Test the Best: Classification Accuracies of Four Cognitive Rating Scales for Parkinson's Disease Mild Cognitive Impairment.

OBJECTIVE: A progressive cognitive impairment is one of the frequent non-motor symptoms during Parkinson's disease (PD) course. A short and valid screening tool is needed to detect an incipient cognitive deficit at the mild cognitive impairment stage in Parkinson's disease (PD-MCI). METHOD: The present study aims to evaluate the classification accuracies of four cognitive screenings: Montreal Cognitive Assessment (MoCA), Mattis Dementia Rating Scale second edition (DRS-2), Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) in a cohort of PD patients (PD-MCI, n = 46; and Parkinson's disease with normal cognition, PD-NC, n = 95) and Controls (n = 66). All subjects underwent a standard neuropsychological battery as recommended by the International Parkinson and Movement Disorder Society and underwent all four screening tools. RESULTS: In the detection of PD-MCI versus PD-NC, the MoCA showed a sensitivity of 84% and a specificity of 66% with a screening cutoff score at ≤25 points. The MoCA's AUC was 86% (95% CI 78.7-93.1). In the detection of PD-MCI versus Controls, the FAB displayed 84% sensitivity and 79% specificity with a cutoff ≤16 points, to screen. The FAB's AUC was 87% (79.0-95.0). CONCLUSIONS: Our results show that the MoCA is the most discriminative tool for screening MCI in the PD population.

Differences in Subjective Cognitive Complaints Between Non-Demented Older Adults from a Memory Clinic and the Community.

BACKGROUND: Subjective cognitive complaints (SCCs) may represent an early cognitive marker of Alzheimer's disease (AD). There is a need to identify specific SCCs associated with an increased likelihood of underlying AD. OBJECTIVE: Using the Questionnaire of Cognitive Complaints (QPC), we evaluated the pattern of SCCs in a clinical sample of non-demented older adults in comparison to cognitively healthy community-dwelling volunteers (HV). METHODS: In total, 142 non-demented older adults from the Czech Brain Aging Study referred to two memory clinics for their SCCs were classified as having subjective cognitive decline (SCD, n = 85) or amnestic mild cognitive impairment (aMCI, n = 57) based on a neuropsychological evaluation. Furthermore, 82 age-, education-, and gender-matched HV were recruited. All subjects completed the QPC assessing the presence of specific SCCs in the last six months. RESULTS: Both SCD and aMCI groups reported almost two times more SCCs than HV, but they did not differ from each other in the total QPC score. Impression of memory change and Impression of worse memory in comparison to peers were significantly more prevalent in both SCD and aMCI groups in comparison to HV; however, only the latter one was associated with lower cognitive performance. CONCLUSION: The pattern of QPC-SCCs reported by SCD individuals was more similar to aMCI individuals than to HV. A complaint about memory change seems unspecific to pathological aging whereas a complaint about worse memory in comparison to peers might be one of the promising items from QPC questionnaire potentially reflecting subtle cognitive changes.

The effect of Alzheimer's disease on spatial navigation strategies.

Hippocampal and basal forebrain (BF) atrophy is associated with allocentric navigation impairment in Alzheimer's disease (AD) and may lead to recruitment of compensatory navigation strategies. We examined navigation strategy preference, its association with allocentric navigation, and the role of hippocampal and BF volumes in this association in early clinical stages of AD. Sixty nine participants-amnestic mild cognitive impairment (aMCI) due to AD (n = 28), AD dementia (n = 21), and cognitively normal (CN) older adults (n = 20)-underwent virtual Y-maze strategy assessment, real-space navigation testing, cognitive assessment, and hippocampal and BF volumetry. Preference for egocentric over allocentric strategy increased with AD severity (aMCI: 67% vs. 33%; dementia: 94% vs. 6%), which contrasted with preference in the CN group (39% vs. 61%). Those with aMCI who preferred egocentric strategy had worse allocentric navigation. Among those with aMCI, hippocampal and BF atrophy explained up to 25% of the association between strategy preference and allocentric navigation. The preference for egocentric strategy in AD may reflect recruitment of compensatory extrahippocampal navigation strategies as adaptation to hippocampal and BF neurodegeneration.

The Reliability of Clock Drawing Test Scoring Systems Modeled on the Normative Data in Healthy Aging and Nonamnestic Mild Cognitive Impairment.

The Clock Drawing Test (CDT) is a commonly used tool in clinical practice and research for cognitive screening among older adults. The main goal of the present study was to analyze the interrater reliability of three different CDT scoring systems (by Shulman et al., Babins et al., and Cohen et al.). We used a clock with a predrawn circle. The CDT was evaluated by three independent raters based on the normative data set of healthy older and very old adults and patients with nonamnestic mild cognitive impairment (naMCI; N = 438; aged 61-94). We confirmed a high interrater reliability measured by the intraclass correlation coefficients (ICCs): Shulman ICC = .809, Babins ICC = .894, and Cohen ICC = .862, all p < .001. We found that age and education levels have a significant effect on CDT performance, yet there was no influence of gender. Finally, the scoring systems differentiated between naMCI and age- and education-matched controls: Shulman's area under the receiver operating characteristic curve (AUC) = .84, Cohen AUC = .71, all p < .001; and a slightly lower discriminative ability was shown by Babins: AUC = .65, p = .012.