Prevalence of multiple sclerosis in First Nations people of Alberta

BACKGROUND: Multiple Sclerosis (MS) is reported to be uncommon among North American aboriginals despite frequent intermarriage with people of European ancestry, but few population-based studies have been conducted. The purpose of this study was to determine the prevalence of MS among First Nations aboriginal people in Alberta, Canada compared to the general population. METHODS: All hospital in-patient and physician fee-for-service records between 1994 and 2002 where a diagnosis of MS was mentioned were extracted from government health databases in the province of Alberta. First Nations people can be identified since the federal government (Health Canada) pays health care insurance premiums on their behalf. Multiple Sclerosis prevalence per 100,000 population for both First Nations people and the general population of Alberta were calculated for each year during this time span. RESULTS: Among First Nations in Alberta, MS prevalence was 56.3 per 100,000 in 1994 and 99.9 per 100,000 in 2002, an increase of 43.6%. In 2002 prevalence was 158.1 and 38.0 for females and males respectively, a female to male ratio of 4.2:1. Multiple Sclerosis prevalence among the general population of Alberta was 262.6 per 100,000 in 1994 and 335.0 per 100,000 in 2002, an increase of 21.6%. In 2002 prevalence was 481.5 and 187.5 for females and males respectively, a female to male ratio of 2.6:1. Peak prevalence for both First Nations and general population females in 2002 was age 50-59, also 50-59 for both First Nations and general population males. CONCLUSION: While MS prevalence in First Nations people is lower than in the general population of Alberta, it is not rare by worldwide standards.     

Incidence and prevalence of amyotrophic lateral sclerosis in Harris County, Texas, 1985-1988

The incidence of amyotrophic lateral sclerosis was determined in Harris County, Texas, for the period 1985 through 1988. Amyotrophic lateral sclerosis cases were ascertained from four sources: area neurologists, hospitals, death certificates, and the Muscular Dystrophy Association. The age-adjusted incidences of 1.27 per 100,000 person-years in males and 1.03 per 100,000 person-years in females were lower than recent rates in the northern US, Canadian, and northern European studies but higher than rates in southern European studies. Comparisons with other recent incidence studies show less uniformity in occurrence of amyotrophic lateral sclerosis, in both the overall rates and in the age- and sex-specific patterns, than was suggested by mortality studies. The incidence of amyotrophic lateral sclerosis among blacks and whites was similar. Hispanic males had incidences similar to white males, although a deficit of female Hispanic cases was found in Harris County. The prevalence of amyotrophic lateral sclerosis peaked in the 65- to 74-year age group at 33 per 100,000 population among males and 19 per 100,000 population for females.     

An increase in the incidence of multiple sclerosis in Western Norway

Abstract– In the county of Hordaland, Western Norway, the prevalence of MS has been shown to have increased from 20/100,000 in 1963 to 60/100,000 in 1983. This study shows that the increase in prevalence was caused by a highly significant and marked increase in incidence over a 30-year period. The average annual incidence of about 2 per 100,000 population in 1953–1962 increased to 4 per 100,000 in the period 1968–1977. The rise in incidence was parallel for both sexes until 1970. In the last 10 years, the incidence has continued to increase among females, whereas a decrease has been observed among males.     

The prevalence of transsexualism in Singapore

The prevalence of transsexualism in Singapore was estimated by counting all the patients who sought sex-reassignment surgery and were subsequently diagnosed as transsexuals by psychiatrists. Up to 1986, there were a total of 458 Singapore-born transsexuals, of which 343 were males and 115 were females. This was a prevalence of 35.2 per 100,000 population age 15 and above (or 1/2900) for male transsexualism, and 12.0 per 100,000 (or 1/8300) for female transsexualism. The sex ratio was about 3 males to 1 female. The main reason for the high prevalence was the availability of sex-reassignment surgery.     

Brief Report: Non-Random X Chromosome Inactivation in Females with Autism

Autism is a heterogeneous neurodevelopmental disorder with a 3–4 times higher sex ratio in males than females. X chromosome genes may contribute to this higher sex ratio through unusual skewing of X chromosome inactivation. We studied X chromosome skewness in 30 females with classical autism and 35 similarly aged unaffected female siblings as controls using the polymorphic androgen receptor (AR) gene. Significantly, increased X chromosome skewness (e.g., >80:20%) was detected in our autism group (33%) compared to unaffected females (11%). X chromosome skewness was also seen in 50% of the mothers with autistic daughters. No mutation was seen in the promoter region of the XIST gene reported to be involved in X chromosome inactivation in our subjects. X chromosome skewness has been reported in female carriers of other neurological disorders such as X-linked mental retardation, adrenoleukodystrophy and Rett syndrome.     

The prevalence of motor neurone disease in the Province of Alberta.

Using data from the Alberta Health Care Insurance Plan, the prevalence of motor neurone disease (MND) was estimated for the Province of Alberta, Canada. Between January 1, 1994 and December 31, 1995, 208 cases of MND (125 males, 83 females) were identified from physician billing records giving a period prevalence of 7.38 (8.9 for males, 5.9 for females) per 100,000 population. On prevalence day, July 1, 1995, there were 171 cases (103 males, 68 females) of MND giving a point prevalence estimate of 6.07 (7.3 for males, 4.8 for females) per 100,000 population. Males were more likely to be diagnosed (OR = 1.52, 95% CI 1.1, 2.1) with MND and there was an increased risk of receiving a diagnosis with increasing age (chi 2trend = 281, p < 0.001). The mean age of the cases was 59.2 years (58.5 for males, 60.3 for females) and did not differ significantly between the sexes. Geographically, there was no statistically significant difference in the prevalence across regions of the Province. During the study period, 28% of the cases had died (30% of males, 25% of females). The prevalence of MND in Alberta, is among the highest reported in the literature and requires additional investigation to verify these estimates and identify possible causative factors.     

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.     

50-year trends in the incidence of anorexia nervosa in Rochester, Minn.: a population-based study

OBJECTIVE: The aim of the study was to determine incidence and prevalence rates and long-term trends in incidence of anorexia nervosa by identifying all persons residing in the community of Rochester, Minn., during the 50-year period 1935 through 1984 who had the disorder. METHOD: From a community-based epidemiologic resource, 13,559 medical records with diagnoses of amenorrhea, starvation, weight loss, anorexia nervosa, or other conditions were screened to identify true cases of anorexia nervosa determined by using standard diagnostic criteria. RESULTS: One hundred eighty-one residents (166 female and 15 male) fulfilled the diagnostic criteria for anorexia nervosa; these were the incidence cases. Due to a quadratic trend in the rates for girls 10-19 years old, the incidence rate among female residents fell from 16.6 per 100,000 person-years in the 1935-1939 period to a low of 7.0 in 1950-1954 and increased to 26.3 in 1980-1984. The incidence rates for women 20 years old and older and for males remained constant. For females 15-24 years old, there was a linear increase. The overall age-adjusted incidence rate per 100,000 person-years was 14.6 for females and 1.8 for males. The prevalence rate per 100,000 population was 269.9 for females and 22.5 for males. CONCLUSIONS: Anorexia nervosa is more common than previously recognized. Among girls 15-19 years old it is a very common chronic illness. Its incidence has increased among females 15-24 years old but not among older women or among males.     

Factors in the rising prevalence of multiple sclerosis in the north-east of Ireland

BACKGROUND: Northern Ireland is recognized as an area of high risk for multiple sclerosis. The original study of Allison and Millar in 1951 found a prevalence of 51/100,000 and mean annual incidence of 2.74/100,000/year. Subsequent studies in 1961, 1986, and 1996 suggested rising prevalence--80, 138, and 168.2/100,000, respectively. METHODS: In 2004, we surveyed the North-East of Northern Ireland (population 160,446, area 2030 km(2)) using multiple sources of case ascertainment, all satisfying the Poser criteria for definite or probable multiple sclerosis (MS) or the McDonald criteria. RESULTS: From a provisional list of 469 cases, 370 (123 males, 247 females) were identified. The prevalence was 230.6 per 100,000 (95% CI 207.0-255.4) with significantly higher prevalence in females (300.8/100,000) than males (157.0/100,000). Direct standardization to the 1961 Northern Ireland population reduced the overall prevalence rate to 200.5/100,000 (95% CI 193.2-208.0), in females to 270.2/100,000 (95% CI 258.8-282.4) and in males to 131.1/100,000 (95% CI 122.8-139.9). In 1996, incidence had risen to 9.3/100,000/year (14 cases in population of 151,000) with a higher incidence in females (10.3/100,000/year) than males (8.3/100,000/year). CONCLUSIONS: Northern Ireland continues to have a rising prevalence of MS. The increase in incidence suggests a true increase in the disease.     

The epidemiology of anorexia nervosa in Denmark from 1973 to 1987: a nationwide register study of psychiatric admission

A nationwide register study of psychiatric admission for anorexia nervosa in Denmark yielded average incidence rates of 1.9 per 100,000 per year for females and 0.17 per 100,000 per year for males. The prevalence was 6.7 per 100,000 per year for females and 0.6 per 100,000 per year for males. The female-male ratio for first admissions was 11.8:1. The incidence of anorexia nervosa showed no trend in the general population, but an increase was found among psychiatric inpatients. This increase was explained by a reduction by one third in all psychiatric first admissions and in available psychiatric beds and augmented by an increase in readmissions of anorectic patients. Males were younger than females at first admission. Females were older at first admission from 1973 to 1977 than in later periods. Of males readmitted for non-eating disorders, more were psychotics and fewer psychopaths than among females. Age-period and age-cohort analysis of the 10- to 24-year-old females showed that only age exerted a significant independent influence on first-admission rates, whereas all 3 factors exerted significant independent influence on readmission rates. This might reflect changes in admission policy, greater diagnostic vigilance and changes in attitude towards weight, shape and fitness.     

Non-compaction cardiomyopathy and early respiratory failure in an adult symptomatic female carrier of centronuclear myopathy caused by a MTM1 mutation

X-linked myotubular myopathy (XLMTM) is a rare neuromuscular condition caused by mutations in the MTM1 gene. Female carriers are believed to be usually asymptomatic; nevertheless, recent reports have displayed a wide a spectrum of clinical involvement in females suggesting that MTM1 mutations might be underestimated in this population. Here we report a 55-year-old woman manifesting with an abrupt respiratory decline, whose respiratory function tests revealed a severe restrictive ventilatory defect. The neurological examination identified mild proximal leg weakness and her cardiac evaluation showed a non-compaction cardiomyopathy with normal left ventricle function. Muscle biopsy was consistent with centronuclear myopathy. Next-generation sequencing of 49 genes related to congenital myopathies allowed the identification of a 4 bp deletion in the MTM1 gene, leading to a truncating mutation previously described in males but for the first time reported in a female patient.     

Motor neuron disease in the Province of Turin, Italy, 1971-1980

The incidence and prevalence of motor neuron disease (MND) in the Province of Turin, North-West Italy, were investigated for the period 1971-1980. The crude incidence rate of MND was 0.67/100,000/year. The annual incidence rate, age and sex adjusted to the Italian population in 1971 was 0.69 cases per 100,000 inhabitants, 0.94 for men and 0.45 for women, with a male to female incidence ratio of 2.09:1. The prevalence of MND was 2.62/100,000, 3.57 for males and 1.71 for females. The mean age at the time of diagnosis was 55.6 years. Annual incidence rates increased with advancing age. Amyotrophic lateral sclerosis was found to be 4 times more frequent than progressive muscular atrophy (0.53/100,000/year v. 0.14/100,000/year). The distribution of MND was uneven in the Province suggesting a proportional relationship to the distribution of population density. Possible explanations of this finding are discussed.     

The prevalence of multiple sclerosis in the north–west Italian province of Genoa

The objective of this study was to assess the prevalence of multiple sclerosis (MS), calculated as point prevalence on 31 December 1997, in the province of Genoa, North–western Italy. Methods The province of Genoa is located in North–western Italy, an area of 1835 km². On the point prevalence day the population consisted of 913,218 inhabitants. MS cases were identified by analysing archives of the hospitals with neurological or rehabilitation wards, neurologists serving the community, files of local chapters of the Italian MS society, all requests for oligoclonal bands analysis on CSF in the studied area. Patients included in the study were MS cases diagnosed before 31 December 1997 according to the Poser criteria resident in the province under study. Results A total of 857 subjects were alive and residing in the province of Genoa on the prevalence day. The overall crude prevalence rate was 94 per 100,000 (95% CI 88–100); 291 were males (34%) with a crude prevalence of 67 per 100,000 (95 % CI 60–76) and 566 were females (66%) with a prevalence of 118 per 100,000 (95% CI 108–128). The female/male ratio was 1.9. When age and sex were adjusted to the Italian standard population of 1991 prevalence was 85 per 100,000. Five hundred and thirty two out of the 857 patients agreed to be interviewed. The interviewed sample was representative of the prevalence sample: sex and gender distributions were identical in the two samples. The overall mean age was 48 (± 13) years (48 ± 12 years in males; 48 ± 14 years in females). Mean disease duration was 15 (± 10) years for males and 16 (± 11) years for females. Two hundred and ninety one (55 %) subjects had a relapsing remitting (RR) clinical course, 150 (28%) were secondary progressive (SP) and 91 (17%) were primary progressive (PP). Mean EDSS score was 5 (± 2; median 5). The mean age at time of onset was 33 (±10) years for males and 32 (± 11) years for females. The disease onset was monosymptomatic in 76% (n = 407) patients and polysymptomatic in 24% (n = 125). The mean length of time between clinical onset and diagnosis was 5 (± 6) years. Conclusion We confirmed that the province of Genoa is a very high risk area for MS. We found a high rate of patients with a PP course; also the proportion of patients with high disability scores is greater compared to previous studies.     

Contribution of incidence to increasing prevalence of multiple sclerosis in Alberta, Canada

Alberta Health Care Insurance Plan (AHCIP) data were used to calculate prevalence and incidence rates for multiple sclerosis (MS) in the general population of Alberta from 1990 to 2004. Multiple sclerosis prevalence rose steadily each year over this time period, from 217.6/100,000 individuals in 1990 to 357.6/100,000 in 2004. Multiple sclerosis incidence fluctuated with a slight increase from 1990 to 2004, at 20.9/100,000 and 23.9/100,000, respectively. Age-specific prevalence rates were higher between ages 30 and 60 in 2004 than in 1990. The pattern of age-specific incidence rates was similar in 1990 and 2004, with a slight shift toward diagnosis in younger years. Gender-specific prevalence rates were higher for females in both 1990 and 2004, with a greater increase in females (43%) than males (29%). Gender-specific incidence rates were higher for females than males in both years, but there was no differential increase in incidence by gender from 1990 to 2004. The 2004 Alberta MS prevalence rate remains among the highest reported worldwide. Both increasing incidence and longer duration have likely contributed to increasing MS prevalence in the province.     

Neurological symptoms in individuals with fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP), a rare, disabling condition caused by gain-of-function mutations of a bone morphogenetic protein (BMP) type I receptor, leads to episodes of heterotopic ossification and resultant immobility. Neurological problems have not been associated with FOP, but neurological symptoms are commonly reported by FOP patients. To determine the prevalence of neurological symptoms and their characteristics in individuals with FOP, we conducted a survey of the 470 patient members of the International FOP Association (IFOPA) using a questionnaire about neurological symptoms. There were 168 responses (105 females, 63 males; age 1.5?C68?years) from 30 countries representing 36?% of IFOPA members. Chronic neurological symptoms were reported by 86 (51?%). Prevalence of neuropathic pain (NP) was significantly increased (P?<?0.001) compared to the general population, and tenfold more common in females (15?%) than males (1.6?%). Of those with NP, 94?% reported other sensory abnormalities. Prevalence of recurrent severe headaches (HA) (26?%) was similar to that in the general population, but prevalence in females with FOP (36?%) was almost fourfold greater than in males. Prevalence of NP, HA, and other sensory abnormalities was substantially higher in post-pubertal females; 33?% reported symptoms worsened during menstrual periods. Worsening of neurological symptoms during FOP flare-ups was reported by 23?%. Three patients with FOP (1.8?%) reported myoclonus, a prevalence much greater than reported in the general population (P?<?0.001). Our worldwide survey indicates that neurological symptoms are common in FOP. We speculate that these symptoms are related to effects of dysregulated BMP signaling on the central and/or peripheral nervous systems.     

EPIDEMIOLOGY of PARKINSON''S DISEASE IN FINLAND

This investigation was conducted to clarify the epidemiology of Parkinson's disease in Finland. A community survey was made in a selected area in southwest Finland in addition to an analysis of Finnish mortality statistics for Parkinson's disease. The annual mortality rate from Parkinson's disease was found to average 2 per 100,000 population. Almost 70 per cent of the deaths occurred between 65-79 years of age. The total and age-specific mortality rates for males were greater than those for females whereas the proportionate mortality rates were almost identical. This was considered to indicate that suggestions of greater male prevalence, based on mortality statistics, do not appear justified. On prevalence day, Dec. 31st, 1971, 484 patients with Parkinson's disease (of which 444 were personally examined) lived in the area of investigation (population 402,988), the prevalence rate being 120.1 per 100,000 population. The highest annual incidence rate was 16.6 per 100,000 population. The age-specific prevalence rates showed a rapid increase after the 50th year of age. The greatest prevalence was shown by the age group 70-79 years of age in which almost 0.8 per cent of the population are affected. Age-specific incidence rates also displayed an increase after the 50th year of age. The greatest incidence was observed in the age group 70-79 years of age in which almost 1 per 1,000 of the population are annually affected by the disease. A difference between the sexes was demonstrable in the prevalence and incidence rates showing greater values for females, but in the age-specific frequencies the differences were reduced. This probably reflects the difference between the age structures of the male and female populations, suggesting that both sexes have a similar risk of being affected by the disease. The permanent age structure shown by idiopathic patients in comparison with previous investigations as well as the increased mean age and proportionate decrease of postencephalitic patients was found to be in disagreement with the cohort theory according to which all parkinsonian patients are previously victims of encephalitis lethargica.     

Venous thromboembolism hospitalizations among American Indians and Alaska Natives

Cardiovascular disease (CVD) has been reported to be on the increase in the American Indian/Alaska Native (AI/AN) population. The Indian Health Service (IHS) hospital discharge database was used to describe venous thromboembolism (VTE)-associated hospitalizations among patients receiving IHS-reported medical care in the United States from 1980 through 1996. The average overall VTE-associated hospitalization rate in the AI/AN population during 1980–1996 was 33.1 per 100,000, however, the rate significantly decreased from 38.4 per 100,000 AI/ANs in 1980–1982 to 33.2 in 1994–1996. The average age at hospitalization was 50.4 years, which was consistent during the 17-year period. The overall annual VTE hospitalization rate was higher for females than for males (38.0 versus 27.7 per 100,000). The female VTE hospitalization rates decreased significantly from 46.1 per 100,000 in 1980–1982 to 36.7 per 100,000 in 1994–1996 (risk ratio: RR=1.3; 95% confidence interval: CI=1.1–1.4), while the rates for males remained unchanged. The VTE hospitalization rates also varied by geographic region. The hospitalization rate was highest in the East region (52.2 per 100,000) and lowest in the Alaska region (16.1 per 100,000). These data indicate that the overall VTE rate for AI/ANs may not have only decreased, but appears lower than the reported rate for Caucasians.     

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.     

Prevalence of primary focal and segmental dystonia in Oslo

All patients seeking medical treatment for primary focal and segmental dystonia in Oslo, Norway, were identified in a service-based prevalence study. A total of 129 patients with focal and segmental dystonia were treated. The total prevalence was 25.4 per 100,000, but the prevalence increased with age from 4.1 (age < 30) to 58.7 (age > 70). The prevalence in subjects of European descent was 28.3 per 100,000, much higher than among first-generation immigrants of Asian and African descent.