Screening Parkinson's disease: a validated questionnaire of high specificity and sensitivity

Risk of Parkinson's disease in older people with tremor: A population-based prospective study

BackgroundTremor is prevalent among older adults and is suggested to be associated with the subsequent development of Parkinson's disease (PD). However, prospective evidence for the association is scarce.ObjectiveThis population-based prospective study aimed to estimate PD risk and to explore predictive factors for PD conversion in community-dwelling older people with tremor.MethodsThe study was based on the Beijing Longitudinal Study on Aging (BLSA) II. Tremor was assessed using a validated self-administered method. Participants without parkinsonism and with any tremor were followed for an average of 7.7 years. The standardized incidence ratio (SIR) was used to estimate the risk of developing PD in older people with tremor, with age- and sex-specific incidence rates of PD in the general Chinese population as a reference. Risk factors, prodromal symptoms, and tremor features were assessed to identify predictors for incident PD.ResultsSeventeen (8.4%) of 202 participants with tremor developed parkinsonism, including 9 (4.4%) diagnosed with PD. The presence of any tremor was associated with an increased risk of developing PD (SIR: 3.12, 95% confidence interval [CI]: 1.52-5.73). Sensitivity analyses yielded similar results. Probable REM sleep behavior disorder (RBD), identified using the RBD Questionnaire-Hong Kong, and self-report of new-onset rest tremor predicted PD conversion.ConclusionsTremor is associated with an elevated risk of PD in the general older population. Screening for RBD and monitoring the evolution of tremor characteristics using simple questionnaires may help identify individuals at high risk for PD among community-dwelling older adults with tremor.

Multimorbidity and its association with mental health in an adult population of Peru

BACKGROUND

Motivation for the study. The presence of multimorbidity is increasingly frequent in the general population, and this may be associated with mental health problems. Main findings. The presence of multimorbidity, and a great number of chronic conditions, was associated with a higher prevalence of depressive symptoms, anxiety and perceived stress in an adult population in a region of northern Peru. Implications. Our findings suggest the need for adequate mental health management in patients with more than one chronic disease.

OBJECTIVE.

To evaluate the association between multimorbidity and mental health in adults aged 30 to 69 years.

MATERIALS AND METHODS.

Secondary data analysis of a population-based study conducted in the peri-urban area of Tumbes in the northern coast of Peru. The dependent variables were: depressive symptoms, using the PHQ-9; anxiety symptoms, using the Goldberg scale; and perceived stress, assessed with the Cohen's 14-question scale. The exposure variable was the presence of multimorbidity (presence or not of two or more chronic conditions and the number of chronic conditions). We assessed associations using crude and adjusted Poisson regression models.

RESULTS.

Data from 1600 participants were analyzed, mean age was 48.1 years (SD: 10.5), and 50.4% were women. The prevalence of multimorbidity was 15.9%, 23.3% presented depressive symptoms, 42.0% anxiety symptoms and 31.4% had high levels of perceived stress. The multivariable model showed that multimorbidity was associated with a higher prevalence of depressive symptoms (61%, 95%CI: 32% - 98%), anxiety symptoms (46%, 95%CI: 28% - 66%) and high (22%, 95%CI: 14% - 33%) but not moderate levels of perceived stress (6%; 95%CI: 0% - 12%). A higher number of chronic conditions was associated with higher prevalence of depressive symptoms, anxiety symptoms, and perceived stress levels.

CONCLUSIONS.

The presence of multimorbidity is associated with a higher prevalence of depressive symptoms, anxiety symptoms, and perceived stress levels. Our results suggest the need for adequate mental health management in patients with multimorbidity.

Estimating the prevalence, factors, and conditions associated with Parkinson disease: a population-based study in Peru

This study aimed to estimate the population-based Parkinson disease prevalence, and to explore potentially associated factors and conditions. A population-based survey was conducted in Northern Peru. Symptoms compatible with Parkinson's were defined using a validated Spanish questionnaire (≥ 42 points suggest Parkinson's). Potential factors (e.g., age, sex, etc.) and clinical conditions (e.g., depressive symptoms, perceived stress, etc.) associated with Parkinson's were assessed. In total, 1,609 subjects were included, mean age of participants was 48.2 (SD: 10.6), and 810 (50.3%) were women. Parkinson's prevalence was 1.6% (95%CI: 1.0; 2.4). Those aged ≥ 55 years, and those who reported using wood as fuel for household cooking had a Parkinson's prevalence from 3.5 to 4 times greater than those who did not. The presence of depressive symptoms, anxiety symptoms, perceived stress, poor sleep quality, and cognitive impairment was more common among those with Parkinson's, and quality of life in these participants was lower than those without Parkinson's. In conclusion, 1.6% of the population shows symptoms compatible with Parkinson's. Age and use of wood for household cooking were factors associated with Parkinson's. Several mental health conditions and lower quality of life were more frequent among those with Parkinson's. Appropriate strategies are required to detect, prevent, and manage Parkinson's cases.

Severity of Daytime Sleepiness and Parkinsonian-Like Symptoms in Korean Adults Aged 50-64 Years

Background and Purpose

While excessive daytime sleepiness can predate Parkinson’s disease in late-life, its association with parkinsonian-like (P-L) symptoms in middle age are unknown. Since neurodegeneration can appear decades before a diagnosis of Parkinson’s disease, identifying clinical features associated with this early progression is important. The purpose of this study was to determine the association of daytime sleepiness with P-L symptoms in a population-based sample of middle-aged Korean adults.

Methods

During 2013 and 2014, daytime sleepiness and P-L symptoms were assessed in 2,063 males and females aged 50–64 years who were participating in the Korean Genome and Epidemiology Study. The severity of daytime sleepiness was quantified by the score on the Epworth Sleepiness Scale (ESS). Self-reported P-L symptoms included nine motor disorders commonly associated with Parkinson’s disease. Participants with parkinsonism and related conditions are excluded.

Results

The prevalence of excessive daytime sleepiness (ESS score >10) was 7.0%. The frequencies of P-L symptoms ranged from 0.5% (for “trouble buttoning buttons”) to 18.4% (for “handwriting smaller than it once was”). After adjustment for covariates and multiple testing, the relative odds of P-L symptoms comparing the 80th and 20th percentiles of ESS scores was 1.6 (p=0.001) for “voice is softer than it once was,” 2.1 (p<0.001) for “balance when walking is poor,” and 1.5 (p=0.002) for “loss of facial expression.” The prevalence of excessive daytime sleepiness increased from 6.3% to 19.8% when the number of symptoms increased from zero to three (p=0.004).

Conclusions

In Korean adults aged 50–64 years, daytime sleepiness is significantly associated with P-L symptoms. Whether coexisting daytime sleepiness and P-L symptoms predate extrapyramidal and other impairments in later life warrants further investigation.

Prevalence of Prodromal Symptoms of Parkinson's Disease in the Late Middle-Aged Population

BACKGROUND

The prodromal phase of Parkinson's disease (PD) can last up to 20 years and is characterized by a variety of non-motor symptoms.

OBJECTIVE

To determine the prevalence of a selection of non-motor symptoms known to be associated with an increased risk of developing PD in a late middle-aged population-based sample and to determine their association with motor function.

METHODS

At a mean age of 60.3 years, 775 subjects were recruited from the Longitudinal Aging Study Amsterdam (LASA). Hyposmia, cognitive impairment, patient-reported constipation, possible REM-sleep behavior disorder, depression, and anxiety were indexed as known PD risk factors. Additionally, 1) the PD screening questionnaire, 2) four physical performance tests, and 3) a functional limitations questionnaire, were used to determine whether the presence of two or more PD risk factors was associated with reduced motor function.

RESULTS

The prevalence of single risk factors ranged between 3 and 13%. Approximately 11% of subjects had two or more PD risk factors. Motor functioning of subjects with two or more PD risk factors was significantly worse than performance of subjects without or with a single risk factor (all p values≤0.001).

CONCLUSION

Approximately 11% of the late middle-aged population has two or more known PD risk factors. Among these subjects self-perceived PD symptoms and reduced physical performance are more prevalent, suggesting that at least some of these subjects may be in the prodromal phase of PD.

Assessment of Cognitive Symptoms in Brain Bank-Registered Control Subjects: Feasibility and Utility of a Telephone-Based Screening

Background: For neuroscience research, the study of brain tissue of neurologically unimpaired subjects is crucial to interpret findings in neurodegenerative diseases. Sub-optimal neurological follow-up and the presence of neuropathological lesions in supposedly asymptomatic subjects casts doubt as to whether these subjects present an undetected underlying neurodegenerative disease or are resilient to neurodegeneration. Objective: We aimed to assess whether the control donors registered in the Neurological Tissue Bank-Hospital Clínic-IDIBAPS (NTB-HCI) are still free of cognitive symptoms at follow-up and to evaluate the feasibility and utility of a telephone-based screening. Methods: All control subjects older than 65 years registered at the NTB-HCI database were selected for the study. After a structured telephone interview, those subjects already diagnosed with a neurological disease were excluded. Then, a cognitive screening was performed, including the telephone version of the Mini-Mental State Examination (t-MMSE) and the eight-item interview (AD-8) to the subject and to one informant. Results: In total, 73.8% of the registered donors collaborated in the study. Only 21.4% had at least one of the three cognitive screening tools impaired, and 2.7% had a profile highly suggestive of cognitive impairment. AD-8i correlated moderately with t-MMSE. Conclusion: Telephone-based neurologic screening in control donors is feasible and was within the normal range in most of the subjects in our cohort. Albeit, the involvement of neurologists and periodic neurological screenings are desirable in a control subjects brain donor program, AD8-i could be used to screen the control’s neurological status in the absence of accurate clinical data at the time of the death.

Sleep Disorders and Future Diagnosis of Parkinsonism: A Prospective Study Using the Canadian Longitudinal Study on Aging

BACKGROUND

Earlier detection of parkinsonism, specifically during its prodromal stage, may be key to preventing its progression. Previous studies have produced contradictory results on the association between sleep symptoms and prodromal parkinsonism.

OBJECTIVE

We conducted a prospective study within the Canadian Longitudinal Study on Aging (CLSA) to determine whether self-reported symptoms of insomnia, somnolence, apnea, and restless legs syndrome predate the diagnosis of parkinsonism after three years of follow-up.

METHODS

At baseline, amongst other information, participants completed a questionnaire for difficulty initiating or maintaining sleep, daytime somnolence, snoring or stopping breathing during sleep, and symptoms of restless legs syndrome. After 3 years of follow-up, baseline responses from participants who self-reported a new diagnosis of parkinsonism (cases) were compared to those who did not (controls). For each case, 10 controls were individually matched by age, sex, education, BMI, caffeine, smoking, and alcohol. Binary unconditional logistic regression models were used to estimate the association between sleep symptoms and new-onset parkinsonism, adjusting for age, sex, education, BMI, smoking, alcohol, and caffeine.

RESULTS

We identified 58 incident-parkinsonism cases and 580 matched controls (65.5%male, mean age = 69.60, SD = 8.0). Baseline symptoms of sleep-onset insomnia (12.1%vs. 13.0%, Adjusted OR[95%CI] = 0.87[0.32,2.33]), sleep-maintenance insomnia (24.1%vs. 20.2%, AOR = 1.01[0.46,2.20]), daytime somnolence (8.6%vs. 7.4%, AOR = 1.11[0.37,3.39]), obstructive sleep apnea (27.3%vs. 26.2%, AOR = 0.84[0.40,1.79]), and restless leg syndrome (20.6%vs. 9.9%, AOR = 1.34[0.42,4.25]) were similar among those who developed parkinsonism and those who did not.

CONCLUSION

Symptoms of insomnia, somnolence, apnea, and restless legs did not predate a new diagnosis of parkinsonism over 3 years.

Risk factors for possible REM sleep behavior disorders: A community-based study in Beijing

OBJECTIVE

To explore the risk factors for idiopathic REM sleep behavior disorder (RBD) in a community population in Beijing.

METHODS

Participants aged 55 years and above were recruited from the Beijing Longitudinal Study on Aging II cohort. We identified individuals with possible RBD (pRBD) using the validated RBD Questionnaire-Hong Kong in 2010. A series of environmental, lifestyle, and other potential risk factors were assessed via standardized questionnaires in 2009. Multivariable logistic regression analysis was performed to investigate the association between the studied factors and pRBD.

RESULTS

Of 7,225 participants who were free of parkinsonism and dementia, 219 (3.0%) individuals were considered as having pRBD. Participants with pRBD reported more nonmotor and motor symptoms of Parkinson disease (PD) with adjusted odds ratios (ORs) ranging from 1.10 to 4.40. Participants with pRBD were more likely to report a family history of parkinsonism or dementia (OR 3.03, 95% confidence interval [CI] 1.23-7.46). There was a significant association between pRBD and self-reported hyperlipidemia (OR 1.51, 95% CI 1.09-2.10), ever smoking (OR 1.79, 95% CI 1.20-2.65), prior carbon monoxide (CO) poisoning (OR 2.30, 95% CI 1.39-3.83), and nonoccupational exposure to pesticides (OR 2.21, 95% CI 1.40-3.50).

CONCLUSION

Our study replicated previously reported associations between pRBD and hyperlipidemia, smoking, pesticide exposure, and several prodromal PD symptoms. We also found previously unreported links with a positive family history of parkinsonism or dementia and CO poisoning. Risk factor profiles for pRBD partially resemble those defined for PD, but also differ in distinct ways.

Parkinson's Disease-Related Motor and Nonmotor Symptoms in the Lancaster Amish

INTRODUCTION

Previous research has suggested that the Amish may experience a relatively high prevalence of Parkinson's disease (PD) and/or parkinsonian motor signs.

METHODS

In a large sample from the Amish community in Lancaster County, Pennsylvania, age ≥18 years, we assessed the prevalence of self-reported PD diagnosis. For those without self-reported PD diagnosis, we assessed the frequency of PD-related motor symptoms using a 9-item questionnaire that was designed by the PD Epidemiology Research Group. Lastly, we queried study participants for the presence of 2 nonmotor symptoms that have been commonly linked to PD: bowel movement frequency and daytime sleepiness.

RESULTS

Among 2,025 subjects who answered the PD questionnaire, 430 were older than 60 years. Of 430 participants ≥60 years, 5 (1.2%) reported a PD diagnosis. Of those without a PD diagnosis, 10.5% reported ≥1 and 1.2% ≥ 4 motor symptoms for the 9-item PD screening questionnaire. Of the 3,789 subjects who answered the question about bowel movement frequency, 0.7% reported ≤3 bowel movements per week. Among 1,710 subjects who answered the question about daytime sleepiness, 8.1% of the participants reported "always" sleepy during the day.

DISCUSSION

These data neither support a markedly higher PD prevalence in the older Lancaster Amish nor do they show dramatically higher motor and/or selected nonmotor symptoms than the general population. Future studies that employ more rigorous procedures for case identification and PD-specific preclinical symptoms/tests are needed to determine the potential differences and similarities among different Amish populations and between Amish and non-Amish populations.

Validation of Parkinson's Disease-Related Questionnaires in South Africa

Background

There are very few epidemiological studies investigating Parkinson's disease (PD) in Africa. The hundreds of local languages and dialects make traditional screening and clinical evaluation tools difficult to use.

Objective

The objective of the study was to validate two commonly used PD questionnaires in an African population.

Methods

The PD Screening Questionnaire (PDSQ) and Parkinson's Disease Questionnaire (PDQ-39) were modified and translated into Afrikaans, Setswana, and isiZulu and administered to a sample of healthy local residents. We assessed the internal consistencies and cluster characteristics of the questionnaires, using a Cronbach's alpha test and exploratory factor analysis. The questionnaires were then administered to a population-based sample of 416 research participants. We evaluated the correlations between the questionnaires and both a timed motor task and the Unified Parkinson's Disease Rating Scale motor subsection 3 (UPDRS3), using locally weighted scatterplot smoothing (LOWESS) regression analysis and Spearman's rank correlation.

Results

Both questionnaires had high overall internal consistency (Cronbach's alpha = 0.86 and 0.95, respectively). The modified PDQ-39 had evidence of five subscales, with Factor 1 explaining 57% and Factor 2 explaining 14%, of the variance in responses. The PDSQ and PDQ-39 scores were correlated with the UPDRS3 score (ρ = 0.35, P < 0.001; and ρ = 0.28, P < 0.001, respectively).

Conclusion

The translated PDSQ and PDQ-39 questionnaires demonstrated high internal consistency and correlations with clinical severity of parkinsonism and a timed motor task, suggesting that they are valid tools for field-based epidemiological studies.

Translation, Validation, Diagnostic Accuracy, and Reliability of Screening Questionnaire for Parkinsonism in Three African Countries

BACKGROUND

Availability of validated Parkinson's disease (PD) questionnaires in languages spoken in Africa will enable the conduct of epidemiological studies.

OBJECTIVE

The aims of the current study were to develop cross-cultural translated and validated Arabic and French versions of a PD screening questionnaire, and determine its diagnostic accuracy for recognition of parkinsonism in early and moderate-advanced PD in three countries (Cameroon (French), Egypt (Arabic), and Nigeria (English)).

METHODS

This cross-sectional study screened 159 participants (81 PD and 78 controls) using the PD screening questionnaire. The questionnaire was translated into Arabic and French versions using standard protocols. Cognitive function was assessed using the Montreal Cognitive Assessment and the Identification and Intervention for Dementia in Elderly Africans cognitive screen. Co-morbidity burden was documented using the Charlson Comorbidity Index. PD severity and stage were evaluated using the MDS Unified Parkinson Disease Rating Scale and the Hoehn and Yahr scale respectively.

RESULTS

Both PD patients and controls were matched regarding age, gender, education, and co-morbidity burden. The PD screening questionnaire scores were significantly higher in PD (median 8.0, IQR 6.0-10.0) in contrast to controls (0.0, IQR 0.0-0.0) (p < 0.0001), with a similar pattern and level of significance across all country sites. In ROC analysis, the questionnaire demonstrated high diagnostic accuracy for PD overall, with an AUC of 0.992 (95% CI 0.981-1.002).

CONCLUSION

The Arabic, French, and English versions of this PD screening questionnaire are valid and accurate screening instruments for recognition of Parkinsonism. This paves the way for conducting epidemiological studies in many African countries.

The motor prodromes of parkinson's disease: from bedside observation to large-scale application

There is sufficient evidence that the pathological process that causes Parkinson's disease begins years before the clinical diagnosis is made. Over the last 15 years, there has been much interest in the existence of a prodrome in some patients, with a particular focus on non-motor symptoms such as reduced sense of smell, REM-sleep disorder, depression, and constipation. Given that the diagnostic criteria for Parkinson's disease depends on the presence of bradykinesia, it is somewhat surprising that there has been much less research into the possibility of subtle motor dysfunction as a pre-diagnostic pointer. This review will focus on early motor features and provide some advice on how to detect and measure them.

Vascular Parkinsonism in a Tertiary Care Stroke Prevention Clinic and the Development of a New Screening Strategy

OBJECTIVES

To determine the prevalence of vascular parkinsonism (VasP) in a stroke prevention clinic (SPC).

BACKGROUND

VasP can be defined by an onset of parkinsonism with prominent gait problems occurring within 1 year of stroke.

METHODS

We created a screening strategy based on the Tanner Questionnaire (TQ), a validated scale for parkinsonism, and the creation of a 4-point Five-Minute Assessment Scale (FMAS) operationalizing Zijlmans' criteria for the diagnosis of VasP. Consecutive stroke patients were screened over a 12-month period using the TQ and the FMAS. SAS statistical software was used.

RESULTS

Two hundred forty patients (52.5% females) were screened (mean age of 65 years, standard deviation, 14.5). Twenty-five percent of patients had a TQ score ≥ 4 with a median FMAS of 2. In this group, 32.6% (15/46) were found to have parkinsonism. Seventeen percent (8/46) were diagnosed with VasP having an FMAS of 4. Seventy-five of the participants obtained a TQ ≤ 3, with a median FMAS of 1. Only 1 patient in this group had parkinsonism (1.9%; 1/194). Using a cutoff of 4 points in the TQ resulted in a sensitivity of 93.8%, a specificity of 86.2% for parkinsonism, and a sensitivity of 100% with a specificity of 83% for VasP. Patients with FMAS = 4 (VasP) attained higher scores in the TQ with a median of 5 (Spearman rank correlation coefficient for the TQ and the FMAS (r_s) = .447, P < .0005).

CONCLUSIONS

We documented a prevalence of 3% (8/240) for VasP in an SPC. We propose a new, easier, and unified 2-step TQ-FMAS screening strategy for this condition.

A screening tool to detect clinical manganese neurotoxicity

Manganese (Mn) over-exposure in occupational settings is associated with basal ganglia toxicity and a movement disorder characterized by parkinsonism (i.e., the signs and symptoms of Parkinson disease). A simple test to help non-neurologists identify workers with clinical Mn neurotoxicity represents an unmet need. In a cohort of Mn-exposed workers from welding worksites, with extensive clinical data, we developed a linear regression model to predict the Unified Parkinson Disease Rating Scale motor subsection part 3 (UPDRS3) score. We primarily considered factors easily obtained in a primary care or occupational medicine clinic, specifically easily assessed signs of parkinsonism and factors likely to be associated with UPDRS3 such as age, timed motor task results, and selected symptoms/conditions. Secondarily we considered other demographic variables and welding exposure. We based the model on 596 examined workers age≤65years and with timed motor task data. We selected the model based on simplicity for clinical application, biologic plausibility, and statistical significance and magnitude of regression coefficients. The model contained age, timed motor task scores for each hand, and indicators of action tremor, speech difficulty, anxiety, depression, loneliness, pain and current cigarette smoking. When we examined how well the model identified workers with clinically significant parkinsonism (UPDRS3≥15) the receiver operating characteristic area under the curve (AUC) was 0.72 (95% confidence interval [CI] 0.67, 0.77). With a cut point that provided 80% sensitivity, specificity was 52%, the positive predictive value in our cohort was 29%, and the negative predictive value was 92%. Using the same cut point for predicted UPDRS3, the AUC was nearly identical for UPDRS3≥10, and was 0.83 (95% CI 0.76, 0.90) for UPDRS3≥20. Since welding exposure data was not required after including its putative effects, this model may help identify workers with clinically significant Mn neurotoxicity in a variety of settings, as a first step in a tiered occupational screening program.

Prevalence and associated comorbidities of restless legs syndrome (RLS): Data from a large population-based door-to-door survey on 19176 adults in Tehran, Iran

BACKGROUND

Discrepancies have been reported in the prevalence rate of restless legs syndrome (RLS) among different ethnic groups and geographic populations. Furthermore, there are disagreements on determinant factors and associated comorbidities of RLS. We aimed to estimate prevalence of RLS and investigate its associated comorbid conditions and risk factors in a large population-based door-to-door survey.

METHODS

Following a multistage random sampling from the households lived in 22 urban districts of Tehran, Iran, 19176 participants with ≥30 years of age were recruited. Trained surveyors filled study checklist consisting of baseline characteristics, risk factors and comorbidity profile and the International RLS Study Group (IRLSSG) diagnostic criteria through face-to-face interviews.

RESULTS

In total, 1580 individuals were positively screened for RLS resulting in a standardized prevalence rate of 60.0/1000. There was a gradual increase in RLS prevalence by advancing age, however, sex difference disappeared after adjustment. Parkinsonism [adjusted odds' ratio (adj-OR) = 7.4 (95% CI: 5.3-10.4)], peripheral neuropathy [adj-OR = 3.7 (95% CI: 3.3-4.1)], subjective cognitive impairment (SCI) [adj-OR = 3.1 (95% CI: 2.7-3.4)], acting out dreams [adj-OR = 2.8 (95% CI: 2.5-3.2)], hyposmia [adj-OR = 2.5 (95% CI: 2.2-2.9)], active smoking [adj-OR = 1.5 (95% CI: 1.3-1.9)] and additional number of cardiometabolic diseases associated with higher risk of RLS [adj-OR = 1.6 (95% CI: 1.2-2.3)].

CONCLUSION

Our findings showed that neuro-cognitive co-morbidities such as parkinsonism, peripheral neuropathy, SCI, acting out dreams and hyposmia as well as cardio-metabolic risk factors and diseases were independent determinants of RLS. It is recommended to screen individuals with either these comorbid conditions for RLS or the ones with RLS for the accompanying diseases.

Micrographia, much beyond the writer's hand

INTRODUCTION

This review on micrographia aims to draw the clinician's attention to non-Parkinsonian etiologies, provide clues to differential diagnosis, and summarize current knowledge on the phenomenology, etiology, and mechanisms underlying micrographia.

METHODS

A systematic review of the existing literature was performed.

RESULTS

Micrographia, namely small sized handwriting has long been attributed to Parkinson's disease. However, it has often been observed as part of the clinical picture of additional neurodegenerative disorders, sometimes antedating the motor signs, or following focal basal ganglia lesions without any accompanying parkinsonism, suggesting that bradykinesia and rigidity are not sine-qua-non for the development of this phenomenon. Therefore, micrographia in a patient with no signs of parkinsonism may prompt the clinician to perform imaging in order to exclude a focal basal ganglia lesion. Dopaminergic etiology in this and other cases is doubtful, since levodopa ameliorates letter stroke size only partially, and only in some patients. Parkinsonian handwriting is often characterized by lack of fluency, slowness, and less frequently by micrographia. Deviations from kinematic laws of motion that govern normal movement, including the lack of movement smoothness and inability to scale movement amplitude to the desired size, may reflect impairments in motion planning, possible loss of automaticity and reduced movement vigor.

CONCLUSIONS

The etiology, neuroanatomy, mechanisms and models of micrographia are discussed. Dysfunction of the basal ganglia circuitry induced by neurodegeneration or disruption by focal damage give rise to micrographia.

A door-to-door survey to estimate the prevalence of Parkinsonism in Pakistan

INTRODUCTION

Parkinson's disease (PD) occurs in all races and cultures, and population-related differences in frequency may provide etiological clues. The present study was designed to explore the prevalence of PD and Parkinsonism in Pakistan, the world's sixth most populous country, for which no published prevalence data are available.

METHODS

We conducted a three-phase door-to-door survey in two districts of the Khyber Pakhtunkhwa province of Pakistan, to assess the prevalence of PD and Parkinsonism in a sample of 4,000 individuals aged 50 years and above.

RESULTS

We identified 14 cases of Parkinsonism, eleven with a diagnosis of idiopathic PD. The overall prevalence estimates were 1.7/100 (95% confidence interval [CI]: 0.9-2.46) for Parkinsonism and 1.28/100 (95% CI: 0.6-1.94) for PD in persons aged 65 years and above. The age-standardized prevalence of PD (aged 65 years and above), normalized to the USA population in 2000, was 1.33/100, which is similar to that observed in other human populations. Of the total 14 cases, five were newly diagnosed and four had a family history of PD.

CONCLUSION

The estimated prevalence rates in Pakistan are similar to those observed in other human populations. The frequency of familial Parkinsonism is also equivalent to previous estimates.

Neural correlates underlying micrographia in Parkinson's disease

Micrographia is a common symptom in Parkinson's disease, which manifests as either a consistent or progressive reduction in the size of handwriting or both. Neural correlates underlying micrographia remain unclear. We used functional magnetic resonance imaging to investigate micrographia-related neural activity and connectivity modulations. In addition, the effect of attention and dopaminergic administration on micrographia was examined. We found that consistent micrographia was associated with decreased activity and connectivity in the basal ganglia motor circuit; while progressive micrographia was related to the dysfunction of basal ganglia motor circuit together with disconnections between the rostral supplementary motor area, rostral cingulate motor area and cerebellum. Attention significantly improved both consistent and progressive micrographia, accompanied by recruitment of anterior putamen and dorsolateral prefrontal cortex. Levodopa improved consistent micrographia accompanied by increased activity and connectivity in the basal ganglia motor circuit, but had no effect on progressive micrographia. Our findings suggest that consistent micrographia is related to dysfunction of the basal ganglia motor circuit; while dysfunction of the basal ganglia motor circuit and disconnection between the rostral supplementary motor area, rostral cingulate motor area and cerebellum likely contributes to progressive micrographia. Attention improves both types of micrographia by recruiting additional brain networks. Levodopa improves consistent micrographia by restoring the function of the basal ganglia motor circuit, but does not improve progressive micrographia, probably because of failure to repair the disconnected networks.

Motor automaticity in Parkinson's disease

Bradykinesia is the most important feature contributing to motor difficulties in Parkinson's disease (PD). However, the pathophysiology underlying bradykinesia is not fully understood. One important aspect is that PD patients have difficulty in performing learned motor skills automatically, but this problem has been generally overlooked. Here we review motor automaticity associated motor deficits in PD, such as reduced arm swing, decreased stride length, freezing of gait, micrographia and reduced facial expression. Recent neuroimaging studies have revealed some neural mechanisms underlying impaired motor automaticity in PD, including less efficient neural coding of movement, failure to shift automated motor skills to the sensorimotor striatum, instability of the automatic mode within the striatum, and use of attentional control and/or compensatory efforts to execute movements usually performed automatically in healthy people. PD patients lose previously acquired automatic skills due to their impaired sensorimotor striatum, and have difficulty in acquiring new automatic skills or restoring lost motor skills. More investigations on the pathophysiology of motor automaticity, the effect of L-dopa or surgical treatments on automaticity, and the potential role of using measures of automaticity in early diagnosis of PD would be valuable.

From micrographia to Parkinson's disease dysgraphia

Micrographia, an abnormal reduction in writing size, is a specific behavioral deficit associated with Parkinson's disease (PD). In recent years, the availability of graphic tablets has made it possible to study micrographia in unprecedented detail. Consequently, a growing number of studies show that PD patients also exhibit impaired handwriting kinematics. Is micrographia still the most characteristic feature of PD-related handwriting deficits? To answer this question, we identified studies that investigated handwriting in PD, either with conventional pencil-and-paper measures or with graphic tablets, and we reported their findings on key spatiotemporal and kinematic variables. We found that kinematic variables (velocity, fluency) differentiate better between control participants and PD patients, and between off- and on-treatment PD patients, than the traditional measure of static writing size. Although reduced writing size is an important feature of PD handwriting, the deficit is not restricted to micrographia stricto sensu. Therefore, we propose the term PD dysgraphia, which encompasses all deficits characteristic of Parkinsonian handwriting. We conclude that the computerized analysis of handwriting movements is a simple and useful tool that can contribute to both diagnosis and follow-up of PD.

Screening for early detection of parkinsonism using a self-administered questionnaire: a cross-sectional epidemiologic study

BACKGROUND

Manganese (Mn) is a common component of welding fume. Exposure to Mn fume has been associated with parkinsonism. A simple and reliable screening tool to evaluate Mn exposed workers for neurotoxic injury would have broad occupational health application.

METHODS

This study investigated 490 occupational welders recruited from a trade union list. Subjects were examined by a movement disorders specialist using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3). Parkinsonism, intermediate, and normal groups were defined as UPDRS3 score ≥ 15, 6-15, and <6, respectively. Workers completed a health status questionnaire (PDQ39) and a Parkinson disease (PD) Symptoms Questionnaire. Areas under receiver operator curve (AUC) were analyzed based on these scores, adjusted for age, smoking, race, gender, and neurologist, using normal as the reference.

RESULTS

The AUC was 0.79 (95% confidence interval [CI]=0.73-0.84) for PDQ39 and 0.78 (95% CI=0.72-0.85) for PD Symptoms Questionnaire score. At 70% sensitivity, the specificity for PDQ39 score and PD Symptoms Questionnaire score for the prediction of parkinsonism was 73.1% and 80.1%, respectively.

CONCLUSIONS

These results suggest the questionnaires have reasonably good sensitivity and specificity to predict parkinsonism in Mn exposed workers. These questionnaires could be a valuable first step in a tiered screening approach for Mn exposed workers.

Validating chronic disease ascertainment algorithms for use in the Canadian longitudinal study on aging

We validated seven chronic disease ascertainment algorithms for use in the Canadian Longitudinal Study on Aging. The algorithms pertained to diabetes mellitus type 2, parkinsonism, chronic airflow obstruction (CAO), hand osteoarthritis (OA), hip OA, knee OA, and ischemic heart disease. Our target recruitment was 20 cases and controls per disease; some cases were controls for unrelated diseases. Participants completed interviewer-administered disease symptom and medication use questionnaires. Diabetes cases and controls underwent fasting glucose testing; CAO cases and controls underwent spirometry testing. For each disease, the appropriate algorithm was used to classify participants' disease status (positive or negative for disease). We also calculated sensitivity and specificity using physician diagnosis as the reference standard. The final sample involved 176 participants recruited in three Canadian cities between 2009 and 2011. Most estimated sensitivities and specificities were 80 per cent or more, indicating that the seven algorithms correctly identified individuals with the target disease.

Parkinson's disease in patients and obligate carriers of Gaucher disease

BACKGROUND

Gaucher disease is an autosomal recessive disorder caused by glucocerebrosidase gene mutations. Accumulating evidence from several Parkinson's disease cohorts of varying ethnicities suggests that glucocerebrosidase mutations even in the heterozygous state (carriers) may be a susceptibility factor for Parkinson's. Very few studies have analyzed the frequency of Parkinson's in carriers and individuals with Gaucher disease.

OBJECTIVE

To determine frequency of Parkinson's in patients with Gaucher disease and obligate carriers of glucocerebrosidase mutations and compare it with a control group.

METHODS

A questionnaire was completed by 100 Ashkenazi Jewish Gaucher patients followed at our center and 109 ethnicity-matched controls with no personal or family history of Gaucher disease.

RESULTS

Frequency of Parkinson's was higher in Gaucher patients (8/100) than in controls (0/109; P = 0.0024). Frequency of Parkinson's in obligate carriers (11/200) was higher than controls (6/218), but the difference was not statistically significant (P = 0.215). Average age of onset of Parkinson's was earlier in Gaucher patients (57.2) than the general population and in obligate carriers (60) when compared with controls (76.8; P = 0.01). The L444P genotype was more frequent in Gaucher patients who reported a parent with Parkinson's (36.40%) than those who did not (4.50%).

CONCLUSION

Our study suggests that the risk for developing Parkinson's may be higher in affected versus carriers of glucocerebrosidase mutations and suggests that L444P may pose a higher risk of developing Parkinson's than other mutations. It also confirms previous findings that the age of onset of Parkinson's associated with glucocerebrosidase mutations is earlier than in the general population.

Can a screening questionnaire accurately identify mild Parkinsonian signs?

BACKGROUND

Mild parkinsonian signs (MPS) are early features that, when present, increase the risk of neurodegenerative disease and mortality. Current methods to identify MPS are limited to neurological examination. Our objective was to assess the ability of a 9-item Parkinson's Disease Screening Questionnaire (PDSQ), which has high sensitivity in the detection of overt Parkinson's disease (PD), to detect MPS.

METHODS

Measures including the PDSQ, Unified Parkinson's Disease Rating Scale and University of Pennsylvania Smell Identification Test were administered to 267 participants without neurodegenerative disease. Two published definitions of MPS were used to classify cases.

RESULTS

PDSQ scores were higher for cases compared to controls (p < 0.001 for the first case definition and 0.07 for the second). However, the questionnaire had low sensitivity (47 and 59%) and specificity (62 and 63%) in the detection of MPS. Adding factors such as age, gender and smell test score to the questionnaire in a predictive model only marginally improved the test characteristics.

CONCLUSION

The results show the screening questionnaire does not accurately identify MPS. More accurate tests are needed to improve the detection of this early syndrome which can lead to motor disability, neurodegenerative disease and mortality.

Comparing three screening tools for drug-induced parkinsonism in patients with advanced schizophrenia: a pilot study

BACKGROUND

Drug-induced parkinsonism (DIP) is seen in one third of patients exposed to antipsychotic drugs and may lead to complications related to dysphagia and falls. Aside from skilled neurological examination, no tool has been validated to facilitate detection and follow-up.

OBJECTIVE

In this pilot study, three validated screening instruments were tested in an age-biased cohort of schizophrenia patients, including four items of the Liverpool University Neuroleptic Side-Effects Rating Scale (LUNSERS) and two brief questionnaires designed for community survey of parkinsonism.

METHOD

Fifty-six subjects living with chronic schizophrenia between 50 and 75 years of age underwent a motor evaluation along the original Unified Parkinson's Disease Rating Scale-section III and answered questions along the selected screening instruments, and results compared to those of 16 patients with Parkinson's disease (PD) and 15 neurologically unimpaired volunteers. Odds ratios, sensitivity, specificity, and their 95% confidence intervals, were calculated.

RESULTS

All three screening instruments correctly identified the PD state and distinguished PD from healthy participants. Eighteen (32%) schizophrenic patients displayed objective motor signs of parkinsonism. A single item of the LUNSERS (shakiness) significantly distinguished DIP from DIP-free patients, with a sensitivity of 61.1% and a specificity of 83.3%. The positive predictive value was 63.5% and the negative predictive value was 81.9%. The two other screening methods showed insufficient predictive value.

CONCLUSION

Apart from a single query on shakiness, none of the tools examined were adequate to screen for DIP in patients treated for schizophrenia. A different instrument is necessary to monitor this important adverse effect in schizophrenia.

Motor signs in the prodromal phase of Parkinson's disease

Relatively subtle deterioration of the motor system likely occurs well before the patient meets established motor criteria for a clinical diagnosis of Parkinson's disease; ie, the occurrence of at least 2 of the cardinal motor deficits: bradykinesia, rigidity, tremor, and/or postural instability. Powerful compensatory mechanisms may mask these clinical symptoms and make them difficult to identify and evaluate in the earliest stages of the illness. This review summarizes our current knowledge of motor signs that are thought to occur in the prodromal phase of Parkinson's disease and suggests how motor assessment batteries could be designed to detect these subclinical motor deficits with a high degree of accuracy and sensitivity.

Impaired olfaction and other prodromal features in the Parkinson At-Risk Syndrome Study

To test the association between impaired olfaction and other prodromal features of PD in the Parkinson At-Risk Syndrome Study. The onset of olfactory dysfunction in PD typically precedes motor features, suggesting that olfactory testing could be used as a screening test. A combined strategy that uses other prodromal nonmotor features, along with olfactory testing, may be more efficient than hyposmia alone for detecting the risk of PD. Individuals with no neurological diagnosis completed a mail survey, including the 40-item University of Pennsylvania Smell Identification Test, and questions on prodromal features of PD. The frequency of reported nonmotor features was compared across individuals with and without hyposmia. A total of 4,999 subjects completed and returned the survey and smell test. Of these, 669 were at or below the 15th percentile based on age and gender, indicating hyposmia. Hyposmics were significantly more likely to endorse nonmotor features, including anxiety and depression, constipation, and rapid eye movement sleep behavior disorder symptoms, and to report changes in motor function. Twenty-six percent of subjects with combinations of four or more nonmotor features were hyposmic, compared to 12% for those reporting three or fewer nonmotor features (P < 0.0001). Hyposmia is associated with other nonmotor features of PD in undiagnosed individuals. Further assessment of hyposmic subjects using more specific markers for degeneration, such as dopamine transporter imaging, will evaluate whether combining hyposmia and other nonmotor features is useful in assessing the risk of future neurodegeneration.

Micrographia and related deficits in Parkinson's disease: a cross-sectional study

OBJECTIVES

To determine the prevalence and clinical features associated with micrographia in Parkinson's Disease (PD).

SETTING

This study was conducted at a Movement Disorders clinic located in a Veteran Administration Hospital.

PARTICIPANTS

PD subjects were included only if they satisfied UK Parkinson's Disease Society criteria for diagnosis. Subjects with history of severe tremors, dystonia, dyskinesia, strokes, peripheral neuropathy and dementia were excluded.

DESIGN

This was a case-control study where PD subjects were prospectively enrolled and their demographics, Hoehn & Yahr stage, Unified Parkinson's Disease Rating Scale and Mini Mental Status examination (MMSE) scores were recorded. All subjects were specifically asked for micrographia on history and the handwritings were quantitatively documented. Bradykinesia was determined by history and quantified by a finger tap, Purdue pegboard and a timed walk test. Similarly, hypophonia was determined by history and the volume of speech quantified using a decibel meter. Controls were enrolled for validation of handwriting test scores and decibel meter recordings.

PRIMARY OUTCOME MEASURES

Prevalence of micrographia in the PD cohort and the clinical factors that correlate with micrographia.

RESULTS

68 subjects with PD were enrolled (68 men; mean age 72.3 years). Micrographia was identified in 63.2% of the cohort on verbal history and in 50% of the cohort when the handwriting test was used for ascertainment. Micrographia ascertained on history correlated significantly with disease severity (Hoehn & Yahr stage), motor impairment (Unified Parkinson's Disease Rating Scale), cognitive impairment (MMSE) and both bradykinesia and hypophonia determined by history and quantitative testing. Micrographia on handwriting test correlated with age (p=0.02), MMSE testing (p=0.04), hypophonia by history (p=0.01) and bradykinesia by quantitative testing (p=0.04).

CONCLUSION

Micrographia was found in nearly half of the PD cohort. Disease severity and impaired cognition were important clinical correlates. Micrographia had a significant relationship with bradykinesia and hypophonia, suggesting a possible overlap in their pathophysiology.

Screening questionnaires for parkinsonism: a systematic review

Parkinson's disease (PD) is a common, treatable movement disorder that often remains undiagnosed despite clinically manifest symptoms. Screening for parkinsonism could lead to improved detection and earlier treatment, and facilitate research studies of PD prevalence. In order to determine the feasibility of screening, this study evaluated the validity of previously developed screening questionnaires. We systematically searched online databases PubMed and EMBASE for English-language studies published between 1980 and 2009. In each database a "Parkinson(s) disease" or "parkinsonism" term was combined with a screening term ("screening instrument," "screening questionnaire," "screen" or "prevalence survey") and a validity term ("validation," "sensitivity" and "specificity"). Included studies reported the psychometric properties of at least one self-report questionnaire for parkinsonism. Twenty-seven studies met the inclusion criteria. From these studies, 9 screening questionnaires were identified. Sensitivity and specificity estimates varied widely. Sensitivity estimates were as high as 100% when questionnaires were tested among previously diagnosed PD patients and included a high number of parkinsonism specific items, but were as low as 48% when tested among early cases in a community-based sample. Specificity estimates were lower, ranging from 22 to 100%. An older sample, presence of multiple co-morbid conditions and lower literacy led to lower specificity estimates. Higher specificity estimates were seen when the screening questionnaires were administered by a physician. Screening questionnaires can detect symptomatic parkinsonism. However, the performance of these questionnaires varied based on the individual items, study sample, and method of administration. The performance of screening questionnaires in the detection of early or mild parkinsonism was modest.

Short questionnaire for Parkinson's disease as a screening instrument

OBJECTIVE

To validate and simplify a screening questionnaire for the determination of PD.

METHODS

The screening questionnaire for PD was developed with the permission of the author. Reliability of the questionnaire was tested. To validate the questionnaire, 40 patients with PD and 93 controls completed the questionnaire. Multiple logistic regression analysis was used to determine the questions independently associated with PD and a risk score was calculated. The predictive performance of the risk score was evaluated via the area under the curve (AUC) of a receiver operating characteristics (ROC) curve.

RESULTS

The questionnaire showed a Cronbach's alpha coefficient of 0.73 with no difference between the initial and follow up scores. The mean content validity was 0.86. Of the 11 questions, 4 were independently associated with PD and were used to calculate the risk score. The scores of these questions were 2 (clumsiness)+4 (tremor)+2 (masked face)+2 (loss of balance while turning). The AUC of a ROC curve for the sum of risk score was 0.95. With a cutoff score of 5 or higher, the sensitivity and specificity were 0.88 and 0.95, respectively.

CONCLUSIONS

The screening questionnaire for PD is a reliable and valid instrument. The predictive performance of the simplified questionnaire is as good as the original.

Effects of parkinsonism on health status in welding exposed workers

BACKGROUND

Previous studies suggest that welders frequently display parkinsonian signs, such as bradykinesia and tremor. Demonstrating that these parkinsonian findings are associated with reductions in quality of life (QoL) or health status could have important repercussions for worker safety and performance.

METHODS

Subjects included 394 active workers exposed to welding fumes and evaluated for parkinsonism by movement disorders experts in a worksite-based epidemiology study. Subjects were diagnosed with parkinsonism if the Unified Parkinson Disease Rating Scale motor subsection part 3 (UPDRS3) score was ≥15. All subjects completed a Parkinson's disease (PD) symptom questionnaire and the PDQ39, a widely used QoL and health status measure for PD.

RESULTS

Total PDQ39 score and all subscores were greater in welders with parkinsonism than welders without parkinsonism, with the most significant differences observed for mobility, emotional well-being, and activities of daily living (ADL's). The PDQ39 scores for welding exposed workers with parkinsonism were similar to scores seen in a group of early PD patients.

CONCLUSION

Parkinsonism in active, welding exposed workers is associated with reductions in health status and QoL affecting a broad range of categories and within the range seen in early PD.

The validity and reliability of a screening questionnaire for Parkinson's disease in a community

OBJECTIVES

Parkinson's disease is one of the most common neurodegenerative diseases in the elderly population. In order to estimate the prevalence of Parkinson's disease in the community, the application of a good screening tool is essential. We evaluated the validity and reliability of a Parkinson's disease screening questionnaire and propose an alternative measure to improve its validity for use in community surveys.

METHODS

We designed the study in a three-phase approach consisting of a screening questionnaire, neurologic examination, and confirmatory examination. A repeated survey was administered to patients with disease detected in the community and on 150 subjects. We examined internal consistency using Cronbach's alpha test, test-retest reliability using the kappa statistic, and validity using sensitivity, specificity, and ROC curves. Unadjusted odds ratios were utilized for the estimation of weights for each questionnaire item.

RESULTS

The Cronbach's alpha of the questionnaire was 0.708. The kappa statistic for test-retest reliability was good to generally fair in most of the items. When newly proposed weighting scores were used, the optimum cut-off value was 7/8. When cut-off value was 5/6 for surveying prevalence in a community, the sensitivity was 0.98, and the specificity was 0.61, with simultaneous improvement in reliability.

CONCLUSIONS

We recommend 5/6 as the ideal cut-off value for the survey of PD prevalence in community. This questionnaire designed for the Korean community could help future epidemiologic studies of PD.

Small CGG repeat expansion alleles of FMR1 gene are associated with parkinsonism

Fragile X-associated tremor/ataxia syndrome (FXTAS) affects older males carrying premutation, that is, expansions of the CGG repeat (in the 55-200 range), in the FMR1 gene. The neurological changes are linked to the excessive FMR1 messenger RNA (mRNA), becoming toxic through a 'gain-of-function'. Because elevated levels of this mRNA are also found in carriers of the smaller expansion (grey zone) alleles, ranging from 40 to 54 CGGs, we tested for a possible role of these alleles in the origin of movement disorders associated with tremor. We screened 228 Australian males affected with idiopathic Parkinson's disease and other causes of parkinsonism recruited from Victoria and Tasmania for premutation and grey zone alleles. The frequencies of either of these alleles were compared with the frequencies in a population-based sample of 578 Guthrie spots from consecutive Tasmanian male newborns (controls). There was a significant excess of premutation carriers (Fisher's exact test p = 0.006). There was also a more than twofold increase in grey zone carriers in the combined sample of the Victorian and Tasmanian cases, with odds ratio (OR ) = 2.36, and 95% confidence intervals (CI): 1.20-4.63, as well as in Tasmanian cases only (OR = 2.33, 95% CI: 1.06-5.13), compared with controls. The results suggest that the FMR1 grey zone alleles, as well as premutation alleles, might contribute to the aetiology of disorders associated with parkinsonism.

A population-based study of parkinsonism in an Amish community

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder with unknown cause. Genetic mutations account for a minority of cases but the role of environmental factors is unclear.

METHODS

We performed a population-based screening for PD in subjects in an Amish community over age 60. PD was diagnosed using standard clinical criteria and the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3). Community prevalence was calculated. We constructed a community pedigree and calculated kinship coefficients, a measure of relatedness between 2 subjects, for every pair of subjects in diagnostic categories: clinically definite PD, UPDRS3 score >9, Mini-Mental State Exam (MMSE) score <25, and normal.

RESULTS

Of 262 eligible subjects, 213 agreed to participate, 15 had PD, 43 had MMSE <25, 73 had UPDRS3 >9. The prevalence of PD was 5,703/100,000 with increasing prevalence in every decade of age. Excluding first-degree relatives, normal subjects were more related to each other (0.0102, SD = 0.0266) than subjects with clinically definite PD (0.0054, SD = 0.0100; p = 0.00003), subjects with UPDRS >9 (0.0076, SD = 0.0155; p = 0.00001), and subjects with MMSE <25 (0.0090, SD = 0.0180; p = 0.00003).

CONCLUSIONS

PD and parkinsonian signs are common in this population and the prevalence increases with age. The finding that subjects with PD were not more related than normal subjects suggests that environmental factors may contribute to the parkinsonian phenotype in this community.

Validity and reliability of an occupational exposure questionnaire for parkinsonism in welders

This study assessed the validity and test-retest reliability of a medical and occupational history questionnaire for workers performing welding in the shipyard industry. This self-report questionnaire was developed for an epidemiologic study of the risk of parkinsonism in welders. Validity participants recruited from three similar shipyards were asked to give consent for access to personnel files and complete the questionnaire. Responses on the questionnaire were compared with information extracted from personnel records. Reliability participants were recruited from the same shipyards and were asked to complete the questionnaire at two different times approximately 4 weeks apart. Percent agreement, kappa, intraclass correlation coefficient (ICC), and sensitivity and specificity were used as measures of validity and/or reliability. Personnel files were obtained for 101 of 143 participants (70%) in the validity study, and 56 of the 95 (58.9%) participants in the reliability study completed the retest of the questionnaire. Validity scores for items extracted from personnel files were high. Percent agreement for employment dates and job titles ranged from 83-100%, while ICC for start and stop dates ranged from 0.93-0.99. Sensitivity and specificity for current job title ranged from 0.5-1.0. Reliability scores for demographic, medical and health behavior items were mainly moderate or high, but ranged from 0.19 to 1.0. Most recent job/title items such as title, types of welding performed, and material used showed substantial to perfect agreement. Certain determinants of exposure such as days and hours per week exposed to welding fumes demonstrated mainly moderate agreement (kappa= 0.42-0.47, percent agreement 63-77%); however, mean days and hours reported did not differ between test and retest. The results of this study suggest that participants' self-report for job title and dates employed are valid compared with employer records. While kappa scores were low for some medical conditions and for caffeine consumption, high kappa scores for job title, dates worked, types of welding, and materials welded suggest participants generated reproducible answers important for occupational exposure assessment.

Complete ascertainment of Parkinson disease in the Swedish Twin Registry

This report describes the ascertainment of Parkinson disease (PD) in all individuals aged 50 years or older (49,814 individuals) from the Swedish Twin Registry. In phase one of the study, all twins were screened for PD using telephone interviews, with a response rate of 72.7%. In phase two, twins with suspected PD were re-contacted to exclude anyone from follow-up who reported parkinsonian symptoms due to diseases other than PD. In the third phase, in-person clinical evaluations were completed for twins who were still considered PD suspects after phase two and for a sample of co-twins. During the clinical evaluations, we also collected blood samples and information about a variety of environmental exposures. Overall prevalence rate for PD was 496 per 100,000 individuals. Among the 132 PD cases identified, there were only three concordant twin pairs. In total 7.2% of PD cases reported a first degree relative with PD.

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.

[18F]FDOPA PET as an endophenotype for Parkinson's Disease linkage studies

Parkinson disease (PD) is a late onset disorder with age-dependent penetrance that may confound genetic studies, since affected individuals may not demonstrate clinical manifestations at the time of evaluation. The use of endophenotypes, biologic surrogates for clinical disease diagnoses, may permit more accurate classification of at-risk subjects. Positron emission tomography (PET) measurements of 6-[18F]fluorodopa ([18F]FDOPA) uptake indicate nigrostriatal neuronal integrity and may provide a useful endophenotype for PD linkage studies. We performed [18F]FDOPA PET in 11 members of a large, multi-incident Amish family with PD, 24 normals and 48 people with clinically definite idiopathic PD (PD controls). Clinical diagnoses in the Amish were clinically definite PD in four, clinically probable in one, clinically possible in five, and normal in one. Abnormal [18F]FDOPA posterior putamen uptake was defined as less than 3 standard deviations below the normal mean. The criteria were applied to the Amish sample to determine a PET endophenotype for each. We performed genetic simulations using SLINK to model the effect phenoconversion with the PET endophenotype had on logarithm of odds (LOD) scores. PET endophenotype confirmed the status of two clinically definite subjects. Two clinically definite Amish PD subjects had normal PETs. Two possible PD were converted to "PET definite PD." The remainder had normal PETs. The average maximum LOD score with the pre-PET was 6.14 +/- 0.84. Simulating phenoconversion of subjects with unknown phenotypes increased the LOD score to 7.36 +/- 1.23. The [18F]FDOPA PET endophenotype permits phenoconversion in multi-incident PD families and may increase LOD score accuracy and power of an informative pedigree.

Validity of a modified Parkinson's disease screening questionnaire in India: effects of literacy of participants and medical training of screeners and implications for screening efforts in developing countries

The prevalence of Parkinson's disease (PD) is low among Indians, except in the Parsis. Data for Indians come from studies using different screening tools and criteria to detect PD. An epidemiological study in India, which has nearly a billion people, more than 18 spoken languages, and varying levels of literacy, requires development and validation of a screening tool for PD. The objectives of this study are to (1) validate a modified version of a widely used screening questionnaire for PD to suit the needs of the Indian population; (2) compare the use of a nonmedical assistant (NMA) with the use of a medical person during screening; and (3) compare the effect of literacy of participants on the validity of the screening tool. The validity of the questionnaire was tested on 125 participants from a home for the elderly. NMAs of similar background and medical personnel administered the modified screening questionnaire. A movement disorder neurologist blind to the responses on the questionnaire, examined participants independently and diagnosed if participants had PD. The questionnaire was validated in the movement disorders clinic, on known PD patients and their family members without PD. In the movement disorders clinic, sensitivity and specificity of the questionnaire were 100% and 89%, respectively. Fifty-seven participants were included for analysis. The questionnaire had a higher sensitivity when NMAs (75%) rather than the medical personnel (61%) administered it, and its specificity was higher with the medical personnel (61%) than with NMAs (55% and 25%). The questionnaire had a higher specificity in literates than illiterates, whereas sensitivity varied considerably. The modified questionnaire translated in a local Indian language had reasonable sensitivity and can be used to screen individuals for PD in epidemiological studies in India. This questionnaire can be administered by NMAs to screen PD and this strategy would reduce manpower costs. Literacy may influence epidemiological estimates when screening PD.

Screening for undiagnosed parkinsonism in people aged 65 years and over in the community

We screened a random sample of 2449 people aged 65 years and over for undiagnosed parkinsonism, using a postal screening questionnaire followed by clinical neurological assessment. Amongst the 1556 (63.5%) patients who responded, four patients with previously undiagnosed parkinsonism were identified, suggesting a prevalence of 257 per 100,000 (95% CI 70, 658) in this age-group. Although only small, the numbers were sufficient to significantly increase the incidence of parkinsonism in an incidence study. Two simple screening questions achieved a high sensitivity for newly diagnosed parkinsonism of 95%, but a low specificity of 28%.

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.

Self-reported parkinsonian symptoms in the EPIC-Norfolk cohort

BACKGROUND

Parkinsonian symptoms have been associated with increased morbidity and mortality. Several studies have reported on the prevalence of signs and symptoms. Symptoms questionnaires can identify potential PD cases for further neurological examination to save resources. They can also provide information about how much of the population reports specific signs and symptoms. The objective of the study was to determine the self-reported prevalence of parkinsonian symptoms from a questionnaire, and to examine their association with age and self-reported Parkinson's disease in a large cohort.

METHODS

A cross-sectional study was conducted within a sub-cohort of the EPIC-Norfolk (European Prospective Investigation of Cancer) cohort study.

RESULTS

The prevalence of six self-reported parkinsonian symptoms are reported for 11,539 individuals who answered all symptoms questions (62% of sub-cohort): rest tremor (4%), difficulty starting to walk (4%), difficulty getting out of a chair (6%), slower walking (34%), smaller handwriting (micrographia- 9%), and less acute sense of smell (olfactory dysfunction- 9%). The presence of individual symptoms increased with age except for difficulty getting out of a chair.

CONCLUSION

The results support previous findings that the presence of self-reported parkinsonian symptoms is strongly associated with age and self-reported PD diagnosis. The data also provide information regarding the prevalence of symptoms in a large, younger population of adults than previously reported in the literature.