Prevalence of Parkinson's disease in Izumo City, Japan

Prevalence of parkinsonism and Parkinson disease in urban and rural populations from Latin America: A community based study

Background

Age and gender specific prevalence rates for parkinsonism and Parkinson's disease (PD) are important to guide research, clinical practice, and public health planning; however, prevalence estimates in Latin America (LatAm) are limited. We aimed to estimate the prevalence of parkinsonism and PD and examine related risk factors in a cohort of elderly individuals from Latin America (LatAm).

Methods

Data from 11,613 adults (65+ years) who participated in a baseline assessment of the 10/66 study and lived in six LatAm countries were analyzed to estimate parkinsonism and PD prevalence. Crude and age-adjusted prevalence were determined by sex and country. Diagnosis of PD was established using the UK Parkinson's Disease Society Brain Bank's clinical criteria.

Findings

In this cohort, the prevalence of parkinsonism was 8.0% (95% CI 7.6%-8.5%), and the prevalence of PD was 2.0% (95% CI 1.7%-2.3%). PD prevalence increased with age from 1.0 to 3.5 (65-69vs. 80 years or older, p < 0.001). Age-adjusted prevalence rates were lower for women than for men. No significant differences were found across countries, except for lower prevalence in urban areas of Peru. PD was positively associated with depression (adjusted prevalence ratio [aPR] 2.06, 95% CI 1.40-3.01, I ² = 56.0%), dementia (aPR 1.57, 95% CI 1.07- 2.32, I ² = 0.0%) and educational level (aPR 1.14, 95% CI 1.01- 1.29, I ² = 58.6%).

Interpretation

The reported prevalence of PD in LatAm is similar to reports from high-income countries (HIC). A significant proportion of cases with PD did not have a previous diagnosis, nor did they seek any medical or neurological attention. These findings underscore the need to improve public health programs for populations currently undergoing rapid demographic aging and epidemiological transition.

Funding

The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Recalling the pathology of Parkinson's disease; lacking exact figure of prevalence and genetic evidence in Asia with an alarming outcome: A time to step-up

Parkinson's disease (PD) is the second most common and progressive neurodegenerative disease globally, with major symptoms like bradykinesia, impaired posture, and tremor. Several genetic and environmental factors have been identified but elucidating the main factors have been challenging due to the disease's complex nature. Diagnosis, prognosis, and management of such diseases are challenging and require effective targeted attention in developing countries. Recently, PD is growing rapidly in many crowded Asian countries as an alarming threat with inadequate knowledge of its prevalence, genetic architecture, and geographic distribution. This study gave an in-depth overview of the prevalence, incidence and genomic/genetics studies published so far in the Asian population. To the best of our knowledge, PD has increased significantly in several Asian countries, including China, South Korea, Japan, Thailand, and Israel over the past few years, requiring a greater level of care and attention. Genetic screening of families with PD at national levels and establishing an official database of PD cases are essential to get a comprehensive and conclusive view of the exact prevalence and genetic diversity of PD in the Asian population to properly manage and treat the disease.

Trends in the incidence and prevalence of Parkinson's disease in Korea: a nationwide, population-based study

BACKGROUND

The lack of adequate and detailed epidemiological data of Parkinson's disease (PD), especially in Asia, is a barrier to future disease burdens and the prospect of effective public health plans. This study aimed to investigate temporal trends in the incidence and prevalence of PD in South Korea from 2010 to 2015, based on uniform diagnostic criteria.

METHODS

This study examined all PD patients registered in a South Korean national registry database of more than 50 million individuals. We analyzed the incidence and prevalence of PD according to age, gender, and region.

RESULTS

The annual incidence of PD was between 22.4-27.8 cases per 100,000 individuals. During the 6-year study period, there were 73,726 new PD patients, 42.3% of whom were men. The standardized incidence of PD increased over time in men but remained constant in women until 2013 but began to increase in 2014. The female-to-male ratio in the incidence of PD was 1.4:1 while the female-to-male ratio in the prevalence of PD was 1.6:1. The age- and gender-standardized prevalence of PD increased from 115.9 cases per 100,000 individuals in 2010 to 139.8 cases per 100,000 individuals in 2015. From 2014, the incidence and prevalence of PD peaked in individuals aged between 80 and 89 years in both men and women. Regional analysis also showed an increased prevalence of PD in all regions of Korea.

CONCLUSIONS

The incidence and prevalence of PD in Korea were higher in women and increased gradually from 2010 to 2015. The findings may contribute to epidemiological studies of PD in Asia, and may provide clues on risk factors for PD.

Region-Based Analysis of Prevalence and Incidence of Parkinson's Disease: Analysis of the National Sample Cohort in South Korea

Background and Purpose

The rapid increases in the elderly population and urbanization in South Korea have influenced both demographics and the environment. This study investigated trends in the prevalence and incidence of Parkinson's disease (PD), and the associations of PD with the urban and rural environments in South Korea.

Methods

This study examined subjects aged 40 years or older in a cohort constructed using the National Sample Cohort data set in South Korea during 2002–2013. We estimated the age-standardized prevalence and incidence of PD based on the 2002 population, and estimated their trends. We analyzed regional differences in these rates by dividing South Korea into three regions based on geographic characteristics and two regions based on the degree of urbanization.

Results

The standardized prevalence rates of PD per 100,000 increased significantly from 75.8 in 2003 to 136.8 in 2012 (p<0.0001), especially in older subjects. The standardized prevalence of PD was highest in metropolitan Seoul. The standardized incidence of PD per 100,000 was 13.9 in 2003 and 10.3 in 2012, with no significant trend (p>0.05). The standardized incidence of PD in younger subjects was lower in eastern Korea than in the other two regions, while in the older subjects it was lower in western Korea than in metropolitan Seoul over almost the entire analyzed period. The standardized incidence of PD did not differ significantly between metropolitan and nonmetropolitan areas.

Conclusions

The standardized prevalence of PD increased steadily from 2003 to 2012 in South Korea, while its standardized incidence has remained constant. There were regional differences in the prevalence and incidence of PD based on the degree of urbanization and the area of agricultural land.

Femur Fractures in Parkinsonism: Analysis of a National Sample Cohort in South Korea

Background and Purpose

Falling with a femur fracture is a serious event that negatively affects the quality of life of elderly individuals as well as patients with parkinsonism. This study investigated the association between parkinsonism and femur fracture and compared the risk of femur fracture between subjects with and without parkinsonism.

Methods

This study examined a population-based matched cohort constructed using the National Sample Cohort data set, which comprises approximately one million subscribers to medical insurance and aid in South Korea. Subjects with parkinsonism during 2003–2013 were identified as the exposed group, and up to five individuals matched for age, sex, and index years were identified as the controls for each parkinsonism subject. The risk of femur fracture for parkinsonism was evaluated using Cox regression.

Results

The incidence of femur fracture according to age, sex, and body mass index varied significantly between subjects with parkinsonism and controls (p<0.001). The presence of parkinsonism was associated with a higher risk of femur fractures for males [hazard ratio (HR)=2.85, 95% confidence interval [CI]=1.87–4.34], subjects younger than 65 years (HR=2.89, 95% CI=1.64–5.11), and underweight subjects (HR=3.90, 95% CI=1.82–8.35). The adjusted HR for femur fracture with parkinsonism was highest within 2 years of the disease diagnosis (HR=3.10, 95% CI=2.12–4.53).

Conclusions

Our study found that the presence of parkinsonism is more strongly related to femur fracture in males, and increases the influence of traditional risk factors on femur fracture. It is necessary to consider how factors associated with the amount of ambulatory activity–even in an early diagnosed state–can play an important role in femur fracture in subjects with parkinsonism.

Systematic review of the prevalence and incidence of Parkinson's disease in the People's Republic of China

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disease, and obtaining accurate epidemiological data for this disease is very important for policy-making in public health. The purpose of this study was to determine the prevalence and incidence of PD in the People's Republic of China and explore possible future research directions.

METHODS

We systematically retrieved studies of the prevalence and incidence of PD in the People's Republic of China, Taiwan, and Hong Kong, and standardized the data according to the world's population in 2000.

RESULTS

Fifteen eligible studies were retrieved. Most were cross-sectional studies, and two thirds of the research was from the People's Republic of China. The prevalence of PD was reported in all the studies, but only two studies reported incidence data. The prevalence of PD in the People's Republic of China ranged from 16 to 440.3/100,000, and the annual incidence ranged from 1.5 to 8.7/100,000.

CONCLUSION

The prevalence of PD in the People's Republic of China has been widely investigated in the studies published to date. However, due to methodological heterogeneity, the data reported by the different studies are not comparable. There is still a lack of information on the incidence of PD in the People's Republic of China. Therefore, future research is required to answer this question.

The prevalence of Parkinson's disease: a systematic review and meta-analysis

Parkinson's Disease (PD) is a common neurodegenerative disorder. We sought to synthesize studies on the prevalence of PD to obtain an overall view of how the prevalence of this disease varies by age, by sex, and by geographic location. We searched MEDLINE and EMBASE for epidemiological studies of PD from 1985 to 2010. Data were analyzed by age group, geographic location, and sex. Geographic location was stratified by the following groups: 1) Asia, 2) Africa, 3) South America, and 4) Europe/North America/Australia. Meta-regression was used to determine whether a significant difference was present between groups. Forty-seven studies were included in the analysis. Meta-analysis of the worldwide data showed a rising prevalence of PD with age (all per 100,000): 41 in 40 to 49 years; 107 in 50 to 59 years; 173 in 55 to 64 years; 428 in 60 to 69 years; 425 in 65 to 74 years; 1087 in 70 to 79 years; and 1903 in older than age 80. A significant difference was seen in prevalence by geographic location only for individuals 70 to 79 years old, with a prevalence of 1,601 in individuals from North America, Europe, and Australia, compared with 646 in individuals from Asia (P < 0.05). A significant difference in prevalence by sex was found only for individuals 50 to 59 years old, with a prevalence of 41 in females and 134 in males (P < 0.05). PD prevalence increases steadily with age. Some differences in prevalence by geographic location and sex can be detected.

Epidemiology and etiology of Parkinson's disease: a review of the evidence

The etiology of Parkinson's disease (PD) is not well understood but likely to involve both genetic and environmental factors. Incidence and prevalence estimates vary to a large extent-at least partly due to methodological differences between studies-but are consistently higher in men than in women. Several genes that cause familial as well as sporadic PD have been identified and familial aggregation studies support a genetic component. Despite a vast literature on lifestyle and environmental possible risk or protection factors, consistent findings are few. There is compelling evidence for protective effects of smoking and coffee, but the biologic mechanisms for these possibly causal relations are poorly understood. Uric acid also seems to be associated with lower PD risk. Evidence that one or several pesticides increase PD risk is suggestive but further research is needed to identify specific compounds that may play a causal role. Evidence is limited on the role of metals, other chemicals and magnetic fields. Important methodological limitations include crude classification of exposure, low frequency and intensity of exposure, inadequate sample size, potential for confounding, retrospective study designs and lack of consistent diagnostic criteria for PD. Studies that assessed possible shared etiological components between PD and other diseases show that REM sleep behavior disorder and mental illness increase PD risk and that PD patients have lower cancer risk, but methodological concerns exist. Future epidemiologic studies of PD should be large, include detailed quantifications of exposure, and collect information on environmental exposures as well as genetic polymorphisms.

Systematic review of the prevalence and incidence of Parkinson's disease in Asia

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disorder in older people, and half of the world's older population lives in Asia. However, the epidemiology of PD in Asian countries is poorly understood. This review assembles evidence on the prevalence and incidence of PD in Asian countries and identifies gaps in our present knowledge.

METHODS

A systematic search of studies published from 1965 to October 2008 was conducted using MEDLINE and EMBASE. The selection criteria were defined a priori. Prevalence and incidence were standardized to the WHO World Standard Population 2000. Twenty-one original studies were selected for the review. Two studies that described the ethnic origin of participants and contained Asian populations were also included in the analysis.

RESULTS

Excluding one study with questionably low prevalence and incidence, the remaining studies reported a standardized all-age prevalence of 51.3 to 176.9 per 100,000 in door-to-door surveys; prevalence in record-based studies ranged from 35.8 to 68.3 per 100,000. The standardized incidence rates were 8.7 per 100,000 person-years in door-to-door surveys and 6.7 to 8.3 per 100,000 person-years in record-based surveys.

CONCLUSIONS

The prevalence of PD in Asian countries was slightly lower than that in Western countries. However, comparison of incidence was difficult because of the small number of studies. Varying methodologies, diagnostic criteria, and case-finding strategies contributed to the considerable variation in the reported prevalence and incidence of PD.

[Analysis of application form for Parkinson's disease provided by the specific diseases treatment research program of Ministry of Health, Labour and Welfare of Japan]

The Ministry of Health, Labour and Welfare (MHLW) of Japan has funded special research programs to investigate etiology and treatment of intractable neurodegenerative diseases. Individual health-care expenditures for registered patients with Parkinson's disease (PD) (Hoehn and Yahr Stage 3-5) have been evaluated by the government. The total number of patients registered with a diagnosis of degenerative parkinsonism including PD, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) was 75,026 in 2004. We analyzed the data from a survey of application forms completed by 23,058 PD patients, which had been entered into the MHLW's computer. The male to female ratio was 1: 1.47, and the mean ages of all patients at registration and at onset were 71.3 years and 62.7 years, respectively. Incidence of young-onset Parkinson's disease was 2.7% of all PD patients. The percentage of PD patients at Hoehn and Yahr Stage 3 was 48.8%, at Stage 4, 23.1%, and at Stage 5, 25.2%. About 60% of patients resided at home, whereas 20% were admitted into the hospital and 20% into a nursing home. The percentages of patients with diurnal fluctuations, dyskinesia and psychotic symptoms were 37.3%, 16.8% and 18.4%, respectively. Ages of patients at registration and at disease onset who presented with diurnal fluctuations and dyskinesia were typically younger and the duration of disease was longer than for those presented without them (p < 0.0001). Patients with psychotic symptoms were older and the duration of disease was longer than those without them (p < 0.0001). Ages of patients receiving ablative surgery were younger than those who received deep brain stimulation (DBS) (57.4 versus 63.1 years, p < 0.01). Approximately 70% of all the patients who underwent stereotactic surgeries were treated within 10 years from onset. The percentage of patients with feeding tube was 6.6%, and the age at registration was older (75.6 versus 71.0 years, p < 0.0001) and duration of disease was longer (11.0 versus 8.4 years, p < 0.0001) in patients with feeding tube than in patients with oral feeding. This is the first analysis of results from the survey of questionnaire for PD provided by MHLW.

Epidemiology of Parkinson's disease

This chapter discusses the epidemiology of Parkinson's disease (PD). Classically, PD refers to progressive parkinsonism caused by loss of pigmented aminergic brainstem neurons without an identifiable cause, while parkinsonism refers simply to the syndrome of bradykinesia, resting tremor, rigidity and postural reflex impairment. Over nearly two centuries, Parkinson's clinical description has provided the framework for clinical investigations, including epidemiologic ones. Descriptions of PD were limited to selected clinical settings until the middle of the 20th century. Since then, epidemiologic approaches have been used not only to investigate the population distribution of PD, but also as a way to glean clues as to the cause of this “idiopathic” disorder. Because PD is relatively infrequent, a large base population must be surveyed to identify sufficient numbers of cases for a study. In some instances, PD cases can be identified through health service rosters within defined geographic areas or in enumerated populations. In others, cases of PD are sought independently of the health care system, such as through door-to-door surveys. While the latter approach is theoretically least likely to exclude cases, the time and cost involved are also greatest using this approach.

Prevalence of Parkinson's disease in the L'Aquila district, central Italy

OBJECTIVE

We estimated the prevalence of Parkinson's disease (PD) in the L'Aquila district.

METHODS

Cases of PD were identified screening all available case sources including general practitioners and antiparkinsonian drug-users by means of pharmacy records. Prevalence of PD was computed considering the prevalence day of December 31, 2001.

RESULTS

On the prevalence day, 682 patients with PD were alive and residing in the L'Aquila district. A total of 354 patients were women and 328 men. The overall crude prevalence rate was 229.3/100,000 (95% CI 212.7-247.1), without any difference between men (227.4/100,000; 95% CI 200.0-257.5) and women (231.1/100,000; 95% CI 202.2-263.1). Prevalence rates increased with age in both sexes and were higher in urban (244.5/100,000; 95% CI 213.7-278.5) than in rural residents (214.7/100,000; 95% CI 189.0-242.9) (SRR = 1.7; 95% CI 1.3-2.1).

CONCLUSIONS

The prevalence of PD in the L'Aquila district was within the range of prevalence rates found in our country and steeply increased with advancing age in both sexes.

A systematic review of prevalence studies of dementia in Parkinson's disease

Substantial variation in the prevalence of dementia in Parkinson's disease (PDD) has been reported. The aim of this study was to review systematically and critically previous studies of the prevalence of PDD using PubMed to search the literature. Studies focusing on PD and PDD, as well as those examining on the epidemiology of dementia subtypes, were included. Predefined inclusion and exclusion criteria were used and the quality of the studies included was rated. Articles were included if: (1) the proportion of PDD among patients with either PD or dementia was reported in an original study; (2) patients had been subjected to prospective clinical examination; and (3) strategies to include all subjects with either PD or dementia within the community or hospital clinics within a geographical area were employed. Twelve studies of the prevalence of PD or PDD (1,767 patients included) and 24 prevalence studies of dementia subtypes (4,711 patients included) met the inclusion criteria. In the PD/PDD studies, the proportion (mean and 95% confidence interval) with PDD in PD was 24.5% (17.4-31.5). There were significant methodological variations between studies and in the four studies that matched the quality criteria most closely, the rate of PDD was 31.1% (20.1-42.1). The prevalence of PDD was estimated as 0.5% in subjects 65 years or older. The percentage of PDD among those with dementia was 3.6% (3.1-4.1), with an estimated prevalence of PDD of 0.2% in subjects aged 65 years or older. Despite methodological variation, this systematic review suggests that 24 to 31% of PD patients have dementia, and that 3 to 4% of the dementia in the population would be due to PDD. The estimated prevalence of PDD in the general population aged 65 years and over is 0.2 to 0.5%.

Differences in age at onset and familial aggregation between clinical types of idiopathic Parkinson's disease

Idiopathic Parkinson's disease (PD) can be subdivided by its patterns of motor symptoms into tremor-dominant (TDT), akinetic-rigid (ART), and mixed type (MT). Our objective was to determine whether age at onset and family history are different in these three types. In total, 366 patients with PD were assigned in a standardized approach to one of the three subtypes. Age at onset and family history were obtained in all patients and all presumably affected family members were examined. Mean ages at disease onset were similar in all three groups, but distribution of age at onset was markedly different: monophasic in TDT with a peak around 60 years, biphasic in ART with two peaks, one in the middle of the sixth decade (earlier onset, ART-EO), another during the first half of the seventh decade (later onset, ART-LO), and increasing with age only in MT patients A positive family history was significantly associated only with TDT (odds ratio = 5.7) and ART-EO (odds ratio = 7.8), but not with MT or ART-LO patients. Segregation analysis suggested an autosomal recessive mode of transmission in ART-EO and an autosomal dominant mode of transmission in TDT.

Current status of Parkinson's disease treatment in Korea

The health insurance system in Korea has been under governmental control, and has covered whole population since 1989. About 97% of Korean people have benefits from this system, while 3% are covered by a Medical Aid system for poor people. According to the statistical yearbook of Health Insurance Review in Korea, the number of claims under Parkinson's Disease, in whole country increased steeply from 44619 in 1995 to 96229 in 2000. If each patient were to take medication for the full duration of their insurance coverage, the average number of visits per year would be 11 in 2000. Thus the number of PD patients calculated using these statistics is about 8600. The prevalence is 19/100000, which is much lower than that in Japan. Considering the significant increase in the number of claims in last few years, however, there are still many PD patients who do not receive an accurate diagnosis and appropriate treatment. The other factor influencing these statistics is the fact that patients were able to buy their medications in drug stores without prescription, i.e. without visiting a hospital (since 2001 this has no longer been allowed). Almost all PD medications are available in Korea. There are several forms of levodopa drugs. Dopamine agonists include bromocriptine, pergolide, dihydroergocriptine, ropinirol, and pramipexole. Other parkinsonian medications are amantadine, benztropin, trihexyphenydil, deprenyl, and entacapone. Recently multicentre clinical trials were performed using ropinirol and entacapone, which showed reliable results. Currently deep brain stimulation is available in a number of medical institutes.

Prevalence of Parkinson's disease in Estonia

OBJECTIVES

To investigate the prevalence of idiopathic Parkinson's disease (PD) in Tartu district of South Estonia, with a population of 153,240 on prevalence day, 1 January 1996.

METHODS

The community-based method of case ascertainment was used, followed by neurologic examination.

RESULTS

The age-adjusted prevalence was 152 per 100,000 population, 159 for urban and 139 for the rural group, 154 for men and 153 for women. The age-specific prevalence increased from 22 per 100,000 population in the age group 40-49 years up to 1232 per 100,000 population in the age group 70-79 years. The mean age of PD patients was 71.4 years, the mean age at onset of the symptoms - 66.9 years.

CONCLUSIONS

When comparing the prevalence rates with other studies of Caucasian populations in Europe, the results are similar except for slightly but not significantly higher prevalence rates in the urban population in Estonia.

Novel three-stage ascertainment method: prevalence of PD and parkinsonism in South Tyrol, Italy

BACKGROUND

A number of community-based studies on the prevalence of PD have been conducted worldwide, but they are often extremely costly and time consuming.

OBJECTIVE

To assess the prevalence of PD and parkinsonism for the population aged between 60 and 85 years in South Tyrol, Northern Italy, using a novel population-based three-stage ascertainment method.

METHODS

Seven hundred fifty persons aged 60 to 85 years from South Tyrol received a validated screening mail questionnaire for parkinsonism. In the second stage of the ascertainment method, trained primary care physicians (PCP) identified all persons with possible parkinsonism among those screened positive. In the third stage, movement disorders specialists excluded or confirmed the diagnosis in all identified people.

RESULTS

The response rate was 87.6%. The prevalence rate per 100 population over 65 years of age was 1.5 (95% CI 0.6 to 2.3) for PD and 2.2 (95% CI 1.2 to 3.3) for parkinsonism after having been adjusted to the 1991 European standard population. Overall, 78% (95% CI 59 to 96%) of patients with parkinsonism were newly detected through the survey.

CONCLUSIONS

The prevalence of PD and parkinsonism in people aged over 65 in South Tyrol was similar to that observed in door-to-door surveys in other European countries. The novel three-stage case ascertainment method employed proved a useful tool to substitute for expensive door-to-door surveys for prevalence studies of parkinsonism, detecting a high number of undiagnosed cases, particularly in geographically remote areas.

Hunting genes in Parkinson's disease from the roots

Parkinson's disease (PD), a common, neurodegenerative disorder, has a worldwide distribution. The genetic basis of PD is not well understood, although some recent leads have emerged. Epidemiological studies suggest that there is significant variation in the prevalence of PD between different populations and rates are highest in populations of European origin. Significant differences in molecular pathology in PD and control brain tissue have been observed between African, British and Indian populations. In view of this epidemiological and pathological evidence, it is proposed that allelic variations in genes that predispose to PD may account for the ethnic variation. Advances in our knowledge about the human genome will allow us to make detailed comparisons between affected and control subjects in different populations. This may help us to understand the reasons for the variation, and a better understanding of the genetic processes underlying the disease process.

Prevalence of Parkinson's disease in lower Aragon, Spain

OBJECTIVE

We attempted to measure the prevalence of Parkinson's disease (PD) and to improve PD diagnosis in Lower Aragon (LA), a rural area located in northeast Spain with an elderly population numbering 60,724.

METHODS

Hospital records and a questionnaire targeted at general practitioners and retirement home personnel were used for case finding. Neurologic diagnoses were ascertained by a neurologist using a clinicoepidemiologic protocol and established diagnostic criteria after examining 84% of patients diagnosed with PD. Using stratified analysis, a comparison was run against reported PD prevalence from worldwide door-to-door surveys.

RESULTS

On the prevalence date, 134 individuals were found to be affected with PD. The prevalence per 100,000 population was 220.6 (crude) and 121.9 when age-adjusted using the European Standard Population. Prevalence increased with age, declining at 90 years and over. Questionnaires returned by general practitioners disclosed 20% of the prevalent PD cases. The prevalence of PD in pooled European populations was 2.56 times (95% confidence interval [CI]: 2.02-3.24) greater than that found in our study.

CONCLUSION

PD prevalence in Lower Aragon ranks at levels similar to those reported for white populations (European and non-European). One out of two individuals with PD was estimated to be undiagnosed before and three out of eight after the study.

Prevalence of parkinsonism and Parkinson's disease in Europe: the EUROPARKINSON Collaborative Study. European Community Concerted Action on the Epidemiology of Parkinson's disease

OBJECTIVES

To assess and compare the prevalence of parkinsonism and Parkinson's disease in five European populations that were surveyed with similar methodology and diagnostic criteria.

METHODS

Joint analysis of five community surveys--Gironde (France), eight centres in Italy, Rotterdam (The Netherlands), Girona (Spain), and Pamplona (Spain)--in which subjects were screened in person for parkinsonism. Overall, these surveys comprised 14,636 participants aged 65 years or older.

RESULTS

The overall prevalence (per 100 population), age adjusted to the 1991 European standard population, was 2.3 for parkinsonism and 1.6 for Parkinson's disease. The overall prevalence of parkinsonism for the age groups 65 to 69, 70 to 74, 75 to 79, 80 to 84, and 85 to 89 years was respectively, 0.9, 1.5, 3.7, 5.0, and 5.1. The corresponding age specific figures for Parkinson's disease were 0.6, 1.0, 2.7, 3.6, and 3.5. After adjusting for age and sex, the prevalence figures did not differ significantly across studies, except for the French study in which prevalence was lower. Prevalence was similar in men and women. Overall, 24% of the subjects with Parkinson's disease were newly detected through the surveys.

CONCLUSIONS

Prevalence of both parkinsonism and Parkinson's disease increased with age, without significant differences between men and women. There was no convincing evidence for differences in prevalence across European countries. A substantial proportion of patients with Parkinson's disease went undetected in the general population.

Geographical variations in mortality from Parkinson's disease in Japan, 1977-1985

Geographical variations in the age-adjusted death rate from Parkinson's disease (PD) were analyzed using Japanese vital statistics for 1977-1985. The highest age-adjusted PD death rate was 2.7 times higher in Tottori (2.9 per 100,000 population aged 25 years and over) than Fukushima (1.1) prefectures. The overall age-adjusted PD death rate was 1.8. The age-adjusted PD death rate was higher in urban (2.0) than in rural (1.7) areas during the period 1979-1985. The age-adjusted PD death rate was higher in the southwest than in the northeast. Correlation coefficients between the age-adjusted PD death rate, and the mean physician-population ratio and the mean neurologist-population ratio were positive, but not statistically significant. The regional variations in the age-adjusted PD death rate were not entirely explained by the availability of medical facilities. Environmental risk factors for PD might differ regionally. Further investigation is needed to explain the differential age-adjusted PD death rate in Japan.

Rising mortality from Parkinson's disease in Japan, 1950-1992

The death rate from Parkinson's disease (PD) were analyzed using Japanese vital statistics for 1950-1992. The age-adjusted PD death rate increased statistically significantly with the years between 1950 and 1992 for both sexes. However, decline in the PD death rate were observed among the population under 65 years old, while striking increases were seen among those over 70 years old. The changing patterns in the PD death rate might be explicable by a constantly improving ascertainment of PD, a true rise in the incidence of PD, particularly among the elderly, and a constantly increasing number of elderly people. There were remarkable differences in the PD death rates among the four marital categories in each sex. The mean age at death in PD increased from about 60 years in 1950 to 77 years in 1992 for both sexes.

Epidemiology of Parkinson's disease

Additional epidemiologic studies may provide important insights into the etiology of Parkinson's disease. Moreover as the elderly population of Europe and the United States grows, accurate public health planning requires accurate incidence and prevalence estimates. The recent development of a therapy that may slow disease progression (see article by Tetrud elsewhere in this issue) makes early identification and treatment of Parkinson's disease particularly important. Investigations of early markers of Parkinson's disease or markers of disease susceptibility are critical areas of future research, requiring careful collaboration between epidemiologists and laboratory scientists.