Prevalence of multiple sclerosis in Barrhead County, Alberta, Canada.

A prevalence study of multiple sclerosis (MS) was carried out in the town of Barrhead and surrounding county of Barrhead, in Alberta, Canada. The prevalence rate for clinically probable/definite multiple sclerosis on January 1, 1990 was 196/100,000. The average annual incidence rates for patients living in the area at onset were 1.31/100,000 for 1950-59, 4.97/100,000 for 1960-69, 3.77/100,000 for 1970-79, and 4.22/100,000 for 1980-89. Fifty percent of the patients were relapsing-remitting. Sixty percent were still walking without assistance. The female-to-male ratio was 1:1. Mean current age, age at onset and duration of illness were 49, 27 and 22 years respectively. The majority of patients (40%) experienced multiple symptom onset. Fifty percent were of single ethnic origin (either British or German); the rest were predominantly North European combinations. Forty percent of patients reported another MS relative. MS had affected the work status of 60% of the patients, 15% of whom were confined to an extended care centre.     

Incidence of multiple sclerosis among First Nations people in Alberta, Canada

Multiple sclerosis (MS) is thought to be rare among North American aboriginals, although few population-based frequency studies have been conducted. Data from government health databases were used to describe the incidence of MS among First Nations aboriginal people in the province of Alberta compared to the general population from 1994 to 2002. The general population rates were consistently higher than First Nations rates, but were essentially stable across this time span for both groups. For First Nations the MS incidence was 7.6 per 100,000 and 20.6 per 100,000 for the general population in 2002. During 2000-2002 for First Nations the incidence was 12.7 for females and 7.6 for males, with a female-to-male ratio of 1.7:1. During the same period the general population incidence was 32.2 for females and 12.7 for males, with a female-to-male ratio of 2.5:1. The peak incidence for both First Nations and the general population of Alberta was in the age group 30-39 years in 2002. The high incidence rates are consistent with high prevalence rates reported for both groups in 2002: 99.9 per 100,000 for First Nations and 335.0 per 100,000 for the general population. While the MS incidence in First Nations people is lower than in the general population of Alberta, it is not rare by worldwide standards.     

Regional variation of multiple sclerosis prevalence in Canada

OBJECTIVE: To describe the regional distribution of multiple sclerosis (MS) prevalence in Canada, controlling for age and sex. METHODS: This study used data from the Canadian Community Health Survey, a large general health survey (n = 131,535) conducted in 2000/2001. Subjects aged 18 and over were included in the current analysis (n = 116,109). The presence of MS was determined by self-report. Prevalence was computed in five regions (Atlantic, Quebec, Ontario, Prairies and British Columbia). Logistic regression was used to compare regions and examine for confounding/interaction by age and sex. RESULTS: The overall Canadian MS prevalence was 240 per 100000 (95%CI: 210 280). Prevalence ranged from 180 (95%CI: 90-260) in Quebec to 350 (95%CI: 230-470) in Atlantic Canada. Logistic regression revealed no statistical difference between the odds of MS in Quebec, Ontario and British Columbia adjusted for age and sex. The adjusted odds of MS in the Prairies and Atlantic regions were significantly higher than in the other regions combined, with odds ratios of 1.7 (95%CI: 1.1-2.4, P <0.01) and 1.6 (95%CI: 1.1-2.4, P <0.05) respectively. Sensitivity analysis demonstrated similar prevalence in the nonaboriginal/nonimmigrant group (n = 96219). CONCLUSION: Results suggest that Canadian MS prevalence differs by region. If validated, these regional differences may facilitate investigation of environmental influences.     

The incidence and prevalence of reported multiple sclerosis

A national survey, sponsored by the National Institute of Neurological and Communicative Disorders and Stroke, to determine the incidence, prevalence, and economic impact of multiple sclerosis has just been completed. These data are the first report of the results. Based on the data gathered, it is estimated that on Januaryuary 1, 1976, there were a reported 123,000 multiple sclerosis patients in the conterminous United States (a rate of 58 per 100,000). The annual incidence for the period 1970–1975 was estimated to be 8,800 (a rate of 4.2 per 100,000). The pattern of the disease being more common among females, whites, persons aged 30 to 50 years, and individuals living above the 37th parallel was also demonstrated. In addition to demographic characteristics, selected disease characteristics of the incidence and prevalence populations were also examined.     

Increasing prevalence and incidence of multiple sclerosis in northern Japan

BACKGROUND: We previously reported that prevalence of multiple sclerosis (MS) in Japan was 8.6/100,000 individuals in 2001. This was much higher than prevalence previously reported from Asian countries. A second epidemiologic survey was conducted to assess changes in MS prevalence and incidence over the last 30 years in Tokachi province of Hokkaido, the northernmost island of Japan. METHODS: The authors studied the frequency of MS in the community of Tokachi Province, where the population has stabilized between 350,000 and 360,000 over the last 30 years. The survey was conducted at the same institutions using the same methods as the first survey in 2001. RESULTS: On March 31, 2006, 47 subjects satisfied Poser's criteria for MS. The prevalence rate increased from 8.6 to 13.1/100,000 individuals between 2001 and 2006. The prevalence of conventional MS (C-MS) increased in five years although the prevalence of optic-spinal MS (OS-MS) did not increase. The mean annual incidence increased from 0.15 (1975-1989) to 0.68 (1990-2004). CONCLUSIONS: The results show the highest MS prevalence in Asia; the increase in MS prevalence in Tokachi Province may be due to increased incidence after 1990.     

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     

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.     

The incidence and prevalence of multiple sclerosis in Newfoundland and Labrador, 1960-1984

A study of the incidence and prevalence of multiple sclerosis on the island of Newfoundland between 1960 and 1984 has yielded a current overall prevalence rate of 55.2 per 100,000, but wide variation is noted in the rates for different parts of the island (range, 15.9 to 105.0 per 100,000). The annual incidence rates for St. John's and the Avalon region of Newfoundland show cyclical variation on an approximate five- or six-year cycle. Suggestive evidence for a temporal link between varying incidence rates in these areas and recurrent local outbreaks of canine distemper was obtained.     

Contribution of relapses to disability in multiple sclerosis

The impact of relapses on long-term disability in multiple sclerosis remains unclear; however some evidence suggests that relapses play an important role in determining subsequent prognosis. We report on outcome, prognostic factors for recovery and the contribution of relapses to the accumulation of fixed disability in a large series of patients with documented relapses. Two hundred and seventynine relapses in 182 patients were assessed before, during and after relapse by expanded disability status scale and data analysed to assess degree of recovery. Factors affecting outcome were considered including sex, age and site of relapse. Mean EDSS prior to relapse was 3.73, during relapse 5.18 and post relapse 4.23. Mean interval to post relapse assessment was 127 days post relapse. Mean residual change in EDSS score (pre to post relapse) was 0.50 points. Overall 49.4 % of patients had a residual increase in disability post relapse of at least 0.5 EDSS points and 32.7 % had an increase of at least 1 point. No significant difference was observed in mean residual EDSS for sex, site of relapse or age at relapse or in the proportion of patients with a residual increase in disability of ≥ 1 EDSS point post relapse. 14.4 % of patients had no increase in EDSS score during relapse compared to pre relapse. These results suggest that acute relapses are commonly associated with an objective worsening of disability in the majority of patients with MS and that recovery is incomplete in approximately half and not influenced by gender, age or site of lesion. Therapies which reduce relapse frequency and/or severity might therefore be expected to slow or prevent worsening of disability if initiated prior to the onset of more permanent damage.     

Epidemiology of multiple sclerosis in Kuwait: new trends in incidence and prevalence

The epidemiology of multiple sclerosis (MS) is undergoing dramatic changes; MS is occurring with increased frequency in many parts of the world. In this retrospective study, we examined the changes in incidence and prevalence of MS in Kuwait in the period between 1993 and 2000. We analyzed the records of patients with clinically defined and laboratory supported MS. The total incidence rate increased from 1.05/100,000 population in 1993 to 2.62/100,000 in 2000. The increased incidence of MS was most pronounced among Kuwaiti women (from 2.26/100,000 in 1993 to 7.79/100,000 in 2000. The total prevalence rate increased from 6.68/100,000 in 1993 to 14.77/100,000 in 2000. It was much higher for Kuwaitis (31.15/100,000), as compared to non-Kuwaitis (5.55/ 100,000), in a complete reversal of the pattern observed before 1990. The prevalence was also higher among Kuwaiti women (35.54/100,000), as compared with Kuwaiti men (26.65/100,000). In conclusion, the incidence and prevalence of MS in Kuwait has increased between the early and late 1990s with no signs of leveling off. In a geographic area that was previously associated with low prevalence, local environmental factors may be responsible for these dramatic changes.     

Contribution to the histoenzymatic changes in multiple sclerosis

Summary The activities of acP, alkP, ATP-ase, TPP-ase, non-specific esterase, ASS, AChE and ChE have been investigated by histochemical methods, in the brain of 2 cases of multiple sclerosis.A decrease in the activity of ASS, AChE, ChE and alkP was noticed in the demyelinated white matter of the plaques. Inside the plaques also a loss of ChE activity in the oligodendroglia was observed, whereas the activity of ATP-ase, TPP-ase and acP was increased.The significance of the changes found of the neuroglia hyperactivity in demyelination is discussed.

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Zusammenfassung Histochemische Untersuchungen der Aktivität der sauren und alkalischen Phosphatase, der ATP-ase, der TPP-ase, der unspezifischen Esterase, der Arylsulfatase, der Acetylcholinesterase und der Cholinesterase im Gehirn von 2 Multiple Sklerosefällen. Die Aktivität der Arylsulfatase, der Acetylcholinesterase, der Cholinesterase und der alkalischen Phosphatase verschwindet in den Entmarkungsherden beinahe vollkommen. Im Bereich der Entmarkungsherde war die Cholinesteraseaktivität der Oligodendrogliazellen völlig gewichen, während die Aktivität der ATP-ase, TPP-ase und der sauren Phosphatase erhöht erschien. Die Bedeutung der festgestellten Hyperaktivität der Neurogliazellen in den Entmarkungsprozessen wird diskutiert.

     

Parkinson's disease, multiple sclerosis and changes of residence in Alberta

BACKGROUND: Our objective is to examine how persons diagnosed with Multiple Sclerosis (MS) and Parkinson's disease (PD) change residence following disease onset. We hypothesize that persons choose to change residence (locally or regionally) in different ways depending on whether or not they have been diagnosed with MS/PD. We also estimate the effects of residence change on measures of disease prevalence made at several different levels of geography. METHODS: Using fee-for service and hospitalization data, we identify cases of MS and PD between 1994 and 2004. Both of these case groups are matched to controls based on age, sex, socioeconomic status and municipality of residence. We tabulate and compare the changes of residence among persons in the case and control groups. We also use these data to estimate the effects that changes in residence have on disease prevalence at three different levels of geography. RESULTS: Both MS and PD patients were more likely to change residence following disease onset compared to groups of matched controls (p<=0.001). Most changes of residence occur within the same municipality. The total magnitude of these changes is small, however, and is unlikely to affect estimates of disease prevalence; over our study period, the largest change in geographical prevalence estimates due to individual changes in residence was about 1%. CONCLUSIONS: Persons diagnosed with MS and PD both have mobility characteristics that differ from those of their respective control groups, and in general, are more likely to move to or between Edmonton and Calgary, and less likely to move out of province. However, the balance of mobility characteristics of persons with PD and MS appear unlikely to greatly affect the patterns observed on maps of disease prevalence.     

Contribution to the epidemiology of multiple sclerosis in Poland

An epidemiological survey of multiple sclerosis was carried out in western Poland. Uneven local distribution of MS was found within 198 communes making up the territory. The disease was less frequent in 1981 than in 1965. A marked increase of population in age classes under 20 during the last decade may account for the observed differences in the prevalence rate. In the town of Gniezno, a new MS cluster was discovered.This text was presented as communication at the Italo-Polish meeting held in Rome on 20–21 April 1985, arranged by the Società Italiana di Neurologia.     

The incidence and prevalence,diagnosis, and treatment of multiple sclerosis in China: a narrative review

Neurological Sciences - In 2018, the first list of rare diseases was published by the National Health Council of China, and multiple sclerosis (MS) was included in this list. Since then, the...     

Epidemiology of multiple sclerosis in the county of Vestfold, eastern Norway: incidence and prevalence calculations

The county of Vestfold in the South-eastern part of Norway has undergone two incidence and prevalence surveys on multiple sclerosis. The prevalence of definite/probable MS on January 1.1963 was 61.6/100000. Based on the same diagnostic criteria, the present study reports a slight increase in prevalence to 86.4/100000 on January 1st 1983. The average annual incidence was calculated for 5 years periods from 1953 to 1983. The time periods 1953–1962 and 1973–1977 showed age-adjusted incidence rates between 4.50 and 5.49/100000 while the 10–year period 1963–1972 showed significantly lower rates. The fluctuating pattern of MS incidence and prevalence over time supports the view that MS is not a stable disease, and that exogenous factors are influencing the disease pattern.