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.     

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     

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     

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.     

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.     

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.     

The influence of ethnicity on the characteristics of multiple sclerosis: A local population study between Persians and Arabs

Background

Based on previous studies, Iran is located in a low risk area in terms of multiple sclerosis (MS). The objective of this study was to determine and compare the incidence, prevalence and demographic characteristics of MS in two ethnic groups of Persian and Arab over the period spanning 2009 in the Khuzestan province, in the Southwest of Iran.

Methods

A cross-sectional case register study was conducted between January and August 2009. All cases in the region whom were referred to the MS society in the city of Ahwaz were participants in the study. The population data from the Iranian Bureau of Statistics were used to calculate the population at risk based on the 1996 and 2006 census data.

Results

A total of 696 patients were identified according to the McDonald criteria during the last 12 years of which 569 patients were Persian. In 2009 the total prevalence and incidence rates of MS were 16.28 and 2.20 per 100,000 individuals. Based on these values, the female to male ratios were 3.11. The Persians manifested more sensory signs and symptoms (40.2%) but motor deficits (19.1%) and cerebellar findings (18.2%) were seen as being more manifest in Arab individuals. The main difference was observed in the progressive types of MS in which 24.7% of the Arab patients showed progressive type symptoms as compared to 15.9% of the cases in the Persian population.

Conclusion

According to this study the authors conclude that the prevalence and incidence of MS were higher in Persians; however progressive forms of MS with motor and cerebellar signs are more frequent in the Arab ethnic group.     

Dysphagia in multiple sclerosis

Objectives: (1) To determine the prevalence of swallowing problems in MS patients and its relation to the overall disability. (2) To define the most frequent symptoms suggestive of dysphagia. (3) To describe the abnormalities on manofluoroscopy (MFS). Methods: Three hundred and eight consecutive MS patients were asked whether they ever had swallowing problems. If so the questionnaire of the Johns Hopkins Swallowing Centre was applied to qualify the dysphagia. A MFS was performed in 30 patients with dysphagia covering the entire spectrum of MS. Overall disability was assessed using the Expanded Disability Status Scale (EDSS). Results: Seventy-three of our 309 patients had permanent dysphagia (24%). Another 5% had a history of transitory swallowing problems only. Permanent dysphagia started to be a problem in mildly impaired patients (EDSS 2–3). Prevalence increased together with rising disability to reach 65% in the most severely disabled subjects (EDSS 8–9). Two alarming symptoms of patients with swallowing problems, coughing or choking during the meal and a history of pneumonia were present in 59%, respectively, 12% of these patients. MFS showed deficiency of the oral phase in all patients, while only the patients with an EDSS higher than 7.5 showed abnormalities of the pharyngeal phase. Conclusions: Permanent dysphagia may already develop in mildly impaired MS patients but becomes a rather frequent finding in MS patients with moderate or severe disability. MFS is a sensitive and useful ancillary examination. Important qualitative changes of the pharyngeal phase on MFS are seen in patients with an EDSS higher than 7.5.     

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     

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.     

Frequency of reported European ancestry among multiple sclerosis patients from four cities in the southern and southeastern regions of Brazil

Recent reports on the prevalence of multiple sclerosis (MS) have described discrepancies between the rates in cities in the northeastern and southeastern regions of Brazil, representing a north–south gradient. European immigrants settled in southeastern and southern Brazil at the beginning of the twentieth century. In this study, we report the frequency of European ancestors among Brazilian MS patients in four cities in the southern and southeastern regions of Brazil.     

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     

Point prevalence and correlates of depression in a national community sample with multiple sclerosis

Objective

The prevalence of depression in multiple sclerosis (MS) is known to be elevated, but nearly all available studies have estimated period prevalence. The objective of this study was to estimate the point prevalence of depression in a representative community sample using the Patient Health Questionnaire, Brief (PHQ-9).

Methods

The data source for this study was the Survey of Living with Neurological Conditions in Canada, which was derived from a representative sample of household residents.

Results

The sample included 630 respondents with MS. With application of the standard PHQ-9 cut point (10 +), the prevalence of depression was 26.0% (95% confidence interval 18.9%–33.0%). Depressed subjects had lower quality of life; an increased frequency of suicidal ideation; and more often reported a negative disease course, high stress, low social support and stigmatization.

Conclusions

This study adds to the existing literature by providing point prevalence data: in any 2-week period, about one quarter of community residents with MS experience substantial levels of depressive symptoms.     

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.     

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.     

Incidence of seroconversion and sero-reversion in patients with multiple sclerosis (MS) who had been treated with natalizumab: A systematic review and meta-analysis

BackgroundNatalizumab is a medication of choice for some patients with relapsing remitting (RR) form of multiple sclerosis (MS). John Cunningham virus (JCV) antibody status is important in cases who are treating with natalizumab. Different studies reported various rates of seroconversion and sero-reversion in patients who had been treated with natalizumab. As there is no systematic review reporting incidence of seroconversion and seroreversion in MS cases who were treated with natalizumab, we aimed to conduct this systematic review and meta-analysis to find pooled incidence of seroconversion and seroreversion in MS cases who were treated with natalizumab.MethodsPubMed, Scopus, EMBASE, CINAHL, Web of Science, Ovid, and google scholar were systematically searched. We also searched the gray literature including references from included studies, and conference abstracts which were published up to April 2019.ResultsThe incidence of seroconversion was reported between 6% and 41% and the incidence of seroreversion was reported between 1% and 11%.The pooled estimate of seroconversion incidence was 19% (95% CI: 13%–25%) (I² = 96.8%, P < 0.001) and the pooled estimate of seroreversion incidence was 5% (95% CI: 3%–8%) (I² = 72.2%, P < 0.001).Subgroup analysis by considering the country of the origin showed that the pooled incidence of seroconversion incidence during the studies was 6% in Asian countries and 21% in European/American countries. The incidence difference between subgroups was significant (p < 0.001).ConclusionIncidence of seroconversion in MS patients who had been treated with natalizumab is higher in European/American countries than Asian countries.     

Clinical and demographical characteristics of primary progressive multiple sclerosis in Isfahan, Iran

Primary progressive multiple sclerosis (PPMS) is an uncommon form of multiple sclerosis (MS) in which the course of disease is progressive from onset. In a retrospective study amongst 1606 MS patients registered in Isfahan MS Society (IMSS) from April 2003 to 31 December 2005, 92 PPMS cases were identified. That means, the frequency of PPMS amongst all included MS patients would be 5.7% (95% CI: 6.7% and 4.7%). The mean expanded disability status scale (EDSS) for the group was 5.09 ± 1.3. The commonest mode of presentation was motor disturbance in 55 (59.8%), other modes of presentation were, vertigo in 15 (16.3%), visual problems in 12 (13%), sensory disturbances in six (6.5%), and diplopia in four (4.3%). The current existing symptoms were motor problems in all 92 (100%), cerebellar symptoms in 46 (50%), and cognitive impairment in only six (6.5%). Interestingly, two (2%) were affected by poliomyelitis during childhood and presenting symptom in both was limb weakness. Primary progressive form of MS is less common in Persian population and some of the rates observed in PPMS patients differ from those in other regions, these differences may be due to different ethnicity of Persian patients or to geographical differences.     

Multiple sclerosis prevalence and possible lead exposure

This study was conducted to estimate the current prevalence of multiple sclerosis (MS) in Jefferson County, Missouri, USA, and to address community concerns about a perceived excess of MS around an active lead smelter. The study population consisted of the residents of Jefferson County, Missouri between 1998 and 2002. An aggressive MS case finding with capture–recapture analysis was used. The spatial clustering was examined using a spatial scan statistic.

The capture–recapture analysis showed the case ascertainment to be 95%. The crude five-year period prevalence of MS in Jefferson County was 105 per 100,000 population (95% confidence interval [CI], 91–121), and 107 per 100,000 (95% CI, 95–119) when age-standardized to the 2000 U.S. population. No significant spatial clusters of MS cases were identified in the study area.

The estimates of MS prevalence in Mid-western community of USA appeared to be comparable to estimates from other areas of similar latitude in the United States and Western Europe. The MS cases did not appear to cluster around the lead smelter.