Epidemiology of multiple sclerosis in Sicily

From epidemiological data obtained over more than 20 years by surveys conducted in different parts of Sicily, it is evident that Sicily is a high-risk area for multiple sclerosis (MS). This is in sharp contrast with the gradient hypothesis. High frequencies have been found in different parts of the island having different geoclimatic features, but at least two cities (Monreale and Enna) had had a prolonged Norman domination. This is in agreement with the hypothesis that MS originated in Northern Europe and spread around the world throughout the raids of the northern peoples. The increase in frequency estimated by follow-up and incidence studies is well established and is only in part linked to the improvement in diagnostic techniques. Finally, it is noteworthy that in the islands of Malta, a few sea miles away from Sicily, the MS prevalence rates are in the range of 4–8 cases per 100 000 persons. This occurrence represents a natural model to investigate MS etiology through analytic studies and genetic analyses.     

Incidence and prevalence of multiple sclerosis in southeastern Iran

Background

Based on data available, Iran is located in a low risk area for multiple sclerosis (MS). The objective of the current study is to determine the age and sex adjusted prevalence and incidence of MS in southeastern Iran.

Methods

This cross-sectional case register study was conducted from January to August 2010. Considering that MS affects people aged between 16 and 50 years, we intended to find the incidence and prevalence of MS during this age range. Since all cases in this area are referred to our university hospital for confirmation of diagnosis, misdiagnosis is rare. Population data, based on the censuses carried out in 1996 and 2006, were obtained from the Iranian Bureau of Statistics to determine the number of people at risk.

Results

Totally 206 patients were identified according to the McDonald criteria. In 2009 the age-adjusted prevalence and incidence rates of MS for 16–50 year-old adults were 13.96 and 2.67 per 100,000 persons, respectively. Based on those values; the female to male ratio was 2.18. Between 2006 and 2009, the incidence rates increased 2.4 and 2.7 times in women and men, respectively. In 2009, the prevalence rates among the age ranges of <15, 16–35, 36–50 and ≥51 years were 1.44, 14.34, 12.24 and 1.45 per 100,000 persons, respectively, and the relapsing-remitting type of MS was the most prevalent form (65.8%).

Conclusion

According to the Kurtzke geographical distribution, the authors conclude that the prevalence of MS in southeastern Iran is in the intermediate range, and the incidence rate is showing a faster growth rate, compared to previous years.     

Epidemiology of multiple sclerosis in Arabs in Kuwait: A comparative study between Kuwaitis and Palestinians

On December 31, 1988 there were 201 registered multiple sclerosis patients in Kuwait, an overall prevalence rate (PR) of 10.2 per 100000; among them were 186 Arabs, of whom 72 were Palestinians and 51 Kuwaitis. Comparison of these two subgroups, who had a similar age distribution revealed that the disease was2 1/2 times more frequent among Palestinians (PR 23.8/100 000) than among Kuwaitis (PR 9.5/100 000). Palestinians also showed significant differences from Kuwaitis in eye color, blood group distribution and HLA-DR and HLA-DQW epitopes frequency. This suggests that genetic rather than environmental factors might be the underlying cause for the high susceptibility to develop MS among Arabs originating from the Eastern Mediterranean basin.     

A prospective study of the incidence, prevalence and mortality of multiple sclerosis in Leeds

Objective: To establish the prospective incidence of multiple sclerosis and mortality rates of people with multiple sclerosis in Leeds Health Authority and an updated prevalence of multiple sclerosis on 31 October 1999. Methods A population based prevalence register established on 30 April 1996 was maintained by prospectively registering all new cases of multiple sclerosis, flagging all cases with the National Health Service Central Register for notification of deaths and by registering all new clinical events. General practitioners notified patients with multiple sclerosis moving into or out of the area. Results 136 incident cases were prospectively registered from 30 April 1996 living in Leeds Health Authority (with an estimated resident population of 728 840). 57 deaths were notified. 792 people with multiple sclerosis were identified living in Leeds on 31 October 1999. The mean annual incidence rate for the three-year period 1996–1998 was 6.1/10⁵ (95 % CI: 5.1–7.2). The sex ratio of incident cases was 2.3 to 1 women to men. On 31 October 1999 the prevalence of multiple sclerosis in the Leeds Health Authority was 108.7/10⁵ (95 % CI: 101.2–116.5). This compares with a prevalence of 97.3/10⁵ (95 % CI: 90.3 –104.7) on 30 April 1996. The prevalence of definite and probable multiple sclerosis was 93.3/10⁵ (95 % CI: 86.4–100.6) and of suspected multiple sclerosis was 15.4/10⁵ (95 % CI 12.7 –18.5). Crude annual mortality rates of people with multiple sclerosis for 1997 and 1998 were 1.9/10⁵ (95 % CI: 1.1 to 3.2) and 3.2/10⁵ (95 % CI: 2.0 to 4.7). Multiple sclerosis was noted as the underlying cause of death in 8 (14 %) cases. Conclusion The incidence of multiple sclerosis in the Leeds Health Authority is similar to that in the south of the United Kingdom. The difference in successive prevalence figures is less than that published in other serial studies. Multiple sclerosis was notified as the underlying cause of death in a minority of deaths in people with multiple sclerosis. Received: 5 December 2000, Received in revised form: 23 March 2001, Accepted: 10 July 2001     

Prevalence and incidence of multiple sclerosis in the city of Monreale, Italy

The prevalence and incidence of multiple sclerosis (MS) in the city of Monreale, southern Italy were ascertained 10 years after a preliminary study in the same area. The study was undertaken in a population of 26,256 people. The patients were classified according to Poser’s criteria. The prevalence of MS on 31 December 1991 was 72.4 per 100,000 population. The incidence of MS for the period 1981–1991 was 3.3/100,000 per year. The mean period between onset and diagnosis of MS was 4.9 years for those patients found during this survey and 9.2 years for those in the first study. This study shows an increase of MS prevalence in Monreale city and a high incidence. The findings parallel the reduction of the lag time between onset and diagnosis. Received: 25 March 1997 Received in revised form: 30 June 1997 Accepted: 10 July 1997     

The prevalence of migraine in multiple sclerosis (MS): A systematic review and meta-analysis

ObjectivesWe designed this systematic review to estimate pooled prevalence of migraine in patients with multiple sclerosis (MS).MethodsWe searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, google scholar and gray literature including references from identified studies, conference abstracts which were published up to December 2019.The search strategy included the MeSH and text words as ((Disorder, Migraine OR Disorders, Migraine Disorder OR Migraine OR Migraines, OR Migraine Headache OR Migraine Headaches) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).ResultsThe literature search found 2100 articles. After eliminating duplicates, 1500 articles remained. Eleven articles and twelve abstract conference papers were included for final analysis.A total of 11,372 MS cases and 2627 MS patients with migraine included in the analysis. The prevalence of migraine ranged from 2% to 67%.The pooled prevalence of migraine in included studies was 31% (95%CI: 22%–40%) (I² = 99.3%, p < 0.001). The pooled prevalence of migraine in different continents were significantly different (p < 0.001).The pooled prevalence was 24% in Asian countries, 43% in American countries, 25% in European countries and 43% in African countries.ConclusionThe results of this systematic review shows that the prevalence of migraine in MS patients is 31% while the prevalence differs significantly among residents of different continents.     

The prevalence of multiple sclerosis in the world: an update

The systematic study of multiple sclerosis (MS) in populations, started in 1929 by Sydney Allison, now consists of over 400 publications dealing with the prevalence of MS throughout the world. However, any attempt to redefine the pattern of geographical differences in MS frequency remains as difficult as ever. The comparison of prevalence studies carried out in different areas and times is made difficult by the variability in surveyed population sizes, age structures, ethnic origins and composition, and the difficult quantification of numerators, especially regarding the recognition of benign and very early cases. Additionally, complete case ascertainment depends on access to medical care, local medical expertise, number of neurologists, accessibility and availability of new diagnostic procedures, the degree of public awareness about MS, and the investigators' zeal and resources. Critical examination of the more recent data on MS prevalence leads to some revisions of previously held concepts, the most interesting of which is the appreciation of the greater influence of genetic factors on disease acquisition. The rarity of MS among Samis, Turkmen, Uzbeks, Kazakhs, Kyrgyzis, native Siberians, North and South Amerindians, Chinese, Japanese, African blacks and New Zealand Maoris, as well as the high risk among Sardinians, Parsis and Palestinians, clearly indicate that the different susceptibilities of distinct racial and ethnic groups are an important determinant of the uneven geographic distribution of the disease. The updated distribution of MS in Europe, showing many exceptions to the previously described north-south gradient, requires more explanation than simply a prevalence-latitude relationship. Prevalence data imply that racial and ethnic differences are important in influencing the worldwide distribution of MS and that its geography must be interpreted in terms of the probable discontinuous distribution of genetic susceptibility alleles, which can however be modified by environment. Because the environmental and genetic determinants of geographic gradients are by no means mutually exclusive, the race versus place controversy is, to some extent, a useless and sterile debate.     

Clinical characteristics of multiple sclerosis in Lebanon

The epidemiologic, clinical, radiological and laboratory characterization of multiple sclerosis (MS) is very well documented in Caucasian and Japanese populations, but very little is known about MS in the Arab world. Such knowledge is becoming of paramount importance, with the recent advances in therapies, MRI techniques and other diagnostic procedures. We report a cohort of Lebanese MS patients, including details of their clinical and laboratory characteristics. The medical records of 202 patients fulfilling the Mc Donald's diagnostic criteria, and followed in our tertiary care center were reviewed. This cohort is highly representative of the disease in Lebanon where the number of MS patients is estimated to be between 1200 and 1700. The peak age of onset of MS in our cohort was in the third decade with 62.4% of patients developing their first symptoms between 20 and 39 years. The female/male ratio was 1.8/1.0. A positive family history for MS was present in 5% of patients. The most frequent presenting symptoms were brainstem-cerebellar (46.2%) followed by sensory (42.5%), motor (33.9%) and visual (29.6%). Of the total number of patients, 85.1% had relapsing remitting MS at onset, and 7.9% primary progressive MS. Benign MS defined as EDSS<=2.0 after 10 years from onset was present in 20% of patients. The mean time from onset to secondary progressive MS was around 9 years. Visual, brainstem, and somatosensory evoked potentials were abnormal in 65.6%, 27.8%, and 50.7% of patients tested respectively. Cerebrospinal fluid showed pleocytosis in 32.6%, increased IgG synthesis in 45.2%, positive oligoclonal bands in 40%, and elevated protein in 34% of patients tested. Although some of the clinical characteristics of our MS population were different compared to western series, the natural history of the disease was similar.     

Prevalence of multiple sclerosis in the province of Teruel, Spain

There have been few reports about the frequency of multiple sclerosis (MS) in Spain. We undertook a prevalence study in the province of Teruel, which is served by two hospitals as referral centres for a population of 143,680. We found a total of 46 patients who fulfilled Poser’s criteria for clinically definite or probable MS with a prevalence rate of 32/100,000 [95% confidence interval (CI): 22.8–41.3]. The prevalence rates for males and females were 23.5 (95% CI: 12.3– 34.7) and 40.6 (95% CI: 25.8–55.4) respectively. We found an incidence rate of 2.2/year per 100,000 in the last 5 years. The sex ratio (females/ males) was 1.7. The mean age on prevalence day was 40.6 years (range: 15–76). The clinical course was relapsing-remitting in 82% of patients, progressive in 9% and secondary progressive in the other 9%. The mean EDSS score was 3.73 (range: 1–8.5). Our results confirm the hypothesis that Spain is an area at high risk for MS. Received: 7 May 1996 Received in revised form: 17 September 1996 Accepted: 23 September 1996     

Prevalence of multiple sclerosis in Valladolid, northern Spain

The aim of this study was to ascertain the prevalence of multiple sclerosis (MS) in a northern Spanish region and to compare it with that from the most recent epidemiological studies in the country. MS prevalence was studied for a period of 2 years using multiple sources of information in the province of Valladolid, with a sample comprising a total population of 92,632. Patients were classified according to the Poser criteria. The crude prevalence of definite and probable MS was 58.3 per 100,000 (95% confidence interval: 43.7–75.7). The same methods have been used in ascertaining similar prevalence rates in Vélez-Málaga, Osona, and Gijón and a slightly lower rate in Teruel. Our survey confirms Spain as a high-risk area for MS, with prevalence rates over 50 per 100,000. Received: 4 March 1998 Received in revised form: 13 May 1998 Accepted: 10 June 1998     

高同型半胱氨酸血症与多发性硬化的关系研究

目的 用Meta分析的方法研究血同型半胱氨酸水平与多发性硬化症(MS)的关系并初步探讨其可能机制.方法 收集Medline 和中国期刊网的关于血同型半胱氨酸、维生素B12、叶酸与MS的相关文献,并分别对其进行Meta 分析.结果 分别有10篇、10篇、8篇文献进入血同型半胱氨酸、血维生素B12、血叶酸与MS关系的Meta 分析.结果 显示与对照组相比MS患者血同型半胱氨酸水平显著升高,而血维生素B12、叶酸水平无明显差异.结论 MS患者可能存在不伴维生素B12、叶酸缺乏的高同型半胱氨酸血症,可能在其病理过程中发挥作用.     

A double blind study on azathioprine efficacy in multiple sclerosis: final report

Forty patients, affected by multiple sclerosis with remitting-relapsing or progressive course, were included in a double blind study of treatment with azathioprine (2 mg/kg/day) lasting 3 years. The mean changes on the Expanded Disability Status Scale and in the survival analysis show a trend in favour of azathioprine both in slowing disease progression and reducing relapse frequency. These findings, repeatedly observed in similar trials, indicate that azathioprine should be used in the treatment of multiple sclerosis.     

Prevalence and clinical features of multiple sclerosis in Latin America

Multiple sclerosis (MS) in Latin America (LA) is considered to have a low to medium prevalence. However, accurate information on MS in LA is scarce. The aim of this study was to compare clinical characteristics among LA patients through a systematic review of the literature. A systematic search (Spanish, Portuguese and English) was done for all clinical studies of MS in humans (MEDLINE, PubMed, Scielo, BIREME, EMBASE and LILACS) up to May 2011 being focused on a well-defined Latin American population (peer-reviewed journal) following the MOOSE guidelines. The search strategy included combinations of different Mesh terms (two independent researchers). Classification of each article by using the Oxford Centre for Evidence-based Medicine – Levels of Evidence was done. The total number of patients per country for each specific characteristic was compiled. Chi-square test was used to compare the characteristics in the studies retrieved per country. There were 38 articles fulfilling the inclusion criteria, accounting for 4524 patients. Relapsing-remitting form was the most frequent in LA patients and the main initial symptom was motor, followed by optic neuritis and sensorial. A mild expanded disability status scale was the most prevalent in all LA countries. Factors accounting for differences in distribution and clinical course across LA countries include genetics, environment, diagnostic techniques, socioeconomic structure and medical facilities.     

Incidence of multiple sclerosis in Bagheria City, Sicily, Italy

We investigated the incidence of multiple sclerosis (MS) in a Sicilian community located a sea level. The study was a retrospective search for MS patients. Incidence was studied in the period from 1 January 1985 to 31 December 1994. We searched for definite MS patients, according to Poser's criteria, among the population resident in Bagheria (Palermo province). There were 25 subjects affected by MS, of which 20 were incident MS patients. The average annual incidence was 4.4 per 100 000 persons (n = 453 385 person-years). The incidence increased over time (1985–1989 = 3.5, 1990–1994 = 5.3). A parallel decrease of the interval between onset and diagnosis of MS was observed (1985–1989, 3.7 years, 95% CI = 1.6–7.3; 1990–1994, 1.9 years, 95% CI = 1.0–3.3). These results confirm that MS is frequent in Sicily. Received: 19 October 2000 / Accepted in revised form: 18 December 2000     

Prevalence and pattern of multiple sclerosis in Benghazi, north-eastern Libya

A search for Libyan patients with multiple sclerosis (MS) was made in Benghazi, located on the southern Mediterranean coast at a latitude of 32 degrees N. Twenty-one clinically definite and probable cases were detected during the period July 1982-June 1984. On the basis of 2 probable incidental cases, the incidence for 1983 was 0.8 per 100 000 of the population at risk (10-50 years). On July 1st, 1984, the rough prevalence rate for the total population was 4 per 100 000 and the age-adjusted prevalence rate was 5.9 per 100 000. This study suggests that Benghazi falls within the medium frequency band for MS. High prevalence of brainstem involvement and cerebellar dysfunction and infrequent occurrence of the severe optic-spinal form and sphincter disturbance indicates that the present group of patients resembles Western pattern of MS as opposed to Asian MS.     

The multiple sclerosis trait and the development of multiple sclerosis: genetic vulnerability and environmental effect

The remarkably low rate of concordance of multiple sclerosis (MS) in monozygotic twins has never been fully explained but it implies the possibility of a systemic condition called the multiple sclerosis trait (MST), which is quite different from asymptomatic MS. It results from the action of an antigenic challenge on the immune system of a genetically vulnerable person that does not cause damage to the nervous parenchyma; it may never evolve into the disease MS. A subsequent environmental viral-antigenic event in some MST-carriers can change the trait into the disease. This event could be an infection, which need not be symptomatic, or a vaccination. The MS may become symptomatic, remain asymptomatic, or manifested only by lesions visible by MRI. It is likely that the development of the MST, called activation, occurs early in life, while the transition from MST to MS, called acquisition, takes place at puberty in most patients. Differences in prevalence between pre-puberal migrants, and the locally born children of migrants, and their population of origin may also be explained by the MST.     

Systematic review and meta-analysis of observational studies to understand the prevalence of restless legs syndrome in multiple sclerosis: an update

ObjectiveMultiple sclerosis (MS) is related to the demyelination of intracranial nerves at multiple sites, while restless legs syndrome (RLS) appears to be caused by dysfunction of the dopaminergic system. Since RLS prevalence is higher among MS patients than in the general population, we carried out an updated meta-analysis to understand whether the two diseases might be associated.MethodWeb of Science, PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed databases were searched for observational and case-controlled studies of RLS prevalence in MS. Eligible studies were meta-analyzed using Stata 12.0.ResultsPooled RLS prevalence among MS patients of various ethnicities was 26%, and prevalence was lower in Asia (20%) than outside Asia (27%). Prevalence was higher among cross-sectional studies (30%) than among case–control studies (23%). RLS prevalence was higher among female than male MS patients (26% vs. 17%), and it was higher among MS patients than among healthy controls (OR 3.96, 95%CI 3.29–4.77, p < 0.001).ConclusionOur meta-analysis updates the most recent meta-analysis in 2013 and provides perhaps the first reliable pooled estimate of RLS prevalence in MS. The available evidence strongly suggests that RLS risk is higher among MS patients than healthy controls.     

Low back pain in patients with multiple sclerosis: A systematic review and the prevalence in a French multiple sclerosis population

PurposeThe prevalence and management of back pain in MS patients was assessed by a systematic review, and the results of a survey on the characteristics of low back pain in a sample of French MS patients are reported.MethodsA systematic search was conducted according to the PRISMA guidelines. The outcomes of interest included the prevalence of back pain, severity of pain and impact on daily activities. Moreover, the prevalence of low back pain and its consequences on daily living in a large French MS population were assessed.ResultsFourteen studies were included in the systematic review. The prevalence of back pain in MS patients ranged from 8.6 to 50%, but that of low back pain in particular ranged from 41.6 to 52.4%. Concerning the survey, 237 patients participated in the online questionnaire. The prevalence of low back pain in the French MS patients was 76.4%. The patients with chronic low back pain had more limitations in their daily life activities than those without chronic low back pain.ConclusionPatients with MS commonly suffer from low back pain, but it is still an underdiagnosed cause of pain that reduces one's ability to perform activities in daily life.     

Incidence of multiple sclerosis: a periodic or stable phenomenon

Summary For diseases of unknown aetiology, the question as to whether the incidence is constant or variable is very important. A study on multiple sclerosis in a defined northern area of the German Democratic Republic showed a prevalence of 68.6 and an incidence rate of 3.0. Retrospective and prospective investigations concerning an observation period of 22 years revealed cyclic periods (6–7 years) of high incidence rates (up to 4.5) interrupted by shorter intervals (4–5 years) with low rates (about 1.8). The differences (1963–1968 vs. 1969–1973, 1974–1978 vs. 1979–1983) are significant. In accordance with the findings of Kurtzke et al. on a cyclic outbreak of multiple sclerosis in the Faroes and Iceland, our results are considered to be a consequence of environmental factors, such as epidemic viral infections.