Prevalence and age of onset of Parkinson's disease in Cardiff: a community based cross sectional study and meta-analysis

The cost-effectiveness of deep brain stimulation in combination with best medical therapy, versus best medical therapy alone, in advanced Parkinson's disease

Parkinson’s disease (PD) is a complex progressive movement disorder leading to motor and non-motor symptoms that become increasingly debilitating as the disease advances, considerably reducing quality of life. Advanced treatment options include deep brain stimulation (DBS). While clinical effectiveness of DBS has been demonstrated in a number of randomised controlled trials (RCT), evidence on cost-effectiveness is limited. The cost-effectiveness of DBS combined with BMT, versus BMT alone, was evaluated from a UK payer perspective. Individual patient-level data on the effect of DBS on PD symptom progression from a large 6-month RCT were used to develop a Markov model representing clinical progression and capture treatment effect and costs. A 5-year time horizon was used, and an incremental cost-effectiveness ratio (ICER) was calculated in terms of cost per quality-adjusted life-years (QALY) and uncertainty assessed in deterministic sensitivity analyses. Total discounted costs in the DBS and BMT groups over 5 years were £68,970 and £48,243, respectively, with QALYs of 2.21 and 1.21, giving an incremental cost-effectiveness ratio of £20,678 per QALY gained. Utility weights in each health state and costs of on-going medication appear to be the key drivers of uncertainty in the model. The results suggest that DBS is a cost-effective intervention in patients with advanced PD who are eligible for surgery, providing good value for money to health care payers.

Parkinson's disease: how is employment affected?

BACKGROUND

Rates of unemployment and early retirement are increased in Parkinson's disease (PD) and contribute to disease burden.

AIMS

To investigate time to loss of employment from PD onset and predictors of continued employment; to identify common issues and possible interventions in the workplace.

METHODS

Eighty-eight patients with PD diagnosed at age≤65 years took part in a retrospective cohort study. Veterans RAND Short Form-36 and an employment survey were administered.

RESULTS

Unemployment rates for males were increased compared to the general Irish population (standardized ratio of 1.6, 95% CI 1.2-2.2, P<0.05). There was no significant difference for females. Median retirement age was 58 years for males and 61 years for females compared to 63.5 and 65 years, respectively, in the general population. In survival analysis, median time to loss of employment was 7 years (95% CI 4.8-9.2). After 5 years, 40% remained working and 14% after 10 years. Early age of PD onset (P<0.001), early diagnosis (P<0.002) and high scores in vitality (P<0.005) were associated with prolonged employment. There was no association with sex, education, type or hours of work. Slowness, fatigue and tremor were the most challenging symptoms at work. Changes in work schedule and type of work were suggested helpful adjustments.

CONCLUSION

Loss of employment places a significant socioeconomic burden on young PD patients. More detailed examination of specific issues and reasonable adjustments is needed, along with patient and employer education.

Time trends in incidence of Parkinson's disease diagnosis in UK primary care

To examine time trends and the influence of socio-demographic and geographic factors on incidence of Parkinson's disease (PD) diagnosis in a large UK population-based cohort from The Health Improvement Network (THIN), a UK primary care database. All patients aged over 50 years and contributing data to THIN between January 1999 and December 2009 were extracted and the incidence rates of PD diagnoses were determined by age, gender, time period, social deprivation score and urban/rural status. The overall incidence of PD diagnosis for people over 50 years was 84 per 100,000 person years (95 % CI 82-85). After accounting for socio-demographic factors, the adjusted incidence rates in men were 46 % higher (95 % CI 43-48 %) than in women. Adjusted incidence rates were also 12 % higher in urban than rural areas (95 % CI 4-20 %) and slightly lower in less socially deprived areas. Over time there was a downward trend in PD diagnosis with the adjusted incidence rates declining by around 6 % every calendar year (95 % CI 5-6 %) between 1999 and 2009. Broadening the definition of PD from diagnostic codes to include symptoms and antiparkinsonian drug prescriptions increased the overall incidence to 118 per 100,000 person years (95 % CI 116-120) and showed a much weaker downward trend over time of around 1 % per calendar year (95 % CI 1-2 %). With the broader definition, the adjusted incidence rates remained significantly higher in men compared to women and in urban areas compared with rural areas but not in socially deprived areas. The PD diagnosis rates in the primary care setting were, as expected, higher in men, and slightly higher in urban areas, but not different between socio-economic groups. There was a decline in PD diagnosis in the primary care setting, which may largely represent changes in diagnosis and/or coding rather than a true decline in incidence.

Genetics of Parkinson disease and other movement disorders

PURPOSE OF REVIEW

We will review the recent advances in the genetics of Parkinson disease and other movement disorders such as dystonia, essential tremor and restless legs syndrome (RLS).

RECENT FINDINGS

Mutations in VPS35 were identified as a novel cause of autosomal dominant Parkinson disease using exome sequencing. Next generation sequencing (NGS) was also used to identify PRRT2 mutations as a cause of paroxysmal kinesigenic dyskinesia (DYT10). Using a different technique, that is linkage analysis, mutations in EIF4G1 were implicated as a cause of Parkinson disease and mutations in SLC20A2 as a cause of familial idiopathic basal ganglia calcification. Furthermore, genome-wide association studies (GWAS) and meta-analyses have confirmed known risk genes and identified new risk loci in Parkinson disease, RLS and essential tremor. New models to study genetic forms of Parkinson disease, such as stem cell-derived neurons, have helped to elucidate disease-relevant molecular pathways, such as the molecular link between Gaucher disease and Parkinson disease.

SUMMARY

New genes have been implicated in Parkinson disease and other movement disorders through the use of NGS. The identification of risk variants has been facilitated by GWAS and meta-analyses. Furthermore, new models are being developed to study the molecular mechanisms involved in the pathogenesis of these diseases.

Using genome-wide complex trait analysis to quantify 'missing heritability' in Parkinson's disease

Genome-wide association studies (GWASs) have been successful at identifying single-nucleotide polymorphisms (SNPs) highly associated with common traits; however, a great deal of the heritable variation associated with common traits remains unaccounted for within the genome. Genome-wide complex trait analysis (GCTA) is a statistical method that applies a linear mixed model to estimate phenotypic variance of complex traits explained by genome-wide SNPs, including those not associated with the trait in a GWAS. We applied GCTA to 8 cohorts containing 7096 case and 19 455 control individuals of European ancestry in order to examine the missing heritability present in Parkinson's disease (PD). We meta-analyzed our initial results to produce robust heritability estimates for PD types across cohorts. Our results identify 27% (95% CI 17-38, P = 8.08E - 08) phenotypic variance associated with all types of PD, 15% (95% CI -0.2 to 33, P = 0.09) phenotypic variance associated with early-onset PD and 31% (95% CI 17-44, P = 1.34E - 05) phenotypic variance associated with late-onset PD. This is a substantial increase from the genetic variance identified by top GWAS hits alone (between 3 and 5%) and indicates there are substantially more risk loci to be identified. Our results suggest that although GWASs are a useful tool in identifying the most common variants associated with complex disease, a great deal of common variants of small effect remain to be discovered.

Epidemiology and neuropsychiatric manifestations of Young Onset Parkinson's Disease in the United States

BACKGROUND

To determine the demographic distribution of Young Onset Parkinson's Disease (YOPD) in the United States and to quantify the burden of neuropsychiatric disease manifestations.

METHODS

Cross sectional study of 3,459,986 disabled Americans, aged 30-54, who were receiving Medicare benefits in the year 2005. We calculated race and sex distributions of YOPD and used logistic regression to compare the likelihood of common and uncommon psychiatric disorders between beneficiaries with YOPD and the general disability beneficiary population, adjusting for race, age, and sex.

RESULTS

We identified 14,354 Medicare beneficiaries with YOPD (prevalence = 414.9 per 100,000 disabled Americans). White men comprised the majority of cases (48.9%), followed by White women (34.7%), Black men (6.8%), Black women (5.0%), Hispanic men (2.4%), and Hispanic women (1.2%). Asian men (0.6%) and Asian women (0.4%) were the least common race-sex pairs with a YOPD diagnosis in this population (chi square, p < 0.001). Compared to the general population of medically disabled Americans, those with YOPD were more likely to receive medical care for depression (OR: 1.89, 1.83-1.95), dementia (OR: 7.73, 7.38-8.09), substance abuse/dependence (OR: 3.00, 2.99-3.01), and were more likely to be hospitalized for psychosis (OR: 3.36, 3.19-3.53), personality/impulse control disorders (OR: 4.56, 3.28-6.34), and psychosocial dysfunction (OR: 3.85, 2.89-5.14).

CONCLUSIONS

Young Onset Parkinson's Disease is most common among white males in our study population. Psychiatric illness, addiction, and cognitive impairment are more common in YOPD than in the general population of disabled Medicare beneficiaries. These may be key disabling factors in YOPD.

Fixing the broken system of genetic locus symbols: Parkinson disease and dystonia as examples

Originally, locus symbols (e.g., DYT1) were introduced to specify chromosomal regions that had been linked to a familial disorder with a yet unknown gene. Symbols were systematically assigned in a numerical series to designate mapped loci for a specific phenotype or group of phenotypes. Since the system of designating and using locus symbols was originally established, both our knowledge and our techniques of gene discovery have evolved substantially. The current system has problems that are sources of confusion, perpetuate misinformation, and misrepresent the system as a useful reference tool for a list of inherited disorders of a particular phenotypic class. These include erroneously assigned loci, duplicated loci, missing symbols, missing loci, unconfirmed loci in a consecutively numbered system, combining causative genes and risk factor genes in the same list, and discordance between phenotype and list assignment. In this article, we describe these problems and their impact, and propose solutions. The system could be significantly improved by creating distinct lists for clinical and research purposes, creating more informative locus symbols, distinguishing disease-causing mutations from risk factors, raising the threshold of evidence prior to assigning a locus symbol, paying strict attention to the predominant phenotype when assigning symbols lists, and having a formal system for reviewing and continually revising the list that includes input from both clinical and genetics experts.

Cooperative genome-wide analysis shows increased homozygosity in early onset Parkinson's disease

Parkinson's disease (PD) occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD) is particularly associated with autosomal recessive (AR) mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity.

We carried out genome wide SNP genotyping to look for extended runs of homozygosity (ROHs) in 1,445 EOPD cases and 6,987 controls. Logistic regression analyses showed an increased level of genomic homozygosity in EOPD cases compared to controls. These differences are larger for ROH of 9 Mb and above, where there is a more than three-fold increase in the proportion of cases carrying a ROH. These differences are not explained by occult recessive mutations at existing loci. Controlling for genome wide homozygosity in logistic regression analyses increased the differences between cases and controls, indicating that in EOPD cases ROHs do not simply relate to genome wide measures of inbreeding. Homozygosity at a locus on chromosome19p13.3 was identified as being more common in EOPD cases as compared to controls. Sequencing analysis of genes and predicted transcripts within this locus failed to identify a novel mutation causing EOPD in our cohort.

There is an increased rate of genome wide homozygosity in EOPD, as measured by an increase in ROHs. These ROHs are a signature of inbreeding and do not necessarily harbour disease-causing genetic variants. Although there might be other regions of interest apart from chromosome 19p13.3, we lack the power to detect them with this analysis.

Move for change part I: a European survey evaluating the impact of the EPDA Charter for People with Parkinson's disease

BACKGROUND AND PURPOSE

The 1997 European Parkinson's Disease Association's (EPDA) Charter for People with Parkinson's disease (PD) outlines their rights in terms of standards of care. It states that all patients have the right to: be referred to a doctor with a special interest in PD; receive an accurate diagnosis; have access to support services; receive continuous care; and take part in managing their illness. Move for Change is a three-part series of pan-European patient surveys based on this Charter.

METHODS

This first survey, consisting of 23 questions, focusing on the initial two points of the Charter, was administered online through the EPDA and affiliated patient associations' Web sites. Of 2149 forms received from 35 European countries, 2068 (96.2%) were analyzed, with the remainder excluded, mainly due to incomplete responses.

RESULTS

The majority of patients were diagnosed within 2 years from the onset of first symptoms (82.7%; range, <1 year to ≥5 years). In relation to diagnosis delivery, 45.3% of patients stated that it was 'poor' or 'very poor'. During the 2 years following diagnosis, 43.8% of respondents had never seen a PD specialist. Care was usually overseen by generically active neurologists (92.5%) or family doctors (81.0%), with considerable overlap between the two.

CONCLUSIONS

  These data highlight challenges that patients with PD face during the period of diagnosis, despite introduction of the Charter. These findings can assist healthcare professionals and policy makers in improving the level of care for patients and their families across Europe, and we offer suggestions about how this can be achieved.

The impact of motor and non motor symptoms on health state values in newly diagnosed idiopathic Parkinson's disease

The aim of the study was to estimate health state utility values in newly diagnosed idiopathic Parkinson's disease (PD) for use in the assessment of health-related quality-of-life (HRQL), and in the estimation of quality-adjusted life-years (QALYs). Data from 162 patients enrolled in a community-based incidence study of PD were used to estimate health state utility values. Self-report data from the EQ-5D, a generic measure of HRQL, were used to derive preference-based health state utility values. The impact of motor and non motor symptoms, and other clinical and demographic factors, on the derived EQ-5D health state values was examined in univariate and multivariate analyses. The mean health state utility value for recently diagnosed PD patients was estimated at 0.65 ± 0.27. Significant reductions in health state values were attributable to pain (-0.18), motor functioning (-0.16), depression (-0.12), and insomnia (-0.11). Depression had its greatest impact (-0.19) in patients in the less severe stages of PD (i.e. Hoehn Yahr stages ≤2.5). This study shows, through the presentation of QALY values, that there is scope to achieve significant health gains in newly diagnosed idiopathic PD patients via improved management of pain, depression and insomnia, alongside the treatment of primary motor symptoms.

Three year follow up of levodopa plus carbidopa treatment in a prevalent cohort of patients with Parkinson's disease in Hai, Tanzania

It was previously thought that the prevalence of Parkinson's disease (PD) in developing countries, and in particular sub-Saharan Africa (SSA), was lower than the rest of the world. The Hai PD prevalence project [1] diagnosed 32 patients (the majority previously undiagnosed and untreated) with PD from a population of 161,000, giving age standardised prevalence rates of 64 (men) and 20 (women)/100,000, respectively. Subsequently, drug treatment has been commenced for all surviving patients with annual follow up. The aim of the study was to document response to treatment, development of side effects, progression of disease and feasibility and sustainability of supplying medication to patients in rural Tanzania. Eleven patients died before the start of medication, and a further four during follow up. One patient moved away from the study area. At the end of 3 years of treatment, 16 patients were surviving. Only one stopped medication due to side effects (dyskinesia). At 3 years, 9/16 experienced wearing off and a further three had dyskinesias. Non motor symptoms were a problem at initial assessment [2] and continued to be a problem for many of the patients. We have shown that it is possible to find, treat and follow up patients with PD in a rural sub-Saharan African setting. Availability of affordable medication locally is a major issue. Acknowledging that movement disorders and neurological diseases in general are an issue in this setting is important to drive education and training, and for allocation of funding from health care providers in SSA.

Polypharmacy increases the risk of Parkinson's disease in older people in Taiwan: a population-based study

BACKGROUND

Little is known about the relationship between polypharmacy and Parkinson's disease (PD). In the present study, we tested the hypothesis that polypharmacy increases the risk of PD in older people in Taiwan.

METHODS

From a randomly sampled cohort of one million health insurance enrollees, we identified 2827 new cases of PD over the period 2000-2008 aged ≥ 65 years and selected 11 308 age-matched controls without PD. Medication history and baseline comorbidities were compared between the two groups. We defined 'polypharmacy' as an average daily use of five or more prescribed drugs.

RESULTS

Compared with patients using between none and one drug, the odds ratios (ORs) for PD increased to 1.53, 2.08, 2.64, and 2.95 for patients using two to four, five to seven, eight to nine, and ≥ 10 drugs, respectively. The other conditions associated with PD were dementia (OR 3.43), stroke (OR 2.30), depression (OR 2.15), and alcoholism (OR 2.11). Hyperlipidemia (OR 0.90) was inversely associated with PD.

CONCLUSIONS

Polypharmacy was shown to increase the risk of PD in older people in Taiwan, with risk increasing with the number of medications taken daily. Dementia, stroke, depression, and alcoholism were also associated with an increased risk of PD, whereas there was an inverse correlation between PD and hyperlipidemia.

Prevalence of Parkinson's disease and atypical parkinsonian syndromes in a rural Japanese district

OBJECTIVES

To investigate the prevalence of Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) in a rural Japanese district.

METHOD

Collaboration with the medical institutions, the long-term care insurance system facilities, and the public health office.

RESULTS

The crude prevalence rates were 175 per 100,000 (95% CI: 143-206) for PD, 18 (8-28) for progressive supranuclear palsy, 17 (7-26) for multiple system atrophy (MSA), and 9 (2-16) for corticobasal degeneration. The age-adjusted prevalence rates were 109 per 100,000 (88-134), 10 (2-17), 13 (4-21), and 6 (0-12), for each condition. There was a preponderance of women with PD and of men with APS. Nine of the 116 PD patients and 7 of the 29 APS patients were newly diagnosed in this study.

CONCLUSIONS

There are high prevalence rates for PD and APS and suboptimal recognition of APS. This is the first epidemiological prevalence study of MSA from Japan.

Quality of life in young- compared with late-onset Parkinson's disease

The impact of Parkinson's disease on quality of life may vary depending on age at onset. We investigated the effect of age at onset on quality of life in a large Parkinson's disease population (n = 426) using a disease-specific rating scale (PDQ-39) and with careful adjustment for confounding and intermediary factors. We also explored the relationship between depression and excessive daytime sleepiness by age at onset and compared this with the general population. We found that a younger age at onset was significantly associated with worse overall quality of life scores (odds ratio, 2.66; 95% confidence interval, 1.39-5.09; P = .003), but this was attenuated by adjustment for depression as an intermediary factor (odds ratio, 1.86; 95% confidence interval, 0.84-4.11; P = .13). Younger onset was also a risk factor for poor emotional well-being independent of depression status. Risk of depression and excessive daytime sleepiness were elevated in patients with Parkinson's disease compared with controls (odds ratio, 2.99; 95% confidence interval, 1.93-4.65; P < .001; and odds ratio, 3.84; 95% confidence interval, 2.56-5.75; P < .001, respectively), with similar findings seen in both early- and late-onset groups. Our study highlights the need for accurate diagnosis and treatment of depression in younger-onset patients in order to improve quality of life.

How well do we recognise non-motor symptoms in a British Parkinson's disease population?

Although awareness of non-motor symptoms in Parkinson's disease (PD) has recently increased, little is known about their recognition and treatment in routine clinical practice. We therefore applied non-motor rating scales for dementia, depression, anxiety and excessive daytime sleepiness to a community-ascertained cohort of 202 PD patients. Hospital case notes were reviewed for evidence that the non-motor problems had been recognized and whether any action had been taken to ameliorate or assess these symptoms. The prevalence of each non-motor problem was as follows: dementia 25.3% (95% CI 19.0, 32.4), depression 37.3% (95% CI 30.6, 44.4), anxiety 31.3% (95% CI 25.0, 38.2), excessive daytime sleepiness 59.4% (95% CI 52.2, 66.3). However, these features were only recognised in 27.2, 38.7, 9.5, and 12.8%, respectively. We did not identify any specific factor that predicted under-recognition. Our study shows that when rating scales are applied to formally assess for non-motor symptoms a large clinical 'iceberg effect' emerges with the majority of symptoms going unrecognised and untreated.

How common and what are the determinants of sub-optimal care for Parkinson's disease patients: the Milton Keynes community study

OBJECTIVES

Limited data currently exists within the UK addressing the level of Parkinson's disease (PD) healthcare provision. We investigated whether care for PD patients in a UK community met national guidelines, and the determinants of sub-optimal care for this patient group.

METHODS

340 PD patients were identified from a population of 242,606 (crude prevalence 140 per 100,000 (95% CI 126-156 per 100,000), age-adjusted prevalence 199 per 100,000 (95% CI 178-221 per 100,000)). 248 out of 340 (73%) PD patients identified took part, completing rating scales assessing cognitive, non-motor and sociodemographic variables.

RESULTS AND CONCLUSIONS

9% of patients had never seen a neurologist for their PD and 18.5% were sub-optimally managed; defined as (a) delay between initial diagnosis and first consultation by a specialist >1 year and (b) patients who had not had specialist PD review for >1 year. Older age, poor cognition and worse mobility were major factors in determining sub-optimal care whilst lower education level and tremor as initial symptom were more modest predictors. 20% of patients had been started on dopaminergic therapies including ergot-derived agonists by their GP prior to referral and less than a third had seen allied health professionals throughout their illness. Further work is required to test whether these findings are generalizable across the country and identify what can be done to ensure equal access to specialist care so that all PD patients have access to best practice.

The motor phenotype of Parkinson's disease in relation to age at onset

BACKGROUND

Parkinson's disease (PD) is heterogeneous and age at onset may define variation in clinical phenotype. Most previous studies have used various age cut-offs and have been based on clinical case series.

METHODS

We have studied the association between clinical features and age of onset in 358 community-based and regional patients with PD.

RESULTS

Tremor at presentation is twice as common in those with onset over 64 years as compared to those with onset under 45 (early onset PD - EOPD) and becomes more common with increasing age at onset (p values for trend ≤ 0.004). Dystonia affects 60% of those with EOPD, shows a curvilinear relationship with age at onset (cubic versus linear p=0.01) with highest risk in patients whose disease began before 48 years. In this study age at onset was a strong predictor of the development of dyskinesias, with younger age associated with a higher risk of dyskinesias. Following multivariable analysis, allowing for possibly confounding factors (disease duration, L-DOPA dosage, L-DOPA treatment duration) younger age at onset, (less than 55 years) predicted the development of L-DOPA induced dyskinesia (odds ratio <45 years 2.1, 95% CI 1.0, 4.8; odds ratio < 55 years 3.8, 95% CI 1.8, 8.0). Only 2/70 (2.9%) EOPD patients carried pathogenic parkin or PINK1 mutations and the clinical differences between early and late onset disease were not explained by the presence of mutations in these genes.

DISCUSSION

This study highlights the clinical differences between early and late onset PD, which have important implications for diagnosis and management.

Eficácia de tratamento fisioterapêutico no equilíbrio estático e dinâmico de pacientes com doença de Parkinson

Distúrbios de equilíbrio são um dos sinais mais prevalentes na doença de Parkinson (DP), que contribuem para a perda da independência funcional dos sujeitos acometidos. O objetivo deste trabalho foi verificar a eficácia de um programa de treinamento fisioterapêutico específico sobre o equilíbrio estático e dinâmico de pacientes com DP. Vinte e três pacientes com DP idiopática, divididos em dois grupos, experimental e controle, foram avaliados pela escala de equilíbrio funcional de Berg e pelo teste de levantar e caminhar cronometrado (timed up & go). O grupo experimental foi submetido a uma seqüência de exercícios fisioterapêuticos de estimulação motora e cognitiva, com freqüência de três atendimentos semanais durante seis meses. Após o tratamento, foi constatada uma melhora significativa do equilíbrio dos pacientes do grupo experimental em relação ao controle (p<0,05) em ambos os instrumentos. O protocolo fisioterapêutico proposto, de estimulação motora e cognitiva, foi pois eficaz ao promover importante melhora no equilíbrio estático e dinâmico dos sujeitos com doença de Parkinson.