Descriptive epidemiology of motor neuron disease in Benghazi, Libya

A total of 23 patients with motor neuron disease (MND), encompassing 17 cases of amyotrophic lateral sclerosis, 4 of progressive muscular atrophy and 2 of progressive bulbar palsy, was diagnosed in Benghazi, north-eastern Libya, between 1980 and 1985. The male to female ratio was 2.3:1. The average incidence of MND was 0.89/100,000 population/year (0.87 when age and sex-adjusted to the Libyan population). Eighteen patients were alive on the prevalence day, September 15, 1985, which provided a prevalence rate of 3.47/100,000 population (3.42 if adjusted). Age-specific incidence rates were highest in the 50- to 59-year-old age group, 8.14/100,000/year for men and 6.10/100,000/year for women. The median age at the time of diagnosis was 51 years, and the median duration for the 5 dead MND patients after the onset of the disease was 30 months. The median survival time for all MND cases combined was 42 months.     

Incidence and prevalence of motor neuron disease in two Danish counties

A total of 186 cases of motor neuron disease (MND) was identified in two Danish counties during the period 1974-1986. The average annual incidence rate was 1.4/100,000 population, and the male:female ratio of incidence rates was 1.5. Mean age at diagnosis was 64.3 +/- 10.0 years. The incidence rates increased significantly with advancing age and reached a maximum at age 60-79 years, followed by a nonsignificant decrease. The average point prevalence was 3.1/100,000 population. Bulbar symptoms were part of the initial symptoms in 65% of cases, and patients with bulbar onset were older than patients with spinal onset. Age- and sex-specific incidence rates indicated a marked male preponderance amongst the youngest patients, in contrast to a female preponderance in patients above 60 years with bulbar onset of MND. Familial MND accounted for 2.7% of cases.     

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.     

Epidemiological study of motor neuron disease in Hokkaido island--its incidence, prevalence and regional distributions--ALS Study Group]

The incidence, prevalence and regional distributions of sporadic motor neuron disease (MND) from 1980 through 1989 were evaluated in collaboration with multiple neurological institutes in Hokkaido island. Patients with sporadic MND were collected from three sources: 1) neurologist practicing in Hokkaido island, 2) sending inquiries to 620 major hospitals, 3) notification file of MND provided by Japanese Ministry of Welfare and Health. Three hundred and eighty-nine patients with sporadic MND were ascertained for this study. Of 389 patients, 238 patients were men and 151 patients were women, and the ratio of men to women was 1.6:1. The mean age of onset was 58.2 +/- 10.3 years old, 57.7 +/- 10.4 for men and 58.9 +/- 10.0 for women. Their clinical presentations were 303 patients with ALS, 52 patients were PBP and 34 patients were SPMA. The crude incidence rate for both sexes combined for 1980 through 1989 was estimated as 0.69 per 100,000 person-year. The age- and sex-adjusted incidence for men was 0.86 per 100,000 person-year (95% CI, 0.75 to 0.97) and that is higher than 0.53 per 100,000 person-year (95% CI, 0.45 to 0.61) for women. The average, crude prevalence rate from 1985 through 1989 was estimated as 2.25 per 100,000 person-year. There are no overall trends of changing the pattern in incidence and prevalence of MND in Hokkaido island, however the geographic distributions of the incidence of MND according to towns and cities disclosed the presence of some relative clustering areas.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidemiology of motor neuron disease in northern Sweden

All cases of motor neuron disease (MND), encompassing amyotrophic lateral sclerosis (ALS), progressive bulbar paralysis (PBP) and progressive spinal muscular atrophy (PSMA), in northern Sweden, diagnosed between 1969-1980 have been analysed. 128 cases were found, corresponding to an average annual incidence rate of 1.67 per 100,000. The prevalence on December 31, 1980 was 4.8 per 100,000. Age-specific incidence rates were higher in the high age groups with a maximum at 60-64 years for males, at 70-74 years for females and at 65-69 years for the sexes combined. The median age at onset was 61 years. Clustering was not found in mining districts and overrepresentation of miners and stone treaters was not observed. Minor differences in incidence rates, as measured by the standardized morbidity ratio, SMR, were found between the inland, coastal and mountain areas. The median survival time after onset of disease was 32 months for ALS, 30 months for PBP and 70 months for PSMA. The combined survival rate for all MND cases was 28% after 5 years and 15% after 10 years. The male to female ratio was 1.1:1, and 4.7% were familial cases.     

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.     

The epidemiology of motor neurone disease in two counties in the southwest of England

The epidemiology of motor neurone disease (MND) in the counties of Devon and Cornwall in the southwest of England has not previously been studied. A previous study of England and Wales has, however, reported a very high death certification rate of MND in Devon. This study was carried out to establish the prevalence and incidence of MND in Devon and Cornwall and make comparisons with published rates in other populations. We attempted to identify all cases of MND diagnosed in Devon and Cornwall between 2002 and 2007. Case identification was centred on the major hospitals in the two counties and multiple sources of ascertainment were used. All identified cases had their case notes reviewed to establish the diagnosis and classify by type of MND. Point prevalence of MND was established for September 1st, 2007. The overall incidence rate standardised to the 2001 United Kingdom population was 2.52 per 100,000 (95% confidence interval 2.20–2.84). The incidence rate was significantly higher in males (P < 0.001). The estimated male to female incidence ratio was 2.10 (95% CI 1.61–2.73). The crude incidence rate in Cornwall was 3.78 per 100,000 (95% CI 3.03–4.53) and this was significantly higher (P = 0.011) than the rate in Devon, which was 2.61 per 100,000 (95% CI 2.19–3.04). The standardised incidence rate for the study period in Devon was 2.26 per 100,000 (95% CI 1.91–2.60) and in Cornwall it was 3.06 per 100,000 (95% CI 2.44–3.68). The overall standardised point prevalence rate was 5.66 per 100,000 (95% CI 4.49–6.83). The incidence rate of MND in our study is similar to reported findings in large prospective studies of the disease. There is a significant difference between the incidence rates in Devon and Cornwall. There is a need to establish a prospective MND Register to accurately document the epidemiological characteristics of the disease in the two counties.     

Motor neuron disease in the province of Ferrara, Italy, in 1964-1982

We carried out an intensive incidence, prevalence, and mortality survey of motor neuron disease (MND) in the province of Ferrara, northern Italy. Based on 72 patients, the mean incidence per year for the period 1964 through 1982 was 0.98 cases per 100,000. On December 31, 1981, the prevalence rate was 3.95 per 100,000. In the 19-year period the average mortality rate was 0.83 per 100,000 per year. The disease was more common in men, in individuals aged 50 to 70 years, and in residents in rural areas engaged in agricultural work. A retrospective case-control study, confirming a significantly higher frequency of MND in farmers and persons living in rural areas, revealed that the disease was more common in the lower social classes to which most unskilled and heavy laborers belong. In addition, a significantly increased risk for MND was found in patients with previous histories of trauma, but confounding variables may account for this association.     

Increasing incidence of multiple sclerosis among women in Lorraine, Eastern France

This study aims to describe the prevalence and incidence rates of multiple sclerosis (MS) in Lorraine, France, and its secular trend from 1990 to 2002. Cases were sourced from the regional network of MS healthcare workers in the Lorraine region and include all cases with definite or probable MS according to Poser's criteria. We identified 2718 patients with MS on 31 December 2004. The prevalence rate was 120/100,000 (95% confidence interval [CI]: 119-121). Between 1990 and 2002, the average age- and sex-adjusted annual incidence rate was 5.5/100,000 (95% CI: 4.4-6.6). During this same period, there was a significant increase in overall incidence in women but not in men. The mean age at MS onset, disability score five years after onset, number of relapses during the first five years, and proportion of first attack with sequelae or polysymptomatic symptoms were not significantly different between each annual cohort during the study period. The prevalence and incidence rates of MS we found in our study were higher than in previous studies in France. The increase in incidence of MS between 1990 and 2002, mostly in women, was not related to better ascertainment of patients with mild disability.     

Epidemiology of amyotrophic lateral sclerosis in Hordaland county, western Norway

The incidence, prevalence and prognosis of amyotrophic lateral sclerosis (ALS) in the county of Hordaland, western Norway were determined for the years 1978 through 1988. The average annual incidence rate was 1.60 per 100,000 population with a male to female ratio of 1.26 (95% confidence interval: 0.76-2.09). The maximal age-specific annual incidence was 8.12 per 100,000 and occurred in the age-group between 61 and 65 years. The prevalence of ALS was 3.67 per 100,000 on December 31, 1988. The average age at the onset of the disease was 60.9 years ranging from 34 to 82 years of age. Survival was studied with life table techniques. Median survival from the onset of symptoms was 28.0 months overall. In patients with bulbar onset the median survival was 24.0 months whereas it was 40 months in patients with spinal onset of disease (log rank test, P = 0.0004). The difference in survival between ALS with bulbar or spinal onset was not explained by age or sex differences in the two groups.     

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.     

Epidemiology of multiple sclerosis in the region of Szczecin: prevalence and incidence 1993-1995]

In the Province of Szczecin in the period 1993-1995 the incidence was 2.16 and the prevalence 55.32/100,000 on December 31 1995. Incidence and prevalence were higher in women (the difference was higher in Szczecin City) what was not connected with a significantly greater number of women in the population of the province. The study confirmed the presence in the southern part of the province of a focus with prevalence 110.54/100,000. The mean age at disease onset was 37.05 +/- 8.91. In women it was significantly higher than in men and it was nearly 10 years longer in relation to the mean age at onset in the years 1960-1984.     

Clinical and epidemiological features of motor neuron disease in south-western Greece

OBJECTIVE: To evaluate the epidemiological and clinical features of motor neuron disease (MND) in a region (835,000 inhabitants) of south-western Greece. PATIENTS AND METHODS: The medical records of all patients diagnosed with adult-onset MND at the Department of Neurology of the University Hospital of Patras from 1990 to 2003 were reviewed. RESULTS: Overall 133 patients were identified, corresponding to a mean annual incidence rate of 1.13/100,000 population with male preponderance. Eighty-five of them were males (63.9%) and 48 (36.1%) females with a mean age of 61.4 +/- 13.3 years. The most common type of MND was amyotrophic lateral sclerosis (ALS) being identified in 111 (83.5%) patients, whereas 19 cases (14.3%) were classified as progressive spinal muscular atrophy (PSMA) and three (2.2%) cases as progressive bulbar palsy (PBP). The mean age at onset was 60.3 +/- 13.5 years, while the mean delay between age at onset and age at diagnosis was 1.3 +/- 1.1 years. The symptoms at onset involved the lower limbs in 76 (57.2%) cases, upper limbs in 32 (24%) cases, bulbar region in 22 (16.5%) cases and respiratory muscles in three (2.3%) cases. The mean survival time after onset of disease was 20.4 +/- 8.3 months for ALS patients, 15.3 +/- 4.5 months for PBP and 38.1 +/- 26.4 months for PSMA patients. CONCLUSIONS: There was no statistically significant difference in the results of the considered epidemiological parameters of our study to those reported by other similar studies. The study of the patients with MND showed a predominance of ALS patients. No potentially causative clinical associations were found and no relation between socioeconomic factors, occupational exposure and the disease was noted.     

Validating population-based registers for ALS: how accurate is death certification?

The purpose of this study was to determine the accuracy of death certification for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND) as recorded by the Central Statistics Office in the Republic of Ireland, and to examine its utility in capture-recapture analysis. The database of the Irish Central Statistics Office (CSO) was searched for death certificates of individuals over 15 years of age for whom ALS/MND (ICD9) was listed as a primary, secondary or tertiary cause of death from 2002 to 2006. This dataset was compared with mortality data from the Irish Register for ALS/MND for the same period. Three hundred ninety-eight cases with a diagnosis of ALS were identified through the CSO. The cause of death as identified by the CSO was 318 out of 398 (80%) cases known to the Register during the study period. ALS/MND was listed as a cause of death by the CSO in 79 (20%) cases that were unknown to the ALS/MND Register. Of these, ALS/MND was listed as a secondary/tertiary cause of death in 76, and 75% of all such deaths occurred in rural areas. Capture-recapture analysis using the CSO and ALS Register as independent datasets generated a likely over-estimation of the crude incidence of ALS from 2.1/100,000 to 3.45/100,000 in Ireland. Population-based registers are most accurate when ascertaining from a wide network of inter-dependent sources. Death certification for ALS/MND lacks both sensitivity and specificity. Capture-recapture exercises using such data sources are likely to over-estimate the true incidence of disease.     

Multiple sclerosis in Nord-Trøndelag County, Norway: a prevalence and incidence study

Objective – To calculate the prevalence and incidence of multiple sclerosis (MS) in Nord‐Trøndelag County, Norway. Material and methods – The study comprised everyone diagnosed with MS according to the Poser criteria. On 1 January 2000 a total of 208 were identified: 130 women (62.5%) and 78 men (37.5%). We calculated the crude and age‐adjusted annual incidence rates from 1974 to 1999. Results – The prevalence on 1 January 2000 was 163.6 of 100,000, 204.8 of 100,000 for women and 122.6 of 100,000 for men. The age‐adjusted annual incidence increased from 3.9 to 5.6 per 100,000 from 1974 to 1999; women from 4.6 to 6.3 and men from 2.2 to 4.4. After 1984, the incidence among women increased most, peaking at 10.2 per 100,000 in 1984–88. Conclusions – MS incidence is increasing in Nord‐Trøndelag County. The prevalence is among the highest ever in Norway.     

Population based study of late onset cerebellar ataxia in south east Wales

OBJECTIVE: To determine the prevalence and causation of late onset cerebellar ataxia (LOCA) in south east Wales, United Kingdom. METHODS: A population based study of LOCA was conducted in a defined geographical region with a total population of 742,400. Multiple sources of ascertainment were used to identify all cases prevalent on 1 January 2001. The inclusion criteria were: a predominantly progressive cerebellar ataxia with onset of symptoms at age > or = 18 years; and disease duration of > or = 1 year. Cases with known acquired ataxias, ataxic syndromes with associated prominent autonomic dysfunction and/or atypical parkinsonism suggestive of multiple system atrophy and disorders with ataxia as a minor feature were excluded. RESULTS: We identified 76 index cases of LOCA, of whom 63 were sporadic, idiopathic LOCA (ILOCA) and 13 were familial LOCA, of whom six had either spinocerebellar ataxia type 6, Friedreich's ataxia or dominant episodic ataxia. The mean annual incidence rate for the period 1999-2001 was 0.3/100,000 population/year. The crude prevalence rates were 8.4 per 100,000 (95% CI 7.2 to 11.6) for ILOCA and 1.8 per 100,000 (95% CI 0.8 to 2.7) for inherited LOCA. Of the 54/63 (85.7%) patients with ILOCA who were assessed, mean (SD) age at onset of symptoms was 53.8 (14.1) years (range 19 to 78) with a male:female ratio of 2.1:1. The mean disease duration was 8.7 (6.3) years (range 1 to 31). The most frequent presenting complaint was disturbance in gait (90.7%). One-third had a relatively pure cerebellar syndrome (33.3%) and two-thirds (66.7%) had additional extracerebellar neurological features. The majority (92%) were ambulant but only 9.3% were independently self-caring. CONCLUSION: This population based study provides insight into LOCA within a defined region and will inform decisions about the rational use of healthcare resources for patients with LOCA.     

Prevalence of Epilepsy in Adults in Northern Sweden

A multisource medical register review identified persons with active epilepsy in northern Sweden. Seven hundred thirteen persons aged greater than or equal to 17 years with epilepsy were determined on the prevalence day, December 31, 1985. The overall prevalence was 553 in 100,000 (566 in 100,000 if adjusted to the 1980 U.S. population). The ratio of males to females was 1.1, with a male prevalence of 575 and a female prevalence of 530 in 100,000. Age-specific prevalences varied between 530-644 in 100,000 except in persons aged greater than or equal to 70 years, for whom the prevalence was 321 in 100,000. Partial seizures were most common, 333 in 100,000, of whom the majority (250 in 100,000) had seizures that occasionally were secondarily generalized. Mental retardation was the foremost coexistent disorder, noted in 23%. The mean yearly seizure frequency was higher in persons with mental retardation than in nonretarded persons. Seventeen percent had seizures during the last week, 57% during the last year, whereas 16% had greater than or equal to 5 years' freedom from seizures. Most had onset of epilepsy before age 20 years. A presumed etiology was noted in 35%, more often in men than in women. Cerebrovascular disease was the most commonly identified presumed cause. Other nonepileptic diseases/disabilities were noted in 47%.     

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.     

Epidemiological and clinical features of Moyamoya disease in Nanjing,China

Objective

The epidemiology of Moyamoya disease in mainland China has not been documented. Therefore, the present study was designed to examine the epidemiological and clinical features of Moyamoya disease in Nanjing, a provincial capital in China.

Methods

Patient records from multiple hospitals in Nanjing from January 2000 to December 2007 were collected. The clinical features of Moyamoya disease were retrospectively analyzed.

Results

A total of 202 patients were identified. There were 94 males and 108 females, with ages ranging from 2 to 78 years. There was a dual age peak, one in the group of patients 5–9 years of age and another in the group of patients 35–39 years of age. The initial symptoms included cerebral ischemia (81 patients, 40%), cerebral hemorrhage (113 patients, 55.9%) and asymptomatic disease (8 patients, 3.9%). An increasing incidence rate of Moyamoya disease was observed during the period of 2000–2007, with an average detection rate of 0.43 cases/100,000 persons/year (prevalence 3.92/100,000 persons). The incidence of ischemia associated with the disease was 0.16 cases/100,000 people-years and the incidence of hemorrhage was 0.22 cases/100,000 people-years.

Conclusion

This first study on the epidemiological and clinical features of Moyamoya disease in mainland China indicated an increasing incidence of Moyamoya disease with bimodal incidence distribution appearing more frequently in adults.     

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.