obtained the total number of scripts for medications that were used exclusively for the treatment of MS written in Australia for the period January–December 2010. The percentage of MS patients using medications (42–55%) was taken from state-specific surveys of MS Society clients. To estimate prevalence we divided the annual number of scripts dispensed by 12 and adjusted for penetration of medications by state.

Results:

The prevalence of MS in Australia in 2010 calculated using the prescription method was 21,283 people (95.5/100,000). This compared to 21,200 people (95.2/100,000) obtained from the Australian Bureau of Statistics (ABS) Survey of Disability, Ageing and Carers (SDAC) survey of 2009 and 20,471 people (91.9/100,000) using MS Society client numbers. Prevalence increased with increasing latitude, with the prevalence for Tasmania over seven times that of the Northern Territory. Results were sensitive to the percentage of people with MS being treated.

Conclusions:

Calculation of prevalence of MS using nation-wide prescription data is a novel method that generates results similar to other potentially more resource-intensive methods.

Geomagnetic disturbances may be environmental risk factor for multiple sclerosis: an ecological study of 111 locations in 24 countries

BACKGROUND

We noticed that a hypothesis based on the effect of geomagnetic disturbances (GMD) has the ability to explain special features of multiple sclerosis (MS). Areas around geomagnetic 60 degree latitude (GM60L) experience the greatest amount of GMD. The easiest way to evaluate our hypothesis was to test the association of MS prevalence (MSP) with angular distance to geomagnetic 60 degree latitude (AMAG60) and compare it with the known association of MS with geographical latitude (GL). We did the same with angular distance to geographic 60 degree latitude (AGRAPH60) as a control.

METHODS

English written papers with MSP keywords, done in Europe (EUR), North America (NA) or Australasia (AUS) were retrieved from the PubMed. Geomagnetic coordinates were determined for each location and AMAG60 was calculated as absolute value of numerical difference between its geomagnetic latitude from GM60L. By an ecological study with using meta-regression analyses, the relationship of MSP with GL, AMAG60 and AGRAPH60 were evaluated separately. MSP data were weighted by square root of number of prevalent cases. Models were compared by their adjusted R square (AR2) and standard error of estimate (SEE).

RESULTS

111 MSP data were entered in the study. In each continent, AMAG60 had the best correlation with MSP, the largest AR2 (0.47, 0.42 and 0.84 for EUR, NA and AUS, respectively) and the least SEE. Merging both hemispheres data, AMAG60 explained 56% of MSP variations with the least SEE (R = 0.75, AR2 = 0.56, SEE = 57), while GL explained 17% (R = 0.41, AR2 = 0.17, SEE = 78.5) and AGRAPH60 explained 12% of that variations with the highest SEE (R = 0.35, AR2 = 0.12, SEE = 80.5).

CONCLUSIONS

Our results confirmed that AMAG60 is the best describer of MSP variations and has the strongest association with MSP distribution. They clarified that the well-known latitudinal gradient of MSP may be actually a gradient related to GM60L. Moreover, the location of GM60L can elucidate why MSP has parabolic and linear gradient in the north and south hemisphere, respectively. This preliminary evaluation supported that GMD can be the mysterious environmental risk factor for MS. We believe that this hypothesis deserves to be considered for further validation studies.

Gender issues in multiple sclerosis: an update

Although multiple sclerosis (MS) affects both women and men, women are more susceptible to MS than men. Accumulating evidence indicates that the incidence and prevalence of MS is increasing, more so in women than in men. Owing to pregnancy, differing hormonal states and distinct social roles, the impact of MS differs between women and men. Since Patricia K Coyle published a review on gender issues in MS, multiple studies have added to the body of knowledge. This update will summarize the current thinking on gender-related issues in MS and we will address incidence and prevalence, hormonal factors, pregnancy and breastfeeding, genetics, course and prognosis, imaging, treatment and psychosocial aspects. Future progression within this field will help elucidate the cause of and define the treatment of MS.

The changing demographic pattern of multiple sclerosis epidemiology

The uneven distribution of multiple sclerosis (MS) across populations can be attributed to differences in genes and the environment and their interaction. Prevalence and incidence surveys could be affected by inaccuracy of diagnosis and ascertainment, and prevalence also depends on survival. These sources of error might play a part in the geographical and temporal variations. Our literature search and meta-regression analyses indicated an almost universal increase in prevalence and incidence of MS over time; they challenge the well accepted theory of a latitudinal gradient of incidence of MS in Europe and North America, while this gradient is still apparent for Australia and New Zealand; and suggest a general, although not ubiquitous, increase in incidence of MS in females. The latter observation should prompt epidemiological studies to focus on changes in lifestyle in females. New insights into gene-environment and gene-gene interactions complicate interpretations of demographic epidemiology and have made obsolete the idea of simple causative associations between genes or the environment and MS.

Estrogen controls vitamin D3-mediated resistance to experimental autoimmune encephalomyelitis by controlling vitamin D3 metabolism and receptor expression

Multiple sclerosis (MS) is an autoimmune, neurodegenerative disease with a rapidly increasing female gender bias. MS prevalence decreases with increasing sunlight exposure, supporting our hypothesis that the sunlight-dependent hormone 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) is a natural inhibitor of autoimmune T cell responses in MS. We found that vitamin D(3) inhibited experimental autoimmune encephalomyelitis (EAE) in intact female mice, but not in ovariectomized females or males. To learn whether 17beta-estradiol (E(2)) is essential for vitamin D(3)-mediated protection, ovariectomized female mice were given E(2) or placebo and evaluated for vitamin D(3)-mediated EAE resistance. Diestrus-level E(2) implants alone provided no benefit, but they restored vitamin D(3)-mediated EAE resistance in the ovariectomized females. Synergy between E(2) and vitamin D(3) occurred through vitamin D(3)-mediated enhancement of E(2) synthesis, as well as E(2)-mediated enhancement of vitamin D receptor expression in the inflamed CNS. In males, E(2) implants did not enable vitamin D(3) to inhibit EAE. The finding that vitamin D(3)-mediated protection in EAE is female-specific and E(2)-dependent suggests that declining vitamin D(3) supplies due to sun avoidance might be contributing to the rapidly increasing female gender bias in MS. Moreover, declining E(2) synthesis and vitamin D(3)-mediated protection with increasing age might be contributing to MS disease progression in older women.

Sex ratio of multiple sclerosis in Canada: a longitudinal study

BACKGROUND

Incidence of multiple sclerosis is thought to be increasing, but this notion has been difficult to substantiate. In a longitudinal population-based dataset of patients with multiple sclerosis obtained over more than three decades, we did not show a difference in time to diagnosis by sex. We reasoned that if a sex-specific change in incidence was occurring, the female to male sex ratio would serve as a surrogate of incidence change.

METHODS

Since environmental risk factors seem to act early in life, we calculated sex ratios by birth year in 27 074 Canadian patients with multiple sclerosis identified as part of a longitudinal population-based dataset.

FINDINGS

The female to male sex ratio by year of birth has been increasing for at least 50 years and now exceeds 3.2:1 in Canada. Year of birth was a significant predictor for sex ratio (p<0.0001, chi(2)=124.4; rank correlation r=0.84).

INTERPRETATION

The substantial increase in the female to male sex ratio in Canada seems to result from a disproportional increase in incidence of multiple sclerosis in women. This rapid change must have environmental origins even if it is associated with a gene-environment interaction, and implies that a large proportion of multiple sclerosis cases may be preventable in situ. Although the reasons why incidence of the disease is increasing are unknown, there are major implications for health-care provision because lifetime costs of multiple sclerosis exceed pound1 million per case in the UK.

Progressive increase in incidence and prevalence of multiple sclerosis in Newcastle, Australia: a 35-year study

The prevalence of multiple sclerosis (MS) in Newcastle, Australia increased significantly between 1961 and 1981 and the incidence of the disease also increased between the decades 1950-1959 and 1971-1981. The present study sought to determine whether there has been a further increase in the frequency of MS in the subsequent 15 years, and to examine the potential factors underlying this change. The incidence, prevalence and clinical profile of multiple sclerosis were therefore re-examined in Newcastle, Australia in 1996 using comparable diagnostic criteria and methods to those employed in studies in the same region in 1961 and 1981. There has been a significant progressive increase in prevalence from 19.6 to 59.1 per 100,000 population and a significant increase in incidence from 1.2 to 2.4 per 100,000 population from 1961 to 1996. The most pronounced increase in prevalence was in females and in the age-group over 60 years, and there was also an increased incidence in females aged 20-29 years. There was little change in the age of disease onset, but duration of disease in females had increased substantially. The significant increase in prevalence is attributed to increased incidence, particularly in females; and to increased survival. Although such trends in prevalence have been observed in the Northern Hemisphere, this is the first such study in the Southern Hemisphere to show a longitudinal increase in prevalence and incidence over a period of this duration.

Multiple sclerosis is more prevalent in northern New Zealand than previously reported

BACKGROUND

There have been no studies of multiple sclerosis (MS) prevalence from New Zealand (NZ) in the past two decades, and only one in a northern NZ district. Our impression was that the local prevalence of MS was higher than previously published data would suggest. There is limited access to new treatments for MS in NZ.

AIMS

The present paper aims to: (i). measure the prevalence of definite and probable MS in the Bay of Plenty (BOP), a North Island province, (ii). compare this with previous NZ studies, (iii). study the profile of disability in this population-based group and (iv). determine the proportion of MS patients who receive government funding for modern drug treatment (beta-interferons).

METHODS

Patients were identified from a geographically and demographically defined area of the North Island of NZ, using multiple sources of case ascertainment and modern diagnostic criteria. All clinical records were reviewed and data were supported by a telephone interview. All patients' eligibility for -government-funded treatment with beta-interferon was considered.

RESULTS

Eighty-six patients were identified as residents in BOP, NZ, on 15 January 2001. Excluding 'possible' cases, this represented a prevalence of 50/105 (95% confidence interval 40-62/105). Half of the population-based cohort had a disability defined as 'moderate to severe' (i.e. aids needed to walk, unable to take more than a few steps, or worse). Eleven patients (13%) had a primarily progressive form of MS. Eleven patients (13%) had the relapsing--remitting form of the disease and qualified for -government-funded treatment with beta-interferon.

CONCLUSION

The prevalence of MS in the defined region was twice as high as that reported from an adjacent area, the Waikato, 20 years previous. Our data will help to update NZ prevalence statistics and are of direct relevance to current funding issues for modern treatments which, in NZ, are presently limited to a proportion of patients with relapsing- remitting disease.