Increasing prevalence of multiple sclerosis in Finland

Objectives – To follow‐up the prevalence trends of MS from 1983 to 1993 in western and southern Finland. MS epidemiology has been previously followed from 1964 to 1978 in these regions. The updated prevalences were correlated with incidence trends in the same period. Methods– Age‐adjusted and age‐specific MS prevalence rates were calculated for cases classified by Poser's criteria. Results– In the western health‐care districts, Seinäjoki and Vaasa, prevalences in 1993 were 202/10⁵ and 111/10⁵. In the southern district Uusimaa the respective figure was 108/10⁵. In Seinäjoki a significant 1.7‐fold increase was found in 1993 as compared to 1983, mainly due to increased incidence. In Uusimaa a significant 1.2‐fold increase in prevalence was found in the presence of stable incidence. In Vaasa prevalence was stable, although incidence was declining. Conclusion– The prevalence of MS is increasing in Seinäjoki and Uusimaa but not in Vaasa. Both the prevalence and incidence in Seinäjoki are now among the highest reported.     

A possible spatial and temporal cluster of multiple sclerosis in the town of Linguaglossa,Sicily

We carried out an epidemiological survey to determine prevalence and incidence of multiple sclerosis in the little town of Linguaglossa in the Province of Catania. We calculated prevalence rate as point prevalence at 1 January 2001 and incidence during 1991–2000.We studied the frequency of multiple sclerosis in the community of Linguaglossa in a population of 5,422 inhabitants in the 2001 census. The primary sources for the case ascertainment were the general practitioners of Linguaglossa, the local Italian Multiple Sclerosis Association and the neurological departments, Multiple Sclerosis Centers and private neurologists of the province of Catania. We considered as prevalent and incident cases all patients who satisfied the Poser’s diagnostic criteria. We detected 11 patients with multiple sclerosis who had had the onset of disease on prevalent day (P.D.). The onset–adjusted prevalence rate was 203/100,000 (95% CI 107–352).Prevalence was higher in women (247/100,000) than in men (154/100,000). From 1991 to 2000, 10 subjects with MS had clinical onset of disease. The mean annual incidence risk was 18.2/100,000 (C. I. 95 % 5.9–42.5).Conversely in the same population prevalence on 1 January 1991 was 37/100,000 while the onset adjusted annual incidence risk during the previous decade (1981–1991) was 3.6/100,000. Prevalence and incidence rates of MS during the last decade in the little town of Linguaglossa are higher than those found in the same area during the previous ten years and also than those reported in other Sicilian and Italian surveys suggesting a possible cluster of MS.     

Restless legs syndrome in multiple sclerosis: A case‐control study

The aim of our study was to explore restless legs syndrome (RLS) frequency in multiple sclerosis (MS)‐patients and establish whether RLS could be a symptom of MS. Over a period of 1 year, we consecutively enrolled 202 MS‐patients and 212 healthy controls, matched for sex and age, in a case‐control study. All of them filled in a structured questionnaire according to IRLSSG criteria. Those patients who fit the diagnostic criteria were subsequently examined by a neurologist to verify the effective presence of RLS. A total of 91 MS‐patients (45%) responded positively to the questionnaires. The diagnosis of RLS was carried out in 29subjects (14.4%). Among the healthy controls, a definite diagnosis of RLS was achieved only in 6 subjects (2.8%). The risk of MS patients to present RLS was significantly higher (OR.5.76 P:0.00002) than the general population. None of them was affected by other medical conditions related to RLS developing. The 62 remaining patients presented numbness and weakness of the legs not suggestive of RLS. Our findings confirm a significant correlation between MS and RLS. In our opinion, MS must be definitively included among RLS causes. © 2008 Movement Disorder Society     

An epidemiological study of multiple sclerosis in central Sardinia, Italy

Objectives – To verify morbidity estimates in central Sardinia, Italy. Methods – A prevalence study was performed in the province of Nuoro, Central Sardinia, which has a population of 273,768 inhabitants (135,383 men and 138,385 women). A complete enumeration approach was adopted by using all possible case-collection sources. Results – On prevalence day, December 31, 1993, 394 subjects (124 men and 270 women) living in the study area were known to suffer from definite and probable MS, giving a crude prevalence rate of 143.9 cases per 100,000 people, 91.6 for males and 195.11 for females. The crude prevalence estimated on December 31, 1985, based on 282 MS cases alive in the study area, was 102.94 per 100,000. Conclusion – This study reinforced central Sardinia's position as a high and rising prevalence area for MS.     

A clinical patho-anatomical study of clinically silent multiple sclerosis

This is the first study on the frequency, size, number, and location of plaques in clinically silent MS. Among the present 18 patients in whom MS was unexpectedly diagnosed at autopsy, it had been clinically silent in 13. An estimate of the prevalence of silent MS is about 25% of that diagnosed in vivo. In the silent group, the MS plaques were located mainly in the periventricular areas, and this may explain the silent nature of the disease.     

Epidemiological survey of multiple sclerosis in Catania city

The findings of an epidemiological survey of multiple sclerosis (MS) in the urban area of Catania reveal a new and in some respects original pattern of MS cases recorded on 31 December 1989 (prevalence day).They explain why special attention should be paid to patients residing in that area, which shows a remarkable upward trend of the MS prevalence rates calling for further study and for more targeted intervention in the fields of prevention, treatment and rehabilitation.

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Sommario Vengono riportati i dati riguardanti un'indagine epidemiologica sulla Sclerosi Multipla (SM) nell'area urbana di Catania.Essi mettono in evidenza una nuova e per molti versi originale tipologia dei casi di SM registrati al 31 dicembre 1989 (giorno di prevalenza) e rendono ragione della particolare attenzione da riservare ai pazienti residenti in tale area geografica ove, in più, si riscontra una rimarchevole tendenza all'incremento degli indici di prevalenza della malattia abbisognevole di ulteriori studi e di più mirati interventi preventivi, terapeutici e riabilitativi.

     

Marked differences in prevalence of multiple sclerosis between ethnic groups in Oslo,Norway

Objectives

Oslo, the capital of Norway, has a high prevalence of multiple sclerosis (MS). In recent decades there has been substantial immigration to Oslo from Asia, the Middle East and Africa. The aim of the study was to estimate the prevalence of MS among non-Western immigrants living in Oslo, adjusted for duration of residence.

Methods

Data were obtained from the MS registry at Ullevål University Hospital. The prevalence of MS was adjusted for ethnicity, age and duration of residence in Norway.

Results

A total of 786 definite MS patients were alive and resident in Oslo on 31 December 2005, yielding a crude prevalence of 148/10⁵. Twentyseven patients were of non-Western origin: Middle East 14, Asia 9, Africa 4. The non-Western patients' mean age at migration was 20. The crude prevalence (95 % CI) of MS patients was 170/10⁵ (159–182) for the Norwegian/Western, 85/10⁵ (50–143) for the Middle East, 21/10⁵ (11–41) for the Asian, and 20/10⁵ (7–53) for the African cohorts. The high MS prevalence in the Middle East cohort and the low prevalence among Asian/African immigrants were also pronounced after adjustment for age and duration of residence.

Conclusions

The Middle East immigrants had a markedly higher prevalence of MS despite a shorter duration of residence than other non-Western patients. These findings suggest that people from the Middle East have a greater genetic disposition for MS. Furthermore, the high age at migration among the non-Western immigrants indicates that possible environmental factors affecting MS risk may also act on adults.

     

Epilepsy and multiple sclerosis in Sicily: a population-based study

PURPOSE: To evaluate the association between epilepsy and multiple sclerosis (MS), we analyzed the incidence of epilepsy in a population-based incidence cohort of MS in Catania, Sicily. METHODS: According to Poser's diagnostic criteria, 170 incident cases of MS have been identified from 1975 to 1994 in the city of Catania. All these subjects underwent a complete neurological examination to confirm the diagnosis of MS and to identify those patients with a history of seizures. Diagnosis of epilepsy was based on the criteria proposed by the International League Against Epilepsy (ILAE) in 1993, and seizures were classified according to the classification of the ILAE, 1981. RESULTS: From 1975 to 1994, 170 subjects with MS had the clinical onset of the disease. The mean annual incidence of MS was 2.3/100,000 (95% CI, 2.0-2.6). Of the 170 defined MS patients, four developed epilepsy after the onset and also diagnosis of MS, giving an incidence rate of epilepsy of 285/100,000 person years at risk (95% CI, 119-684) and 147.8/100,000 when age adjusted to the world standard population. The cumulative risk of developing epilepsy after the onset of MS, evaluated by using the life-table methods, was zero at 1 year and 1.76% at 5 years. Of these four patients, three were classified as having partial seizures with secondary generalization and one with tonic-clonic seizures. CONCLUSIONS: Our data are consistent with those reported in literature suggesting that the risk of developing epilepsy is threefold higher among MS patients than in the general population.     

High prevalence and fast rising incidence of multiple sclerosis in Caltanissetta, Sicily, southern Italy

BACKGROUND: Epidemiological studies conducted in Sicily and Sardinia, the two major Mediterranean islands, showed elevated incidence and prevalence of multiple sclerosis (MS)and a recent increase in disease frequency. OBJECTIVE: To confirm the central highlands of Sicily as areas of increasing MS prevalence and elevated incidence, we performed a follow-up study based on the town of Caltanissetta (Sicily), southern Italy. METHODS: We made a formal diagnostic reappraisal of all living patients found in the previous study performed in 1981. All possible information sources were used to search for patients affected by MS diagnosed according to the Poser criteria. We calculated prevalence ratios, for patients affected by MS who were living and resident in the study area on December 31, 2002. Crude and age- and sex-specific incidence ratios were computed for the period from January 1, 1993, to December 31, 2002. RESULTS: The prevalence of definite MS rose in 20 years from 69.2 (retrospective prevalence rate) to 165.8/100,000 population. We calculated the incidence of definite MS for the period 1970-2000. These rates calculated for 5-year periods increased from 2.3 to 9.2/100,000/year. CONCLUSION: This survey shows the highest prevalence and incidence figures of MS in the Mediterranean area and confirms central Sicily as a very-high-risk area for MS.     

Multiple sclerosis in Oslo, Norway: prevalence on 1 January 1995 and incidence over a 25-year period

The Oslo Multiple Sclerosis (MS) Registry was established in 1990, and this is the first report on the prevalence and incidence of MS in the city of Oslo, Norway. The prevalence rate of definite MS on 1 January 1995 was 120.4/10(5). Inclusion of patients of native Norwegian ancestry only and exclusion of non-Norwegian immigrants yielded a prevalence rate of 136.0/10(5). A similar prevalence rate (136.5/10(5)) was found when patients and immigrants from the other Nordic countries (Finland, Sweden, Denmark) were included. Segregation of the native Norwegian patients according to the counties where they were born showed no significant differences except for a disproportionate increase of patients born in the inland county of Oppland. A total of 794 cases were resident in Oslo at the time of a diagnosis of definite MS in the period 1972-99. The crude average annual incidence rate for each 5-year period, between 1972 and 1996, increased significantly from 3.7/10(5) in the 1972-76 to 8.7/10(5) in the 1992-96 period. The increase was more marked in relapsing-remitting (RR) than in primary progressive disease and in female cases.     

The epidemiology of multiple sclerosis in Finland: increase of prevalence and stability of foci in high-risk areas

ABSTRACT- Reliable data on the epidemiology of multiple sclerosis (MS) in Finland are available from 1964 and 1972. They show that the whole country is a high-risk area of MS with clustering in the western part. A reassessment of the prevalence data was carried out in the southern province of Uusimaa and in the western province of Vaasa, the prevalence day being January 1, 1979. The age-adjusted prevalence was 52.9 per 100,000 in Uusimaa and 92.9 per 100,000 in Vaasa, figures that were three times higher than those recorded for the same areas in 1964. The communities with the highest prevalence rates in the province of Vaasa were the same as those in the survey of 1972; some rates exceeded 200 per 100,000. The increase in the prevalence rates may be due to a better registration of MS cases, but it may also represent a true increase, a possibility that only can be answered by further incidence studies.     

Epidemiology of multiple sclerosis: incidence and prevalence rates in Denmark 1948–64 based on the Danish Multiple Sclerosis Registry

The Danish Multiple Sclerosis Registry (DMSR) is a national register based upon the ethnically homogeneous Danish population of about 5 millions. The DMSR was founded in 1956 following a nationwide Danish prevalence survey of MS in 1949 and a continuous registration of incident cases of MS since January 1, 1948. Included in DMSR are all Danish cases of MS (or suspicion of MS) diagnosed by a neurologist or a department of neurology. The sources of notification are the 22 neurological departments in Denmark, the National Patient Registry, the neuropathological departments, the Registry of Causes of Death, and, up to 1975, the Disablement Insurance Court. Notified cases which do not comply with the standardized diagnostic criteria of the DMSR are excluded. An estimate of the completeness of the DMSR is 90-95% and the validity is around 94%. Age- and sex-specific incidence rates of MS for the interval 1948-64 are presented. The crude annual incidence rate of MS in Denmark was in the year 1948-64 4.42 per 100,000 population, 22% higher in females than males. There was a significant geographical variation of incidence rates and a significant downward trend in incidence rates during the interval, whereas the prevalence rates showed a slight increase.     

Reflection on the geographic distribution of multiple sclerosis in France

The geographic distribution of multiple sclerosis within the 95 Départements and the 21 Régions of France was defined from a 1986 nationwide prevalence series derived from questionnaires. This indicated a significant clustering of high frequency regions in the northeastern part of the country with most significantly low areas in the south and west. Distributions were similar to those for MS death rates by Département and Région for 1968–1977, indicating geographic stability over time; but there was also evidence of diffusion over time. The 1986 prevalence distribution was also compared with all published prevalence rates for communities of France. From all these resources we conclude that all of France falls within the "high frequency zone" for MS, that the nationwide prevalence rate is at least 50 per 100000 population, and that there is evidence of geographic clustering of the disease with temporal spread of the cluster.     

The prealence of multiple sclerosis in the Hungarian city of Szeged

Objectives – The aim of this study was to determine the prevalence of multiple sclerosis in a population in South Hungary. Methods – The diagnosis was established with the aid of the Poser diagnostic criteria and the degree of physical disability was determined on the Kurtzke expanded disability status scale (EDSS). The present medical state (EDSS score) was determined from outpatient clinical control tests. The prevalence, the average age at onset of the disease and the proportions of the various clinical forms were calculated, and the patients' disability status was estimated. Results – In 1996, the prevalence was 65/100,000, and the incidence from January 1,1995 through December 31, 1996 was 7/100,000/year. Discussion – During a period of 2 years, the number of diagnosed patients has almost doubled. The disease can be recognized in an early stage with a minimal neurological deficit. The development of the diagnostics necessitates re-examinations with modern diagnostic procedures. During the last 3 years, the general practitioner system has been reorganized, and the working relationships between the clinic and family doctors have developed considerably. A comparison of the present findings with those in other countries with a similar climate revealed very similar prevalence data.     

Prevalence of multiple sclerosis in Belgrade, Yugoslavia

OBJECTIVES: To estimate the distribution of multiple sclerosis in the Belgrade population. METHODS: All persons who were affected and/or died from multiple sclerosis (Poser's criteria), with residence in the Belgrade region had been collected from January 1, 1985 to December 31, 1996. Prevalence was adjusted by direct method, using world population. RESULTS: From 1985 to 1996, 823 patients were suffering from multiple sclerosis. Sex ratio was 1:1.9. The mean age at onset was 32.2 +/- 9.8 years. A relapsing-remitting course of multiple sclerosis was reported in 50.7% patients, secondary progressive in 36.4%, patients, and primary progressive in 12.9% patients. On December 31, 1996, age-adjusted prevalence of multiple sclerosis in Belgrade was 41.5/100,000, 28.2/100,000 for males, and 54.1/100,000 for females. During the period studied, statistically highly significant increasing trend of multiple sclerosis prevalence was observed (P = 0.0001). CONCLUSIONS: According to findings presented in this study, Belgrade is an area with high prevalence of multiple sclerosis.     

The frequency of multiple sclerosis in Mediterranean Europe

Recent investigations on multiple sclerosis (MS) distribution in Italy, based on relatively small population groups, contradict the current thesis, derived from studies undertaken in populations exceeding 300,000, of a lower spreading of the disease in Mediterranean Europe. Intensive surveys on small populations strengthen the suggestion that Italy is a high-risk area, although MS studies based on prevalence rather than incidence could also be biased by geographic variables making prevalence unsuitable for comparing MS prevalence rates found in different years and/or zones. We report a further epidemiologic study in Barbagia, Sardinia, insular Italy, undertaken both to establish the MS incidence in the last 20 years, and to estimate a new prevalence rate. Based on 31 probable incident cases, the mean incidence per year for the years 1961-1980 was 2.9 per 100,000 (3.2 if age- and sex-standardized to the Italian population). On October 24, 1981, the prevalence per 100,000 was 65.3 (77.9 if standardized to the Italian population). These results confirm that in Barbagia, MS occurs more frequently than expected in a Mediterranean area, and give further support to the idea that MS frequency in Italy is similar to that established for most central and northern European countries.