Factor structure of the Montreal Cognitive Assessment items in a sample with early Parkinson's disease

Salivary levels of disease-related biomarkers in the early stages of Parkinson's and Alzheimer's disease: A cross-sectional study

Introduction

Finding a non-invasive and repeatable tool has been recommended to make an accurate diagnosis of Alzheimer's disease (AD) and Parkinson's disease (PD).

Methods

70 volunteers participated in three groups: 24 with mild dementia of AD, 24 in the first and second stages of PD, and 22 healthy controls. After valuing the scores of cognitive tests, the salivary levels of phosphorylated tau (p-tau), total alpha-synuclein (α-syn), and beta-amyloid 1-42 (Aβ)‏‎ proteins have been evaluated. Finally, the cutoff points, receiver operating characteristic (ROC), sensitivity, and specificity have been calculated to find accurate and detectable biomarkers.

Results

Findings showed that the salivary level of Aβ was higher in both PD (p < 0.01) and AD (p < 0.001) patients than in controls. Moreover, the level of α-syn in both PD and AD patients was similarly lower than in controls (p < 0.05). However, the level of p-tau was only ‎higher in the AD group than in the control (p < 0.01). Salivary Aβ 1-42 level at a 60.3 pg/ml cutoff point revealed an excellent performance for diagnosing AD (AUC: 0.81).

Conclusion

Evaluation of p-tau, α-syn, and Aβ 1-42 levels in the saliva of AD and PD patients could help the early diagnosis. The p-tau level might be valuable for differentiation between AD and PD. Therefore, these hopeful investigations could be done to reduce the usage of invasive diagnostic methods, which alone is a success in alleviating the suffering of AD and PD patients. Moreover, introducing accurate salivary biomarkers according to the pathophysiology of AD and PD should be encouraged.

Cognitive impairment in candidates for allogeneic hematopoietic stem cell transplantation

Hematopoietic cell transplant (HCT) is an increasingly common and curative treatment strategy to improve survival among individuals with malignant and nonmalignant diseases, with over one million HCTs having been performed worldwide. Neurocognitive dysfunction is a common and untoward consequence of HCT for many recipients, although few studies have examined the profile of neurocognitive impairments in HCT or their association with clinical features, such as frailty, or the incidence of pre-HCT neurocognitive impairments across all ages, which may influence post-HCT neurocognitive impairments. We examined the pattern and correlates of pre-transplant neurocognitive dysfunction in a prospective sample of adults undergoing HCT. Neurocognition was assessed using the Montreal Cognitive Assessment Battery. Frailty was assessed using the Short Physical Performance Battery. Linear regression analysis was used to examine the associations between neurocognitive performance and frailty. Neurocognitive screening profiles were also examined by partitioning MoCA into domain scores, including Executive Function and Memory. We also examined the associations between neurocognition, frailty, and clinical outcomes, including length of transplant hospitalization and survival. One hundred and ten adults were evaluated across a wide age range (range: 19-75; mean age = 54.7 [SD = 14.1]). Neurocognitive performance tended to fall below published normative levels (mean MoCA = 25.5 [SD = 4.1]), with 17% of participants demonstrating impaired performance compared with medical normative data (MoCA ≤ 22) and 34% exhibiting impaired performance relative to healthy samples (MoCA ≤ 25). Mild impairments (MoCA ≤ 25) were common across age ranges, including middle-aged patients (23% for age < 50; 35% for age 50-60, 41% for age ≥ 60), particularly for items assessing Executive Function. Greater levels of frailty associated with lower neurocognitive screening scores (r = -0.29, P < 0.01) and Executive Functioning (r = -0.24, P < 0.01), whereas greater age was associated with poorer Memory performance only (r = -0.33, P < 0.01). Greater levels of frailty prior to transplant associated with longer length of stay (β = 0.10, P = 0.046), but were not associated with survival. Neurocognitive impairments are common among adults undergoing HCT and the pattern of performance varies by age. Pre-transplant frailty is associated with neurocognitive functioning and may portend worse post-transplant early clinical outcomes.

Rapid communication: Preliminary validation of a telephone adapted Montreal Cognitive Assessment for the identification of mild cognitive impairment in Parkinson's disease

Objective: In the current pandemic, tele-screening of neuropsychological status has become a necessity. Instruments developed for telephone screening are not as well validated as traditional neuropsychological measures. Therefore, the current study presents preliminary validation of a telephone version of the Montreal Cognitive Assessment (T-MoCA) in individuals with Parkinson's disease (PD).Method: Twenty-one persons with PD completed the T-MoCA along with a traditional neuropsychological battery. Diagnostic accuracy for the presence of PD-related mild cognitive impairment (MCI) and correlations with traditional neuropsychological measures are reported.Results: Individuals with MCI (n = 9) scored lower than individuals without cognitive impairment (17.56 vs. 19.50; t = -2.28, p = .03, d = -1.00). Diagnostic accuracy for MCI ranged from 76% to 81%, with sensitivity ranging from 0.56 to 0.67 and specificity ranging from 0.92 to 1.00. Correlations of T-MoCA derived scores with traditional neuropsychological measures were quite modest, with the exception of the memory impairment scale.Conclusions: This rapid communication presents preliminary validation of the T-MoCA for use in individuals with PD. Caveats and implications for practical use in the current pandemic are discussed.

Factor structure of the Montreal Cognitive Assessment in Parkinson disease

OBJECTIVES

The Montreal Cognitive Assessment (MoCA) is a common tool for screening mild cognitive impairment (MCI) and dementia. Studies in multiple clinical groups provide evidence for various factor structures mapping to different cognitive domains. We tested the factor structure of the MoCA in a large cohort of early Parkinson disease (PD).

MATERIALS AND METHODS

Complete MoCA data were available from an observational cohort study for 1738 patients with recent-onset PD (64.6% male, mean age 67.6, SD 9.2). Confirmatory factor analysis (CFA) was applied to test previously defined two-factor, six-factor, and three-factor models in the full sample and in a subgroup with possible cognitive impairment (MoCA < 26). Secondary analysis used exploratory factor analysis (EFA; principal factors with oblique rotation).

RESULTS

The mean MoCA score was 25.3 (SD 3.4, range 10-30). Fit statistics in the six-factor model (χ² /df 17.77, root mean square error of approximation [RMSEA] 0.10, comparative fit index [CFI] 0.74, Tucker-Lewis index [TLI] 0.69, standardised root mean square residual [SRMR] 0.07) indicated poorer fit than did previous studies. Findings were similar in the two-factor and three-factor models. EFA suggested an alternative six-factor solution (short-term recall, visuospatial-executive, attention/working memory, verbal-executive, orientation, and expressive language), although CFA did not support the validity of the new model.

CONCLUSIONS

The factor structure of the MoCA in early PD was not consistent with that of previous research. This may reflect higher cognitive performance and differing demographics in our sample. The results do not support a clear, clinically relevant factor structure in an early PD group, suggesting that the MoCA should be followed with detailed assessment to obtain domain-specific cognitive profiles.

Initial cognitive changes in Parkinson's disease

The focus on cognitive impairment in neurodegenerative diseases, including PD, is shifting from the dementia stage to earlier stages of impairment, including mild cognitive impairment. This shift is driven primarily by the desire to improve long-term outcomes by delivering therapeutic interventions earlier in the clinical course, even presymptomatically in those at highest risk, and at the initial stage in the pathophysiological cascade that underpins common dementia syndromes. This article focuses on key findings and challenges in studying earliest stages of cognitive decline in PD, including a detailed examination of neuropsychological testing, cognitive performance in early and prodromal PD, epidemiological research for PD mild cognitive impairment to date, and expert recommendations for assessment. © 2018 International Parkinson and Movement Disorder Society.