Prevalence of Parkinson disease in Singapore: Chinese vs Malays vs Indians

Phytopharmaceuticals and Herbal Approaches to Target Neurodegenerative Disorders

Neurodegeneration is characterized as the continuous functional and structural loss of neurons, resulting in various clinical and pathological manifestations and loss of functional anatomy. Medicinal plants have been oppressed from ancient years and are highly considered throughout the world as a rich source of therapeutic means for the prevention, treatment of various ailments. Plant-derived medicinal products are becoming popular in India and other nations. Further herbal therapies shows good impact on chronic long term illnesses including degenerative conditions of neurons and brain. The use of herbal medicines continues to expand rapidly across the world. The active phytochemical constituents of individual plants are sometimes insufficient to achieve the desirable therapeutic effects. Combining the multiple herbs in a particular ratio (polyherbalism) will give a better therapeutic effect and reduce toxicity. Herbal-based nanosystems are also being studied as a way to enhance the delivery and bioavailability of phytochemical compounds for the treatment of neurodegenerative diseases. This review mainly focuses on the importance of the herbal medicines, polyherbalism and herbal-based nanosystems and its clinical significance for neurodegenerative diseases.

The prevalence and incidence of progressive supranuclear palsy and corticobasal syndrome: a systematic review and meta-analysis

INTRODUCTION

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are progressive neurodegenerative syndromes characterised by Parkinsonism with additional features including cognitive dysfunction, falls, and oculomotor abnormalities. Understanding the epidemiology of these conditions is critical to planning for future service provision.

METHODS

We conducted a systematic review of studies reporting incidence and prevalence of CBS and PSP. A search of the PubMed and EMBASE data bases was conducted from their date of inception to 13th July 2021. Meta-analysis of studies sharing similar methodologies was carried out to generate estimated pooled prevalence and incidence.

RESULTS

We found 32 studies meeting our criteria for inclusion. There were 20 studies with data on prevalence and 12 with incidence data of PSP. Prevalence of CBS was reported in eight studies while seven studies reported incidence. Reported estimates of prevalence for PSP ranged from 1.00 (0.9-1.1) to 18 (8-28) per 100,000 while prevalence rates for CBS ranged from 0.83 (0.1-3.0) to 25 (0-59). Incidence rates for PSP and CBS respectively ranged from 0.16 (0.07-0.39) to 2.6 per 100,000 person-years and 0.03 (0-0.18) to 0.8 (0.4-1.3) per 100,000 person-years. A random effects model meta-analysis of studies with similar methodologies yielded a pooled prevalence estimate for PSP of 6.92 (4.33-11.06, I2 = 89%, τ2 = 0.3907) and 3.91 (2.03-7.51, I2 = 72%, τ2 = 0.2573) per 100,000 for CBS.

CONCLUSION

Studies of the epidemiology of PSP and CBS report highly heterogeneous findings. There is a need for further studies using rigorous phenotyping and the most recent diagnostic criteria to understand the true burden of these conditions.

Movement disorders in Indochina: Resource challenges and future solutions

Movement disorders are a major cause of disability worldwide and their increasing prevalence predicts a substantial future burden of care. Impactful patient care requires availability of, and accessibility to, effective medications, knowledge, and disease awareness among both medical professionals and patients, driven by skilled personnel to harness and manage resources. The highest burden of movement disorders is in low-to-middle income countries where resources are often limited and infrastructure is insufficient to meet growing demands. This article focuses on the specific challenges faced in the management and delivery of care for movement disorders in Indochina, the mainland region of Southeast Asia comprising the neighboring countries of Cambodia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. The first Indochina Movement Disorders Conference was held in August 2022 in Ho Chi Minh City, Vietnam, to provide a platform to better understand the situation in the region. Future management of movement disorders in Indochina will require progressive adaptation of existing practices to reflect modern approaches to care delivery. Digital technologies offer an opportunity to strengthen these processes and address the challenges identified in the region. Ultimately, a long-term collaborative approach by regional healthcare providers is key.

Gender Differences in the Prevalence of Parkinson's Disease

Background

Parkinson's disease (PD) affects males more than females. The reasons for the gender differences in PD prevalence remain unclear.

Objective

The objective of this systematic review and meta-analysis was to update the overall male/female prevalence ratios (OPR).

Methods

We updated previous work by searching MEDLINE, SCOPUS, and OVID for articles reporting PD prevalence for both genders between 2011 and 2021. We calculated OPRs and investigated heterogeneity in effect estimates.

Results

We included 19 new articles and 13 articles from a previously published meta-analysis. The OPR was 1.18, 95% CI, [1.03, 1.36]. The OPR was lowest in Asia and appeared to be decreasing over time. Study design, national wealth, and participant age did not explain OPR heterogeneity.

Conclusion

Gender differences in PD prevalence may not be as stark as previously thought. Studies are needed to understand the role of other determinants of gender differences in PD prevalence.

A cross-sectional study of knowledge and practices in the management of patients with Parkinson’s disease amongst public practice-based general practitioners and geriatricians

Background

As most patients are likely to first interface with their community general practitioner (GP) or geriatrician for chronic healthcare conditions, these non-neurologists practitioners are well-placed to diagnose, initiate treatment in symptomatic Parkinson’s disease (PD) patients, and provide regular and timely management of their PD. However, current studies suggest that the role of the GP and geriatrician in providing holistic care for PD patients may be limited by factors such as patient perceptions, and a lack of knowledge base in the quality measures of care. This paper aims to better understand the different management styles between GPs and geriatricians practicing in public institutions in Singapore, qualify the difficulties they face in providing patient-centric care for PD patients, and identify any gaps in quality measures of care.

Methods

A questionnaire was completed anonymously by GPs (n = 43) and geriatricians (n = 33) based at public institutions, on a voluntary basis before a compulsory didactic teaching on PD. Questions were modelled after quality measures set out by the American Academy of Neurology, specifically eliciting information on falls, non-motor symptoms, exercise regime and medication-related symptoms. “PD management practices and styles” questions were answered by the respondents on a 4-point Likert scale.

Results

Geriatricians spent more time in consult with PD patients compared with GPs (median [Q1-Q3] = 20 [15–30] vs 10 [10–15] minutes, p <  0.001). Geriatricians were more comfortable initiating PD medications than GPs (OR = 11.8 [95% CI: 3.54–39.3], p <  0.001), independent of gender, years of practice and duration of consult. Comfort in initiating dopamine replacement therapy (OR 1.06 [1.00–1.36], p = 0.07; aOR = 1.14 [1.02–1.26], p = 0.02) also increased with physician’s years of practice. Unfamiliarity with the types and/or doses of the medications was the most cited barrier faced by GPs (76.7%). Geriatricians were more likely than GPs to ask about falls (100% vs 86.0%, p = 0.025), non-motor symptoms (75.8% vs 53.5%, p = 0.049) and the patient’s regular physical activities (72.7% vs 41.9%, p = 0.01).

Conclusions

This study identified key patterns in the management practices and styles of non-neurologists physicians, and identified gaps in current practice. Our data suggests that interventions directed at education on PD medication prescriptions and provision of patient PD education, creation of best clinical practice guidelines, and accreditation by national bodies may instil greater confidence in practitioners to initiate and continue patient-centric PD care. A longer consultation duration with PD patients should be considered to allow physicians to get a greater scope of the patient’s needs and better manage them.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07503-7.

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.

Parkinson's Disease in Intensive Care Unit: An Observational Study of Frequencies, Causes, and Outcomes

Objective:

To analyze the frequency, causes, and outcomes of admission to the Intensive Care Unit (ICU) among Parkinson's disease (PD) population so that preventive measures can be developed.

Methods:

We prospectively observed patients with diagnosis of PD admitted to ICU from January 2014 to December 2016. Based on etiology for hospital admission, they were divided into two groups – related to PD (further divided into direct or indirect) or not associated with PD at all. Etiology for hospitalization was determined from history and investigational data. The primary outcome was death or discharge from the hospital. Factors contributing to ICU admission were analyzed by comparing these patients with a cohort of 50 PD patients admitted to the neurology ward during the same study period. All values were expressed as mean (standard deviation) and percentages using SPSS version 16.0.

Results:

Fifty-three (36%) out of a total of 146 patients required ICU admission. Most common causes leading to admission in decreasing order of frequency were fever (34%), delirium (16%), falls (12%), encephalopathy (8%), gastrointestinal emergencies (6%); while direct disease-related severe dyskinesias were seen only in two patients (4%). 13.7% needed mechanical ventilation and mean duration of ventilation was 5.94 days with mortality rate of 20%. Significant factors predicting ICU admission, and thus, poor outcomes were age >65 years, history of previous admission within the last 12 months, delirium, and hypoalbuminemia. There was no significant association between the incidence of ICU admission and duration of disease or severity of the disease.

Conclusions:

Poor outcome in PD patients is due to systemic causes, hence multidisciplinary teamwork may improve outcome in these patients.

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.

Epidemiology of Parkinson's Disease-East Versus West

Background

The cause of PD at present remains unknown. A number of epidemiological studies have been conducted across the globe to ascertain the disease burden and the possible risk factors. In this review, we analyze the various studies from East and West with an aim to observe the important similarities and differences in the disease occurrence and risk factor profile.

Methods

A comprehensive search of descriptive and analytical epidemiological studies was undertaken. The descriptive studies and meta-analysis providing the standardised population rates were selected. The demographics, ethnicity and geographical differences between East and West were analysed. In analytical epidemiology, more established and well-studied non-genetic risk factors for PD were reviewed utilising the prospective cohort studies, case control studies and meta-analysis where available.

Results and Conclusion

PD is more common with increasing age and shows male predominance, which is more obvious in Western studies. The PD prevalence and incidence rates are slightly lower in the East compared to the West. Incidence studies on different ethnic populations in the same country have also found a lower occurrence of PD amongst Easterners compared to Westerners. Setting methodological differences aside, studies from East and West suggest a role for both environmental and genetic risk factors in PD causation. Smoking, caffeine intake and pesticide exposure are well-established risk factors across regions. There is a robust data for dairy product consumption, urate levels and physical activity in the West while studies on certain risk factors like head injury and alcohol show conflicting and mixed results.

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.

Knowledge of Parkinson's Disease in a Multiethnic Urban Asian Setting

BACKGROUND

Public knowledge regarding Parkinson's disease (PD) is important to facilitate good health-seeking behavior, but the literature on this topic is scarce.

OBJECTIVE

We aimed to explore the level of public knowledge regarding PD in a large multiethnic urban Asian cohort, and (as a secondary aim) in a smaller cohort of PD patients and caregivers.

METHODS

A Knowledge of PD Questionnaire (KPDQ) was developed and administered to members of the Malaysian general public, and to PD patients and caregivers. The KPDQ tests recognition of PD symptoms and general knowledge regarding PD.

RESULTS

1,258 members of the general public completed the KPDQ. Tremor was the most widely recognized symptom (recognized by 79.0% of respondents); however, 83.7% incorrectly believed that all PD patients experience tremor. Memory problem was the most widely recognized NMS. Overall, motor symptoms were better recognized than NMS. Common misperceptions were that there is a cure for PD (49.8%) and that PD is usually familial (41.4%). Female gender, Chinese ethnicity, tertiary education, healthcare-related work, and knowing someone with PD were independently associated with higher KPDQ scores. PD patients (n = 116) and caregivers (n = 135) demonstrated superior knowledge compared with the general public group, but one-third of them believed that PD is currently curable.

CONCLUSIONS

This is the only study on public knowledge regarding PD in Asia. Important gaps in knowledge were evident, which could present a barrier to early diagnosis and appropriate treatment of PD. This highlights the need for targeted education campaigns and further research in this area.

Parkinson's Disease and Homocysteine: A Community-Based Study in a Folate and Vitamin B12 Deficient Population

Background. Homocysteine (Hcy) levels were higher in patients with Parkinson's disease (PD). This could be partially explained by levodopa treatment. Whether untreated PD patients have higher Hcy levels is contradictory. Methods. A community-based study was conducted using a two-stage approach for subjects ≥ 55 years to find PD patients in 3 towns of Lüliang City. Blood samples were collected. Serum Hcy, folate, and vitamin B12 concentrations were measured. For each untreated PD patient, 5 controls were selected matched with age and sex to evaluate the relationship between Hcy levels and PD. Results. Of 6338 eligible residents, 72.7% participated in the study. 31 PD cases were identified. The crude prevalence of PD for people ≥ 55 years was 0.67%. Blood samples were collected from 1845 subjects, including 17 untreated PD patients. There was no difference for concentrations of serum Hcy, folate, and vitamin B12 between cases and controls (P > 0.05). In univariate and multivariate analysis, there was significant inverse relation between PD and current smoking (P < 0.05). No other factor was significant statistically. Conclusions. The prevalence of PD was comparable to earlier studies in China. Hyperhomocysteinemia was not a risk factor of PD, as well as folate and vitamin B12 deficiency.

A Method for Automated Classification of Parkinson's Disease Diagnosis Using an Ensemble Average Propagator Template Brain Map Estimated from Diffusion MRI

Parkinson's disease (PD) is a common and debilitating neurodegenerative disorder that affects patients in all countries and of all nationalities. Magnetic resonance imaging (MRI) is currently one of the most widely used diagnostic imaging techniques utilized for detection of neurologic diseases. Changes in structural biomarkers will likely play an important future role in assessing progression of many neurological diseases inclusive of PD. In this paper, we derived structural biomarkers from diffusion MRI (dMRI), a structural modality that allows for non-invasive inference of neuronal fiber connectivity patterns. The structural biomarker we use is the ensemble average propagator (EAP), a probability density function fully characterizing the diffusion locally at a voxel level. To assess changes with respect to a normal anatomy, we construct an unbiased template brain map from the EAP fields of a control population. Use of an EAP captures both orientation and shape information of the diffusion process at each voxel in the dMRI data, and this feature can be a powerful representation to achieve enhanced PD brain mapping. This template brain map construction method is applicable to small animal models as well as to human brains. The differences between the control template brain map and novel patient data can then be assessed via a nonrigid warping algorithm that transforms the novel data into correspondence with the template brain map, thereby capturing the amount of elastic deformation needed to achieve this correspondence. We present the use of a manifold-valued feature called the Cauchy deformation tensor (CDT), which facilitates morphometric analysis and automated classification of a PD versus a control population. Finally, we present preliminary results of automated discrimination between a group of 22 controls and 46 PD patients using CDT. This method may be possibly applied to larger population sizes and other parkinsonian syndromes in the near future.

Unsupervised learning based feature extraction for differential diagnosis of neurodegenerative diseases: A case study on early-stage diagnosis of Parkinson disease

BACKGROUND

The development of MRI based methods could prove extremely valuable for identification of reliable biomarkers to aid diagnosis of neurodegenerative diseases (NDs). A great deal of current research has been aimed at identification biomarkers for both diagnosis at early stage and evaluation of the progression of NDs.

NEW METHOD

We present here a novel synergetic paradigm integrating Kohonen self organizing map (KSOM) and least squares support vector machine (LS-SVM) for individual-level clinical diagnosis of NDs. Feature are extracted in an unsupervised manner using KSOM on preprocessed brain MRIs. Thereafter, these features are fed as input to LSSVM for subject classification.

RESULTS

The applicability of the proposed methodology has been demonstrated using 831 T1-weighted MRIs obtained from Parkinson's Progression Markers Initiative (PPMI) database. We have achieved classification accuracy of up to 99% for differential diagnosis of Parkinson disease with confidence interval of 99.9%.

COMPARISON WITH OTHER EXISTING METHODS

The potential for translation of similar research findings to clinical application is greatly dependent upon two factors (1) accuracy of subject classification achieved and (2) size of the dataset used. Here, we report very high accuracy achieved on one of the largest MRI datasets using multivariate analysis tools.

CONCLUSIONS

In this paper, we describe a methodology that has the potential to be translated into first-line diagnostic tool for NDs. We also demonstrate the applicability of this methodology for diagnosing PD subjects in early stages of the disease, i.e., subjects in age of 31-60 years.

Epidemiology of Idiopathic Normal Pressure Hydrocephalus: A Systematic Review of the Literature

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is an important cause of gait disturbance and cognitive impairment in elderly adults. However, the epidemiology of iNPH is relatively unknown, largely as a result of the paucity of specifically designed population studies. This systematic review aims to assess the prevalence and incidence of iNPH.

METHODS

A systematic literature review on the epidemiology of iNPH was conducted using MEDLINE/PubMed searching for articles published up to June 2014.

RESULTS

The inclusion criteria were met by 21 studies. Of the studies, 12 were specifically designed for detecting cases of iNPH; however, only 4 were prospective. In people >65 years old, pooled prevalence obtained from specific population studies was 1.3%, which was almost 50-fold higher than that inferred from door-to-door surveys of dementia or parkinsonism. Prevalence may be higher in assisted-living and extended-care residents, with 11.6% of patients fulfilling the criteria for suspected iNPH and 2.0% of patients showing permanent improvement after cerebrospinal fluid diversion. The only prospective population-based survey that reported iNPH incidence estimated 1.20 cases/1000 inhabitants/year, 15-fold higher than estimates obtained from studies based on hospital catchment areas. The incidence of shunt surgery for iNPH and shunt-responsive iNPH obtained from incident cases of hospital catchment areas appears to be <2 cases/100,000 inhabitants/year and 1 case/100,000 inhabitants/year, respectively. No population-based study reporting the real values for these 2 parameters could be found.

CONCLUSIONS

iNPH appears to be extremely underdiagnosed. Properly designed and adequately powered population-based studies are required to characterize the epidemiology of this disease accurately.

Prevalence of Parkinsonism and Parkinson's disease in Qena governorate/Egypt: a cross-sectional community-based survey

BACKGROUND AND PURPOSE

In a previous study we found a high crude prevalence rate (CPR) for Parkinson's disease (PD) in Assiut governorate/Egypt. We therefore surveyed a second Nile valley governorate (Qena) to provide confirmatory evidence for the high prevalence rate of PD in Egypt.

SUBJECTS AND METHODS

10 areas in Qena governorate were selected by random sampling to recruit 8027 inhabitants. Positive cases were identified using a modified screening questionnaire, the unified Parkinson disease rating scale (UPDRS), mini-mental state examination (MMSE) and the non-motor symptoms scale (NMSS) for PD.

RESULTS

Forty-four patients were identified with Parkinsonism, giving a CPR of 548/10(5) inhabitants. Among them, 35 patients were diagnosed as PD with CPR of 436/10(5); three cases were diagnosed as drug-induced Parkinsonism with CPR 37/10(5); two cases had atherosclerotic Parkinsonism with CPR 25/10(5).Age-specific CPR of PD among population aged ≥ 50 years old was 2534/10(5).The highest age-specific CPR was recorded among subjects ≥ 75 years old. The CPR showed a tendency to be higher in males than females, urban than rural areas and industrial than non-industrial areas (503 vs 363/10(5), 474 vs 389/10(5) and 655 vs 312/10(5), respectively). There was a significantly higher CPR among illiterate than literate persons (1982 vs 299/10(5) with P = 0.00001). About one quarter of patients had cognitive impairment. All cases had positive symptoms in at least one or more NMS Domains.

CONCLUSION

The overall prevalence of PD disease is high in Nile valley governorates of Upper Egypt compared to other Arabic countries.

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.

Estimating the lifetime economic burden of Parkinson's disease in Singapore

BACKGROUND AND PURPOSE

We aimed to estimate the lifetime cost of Parkinson's disease (PD) from the societal perspective.

METHODS

A convenience sample of English or Chinese-speaking patients with PD was recruited from a PD and Movement Disorders Centre in Singapore to complete a financial burden questionnaire. Sociodemographic and clinical data were retrieved from hospital databases. Markov cohort model analysis was performed (cycle length, 1-year; duration, death or reached 100 years old). Patients were assumed to progress from one Markov state to the next state or death without skipping states or regressing. All model parameters were based on published local data.

RESULTS

In 195 patients with PD (median age: 68.9, male: 51.8%), the simulated lifetime cost of PD was Singapore Dollar (SGD) 60,487 (EUR purchasing power parity 56,253) per patient. Direct medical, non-medical and indirect cost accounted for 18.8%, 12.8% and 68.4% of total lifetime cost, respectively. The top three components of total lifetime cost were productivity losses (67.6%), pharmacotherapy (11.4%) and home care (8.7%). One-way sensitivity analysis and probabilistic sensitivity analyses revealed that estimates were sensitive to cost at H&Y stage 1, 2 and 2.5 and productivity losses.

CONCLUSIONS

The lifetime cost of PD is evaluated for the first time. This cost is substantial and comparable to the lifetime cost of intracerebral haemorrhage in at least one study. Our study identified several priority areas for research and policy formulation: reducing productivity losses, reducing cost of pharmacotherapy, avoiding hospitalization and reducing home care cost.

A national registry to determine the distribution and prevalence of Parkinson's disease in Thailand: implications of urbanization and pesticides as risk factors for Parkinson's disease

BACKGROUND

Parkinson's disease (PD) occurs worldwide but prior to this review of data from the Thailand Parkinson's Disease Registry there had been no nationwide PD registry reported globally.

OBJECTIVE

To determine the distribution and prevalence of PD in Thailand and related risk factors in order to more adequately develop and allocate prevention and treatment resources where they are most needed and to ascertain risk factors that are specific to the Thai population.

DESIGN

The Thailand Parkinson's Disease Registry is a new resource, and data collection began in March 2008. Data is collected by the Registry from physicians, and a mechanism is also provided for patients to self-report. This data was further analyzed by the capture-recapture methodology (CRM) to assess reporting biases.

METHODS

The three main sources of data input to the Registry, i.e. (1) public hospitals, (2) private hospitals and (3) self-registration, require checking for duplicates and also allow estimation of completeness of recording (the degree of underreporting) in this disease registry. There is underreporting because of poor record keeping and administrative procedures in some facilities, and there is an unknown number of persons with PD who are not properly diagnosed because of inadequate facilities and staffing in some areas. Since our data sources should be overlapping in some way, and assuming that the likelihood of being detected in one system is independent of the others, we estimated these data sources' actual coverage and the expected total number of patients utilizing the 'capture-recapture' statistical technique.

RESULTS

As of March 2011, the Thailand PD Registry had identified 40,049 PD patients. Employing log-linear modeling, the CRM analysis based on the three data sets estimated underreporting of 20,516 cases. The revised estimated total is thus 60,565 cases, resulting in a crude and age-adjusted prevalence of 95.34 and 424.57 PD cases/100,000 population, respectively. The prevalence of PD was 126.83/100,000 in urban areas and 90.82/100,000 in rural areas (p < 0.001). Preliminary regional comparisons revealed a higher prevalence of PD in residents of the central plain valley of Thailand, an area with a large amount of pesticide use.

CONCLUSIONS

The combination of a passive registry and the CRM technique allowed us to derive population prevalence estimates for PD in Thailand. Thai PD prevalence estimates were similar to previous ones published for Asian countries; in addition, they suggested that urbanization and exposure to pesticides may both be risk factors for PD in the Thai population.

The curious case of phenocopies in families with genetic Parkinson's disease

Monogenic forms of Parkinson's disease account for ∼3% of all "idiopathic" Parkinson's disease. With reduced penetrance in dominant forms and manifesting heterozygotes in recessive forms of Parkinson's disease, it has been well recognized that inheritance patterns do not always follow classic Mendelian genetics. A novel twist to the puzzle is the presence of phenocopies (i.e., family members with the same clinical syndrome as the mutation carriers, but lacking the familial mutation). We reviewed all pedigrees published between 1997 and 2009 with α-synuclein, leucine-rich repeat kinase 2, Parkin, or PTEN-induced kinase 1 mutations with at least 2 affected individuals and known genetic status for the possible presence of phenocopies. Of 537 patients with clinical Parkinson's disease in 160 families meeting our inclusion criteria, 27 patients (5.0%) from 23 families (14.4%) were phenocopies. Phenocopies represented 3.8% of all blood relatives reported in the pedigrees containing phenocopies and an estimated 1.3% of all blood relatives in all pedigrees included. Both of these rates exceeded age-specific prevalences of Parkinson's disease. In 4 families, the phenocopy was explained by another known mutation: In 2 pedigrees, a monogenic cause was likely; in another 2, secondary parkinsonism was suspected; and in the remaining 15 families, "sporadic Parkinson's disease" was suggested as the cause of disease in the phenocopy. The unexpectedly high number of phenocopies of mostly unknown origin within families with a seemingly known etiology of Parkinson's disease adds another level of complexity to genetic research of Parkinson's disease, as well as to the interpretation of genetic testing results in the clinical diagnostic setting.

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.

Prevalence and risk factors of Parkinson's disease in retired Thai traditional boxers

Boxing is often believed to be a frequent cause for parkinsonism caused by chronic repetitive head injury, with Muhammad Ali frequently cited as an example. The purpose of this study is to determine the prevalence of Parkinson's disease (PD) in retired Thai traditional boxers. Two standardized screening questionnaires were sent to all registered Thai traditional boxers. Subjects who screened positive for parkinsonism were invited for clinical examinations by two independent neurologists. Among 704 boxers (70%) who completed the questionnaires, 8 boxers (1.14%) had parkinsonism: 5 with PD, 1 with progressive supranuclear palsy and 2 with vascular parkinsonism. Boxers with PD were found to have an older mean age than those without PD (P = 0.003). The analysis of probable risk factors disclosed an association between the number of professional bouts (>100 times) and PD (P = 0.01). The crude prevalence of PD in Thai boxers was 0.71% (95% CI: 0.09-1.33), with a significant increase with age. The prevalence rate of PD in those aged 50 and above was 0.17% (95% CI: 0.15-0.20), age-adjusted to the USA 1970 census, which is comparable to that of the general populations. The analysis determined that the number of professional bouts is a risk factor among these boxers, supporting the notion that repetitive head trauma may pose an additional risk to certain individuals who are already susceptible to PD.

Economic burden of Parkinson's disease in Singapore

BACKGROUND

This study was carried out to evaluate the economic burden of Parkinson's disease (PD) and factors independently associated with individual components of total cost in Singapore.

METHODS

A consecutive sample of 195 patients with PD (mean age: 68.2, men: 51.8%) attending a tertiary neuroscience clinic were identified and interviewed using standardized questionnaires including a financial burden questionnaire, two Health Related Quality of Life (HRQoL) questionnaires and the Beck Depression Inventory questionnaire.

RESULTS

Annual total cost of PD from a societal perspective was SGD11345 (USD10129) per patient, with direct cost accounted for 38.5% and indirect cost 61.5%. The main cost components for direct medical cost, direct non-medical cost, and indirect cost was pharmacotherapy (50.4%), home care (76.1%), and productivity loss (97.9%), respectively. In multiple linear regression analysis, higher education, younger age and longer duration of PD were associated with higher total cost.

CONCLUSIONS

Parkinson's disease exerts a considerable burden on patients, health care system and society in Singapore. As productivity loss accounts for a large share of the economic burden imposed by PD, treatments and health care programmes with potential for returning patients to higher productivity are urgently needed.

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.

Ethnic differences in Singapore's dementia prevalence: the stroke, Parkinson's disease, epilepsy, and dementia in Singapore study

OBJECTIVES

To study the prevalence of dementia in Singapore among Chinese, Malays, and Indians.

DESIGN

A two-phase, cross-sectional study of randomly selected population from central Singapore with disproportionate race stratification.

SETTING

Community-based study. Subjects screened to have cognitive impairment at phase 1 in their homes were evaluated clinically for dementia at phase 2 in nearby community centers.

PARTICIPANTS

Fourteen thousand eight hundred seventeen subjects aged 50 and older (67% participation rate).

MEASUREMENTS

The locally validated Abbreviated Mental Test was used to screen for cognitive impairment at phase 1. Dementia was diagnosed at phase 2 as per Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Possible Alzheimer's disease (AD) and possible vascular dementia (VD) were diagnosed along the National Institute of Neurological and Communicative Disorders-Alzheimer's Disease and Related Disorders Association and National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neuroscienes criteria, respectively.

RESULTS

The overall age- and race-standardized dementia prevalence was 1.26% (95% confidence interval (CI)=1.10-1.45). Prevalence (in 5-year age bands) was 0.08% (50-54), 0.08% (55-59), 0.44% (60-64), 1.16% (65-69), 1.84% (70-74), 3.26% (75-79), 8.35% (80-84), and 16.42% (>/=85). From age 50 to 69, 65% of dementia cases were VD; at older ages, 60% were AD. Logistic regression (adjusted for age, sex, education) showed that Malays had twice the risk for AD as Chinese, and Indians had more than twice the risk for AD and VD than Chinese.

CONCLUSION

Singapore's dementia prevalence, primarily influenced by its Chinese majority, is lower than seen in the West. The striking interethnic differences suggest a need for a dementia incidence study and further investigation of underlying genetic and cultural differences between the three ethnic groups in relation to dementia risk.

Vitaminas antioxidantes na Doença de Parkinson

Resumo A doença de Parkinson é uma enfermidade neurodegenerativa caracterizada pela presença de rigidez, tremor e bradicinesia, sendo um dos distúrbios do movimento mais encontrados na população idosa. Estudos mostraram que o estresse oxidativo, o uso prolongado da droga levodopa no tratamento dessa doença e o aumento da concentração plasmática de homocisteína são agentes que agravam os sintomas. Muitos nutrientes estão sendo pesquisados tanto na prevenção como no tratamento da doença, dentre os quais se destacam as vitaminas antioxidantes. Houve recentemente aumento do número de pesquisas sobre a ação dessas vitaminas, atenuando os danos causados ao cérebro nesses pacientes. Desta forma, o artigo teve como objetivo reunir, na literatura científica, informações recentes sobre a influência das vitaminas C, E, B6, B12 e folato na doença de Parkinson. Embora as evidências do efeito dessas vitaminas nos pacientes com a doença sejam comprovadas em algumas pesquisas, ainda há controvérsias entre os autores, sendo necessário realizar mais estudos sobre o assunto.

Differential effects of black versus green tea on risk of Parkinson's disease in the Singapore Chinese Health Study

Data from Asian populations on dietary and lifestyle factors associated with Parkinson's disease are sparse. In 1993-2005, the authors examined these factors in relation to Parkinson's disease in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese men and women. Baseline data were collected through in-person interviews using structured questionnaires. All 157 incident Parkinson's disease cases were identified either through follow-up interviews or via linkage with hospital discharge databases and Parkinson's disease outpatient registries and were confirmed by review of medical records. Current versus never smokers exhibited a reduced risk of Parkinson's disease (relative risk = 0.29, 95% confidence interval: 0.16, 0.52). Total caffeine intake was inversely related to Parkinson's disease risk (p for trend = 0.002); the relative risk for the highest versus lowest quartile was 0.55 (95% confidence interval: 0.35, 0.88). Black tea, a caffeine-containing beverage, showed an inverse association with Parkinson's disease risk that was not confounded by total caffeine intake or tobacco smoking (p for trend = 0.0006; adjusted relative risk for the highest vs. lowest tertile of intake = 0.29, 95% confidence interval: 0.13, 0.67). Green tea drinking was unrelated to Parkinson's disease risk. Diet had no strong influence on risk. Ingredients of black tea other than caffeine appear to be responsible for the beverage's inverse association with Parkinson's disease.

Valproate-induced Parkinsonism in epilepsy patients

We systematically examined 226 epilepsy patients in a tertiary-referral center and found 6 (5.04%) to have valproate-induced Parkinsonism. There was a significantly higher prevalence of patients with Parkinsonism in the group of patients treated with valproate compared to those who were on other antiepileptic drugs (6 [5.04%] of 119 vs. 0 [0%] of 107; chi2 = 5.54; P = 0.025). These six patients had been on valproate for more than 3 years (mean, 75.67 +/- 25.32 months) at an average dose of 750 +/- 273.86 mg/day. The valproate doses were decreased or discontinued with supplementation from another antiepileptic medication. The mean UPDRS motor score significantly improved from 10.67 +/- 5.1 to 4.75 +/- 2.75 (P < 0.05). There was no relapse of seizures. Clinicians working in tertiary-referral centers should have a high index of suspicion for valproate-induced Parkinsonism. Early recognition and switching into another antiepileptic medication may help reduce unnecessary suffering in these patients.

Analysis ofLRRK2 Gly2385Arg genetic variant in non-Chinese Asians

A common LRRK2 missense variant, Gly2385Arg, has been found to be a genetic risk factor for Parkinson's disease (PD) in ethnic Chinese and Japanese. However, the presence of the variant in other non-Chinese Asian patients has not been fully clarified. We performed genetic analysis of the Gly2385Arg variant in 472 non-Chinese Asian subjects in Singapore (comprising of 166 PD and 306 controls of Malay/Indian ethnicity). The frequency of the heterozygous Gly2385Arg genotype was not significantly different in PD compared with controls (1.2% vs. 0.8%, odds ratio = 2.83, 95% CI 0.40, 20.2, P = 0.3). No subjects carried the homozygous genotype. Stratification by Malay and Indian ethnicity revealed that there were two carriers each among 98 (2.0%) Malay PD and 173 (1.2%) Malay controls (odds ratio = 1.78, 95% CI 0.25, 12.8, P = 0.6), but there were no carriers among 66 Indian PD and 133 Indian controls. We demonstrated that the Gly2385Arg variant could be detected in our Malay subjects. However, its frequency was much lower than the 8 to 10% prevalence previously reported in our Singaporean and Taiwanese Chinese PD population. The relevance of Gly2385Arg as a genetic risk factor may be restricted to selected Asian races, and more studies will be needed to confirm our observations.

Incidence of Parkinson's disease in Singapore

To investigate the incidence of Parkinson's disease (PD) in Singapore, a parkinsonism-free cohort of 14,835 participants was followed-up and incident cases of PD identified through phone interviews, medical record reviews and a hospital's database. A movement disorders specialist subsequently verified the diagnosis through a medical records review. The age and sex-adjusted (US 1990 population) incidence rate was 32 per 100,000 person years for individuals aged 50 years and above. The rates differed between Chinese, Malays and Indians (p=0.03). The difference in inter-racial rates needs to be interpreted with caution in view of the small numbers. The incidence of PD in Singapore is comparable with that in Western countries.

Screening for dementia in the older Chinese with a single question test on progressive forgetfulness

OBJECTIVES

To assess the utility of asking for presence of progressive forgetfulness (PF) prior to administering the Abbreviated Mental Test (AMT) when screening for dementia in the community-dwelling elderly Chinese.

METHODS

This was a two-phased community-based survey of elderly subjects (>or=50 yrs). In phase one, subjects were asked for PF and administered the AMT. Those having PF or an impaired AMT performance were evaluated clinically for dementia in phase two, which also included a randomly selected sample of 35 subjects with no PF and who passed the AMT.

RESULTS

2,566 subjects completed phase one interview, of which 128 subjects completed phase two. Overall prevalence of PF, failed AMT and dementia were 2.4%, 2.2%, 0.9% respectively. The sensitivity of PF for dementia was 95.7% with specificity of 45.1%. PF was significantly associated with depression in the young-old (50-74 yrs) but not in the old-old (>or=75 yrs) age group, after adjusting for dementia. The probability of subjects (%) in the four possible diagnostic combinations of PF and AMT in the young-old and (old-old) age groups were 0 (0.06) in the no PF/ passed AMT, 0 (0.44) in the no PF/failed AMT, 0.23 (9.2) in the PF/passed AMT and 3.6 (43) in the PF/failed AMT groups.

CONCLUSION

In screening for the most common dementias, AMT administration is not required if PF is absent. AMT is also of no added utility for diagnosing dementia in older subjects with PF. Younger subjects with PF should be closely evaluated for depression especially if they passed the AMT, and dementia, if they failed the AMT.

Parkinsonism and Parkinson's disease in the elderly: A community-based survey in Brazil (the Bambuí study)

Several community-based surveys on the prevalence of Parkinsonism and Parkinson's disease have been conducted worldwide, with variations on their methodology and results. The objective of this study is to assess the prevalence of Parkinsonism and its causes in a cohort of individuals age 64 years or older in Bambuí, a Brazilian town. In phase I, 1,186 people older than 64 years responded to a 9-question screening questionnaire for Parkinsonism. In phase II, all subjects who scored > or = 2 points on the test were examined independently by at least 2 movement disorder-trained physicians. A movement disorder senior specialist excluded or confirmed the diagnosis in all suspected cases. The response rate was high for both phases (96% for phase I and 94% for phase II). The prevalence rate per 100 population over 64 years of age in this group was 7.2% for Parkinsonism of all types (n = 86). The most frequent causes were idiopathic Parkinson's disease and drug-induced Parkinsonism, with prevalence rates of 3.3% (n = 39) and 2.7% (n = 32), respectively. The prevalence of vascular Parkinsonism was 1.1% (n = 13). We found 1 case of posttraumatic Parkinsonism and another with multiple system atrophy. In this first population-based study of Parkinsonism conducted in Brazil, the prevalence in a cohort of elderly subjects was higher than the observed in other populations worldwide, especially because of the high rates of drug-induced and vascular Parkinsonism. The prevalence of Parkinson's disease was similar to that observed in elderly people in door-to-door surveys in other American, European, and Eastern countries.

Prevalence of essential tremor in Singapore: a study on three races in an Asian country

To investigate the prevalence of Essential Tremor (ET) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians, a community-based survey among a disproportionate random sample of 15,000 individuals (9000 Chinese, 3000 Malays, 3000 Indians) aged 50 years and above was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a screening questionnaire for Parkinson's disease. In phase 2, medical specialists examined participants who screened positive to evaluate for the presence of postural or kinetic tremor of the upper limbs, or head tremor. Participants with suspected ET had their diagnosis confirmed in phase 3 by a movement disorders specialist and fellow based on the latest core diagnostic criteria. Forty participants with classic ET were identified. The prevalence rate (PR) of ET was 2.37 per 1000 (95% CI: 1.65-3.32), age-adjusted to UICC world standard population. The PR was significantly higher in males (p=0.01) and increased significantly with age (p<0.001). Indians (PR=4.94 per 1000, 95% CI: 2.63-9.04) were 1.8 times more likely to have ET than Chinese (PR=2.77 per 1000, 95% CI: 1.78-4.17) (p=0.08). No Malays with ET were identified. The data suggest that the prevalence of ET increases with age, is higher in males and may be higher amongst Indians.