Development and validation of an alternative version of the Parkinson's Disease-Cognitive Rating Scale (PD-CRS)

Parkinson's Disease-Cognitive Rating Scale (PD-CRS): Normative Data and Mild Cognitive Impairment Assessment in Brazil

Background

The Parkinson's Disease-Cognitive Rating Scale (PD-CRS) assesses posterior-cortical and frontal-subcortical cognitive functioning and distinguishes mild cognitive impairment in Parkinson's disease (PD-MCI); however, it was not evaluated in Brazil.

Objectives

To investigate PD-CRS's reliability, validity, normative data, and accuracy for PD-MCI screening in Brazil.

Methods

The effects of age, education, and sex on PD-CRS scores were explored. The instrument was tested in 714 individuals (53% female, 21-94 years), with a broad range of education and no neurodegenerative disorder. Trail Making, Consonant Trigrams, Five-Point, and semantic fluency tests were administered for comparison. A second study enrolled patients with PD and intact cognition (n = 44, 59.75 ± 10.79 years) and with PD-MCI (n = 25, 65.76 ± 10.33 years) to investigate criterion validity. PD-CRS subtests were compared with the Cambridge Automated Neuropsychological Battery memory and executive tasks.

Results

PD-CRS was unidimensional and reliable (McDonald's ω = 0.83). Using robust multiple regressions, age, and education predicted the total and derived scores in the normative sample. At the 85-point cutoff, PD-MCI was detected with 68% sensitivity and 86% specificity (area under the curve = 0.870). PD-CRS scores strongly correlated with executive and verbal/visual memory tests in both normative and clinical samples.

Conclusions

This study investigated the applicability of PD-CRS in the Brazilian context. The scale seems helpful in screening for PD-MCI, with adequate internal consistency and construct validity. The PD-CRS variance is influenced by age and educational level, a critical issue for cognitive testing in countries with educational and cultural heterogeneity.

Psychometric properties and construct validity of the Parkinson’s Disease-Cognitive Rating Scale (PD-CRS) in Colombia

Background

Cognitive impairment is frequent among people living with Parkinson’s disease: up to 40% of patients exhibit symptoms of mild cognitive impairment and 25% meet the criteria for dementia. Parkinson’s Disease Cognitive Rating Scale (PD-CRS) is one of the recommended scales by the Movement Disorders Society Task Force for level 1 screening of dementia. However, its psychometric properties have not been studied in the Colombian population.

Methods

A cross-sectional study was conducted on 100 patients with Parkinson’s disease diagnosed by a movement disorders neurologist. Patients were evaluated with PD-CRS and MoCA. Principal component analysis was conducted, and then confirmatory factor analysis was implemented through the maximum-likelihood method. Internal consistency was evaluated using Cronbach α. Convergent and divergent validity were also calculated and concurrent validity with the MoCA was assessed.

Results

62% were males. Their median age was 68 years (IQR 57–74) and the median disease duration was 4 years (IQR 2–9). 77% were classified in early stages (Hoehn and Yahr stage ≤ 2), while the MDS-UPDRS part III score was 25 (IQR 15.5–38). In the principal component factor analysis, the pattern matrix unveiled a mnesic and a non-mnesic domain. Confirmatory factor analysis showed similar explanatory capacity (λ ≥ 0.50) for items other than naming (λ = 0.34). Cronbach’s α for the full 9-items instrument was 0.74. MoCA and PD-CRS total scores were correlated (ρ = 0.71, p = 0.000). Assuming a cut-off score of 62 points, there is an agreement of 89% with the definition of dementia by MoCA for Colombia (κ = 0.59; p = 0.000).

Conclusion

PD-CRS has acceptable psychometric properties for the Colombian population and has significant correlation and agreement with a validated scale (MoCA).

Parkinson's Disease-Cognitive Rating Scale for Evaluating Cognitive Impairment in Parkinson's Disease: A Systematic Review

The aim of the present systematic review was to examine the evidence on the accuracy and psychometric properties of the Parkinson’s Disease-Cognitive Rating Scale (PD-CRS) for evaluating the presence of cognitive impairment in patients with Parkinson’s disease (PD) as well as to highlight the quality and quantity of research available on the use of the PD-CRS in this population. We searched four databases from inception until July 2020. Eight studies, published between 2008 and 2020, met the inclusion criteria: One cross-sectional study in which participants were assessed with the index test (PD-CRS) and a reference standard diagnostic assessment, in accordance with the Level II criteria of the International Parkinson and Movement Disorder Society (MDS); one case-control study comparing the PD-CRS to an extensive battery of tests (i.e., MDS Level II diagnosis); and six studies comparing the PD-CRS to other short cognitive batteries. In patients with Parkinson’s disease, the PD-CRS test provides information about cortical and sub-cortical cognitive functions. Even if it demonstrated good psychometric properties, the results regarding the optimal threshold for detecting mild cognitive impairment and dementia in PD are somewhat inconsistent. Further cross-sectional studies are necessary to examine the optimum cut-off score for detecting cognitive dysfunction in PD patients.

The Montreal Cognitive Assessment: Is It Suitable for Identifying Mild Cognitive Impairment in Parkinson's Disease?

BACKGROUND

Administering an abbreviated global cognitive test, such as the Montreal Cognitive Assessment (MoCA), is necessary for the recommended first-level diagnostic criteria for mild cognitive impairment (MCI) in Parkinson's disease (PD). Level II requires administering cognitive functioning neuropsychological tests. The MoCA's suitability for identifying PD-MCI is questionable and, despite the importance of cognitive deficits reflected through daily functioning in identifying PD-MCI, knowledge about it is scarce.

OBJECTIVES

To explore neuropsychological test scores of patients with PD who were categorized based on their MoCA scores and to analyze correlations between this categorization and patients' self-reports about daily functional-related cognitive abilities.

METHODS

A total of 78 patients aged 42 to 78 years participated: 46 with low MoCA scores (22-25) and 32 with high MoCA scores (26-30). Medical assessments and level II neuropsychological assessment tools were administered along with standardized self-report questionnaires about daily functioning that reflects patients' cognitive abilities.

RESULTS

A high percentage of the low MoCA group obtained neuropsychological test scores within the normal range; a notable number in the high MoCA group were identified with MCI-level scores on various neuropsychological tests. Suspected PD-MCI according to the level I criteria did not correspond well with the level II criteria. Positive correlations were found among the 3 self-report questionnaires.

CONCLUSIONS

These results support the ongoing discussion of the complexity of capturing PD-MCI. Considering the neuropsychological tests results, assessments that reflect cognitive encounters in real life daily confrontations are warranted among people diagnosed with PD who are at risk for cognitive decline.

Mild cognitive impairment in Parkinson's disease

Understanding on the clinical features and neural mechanisms leading to cognitive impairment and dementia in Parkinson's disease (PD) has notably increased. At time of diagnosis, nearly all PD patients present some degree of cognitive impairment not enough severe as to significantly affect functional independence. However, even mild cognitive changes have a measurable impact to functional capacity in PD. A clinically practical differentiation is based on the importance of executive deficits in the early phases of cognitive impairment in PD and on the evidence stressing the transitional role of posterior-cortical impairment on the progression of PD-MCI to dementia. However, the pattern of cognitive impairment in PD is variable not just to the extents on which are the affected cognitive domains, but also on which are those domains that became affected first. Specific diagnostic criteria for mild cognitive impairment associated with PD (PD-MCI) and dementia (PDD) and operative guidelines for the cognitive assessment have been developed. In the present review, we will describe general notions regarding the mechanisms and the profile of cognitive deterioration in PD, the diagnostic criteria for PD-MCI, and some of the currently recommended assessment approaches.

Global scales for cognitive screening in Parkinson's disease: Critique and recommendations

BACKGROUND

Cognitive impairment is a common nonmotor manifestation of Parkinson's disease, with deficits ranging from mild cognitive difficulties in 1 or more of the cognitive domains to severe dementia. The International Parkinson and Movement Disorder Society commissioned the assessment of the clinimetric properties of cognitive rating scales measuring global cognitive performance in PD to make recommendations regarding their use.

METHODS

A systematic literature search was conducted to identify the scales used to assess global cognitive performance in PD, and the identified scales were reviewed and rated as "recommended," "recommended with caveats," "suggested," or "listed" by the panel using previously established criteria.

RESULTS

A total of 12 cognitive scales were included in this review. Three scales, the Montreal Cognitive Assessment, the Mattis Dementia Rating Scale Second Edition, and the Parkinson's Disease-Cognitive Rating Scale, were classified as "recommended." Two scales were classified as "recommended with caveats": the Mini-Mental Parkinson, because of limited coverage of executive abilities, and the Scales for Outcomes in Parkinson's Disease-Cognition, which has limited data on sensitivity to change. Six other scales were classified as "suggested" and 1 scale as "listed."

CONCLUSIONS

Because of the existence of "recommended" scales for assessment of global cognitive performance in PD, this task force suggests that the development of a new scale for this purpose is not needed at this time. However, global cognitive scales are not a substitute for comprehensive neuropsychological testing. © 2017 International Parkinson and Movement Disorder Society.