Subjective Cognitive Complaints in Parkinson Disease Without Dementia: A Preliminary Study

Motor progression trajectories and risk of mild cognitive impairment in Parkinson's disease: A latent class trajectory model from PPMI cohort

AIMS

Rare studies have investigated the association between heterogeneity of motor progression and risk of early cognitive impairment in Parkinson's disease (PD). In this study, we aim to identify distinct trajectories of motor progression longitudinally and investigate their impact on predicting mild cognitive impairment (MCI).

METHODS

A 5-year cohort including 415 PD patients at baseline was collected from the Parkinson's Progression Markers Initiative. The severity of motor symptoms was evaluated using the Movement Disorder Society Unified Parkinson's Disease Rating Scale part III. The latent class trajectory model and nonlinear mixed-effects model were used to analyze and delineate the longitudinal changes in motor symptoms. Propensity score matching (PSM) was used to minimize the impact of potential confounders. Cox proportional hazard models were applied to calculate hazard ratios for MCI, and a Kaplan-Meier curve was generated using the occurrence of MCI during the follow-up as the time-to-event.

RESULTS

Two latent trajectories were identified: a mild and remitting motor symptoms class (Class 1, 33.01%) and a severe and progressive motor symptom class (Class 2, 66.99%). Patients in Class 2 initially exhibited severe motor symptoms that worsened progressively despite receiving anti-PD medications. In comparison, patients in Class 1 exhibited milder symptoms that improved following drug therapy and a slower progression. During a 5-year follow-up, patients in Class 2 showed a higher risk of developing MCI compared to those in Class 1 before PSM (Log-Rank 28.58, p < 0.001) and after PSM (Log-Rank 8.20, p = 0.004).

CONCLUSIONS

PD patients with severe and progressive motor symptoms are more likely to develop MCI than those with mild and stable motor symptoms.

Perception of cognitive change by individuals with Parkinson's disease or essential tremor seeking deep brain stimulation: Utility of the cognitive change index

OBJECTIVE

The Cognitive Change Index (CCI-20) is a validated questionnaire that assesses subjective cognitive complaints (SCCs) across memory, language, and executive domains. We aimed to: (a) examine the internal consistency and construct validity of the CCI-20 in patients with movement disorders and (b) learn how the CCI-20 corresponds to objective neuropsychological and mood performance in individuals with Parkinson's disease (PD) or essential tremor (ET) seeking deep brain stimulation (DBS).

METHODS

216 participants (N = 149 PD; N = 67 ET) underwent neuropsychological evaluation and received the CCI-20. The proposed domains of the CCI-20 were examined via confirmatory (CFA) and exploratory (EFA) factor analyses. Hierarchical regressions were used to assess the relationship among subjective cognitive complaints, neuropsychological performance and mood symptoms.

RESULTS

PD and ET groups were similar across neuropsychological, mood, and CCI-20 scores and were combined into one group who was well educated (m = 15.01 ± 2.92), in their mid-60's (m = 67.72 ± 9.33), predominantly male (63%), and non-Hispanic White (93.6%). Previously proposed 3-domain CCI-20 model failed to achieve adequate fit. Subsequent EFA revealed two CCI-20 factors: memory and non-memory (p < 0.001; CFI = 0.924). Regressions indicated apathy and depressive symptoms were associated with greater memory and total cognitive complaints, while poor executive function and anxiety were associated with more non-memory complaints.

CONCLUSION

Two distinct dimensions were identified in the CCI-20: memory and non-memory complaints. Non-memory complaints were indicative of worse executive function, consistent with PD and ET cognitive profiles. Mood significantly contributed to all CCI-20 dimensions. Future studies should explore the utility of SCCs in predicting cognitive decline in these populations.

Subjective Cognitive Complaints in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Subjective cognitive complaints (SCCs) in Parkinson's disease (PD) are reported frequently, but their prevalence and association with changes on objective testing are not fully known.

OBJECTIVE

We aimed to determine the prevalence, clinical correlates, and predictive value of SCCs in PD.

METHODS

We conducted a systematic review and meta-analysis. From 204 abstracts, we selected 31 studies (n = 3441 patients), and from these, identified the prevalence, clinical features, associations with neuropsychiatric symptoms, and predictive values of SCCs in PD.

RESULTS

The meta-analysis showed an SCC prevalence of 36%. This prevalence, however, was significantly moderated by study heterogeneity regarding female sex, disease severity, levodopa equivalent daily dosage, exclusion from the overall sample of patients with objective cognitive impairment, and measurement instrument. SCC prevalence did not differ between de novo and treated PD patients. SCCs were weakly and negligibly associated with cognitive changes on objective testing in cross-sectional studies. However, in cognitively healthy patients, SCCs had a risk ratio of 2.71 for later cognitive decline over a mean follow-up of 3.16 years. Moreover, SCCs were moderately related to co-occurring symptoms of depression, anxiety, or apathy and were more strongly related to these neuropsychiatric symptoms than objective cognitive functioning.

CONCLUSION

Our analyses suggest that SCCs in patients with and without objective cognitive impairment are frequent, occurring in more than one third of PD patients. Establishing uniform measurement instruments for identifying PD-related SCCs is critical to understand their implications. Even in cases lacking evidence of objective cognitive impairment and where SCCs might reflect underlying neuropsychiatric symptoms, the possibility of later cognitive deterioration should not be excluded. Therefore, SCCs in PD patients warrant close monitoring for opportunities for targeted and effective interventions. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Different associated factors of subjective cognitive complaints in patients with early and advanced Parkinson's disease

Subjective cognitive complaints (SCCs), defined as cognitive decline reported by subjects or their informants, are common in the early stage of Parkinson's disease (PD). Previous studies have shown a significant association between SCCs and non-motor features as well as objective cognitive decline in PD patients. However, the discrepancy in SCC prevalence and SCC-related factors between patients with early PD and those with advanced PD remains poorly understood. We recruited a total of 114 and 69 early PD patients and advanced PD patients, respectively. Univariate and multivariate logistic regression analyses were performed for early PD and advanced PD patients. The prevalence of SCCs in the early PD and advanced PD groups was 60.5 and 68.1%, respectively. In the early PD group, the presence of SCCs in early PD participants was significantly associated with a higher nonmotor symptoms questionnaire (NMSQ) score (OR = 1.05, 95% CI = 1.00-1.10, p = 0.040). SCCs in the advanced PD group were related to lower attention scores (OR = 0.24, 95% CI = 0.05-0.90, p = 0.043) and lower visuospatial/executive abilities scores (OR = 0.18, 95% CI = 0.04-0.86, p = 0.032). The prevalence and SCC-related factors are distinct in early PD and advanced PD. These findings suggest that SCCs in PD patients with different disease statuses appear to have different related factors that may depend on different disease severities.

Cognitive Impairment in Parkinson's Disease: An Updated Overview Focusing on Emerging Pharmaceutical Treatment Approaches

Cognitive impairment in patients with Parkinson's disease (PD) is one of the commonest and most disabling non-motor manifestations during the course of the disease. The clinical spectrum of PD-related cognitive impairment includes subjective cognitive decline (SCD), mild cognitive impairment (MCI) and PD dementia (PDD). As the disease progresses, cognitive decline creates a significant burden for the family members and/or caregivers of patients with PD, and has a great impact on quality of life. Current pharmacological treatments have demonstrated partial efficacy and failed to halt disease progression, and novel, effective, and safe therapeutic strategies are required. Accumulating preclinical and clinical evidence shows that several agents may provide beneficial effects on patients with PD and cognitive impairment, including ceftriaxone, ambroxol, intranasal insulin, nilotinib, atomoxetine, mevidalen, blarcamesine, prasinezumab, SYN120, ENT-01, NYX-458, GRF6021, fosgonimeton, INT-777, Neuropeptide S, silibinin, osmotin, cordycepin, huperzine A, fibroblast growth factor 21, Poloxamer 188, ginsenoside Rb1, thioredoxin-1, tangeretin, istradefylline and Eugenia uniflora. Potential underlying mechanisms include the inhibition of a-synuclein aggregation, the improvement of mitochondrial function, the regulation of synaptic plasticity, an impact on the gut-brain axis, the modulation of neuroinflammation and the upregulation of neurotrophic factors, as well as cholinergic, dopaminergic, serotoninergic and norepinephrine neurotransmission. In this updated overview, we aim to cover the clinical aspects of the spectrum of PD-related cognitive impairment and discuss recent evidence on emerging treatment approaches that are under investigation at a preclinical and clinical level. Finally, we aim to provide additional insights and propose new ideas for investigation that may be feasible and effective for the spectrum of PD-related cognitive impairment.

Subjective cognitive decline in patients with Parkinson's disease: an updated review

Cognitive impairment in patients with Parkinson's disease (PD) worsens the prognosis of PD and increases caregivers' burden and economic consequences. Recently, subjective cognitive decline (SCD), which refers to self-reported cognitive decline without detectable objective cognitive dysfunction, has been regarded as an at-risk state of mild cognitive impairment (MCI) and a prodromal stage for dementia in Alzheimer's disease (AD). However, studies on PD-SCD have thus far been scarce, and at present there is no consensus regarding the definition of SCD nor a gold standard as an evaluation tool. The present review aimed to look for an association between PD-SCD and objective cognitive function and found that PD with SCD occurred with brain metabolic changes, which were consistent with early aberrant pathological changes in PD. Moreover, PD patients with SCD were likely to progress to future cognitive impairment. It is necessary to establish a guideline for the definition and evaluation of SCD in PD. A larger sample size and more longitudinal investigations are needed to verify the predictive effectiveness of PD-SCD and to detect earlier subtle cognitive decline before MCI.

Subjective Cognitive Complaints in Cognitively Normal Patients With Parkinson's Disease: A Systematic Review

Subjective cognitive complaints (SCCs) refer to self-perceived cognitive decline and are related to objective cognitive decline. SCCs in cognitively normal individuals are considered a preclinical sign of subsequent cognitive impairment due to Alzheimer's disease, and SCCs in cognitively normal patients with Parkinson's disease (PD) are also gaining attention. The aim of this review was to provide an overview of the current research on SCCs in cognitively normal patients with PD. A systematic search found a lack of consistency in the methodologies used to define and measure SCCs. Although the association between SCCs and objective cognitive performance in cognitively normal patients with PD is controversial, SCCs appear to be predictive of subsequent cognitive decline. These findings support the clinical value of SCCs in cognitively normal status in PD; however, further convincing evidence from biomarker studies is needed to provide a pathophysiological basis for these findings. Additionally, a consensus on the definition and assessment of SCCs is needed for further investigations.

Treatment for cognitive and neuropsychiatric non-motor symptoms in Parkinson's disease: current evidence and future perspectives

INTRODUCTION

Non-motor symptoms (NMS) affect patients with Parkinson's disease (PD) from the prodromal to the advanced stages. NMS phenotypes greatly vary and have a huge impact on patients' and caregivers' quality of life (QoL). The management of cognitive and neuropsychiatric NMS remains an unmet need.

AREAS COVERED

The authors, herein, review the dopaminergic and non-dopaminergic pathogenesis, clinical features, assessment, and pharmacological and non-pharmacological treatments of cognitive and neuropsychiatric NMS in PD. They discuss the current evidence and report the findings of an overview of ongoing trials on pharmacological and selected non-pharmacological strategies.

EXPERT OPINION

The treatment of cognitive and neuropsychiatric NMS in PD is poorly explored, and therapeutic options are unsatisfactory. Pharmacological treatment of cognitive NMS is based on symptomatic active principles used in Alzheimer's disease. Dopamine agonists, selective serotonin, and serotonin-norepinephrine reuptake inhibitors have some evidence on PD-related depression. Clozapine, quetiapine, and pimavanserin may be considered for psychosis in PD. Evidence on the treatment of other neuropsychiatric NMS is limited or lacking. Addressing pathophysiological and clinical issues, which hamper solid evidence on the treatment of cognitive and neuropsychiatric NMS, may reduce the impact on QoL for PD patients and their caregivers.

Prevalence and affective correlates of subjective cognitive decline in patients with de novo Parkinson's disease

OBJECTIVES

The novel concept of subjective cognitive decline (SCD) in Parkinson's disease (PD) refers to subjective cognitive impairment without concurrent objective cognitive deficits. This study aimed to determine the prevalence and affective correlates of SCD in de novo PD patients.

MATERIALS AND METHODS

A total of 139 de novo PD patients underwent comprehensive neuropsychological evaluation. PD patients with SCD (PD-SCD) did not meet the diagnostic criteria for mild cognitive impairment in PD (PD-MCI) based on the Movement Disorder Society Level II Criteria and were defined by a Domain-5 Score ≥1 on the Non-Motor Symptoms Questionnaire. Affective symptoms were measured using the Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA).

RESULTS

In de novo PD cohort, the prevalence of SCD was 28.1%. PD-SCD patients performed significantly better than PD-MCI patients on tests of five cognitive domains. The more commonly affected domains in PD-SCD patients were memory (28.2%) and attention/working memory (25.6%). Multivariable linear regression analysis revealed that PD-SCD was significantly associated with both HAMD (β = 4.518, 95% CI = 0.754-8.281, p = .019) and HAMA scores (β = 4.259, 95% CI = 1.054-7.464, p = .010). Furthermore, binary logistic regression analysis revealed that higher HAMD (OR = 1.128, 95% CI = 1.019-1.249, p = .020) and HAMA scores (OR = 1.176, 95% CI = 1.030-1.343, p = .017) increased the risk of PD-SCD.

CONCLUSIONS

Our findings suggest that SCD is highly prevalent in de novo PD patients. The presence of PD-SCD is suggestive of an underlying affective disorder.

Caring for patients with cognitive dysfunction, fluctuations and dementia caused by Parkinson's disease

Cognitive dysfunction is one of the most prevalent non-motor symptoms in patients with Parkinson's disease (PD). While it tends to worsen in the later stages of disease, it can occur at any time, with 15-20% of patients exhibiting cognitive deficits at diagnosis (Aarsland et al., 2010; Goldman and Sieg, 2020). The characteristic features of cognitive dysfunction include impairment in executive function, visuospatial abilities, and attention, which vary in severity from subtle impairment to overt dementia (Martinez-Horta and Kulisevsky, 2019). To complicate matters, cognitive dysfunction is prone to fluctuate in PD patients, impacting diagnosis and the ability to assess progression and decision-making capacity. The diagnosis of cognitive impairment or dementia has a huge impact on patient independence, quality of life, life expectancy and caregiver burden (Corallo et al., 2017; Lawson et al., 2016; Leroi et al., 2012). It is therefore essential that physicians caring for patients with PD provide education, screening and treatment for this aspect of the disease. In this chapter, we provide a practical guide for the assessment and management of various degrees of cognitive dysfunction in patients with PD by approaching the disease at different stages. We address risk factors for cognitive dysfunction, prevention strategies prior to making the diagnosis, available tools for screening. Lastly, we review aspects of care, management and considerations, including decision-making capacity, that occur after the patient has been diagnosed with cognitive dysfunction or dementia.

Subjective cognitive decline in idiopathic Parkinson´s disease: A systematic review

Cognitive symptoms of Parkinson's disease (PD) have been long underestimated, but are some of the most disabling non-motor features of the disease. In order to establish signs that allow for earlier detection of cognitive decline in PD, the concept of `subjective cognitive decline´ (SCD) has gained a growing interest. SCD refers to patients who report a decline in subjective cognitive capacities, while their results on neuropsychological tests are within the normal performance range, indicating adequate cognitive functions. The aim of this review was to evaluate the concept of SCD in PD and give an overview of the current research. A systematic literature search in PubMed was performed to identify articles published before December 2020. We included 18 studies with a total of n = 2,654 patients. While there is currently no consensus on research or clinical criteria for SCD in PD, this review presents the accumulated evidence for SCD in PD patients and supports the importance of early identification of cognitive deficits, due to the relatively high prevalence for SCD in PD and the added risk of future cognitive impairment it entails. The publications included in this review indicate that SCD may be part of the PD spectrum but further research is needed. Expanding research on SCD in PD will allow for earlier detection of cognitive impairment and may foster preventive interventions.

Reliability and Validity of the Subjective Cognitive Complaints Questionnaire for Parkinson’s Disease (SCCQ-PD)

Background and Purpose

Subjective cognitive complaints (SCCs) are gaining attention as a self-perceived symptom for cognitive impairment in patients with Parkinson’s disease (PD), but there are few suitable tools for assessing SCCs in PD. This study aimed to develop and validate a questionnaire for assessing SCCs in PD, called the Subjective Cognitive Complaints Questionnaire for Parkinson’s Disease (SCCQ-PD).

Methods

The SCCQ-PD consists of 12 yes/no questions on subjective cognitive function, and the questionnaire was completed by patients with PD (score-P) and their caregivers (score-C). The cognitive function of patients was examined using comprehensive neuropsychological tests.

Results

This study included 73 patients (38 cognitively normal, 25 with mild cognitive impairment [MCI], and 10 demented) and their caregivers. Score-P and score-C had excellent reliability (Kuder-Richardson formula 20 coefficients of 0.893 and 0.931, respectively), and the scores exhibited a strong intercorrelation. Both score-P and score-C were negatively correlated with cognitive performance, and both were excellent in discriminating demented patients from those with normal cognition or MCI (areas under the receiver operating characteristic curve of 0.83 and 0.88, respectively).

Conclusions

The SCCQ-PD is a reliable tool for assessing SCCs in patients with PD. SCCs measured using the SCCQ-PD are correlated with objective cognitive decline and useful for discriminating demented patients from nondemented patients.

Changes in Self- and Informant-Reported Frontal Behaviors in Parkinson's Disease: A Longitudinal Study

OBJECTIVE

Frontal behaviors (i.e., executive dysfunction, disinhibition, apathy) are common in Parkinson's disease (PD). However, it is unclear if patient and informant reports of patient frontal behaviors are in agreement over time.

METHOD

Sixty-two PD patients without dementia and their informants (87% spouses/partners) completed the self- and informant-versions of the Frontal Systems Behavior Scale at baseline and 2-year follow-up. Dyad ratings were compared and predictors of behavior ratings were examined.

RESULTS

Patient and informant reports at baseline and follow-up were in agreement, with significant increases in overall frontal behaviors, executive dysfunction, and apathy. Higher levels of baseline patient depression and caregiver burden predicted decrements in patient-reported executive function; worse patient cognition at baseline predicted worsening apathy as rated by informants.

CONCLUSIONS

PD patients and their informants are concordant in their ratings of worsening frontal behaviors over time. Targeting patient depression, cognition, and caregiver burden may improve decrements in frontal behaviors (executive dysfunction and apathy) in PD.

Correlates of the discrepancy between objective and subjective cognitive functioning in non-demented patients with Parkinson's disease

Background

Subjective complaints of cognitive deficits are not necessarily consistent with objective evidence of cognitive impairment in Parkinson’s disease (PD). Here we examined the factors associated with the objective-subjective cognitive discrepancy.

Methods

We consecutively enrolled 90 non-demented patients with PD who completed the Parkinson’s Disease Cognitive Functional Rating Scale (subjective cognitive measure) and the Montreal Cognitive Assessment (MoCA; objective cognitive measure). The patients were classified as “Overestimators”, “Accurate estimators”, and “Underestimators” on the basis of the discrepancy between the objective vs. subjective cognitive measures. To identify the factors distinguishing these groups from each other, we used chi-square tests or one-way analyses of variance, completed by logistic and linear regression analyses.

Results

Forty-nine patients (54.45%) were classified as “Accurate estimators”, 29 (32.22%) as “Underestimators”, and 12 (13.33%) as “Overestimators”. Relative to the other groups, the “Underestimators” scored higher on the Fatigue Severity Scale (FSS), Beck Depression Inventory (BDI), and Parkinson Anxiety Scale (p < 0.01). Logistic regression confirmed that FSS and BDI scores distinguished the “Underestimators” group from the others (p < 0.05). Linear regression analyses also indicated that FSS and BDI scores positively related to objective-subjective cognitive discrepancy (p < 0.01). “Overestimators” scored lower than other groups on the MoCA’s total score and attention and working memory subscores (p < 0.01).

Conclusion

In more than 45% of consecutive non-demented patients with PD, we found a ‘mismatch’ between objective and subjective measures of cognitive functioning. Such discrepancy, which was related to the presence of fatigue and depressive symptoms and frontal executive impairments, should be carefully evaluated in clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10519-4.

Disentangling the Role of Working Memory in Parkinson's Disease

Working memory (WM) represents a core cognitive function with a major striatal contribution, and thus WM deficits, commonly observed in Parkinson’s disease (PD), could also relate to many other problems in PD patients. Our online study aimed to determine the subdomains of WM that are particularly affected in PD and to clarify the links between WM and everyday cognitive deficits, other executive functions, psychiatric and PD symptoms, as well as early cognitive impairment. Fifty-two mild-to-moderate PD patients and 54 healthy controls performed seven WM tasks tapping selective updating, continuous monitoring, or maintenance of currently active information. Self-ratings of everyday cognition, depression, and apathy symptoms, as well as screenings of global cognitive impairment, were also collected. The data were analyzed using structural equation modeling. Of the three WM domains, only selective updating was directly predictive of PD group membership. More widespread WM deficits were observed only in relation to global cognitive impairment in PD patients. Self-rated everyday cognition or psychiatric symptoms were not linked to WM performance but correlated with each other. Our findings suggest that WM has a rather limited role in the clinical manifestation of PD. Nevertheless, due to its elementary link to striatal function, the updating component of WM could be a candidate for a cognitive marker of PD also in patients who are otherwise cognitively well-preserved.

The sampling precision of research in five major areas of psychology

After obtaining a sample of published, peer-reviewed articles from journals with high and low impact factors in social, cognitive, neuro-, developmental, and clinical psychology, we used a priori equations recently derived by Trafimow (Educational and Psychological Measurement, 77, 831-854, 2017; Trafimow & MacDonald in Educational and Psychological Measurement, 77, 204-219, 2017) to compute the articles' median levels of precision. Our findings indicate that developmental research performs best with respect to precision, whereas cognitive research performs the worst; however, none of the psychology subfields excelled. In addition, we found important differences in precision between journals in the upper versus lower echelons with respect to impact factors in cognitive, neuro-, and clinical psychology, whereas the difference was dramatically attenuated for social and developmental psychology. Implications are discussed.

Subjective cognitive complaints in patients with Parkinson's disease

Mild cognitive impairment (MCI) is common in Parkinson's disease (PD), affecting almost all patients with PD at some time. It has been shown that patients with PD, who express subjective cognitive complaints, are at a higher risk of eventually developing PD-MCI. This is corroborated by the Movement Disorders Society's (MDS) diagnostic criteria from 2012 for PD-MCI, from which it follows that a subjective cognitive complaint must be present in addition to objective cognitive impairment for a patient with PD to receive a diagnosis of PD-MCI. Nevertheless, there is currently no standardized measurement available for assessing subjective cognitive complaints. Therefore, this review aims to generate an overview of how subjective cognitive complaints are commonly operationalized in the empirical literature as well as whether they are found to be associated with the level of cognitive impairment. The findings revealed that a broad range of measures has been used to obtain subjective cognitive complaints and that there is little consistency between different studies with regard to how they have obtained these complaints, from whom they had obtained them, how many they have obtained, which types of complaints they have obtained and whether they were associated with cognitive impairment. Given the fact that the presence of subjective cognitive complaints is a requirement for setting a diagnosis, there is a need for more methodological consensus with regard to the measurement hereof.

Subjective memory decline in Parkinson's disease patients with and without fatigue

INTRODUCTION

Previous studies on Parkinson's disease (PD) have shown that memory complaints and fatigue co-occur since premotor stages of disease, but whether Subjective Memory Decline (SMD, defined as memory complaints with normal objective cognitive performance) and fatigue were associated in PD has not been explored yet.

METHODS

One-hundred PD patients underwent measures of memory complaints (Multifactorial Memory Questionnaire, MMQ), neuropsychological test (Parkinson's Disease-Cognitive Rating Scale), and assessment of behavioural symptoms. Fatigue was diagnosed according to current diagnostic criteria. Mann-Whitney test or Pearson chi-square test were used to compare fatigued and nonfatigued patients for prevalence of SMD and for demographic, clinical, and behavioural features, memory complaint, and objective cognitive measures. The confounding effect of sample's features on results was controlled by logistic regression and Quade's rank analysis.

RESULTS

Twenty-three patients were diagnosed as fatigued whereas 15 patients met SMD criteria. Fatigued patients showed higher levodopa equivalent daily dose and more marked behavioural symptoms than nonfatigued patients (p_s< 0.01). The prevalence of SMD was higher in fatigued patients than in those nonfatigued (35% vs 9%, p < 0.01). After controlling for confounds, the patients with fatigue had an odds ratio for SMD 5.97 [CI 95%, 1.18-30.03] times higher and presented significantly lower scores on Contentment subscales of MMQ (p < 0.01) than those without fatigue.

CONCLUSION

Fatigue in PD is associated with SMD mainly characterized by less contentment with one's own memory ability. These findings suggest possible shared pathogenic mechanisms underlying these two nonmotor manifestations and foster to identify potential phenotypes of patients requiring multistrategic therapeutic approaches.

"Pseudo-syndromes" associated with Parkinson disease, dementia, apathy, anxiety, and depression

PURPOSE OF REVIEW

Physicians treating patients with Parkinson disease must evaluate not only motor symptoms but also acquire expertise in assessing the complex behavioral features that often accompany the disease, such as dementia, apathy, anxiety, and depression.

RECENT FINDINGS

There is a risk of diagnostic confusion and error because many of the behavioral and motor symptoms accentuate, overlap, or mimic each other.

SUMMARY

Awareness of potential diagnostic pitfalls and "pseudo-syndromes" should lead to more accurate clinical assessment and better care for our patients.

Unsupervised online neuropsychological test performance for individuals with mild cognitive impairment and dementia: Results from the Brain Health Registry

Introduction

The purpose of this study is to compare online neuropsychological test performance of older adults across self-reported diagnoses of being cognitively normal, mild cognitive impairment, and dementia due to Alzheimer's disease and to determine the association of memory concerns and family history of dementia on cognitive performance.

Methods

Participants completed the Cogstate Brief Battery unsupervised at home.

Results

Data from 6463 participants over the age of 55 years were analyzed. Adults with the diagnosis of mild cognitive impairment and Alzheimer's disease were associated with poorer performance on all cognitive tests than cognitively normal adults (P < .05 for all), and online cognitive test performance significantly improved diagnostic classification (P < .001). Poorer performance on all cognitive measures was associated with memory concern (P < .001 for all) but not family history of dementia.

Discussion

Our results provide preliminary support for the use of cognitive tests taken online without supervision as a means to improve the efficiency of participant screening and recruitment for clinical trials.

In Vivo cortical tau in Parkinson's disease using 18F-AV-1451 positron emission tomography

BACKGROUND

Alzheimer's disease copathology is common in PD at autopsy. In non-PD subjects with mild cognitive impairment, tau depositions can be detected using 18F-AV-1451 PET. We hypothesized that 18F-AV-1451 PET would show tau aggregation in PD with mild cognitive impairment and correlate with cognitive dysfunction.

OBJECTIVES

To describe tau aggregation in PD patients.

METHODS

Twenty-six PD patients and 23 controls had 18F-AV-1451 PET and neuropsychological assessment to detect mild cognitive impairment.

RESULTS

Nine PD patients (35%) were identified with mild cognitive impairment. Regional analyses showed no significant differences between groups. Voxel-wise analyses showed no correlation with cognitive domain z-scores within patients. One patient with mild cognitive impairment was estimated Braak tau stage 5; all other patients were stage 0.

CONCLUSION

Our results indicate that tau pathology, as detected by 18F-AV-1451, is uncommon in PD with mild cognitive impairment and shows no significant correlation with cognitive dysfunction at this stage. © 2017 International Parkinson and Movement Disorder Society.

Anxiety is associated with cognitive impairment in newly-diagnosed Parkinson's disease

Introduction

Anxiety and mild cognitive impairment (MCI) are prevalent non-motor manifestations of Parkinson's disease (PD). While few studies have demonstrated a possible link between cognitive dysfunction and anxiety in PD, to our knowledge, no studies have directly examined the association between them. This study investigated the association between anxiety and cognitive deficits in newly diagnosed PD patients.

Methods

Patients with newly diagnosed PD (N = 185) were recruited from community and outpatient clinics. Anxiety was assessed using the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) clinician rated anxiety item, which has previously been validated against a standardized criteria for the diagnosis of anxiety disorders in PD. Participants scoring ≥2 were classified as anxious. A threshold of 1 SD below normative values (obtained from controls) was used to define cognitive impairment. Impairments in specific cognitive domains were identified as being >1 SD below controls in ≥1 test per domain.

Results

After controlling for age, education and motor severity, patients with anxiety were three times more likely to have cognitive impairment compared to those without anxiety (OR = 3.0, 95% CI = 1.2–7.3, p < 0.05). Patients with anxiety were more than twice as likely to be classified as having cognitive impairment due to impairment in the memory domain compared with PD without anxiety (OR = 2.3, 95% CI = 1.0–5.1, p < 0.05), whilst no associations were found between anxiety and performance on other cognitive domains.

Conclusion

This study shows an association between anxiety and cognitive impairment (specifically memory impairment). Examining the neural basis of this association warrants future research in this developing field.

•

Anxiety was associated with mild cognitive impairment (MCI) in PD.

•

Patients with anxiety were three times more likely to have cognitive impairment.

•

Anxiety was specifically associated with impairments in the memory domain.

Cognitive impairment in Parkinson's disease: Association between patient-reported and clinically measured outcomes

BACKGROUND

In Parkinson's disease, the association between objective and patient-reported measures of cognitive dysfunction is unknown and highly relevant to research and clinical care.

OBJECTIVE

To determine which cognitive domain-specific Montreal Cognitive Assessment (MoCA) subscores are most strongly associated with patient-reported cognitive impairment on question 1 (Q1) of the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS).

METHODS

We analyzed data from 759 PD participants and 481 persons without PD with in a retrospective, cross sectional analysis using data from the NINDS Parkinson's Disease Biomarkers Program (PDBP), a longitudinal, multicenter biomarker study. The relationship between a patient-reported cognitive rating (MDS-UPDRS q1.1) and objective cognitive assessments (MoCA) was assessed using multinomial logistic regression modeling and the outcomes reported as conditional odds ratios (cOR's) representing the relative odds of a participant reporting cognitive impairment that is "slight" versus "normal" on MDS-UPDRSq1.1 for a one unit increase in a MoCA sub-score, adjusted for age and education.

RESULTS

In PD participants, changes in visuospatial-executive performance and memory had the most significant impact on subjective cognitive impairment. A 1-point increase in visuospatial-executive function decreased the chance of reporting a MDS-UPDRS Q1 score of "slight" versus "normal" by a factor of 0.686 (p < 0.001) and each 1 point improvement in delayed recall decreased the odds of reporting "slight" cognitive impairment by a factor of 0.836 (p < 0.001).

CONCLUSIONS

Conversion from a PD patient's report of "normal" to "slight" cognitive impairment may be associated with changes in visuospatial-executive dysfunction and memory more than other cognitive domains.

Preclinical Alzheimer's disease: Definition, natural history, and diagnostic criteria

During the past decade, a conceptual shift occurred in the field of Alzheimer's disease (AD) considering the disease as a continuum. Thanks to evolving biomarker research and substantial discoveries, it is now possible to identify the disease even at the preclinical stage before the occurrence of the first clinical symptoms. This preclinical stage of AD has become a major research focus as the field postulates that early intervention may offer the best chance of therapeutic success. To date, very little evidence is established on this "silent" stage of the disease. A clarification is needed about the definitions and lexicon, the limits, the natural history, the markers of progression, and the ethical consequence of detecting the disease at this asymptomatic stage. This article is aimed at addressing all the different issues by providing for each of them an updated review of the literature and evidence, with practical recommendations.