Intermediate scale for assessment of Parkinson's disease. Characteristics and structure

Long-Term Effects of Subthalamic Stimulation on Motor Symptoms and Quality of Life in Patients with Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting both motor functions and quality of life (QoL). This study compared motor symptoms and QoL in patients with PD before and at 1 and 5 years after subthalamic nucleus deep brain stimulation (STN-DBS) surgery in Taiwan. This study included 53 patients with PD undergoing STN-DBS. The motor symptoms improved by 39.71 ± 26.52% and 18.83 ± 37.15% in the Unified Parkinson's Disease Rating Scale (UPDRS) part II and by 36.83 ± 22.51% and 22.75 ± 36.32% in the UPDRS part III at 1 and 5 years after STN-DBS in the off-medication/on-stimulation state, respectively. The Hoehn and Yahr stage significantly improved at the 1-year follow-up but declined progressively and returned to the baseline stage 5 years post-surgery. The Schwab and England Activities of Daily Living improved and sustained for 5 years following STN-DBS. Levodopa equivalent daily dose decreased by 35.32 ± 35.87% and 15.26 ± 65.76% at 1 and 5 years post-surgery, respectively. The QoL revealed significant improvement at 1 year post-surgery; however, patients regressed to near baseline levels 5 years post-surgery. The long-term effects of STN-DBS on motor symptoms were maintained over 5 years after STN-DBS surgery. At the same time, STN-DBS had no long-lasting effect on QoL. The study findings will enable clinicians to become more aware of visible and invisible manifestations of PD.

Clinical Assessments in Parkinson's Disease: Scales and Monitoring

Measurement of disease state is essential in both clinical practice and research in order to assess the severity and progression of a patient's disease status, effect of treatment, and alterations in other relevant factors. Parkinson's disease (PD) is a complex disorder expressed through many motor and nonmotor manifestations, which cause disabilities that can vary both gradually over time or come on suddenly. In addition, there is a wide interpatient variability making the appraisal of the many facets of this disease difficult. Two kinds of measure are used for the evaluation of PD. The first is subjective, inferential, based on rater-based interview and examination or patient self-assessment, and consist of rating scales and questionnaires. These evaluations provide estimations of conceptual, nonobservable factors (e.g., symptoms), usually scored on an ordinal scale. The second type of measure is objective, factual, based on technology-based devices capturing physical characteristics of the pathological phenomena (e.g., sensors to measure the frequency and amplitude of tremor). These instrumental evaluations furnish appraisals with real numbers on an interval scale for which a unit exists. In both categories of measures, a broad variety of tools exist. This chapter aims to present an up-to-date summary of the most relevant characteristics of the most widely used scales, questionnaires, and technological resources currently applied to the assessment of PD. The review concludes that, in our opinion: (1) no assessment methods can substitute the clinical judgment and (2) subjective and objective measures in PD complement each other, each method having strengths and weaknesses.

Activities of daily living questionnaire from patients' perspectives in Parkinson's disease: a cross-sectional study

Background

The aim of this study was to develop an assessment tool for activities of daily living (ADL) from the perspective of patients with Parkinson’s disease (PD) and examine the validity and reliability of the assessment.

Methods

A preliminary 45-item questionnaire was developed through intensive interviews with 54 patients with PD and administered to another group of 248 patients with PD. Based on clinical and statistical analyses, 20 ADL-items were selected. The final 20-item questionnaire was examined in the other group of 59 patients with PD.

Results

The new ADL questionnaire showed high internal consistency (Cronbach’s α, 0.962–0.966) and acceptable test-retest reliability (0.632–0.984). Concurrent validity was shown as a significant positive correlation between the new ADL questionnaire and other ADL or clinical instruments. The Hoehn and Yahr stage showed the highest degree of correlation with the new ADL questionnaire, followed by the other ADL scales (Schwab and England ADL and the ADL subscore of the Unified Parkinson’s Disease Rating Scale). Additionally, a regression analysis was conducted with the disease-specific quality of life questionnaire, and the new ADL questionnaire was the most powerful predictor of quality of life among the clinical instruments.

Conclusions

The new ADL questionnaire is a valid tool for assessing ADL from the perspectives of patients with PD.

Trunk muscle exercises as a means of improving postural stability in people with Parkinson's disease: a protocol for a randomised controlled trial

INTRODUCTION

Exercise has been shown to improve clinical measures of strength, balance and mobility, and in some cases, has improved symptoms of tremor and rigidity in people with Parkinson's disease (PD). However, to date, no research has examined whether improvements in trunk control can remedy deficits in dynamic postural stability in this population. The proposed randomised controlled trial aims to establish whether a 12-week exercise programme aimed at improving dynamic postural stability in people with PD; (1) is more effective than education; (2) is more effective when training frequency is increased; and (3) provides greater long-term benefits than education.

METHODS/DESIGN

Forty-five community-dwelling individuals diagnosed with idiopathic PD with a falls history will be recruited. Participants will complete baseline assessments including tests of cognition, vision, disease severity, fear of falling, mobility and quality of life. Additionally, participants will complete a series of standing balance tasks to evaluate static postural stability, while dynamic postural control will be measured during walking using head and trunk-mounted three-dimensional accelerometers. Following baseline testing, participants will be randomly-assigned to one of three intervention groups, who will receive either exercise once per week, exercise 3 days/week, or education. Participants will repeat the same battery of tests conducted at baseline after the 12-week intervention and again following a further 12-week sustainability period.

DISCUSSION

This study has the potential to show that low-intensity and progressive trunk exercises can provide a non-invasive and effective means for maintaining or improving postural stability for people with PD. Importantly, if the programme is noted to be effective, it could be easily performed by patients within their home environment or under the guidance of available allied health professionals.

TRIAL REGISTRATION NUMBER

The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613001175763).

Longitudinal metric properties of disability rating scales for Parkinson's disease

OBJECTIVES

This study analyzes the longitudinal metric attributes of three Parkinson's disease (PD) disability scales, taking Hoehn and Yahr (HY) staging as the reference measure of PD progression.

METHODS

A sample of 87 PD patients was assessed during regular medical visits, using the HY, the Unified Parkinson's Disease Rating Scale--Activities of Daily Living Section (UPDRS-ADL), the Schwab and England Scale (SES), and the Intermediate Scale for Assessment of PD (ISAPD), across a follow-up period of 2.6 +/- 1.0 years.

RESULTS

The following cross-sectional attributes were analyzed, at baseline and again on conclusion of the study: floor and ceiling effects, convergent validity, reliability, and standard error of measurement, all of which were found to be adequate. Longitudinal reproducibility values (intraclass correlation coefficient) were 0.81 (ISAPD) to 0.84 (UPDRS-ADL). Insofar as longitudinal validity was concerned, the change scores of the three disability scales correlated significantly with the HY change score, absolute value r = 0.33 to 0.45, P < 0.003. Slightly lower values were found when taking the annual rate of change, absolute value r = 0.20 to 0.36. The three scales were acceptable, even though there were small differences among them. The "minimal clinically important difference" proposed for these scales is: SES, -6; UPDRS-ADL, +2; ISAPD, +1.5 points.

CONCLUSIONS

The three scales proved adequate for longitudinal assessment of PD disability. UPDRS-ADL was more precise and ISAPD more consistent. Magnitude of change and correlation with change in HY were slightly higher with the ISAPD. Effect size and standardized response mean for the minimal change in HY were higher for the UPDRS-ADL.

Global versus factor-related impression of severity in Parkinson's disease: a new clinimetric index (CISI-PD)

In Parkinson's disease (PD), the Clinical Global Impression of Severity (CGIS) is often used as an additional outcome in clinical trials. It is hypothesized that this measure summarizes clinical assessment and is mainly influenced by the rating of four domains, namely, motor signs, disability, motor complications, and cognitive impairment. Ratings of these four factors were combined to form a new Clinical Impression of Severity Index for Parkinson's Disease (CISI-PD). A sample of 150 PD patients was evaluated using the following scales: Hoehn and Yahr staging, Schwab and England scale, Unified Parkinson's Disease Rating Scale, Scales for Outcomes in Parkinson's Disease-Motor Scale, CGIS, and CISI-PD. The results show that the CGIS is closely related to the above-mentioned measures (r=0.49-0.89). CISI-PD correlation with these scales was very similar (r=0.55-0.91), to the extent that the difference between corresponding coefficients was systematically less than 0.10. A multiple regression model showed that 92% of the CIGS variance was explained by the four CISI-PD items. Finally, the CISI-PD displayed adequate psychometric properties, with satisfactory internal consistency (alpha=0.90) and convergent (r>0.75) and known-groups validity. The CISI-PD is a valid and reliable measure that expands the information obtained via the CGIS.

Metric attributes of the unified Parkinson's disease rating scale 3.0 battery: Part II, construct and content validity

This article is the second of a two-part series concerning the metric properties of the following three Parkinson's disease (PD) scales: modified Hoehn and Yahr staging (H&Y), Schwab and England (S&E), and Unified Parkinson's Disease Rating Scale (UPDRS) 3.0. Part II focuses on construct and content validity. To assess construct validity, a sample of 1,136 PD patients completed the above-mentioned PD scales. Correlation coefficients between measures of disability and dysfunction [S&E, UPDRS Activities of Daily Living (ADL), and UPDRS Motor Examination] were |r| = 0.69-0.77, indicating good convergent validity. Results showed that the S&E (F(5,945) = 193.47; P < 0.0001) and UPDRS subscales discriminated between modified H&Y stages (F(20,2784) = 25.28; P < 0.001). A panel of 12 to 13 international experts rated the relevance of the scales and items. This enabled the scales' content validity index to be calculated, which ranged from 41.7% (UPDRS Mentation) to 83.3% (UPDRS Motor Examination). In conclusion, while the modified H&Y, S&E, and UPDRS displayed satisfactory construct validity, the content validity of all scales except UPDRS Motor Examination failed to attain adequate standards.

Impact of Fatigue in Parkinson’s Disease: The Fatigue Impact Scale for Daily Use (D-FIS)

The Fatigue Impact Scale for Daily Use (D-FIS) was used in a cross-sectional study including 142 consecutive Parkinson's disease (PD) patients. Usual clinical measures for PD, the Montgomery-Asberg Depression Rating Scale and the Parkinson's Disease Questionnaire-8 items were applied. In addition to the D-FIS, patients with fatigue (67.6%, PWF) completed the Multidimensional Fatigue Inventory (MFI), a visual analogue scale for fatigue (VAS-F) and a Global Perception of Fatigue scale (GPF). Relevant psychometric D-FIS results were: floor effect = 4.2%; ceiling effect = 1.1%; skewness = 0.44; item homogeneity = 0.63; Cronbach's alpha = 0.93; item-total correlation = 0.68 (item 1)-0.82 (item 8); standard error of measurement = 2.15; convergent validity with other fatigue measures = 0.54 [GPF]-0.62 [VAS-F] (p<0.001). In a multiple linear regression model, fatigue, depression, and disability independently influenced HRQoL, as measured by the PDQ-8. Patients on amantadine had lower prevalence of fatigue. In PD, D-FIS is a consistent and valid measure for fatigue, a frequent symptom previously found to impair patients' HRQoL. Fatigue was also linked to depression and disability in this study.

Metric attributes of the unified Parkinson's disease rating scale 3.0 battery: Part I, feasibility, scaling assumptions, reliability, and precision

This article sought to assess the feasibility, scaling assumptions, reliability, precision, and factor analysis of the three most widely used rating scales in Parkinson's disease (PD): modified Hoehn and Yahr (HY), Schwab and England (SE), and Unified Parkinson's Disease Rating Scale (UPDRS). A multicenter sample of 1,136 PD patients was assessed. The percentage of missing data was 8% for SE, HY, and UPDRS mentation, and almost negligible (<2%) for the other UPDRS subscales. A high floor effect was found for UPDRS mentation (23%) and complications scales (36%). Item content validity, measured by multitrait scaling analysis, was adequate for all UPDRS subscales (scaling successes > 90%). Internal consistency coefficients for the UPDRS scales ranged from 0.79 (mentation) to 0.92 (activities of daily living and motor). Factor structure of the UPDRS mentation, activities of daily living, and complications subscales was replicated. As a whole, the HY, SE, and UPDRS are acceptable, consistent, and potentially sensitive rating scales.

The SCOPA–Motor Scale for assessment of Parkinson's disease is a consistent and valid measure

OBJECTIVE

The SCOPA-Motor Scale (S-MS) for assessment of Parkinson's disease (PD), contains 21 items in three domains: Motor examination, Disability, and Complications. Our objective was to validate the S-MS Spanish version.

STUDY DESIGN AND SETTING

This validation study was based on a multicenter, cross-sectional, one-point-in-time evaluation design. The applied measures were: Unified Parkinson's Disease Rating Scale-3.0 (UPDRS); S-MS; PD Global Evaluation (PDGE); and Clinical Global Impression of severity (CGI). Completeness of data collection, floor and ceiling effect, internal consistency, precision, and construct and discriminative validity were analyzed in 151 PD patients.

RESULTS

Scores from S-MS were fully computable. Floor effect was high for Complications (43.7%). Cronbach's alpha was > 0.90 for every domain, and item-total correlation was > 0.70 except for Examination. Standard error of measurement (SEM) ranged from 0.40 to 2.4. Convergent validity with corresponding UPDRS sections yielded coefficients > 0.90. Discriminative validity across Hoehn and Yahr (HY) and CGI stages was significant (Kruskal-Wallis, P < .0001). Insofar as internal consistency was concerned, alpha-values of the Examination sections were marginally higher for the UPDRS than for the S-MS (a finding perhaps accounted for by redundancy in this part of the UPDRS).

CONCLUSION

The S-MS is a consistent and valid scale, shorter by almost half than the UPDRS.

Measuring outcomes for neurological disorders: a review of disease-specific health status instruments for three degenerative neurological conditions

Health-related quality-of-life measures have been increasingly used in research into neurological disorders in recent years. The aim of this paper is to provide an objective appraisal of the evidence in regard to disease-specific quality-of-life measures used in research on health interventions for three degenerative neurological disorders: multiple sclerosis, motor neurone disease/amyotrophic lateral sclerosis and Parkinson's disease. A comprehensive search strategy was developed to include nine relevant electronic databases. Only studies pertaining to patient-based outcome measurements in multiple sclerosis, motor neurone disease and Parkinson's disease were included. We identified 76 eligible studies. As studies consisted of descriptive and cross-sectional survey study designs, results were reported qualitatively rather than in the form of a meta-analysis. Four disease-specific measures were found for Parkinson's disease, 11 for multiple sclerosis and one for motor neurone disease. We conclude that health-related quality-of-life measures are useful in assessing the impact of treatments and interventions for neurological disorders. However, further research is needed on the development of instruments using psychometric methods and on the validation, utilization and responsiveness of instruments to change.

Quality of life of caregivers in Parkinson?s disease

OBJECTIVE

To assess the impact of PD on informal caregivers of patients and identify the main factors related to caregiver strain.

PATIENTS AND METHODS

Pairs of PD patients and their caregivers. Evaluation by neurologists included the Hoehn and Yahr, Schwab and England, UPDRS (parts 1-3), ISAPD, and Pfeiffer's SPMSQ rating scales. Patients completed the Euro-QoL 5D, PDQ-8, and Hospital Anxiety and Depression Scale. The SQLC was used to assess caregivers' quality of life (QoL), with caregivers, in turn, applying the Euro-QoL and PDQ-8 to assess patients' health-related quality of life (HRQoL). Multiple linear regression models were fitted to ascertain factors linked to the SQLC.

RESULTS

Significant correlations were in evidence between the following scores: SQLC and clinical rating scales and SQLC and patients' HRQoL. Based on multiple regression analysis, patients' functional state (ADL) proved to be the main predictor of caregivers' QoL. Self- and caregiver-assessed patients' HRQoL also proved to be a relevant factor.

CONCLUSIONS

(1) Patients' functional state was significantly related to caregivers' psychosocial burden; (2) patients' HRQoL proved to be an additional factor linked to caregiver QoL; (3) improvement of patient disability and HRQoL might alleviate caregiver strain.

Patients', doctors', and caregivers' assessment of disability using the UPDRS-ADL section: are these ratings interchangeable?

This multicenter study sought to analyze the validity and reliability of the Unified Parkinson's Disease Rating Scale (UPDRS)-section 2 (Activities of Daily Living, ADL) as applied by patients and caregivers. Sixty pairs of PD patients-caregivers were enrolled for study purposes. Neurologists used a set of scales to determine disease severity and patients' functional state. Patients and caregivers used adapted versions of the UPDRS-section 2 in tandem with other measures. Wilcoxon and Mann-Whitney tests, weighted kappa, intraclass and Spearman's correlation coefficients, as well as multivariate linear regression models were applied. On the whole, PD patient self-assessment and caregiver evaluation of patients' disability showed close concordance with neurologists' ratings. Correlation between caregiver ratings and clinical evaluation tended to be slightly lower than that for patient-based self-assessment. Depression showed a positive correlation with disability and had a nonsystematic influence on UPDRS-section 2 (ADL) scores. As expected, there was a significant correlation between perceived disability and health-related quality of life measures. Caregiver burden did not reduce the level of agreement with neurologists as to the overall rating of any given patient's disability. In PD, UPDRS-section 2-based assessment of disability by patients themselves and caregivers is a valid and reliable outcome.

Health-related quality of life evaluation by proxy in Parkinson's disease: Approach using PDQ-8 and EuroQoL-5D

Patient- and caregiver-based scores were compared and agreement levels ascertained to determine the reliability of proxy evaluation of Parkinson's Disease (PD) patients' health-related quality of life (HRQoL) using the EuroQoL and PD questionnaire (PDQ)-8. Of 72 patient-caregiver pairs, 64 (88.88%) returned the questionnaires. The degree of agreement varied for individual dimensions. Proxy evaluation of PD patients' HRQoL showed limitations mainly with assessments using the EuroQoL and especially in patients with severe disease and depression.

A short psychosocial questionnaire for patients with Parkinson's disease: the SCOPA-PS

The purpose of this study was to develop a short questionnaire for psychosocial functioning in patients with Parkinson's Disease (PD). The SCales for Outcomes in Parkinson's disease-PsychoSocial questionnaire (SCOPA-PS) was tested in a survey and compared with other instruments and with medical information. This survey was sent to 205 patents with idiopathic PD. Eighty-six percent of the questionnaires were returned. Cronbach's alpha was 0.83. Two-week test-retest reliability was 0.85 (intraclass correlation coefficient). Construct validity with other scales (Spearman's rho) was 0.82 for the Parkinson's Disease Questionnaire-39-item version (PDQ-39), 0.76 for the PDQ-8, 0.69 for the Hospital Anxiety and Depression Scale, -0.61 for the Euroqol, and -0.60 for a visual analogue scale evaluating Quality-of-Life. The summary index revealed a significant increase with increasing disease severity. The SCOPA-PS is a new, short psychosocial questionnaire for patients with PD with good clinimetric properties.

Contributions of disease severity and perceptions of primary and secondary control to the prediction of psychosocial adjustment to Parkinson's disease

Seventy-four people with Parkinson's disease (PD) completed questionnaires and were interviewed to determine the degree to which the severity of PD and perceptions of primary and secondary control over PD predicted psychosocial adjustment. Significant unique contributions to PD-related participation restrictions were made by disease severity (positive relationship) and perceived internal secondary control (negative relationship). Also, participation restrictions had a significant direct effect, and disease severity and perceived internal secondary control significant indirect effects, on both depressive symptomatology and life satisfaction. Results are consistent with theories that suggest the importance of enhancing internal secondary control processes in situations in which actual control over objective circumstances is limited, such as with chronic and progressive diseases like PD.

Systematic evaluation of rating scales for impairment and disability in Parkinson's disease

We assessed the clinometric characteristics of rating scales used for the evaluation of motor impairment and disability of patients with Parkinson's disease (PD), conducting a systematic review of PD rating scales published from 1960 to the present. Thirty studies describing clinometrics of 11 rating scales used for PD were identified. Outcome measures included validity (including factor structure), reliability (internal consistency, inter-rater, and intrarater) and responsiveness. We traced three impairment scales (Webster, Columbia University Rating Scale [CURS] and Parkinson's Disease Impairment Scale), four disability scales (Schwab and England, Northwestern University Disability Scale [NUDS], Intermediate Scale for Assessment of PD, and Extensive Disability Scale), and four scales evaluating both impairment and disability (New York University, University of California Los Angeles, Unified Parkinson's Disease Rating Scale [UPDRS], and Short Parkinson Evaluation Scale). The scales showed large differences in the extent of representation of items related to signs considered responsive to dopaminergic treatment or to those signs that appear late in the disease course and lack responsiveness to treatment. Regardless of the scale, there was a conspicuous lack of consistency concerning inter-rater reliability of bradykinesia, tremor, and rigidity. Overall disability items displayed moderate to good inter-rater reliability. The available evidence shows that CURS, NUDS, and UPDRS have moderate to good reliability and validity. In contrast to their widespread clinical use for assessment of impairment and disability in PD, the majority of the rating scales have either not been subjected to an extensive clinometric evaluation or have demonstrated clinometric shortcomings. The CURS, NUDS, and UPDRS are the most evaluated, valid, and reliable scales currently available.

Activity-based diary for Parkinson's disease

The objective of this study was to develop a Parkinson's disease diary that evaluates a patient's difficulties in performing activities as a substitute for the amount of "on"- and "off"-time and to assess its clinimetric qualities. In this study, 84 patients with Parkinson's disease kept a diary for 2 or 3 periods of 5 days. Daily, five items were recorded across 11 time periods. Patients simultaneously recorded "on-off" in the traditional way. The diary was easily understood, and median recording time was 5-10 minutes a day. Clinimetric analysis showed that the diary could be reduced successfully to 3 days, in which five items (walking, transfers, manual activities, dyskinesias, and sleep) with four response options (no, slight, moderate, and severe difficulty) were assessed seven times daily. Sumscores of the first three items accurately predicted being "on" or "off" in 93% of the cases, making separate scoring of "on" and "off" unnecessary. The diary was internally consistent and showed good reproducibility. Construct validity with external measures was adequate, and comparisons between patients grouped by disease severity and by degree of fluctuations revealed significant differences in the expected directions. Taken together, this Parkinson's disease diary has a sound clinimetric basis, provides information on the extent of perceived disability, and thereby accurately reflects the severity of "off"-periods and the variability of motor fluctuations.