The tools of the trade: A state of the art “How to Assess Cognition” in the patient with Parkinson's disease: Assessing Cognition in Parkinson's Disease

Analyzing direct effects of education level and estimated IQ between cognitively intact Mexican Americans and Non-Hispanic whites on a confrontational naming task

Confrontational naming is widely used in diagnosing neurodegenerative disorders like MCI and dementia, and previous research indicates that healthy Non-Hispanic Whites outperform Hispanics in such tasks. However, understanding the factors contributing to score differences among ethnic groups remains limited. This study focuses on cognitively intact Mexican Americans and Non-Hispanic White older adults from the TARCC Hispanic Cohort project. Hierarchical regression analyses reveal that sex, age, ethnicity, education level, and estimated IQ significantly predict performance on the Boston Naming Test (BNT). Notably, education level and estimated IQ more strongly influence BNT performance in Mexican Americans than in Non-Hispanic Whites. When controlling for education level, estimated IQ has a more pronounced impact on BNT performance in aging Mexican Americans compared to Non-Hispanic Whites. Conversely, after controlling for estimated IQ, the influence of education level is weaker for Mexican Americans than Non-Hispanic Whites. These findings emphasize the need for careful evaluation of confrontational naming task scores in diverse ethnic groups, emphasizing the critical role of education and estimated IQ in understanding performance disparities.

Cognitive testing in late-stage Parkinson's disease: A critical appraisal of available instruments

OBJECTIVE

For patients with Parkinson's disease (PD), cognitive impairment is one of the most disabling non-motor symptoms, particularly in the late disease stages (LSPD). Without a common cognitive assessment battery, it is difficult to estimate its prevalence and limits comparisons across studies. In addition, some instruments traditionally used in PD may not be adequate for use in LSPD. We sought to identify instruments used to assess cognition in LSPD and to investigate their global characteristics and psychometric properties to recommend a cognitive battery for the LSPD population.

METHOD

We conducted a literature search of EMBASE and MEDLINE for articles reporting the use of cognitive tests in LSPD. The global characteristics and psychometric properties of the four most used cognitive tests in each cognitive domain were verified to recommend a cognitive assessment battery.

RESULTS

Of 60 included studies, 71.7% used screening scales to assess cognition. Of the 53 reported instruments, the Montreal Cognitive Assessment, the Digit Span, the Trail Making Test, the Semantic Fluency test, the Rey Auditory Verbal Learning Test, the Brief Visuospatial Memory Test-Revised, the Boston Naming Test, the Judgment of Line Orientation, and the Clock Drawing Test corresponded best overall to the requirements considered important for selecting instruments in LSPD.

CONCLUSION

Screening scales are frequently used to assess cognition in LSPD. We recommend a cognitive assessment battery that considers the special characteristics of the LSPD population, including being quick and easy to use, with minimized motor demands, and covering all relevant cognitive domains.

Exercising with a robotic exoskeleton can improve memory and gait in people with Parkinson's disease by facilitating progressive exercise intensity

People with Parkinson's disease (PwPD) can benefit from progressive high-intensity exercise facilitated with a lower-extremity exoskeleton, but the mechanisms explaining these benefits are unknown. We explored the relationship between exercise intensity progression and memory and gait outcomes in PwPD who performed 8 weeks (2 × per week) of progressive exercise with and without a lower-extremity powered exoskeleton, as the planned exploratory endpoint analysis of an open-label, parallel, pilot randomized controlled trial. Adults 50-85 years old with a confirmed diagnosis of PD participated. Twenty-seven participants randomized to exercise with (Exo = 13) or without (Nxo = 14) the exoskeleton were included in this exploratory endpoint analysis. Detailed exercise logs were kept and actigraphy was used to measure activity count*min-1 (ACPM) during all exercise sessions. Only the Exo group were able to progressively increase their ACPM over the entire 8-week intervention, whereas the Nxo group plateaued after 4 weeks. Exercise intensity progression correlated with change in the memory sub-scale of the SCOPA-COG and change in gait endurance from the 6MWT, consistent with the prevailing hypotheses linking high-intensity interval exercise to improved muscle and brain function via angiogenic and neurotrophic mechanisms. Facilitating high-intensity exercise with advanced rehabilitation technology is warranted for improving memory and gait endurance in PwPD.Registration: ClinicalTrials.gov, NCT03583879 (7/10/2018).

Detecting Subtle Cognitive Impairment in Patients with Parkinson's Disease and Normal Cognition: A Novel Cognitive Control Challenge Task (C3T)

Patients with Parkinson's disease (PD) often show early deficits in cognitive control, with primary difficulties in flexibility and relatively intact stable representations. The aim of our study was to assess executive function using an ecologically valid approach that combines measures of stability and flexibility. Fourteen patients without cognitive deficits and sixteen comparable control subjects completed a standardized neuropsychological test battery and a newly developed cognitive control challenge task (C3T). We found that the accuracy of C3T performance decreased with age in healthy participants and remained impaired in PD patients regardless of age. In addition, PD patients showed significantly lower overall performance for cognitive control tasks than healthy controls, even when they scored in the normal range on standardized neuropsychological tests. PD Patients responded significantly faster than healthy control subjects regarding flexible cognitive control tasks due to their impulsivity. Correlations showed that the C3T task targets multiple cognitive systems, including working memory, inhibition, and task switching, providing a reliable measure of complex cognitive control. C3T could be a valuable tool for characterizing cognitive deficits associated with PD and appears to be a more sensitive measure than standardized neuropsychological tests. A different assessment approach could potentially detect early signs of the disease and identify opportunities for early intervention with neuroprotective therapies.

Cognitive evaluation in Parkinson's disease: applying the Movement Disorder Society recommendations in a population with a low level of formal education

BACKGROUND

 The diagnosis of cognitive disorders in Parkinson disease (PD) can be very challenging. Aiming at establishing uniform and reliable diagnostic procedures, the International Parkinson's Disease and Movement Disorder Society (MDS) commissioned task forces to delineate diagnostic criteria for mild cognitive impairment (MCI) and dementia in PD.

OBJECTIVES

 To investigate the applicability of the MDS recommendations for cognitive evaluation in a Brazilian sample of patients with PD with low levels of formal education.

METHODS

 A total of 41 patients with PD were subjected to a comprehensive neuropsychological evaluation based on tests proposed by the MDS, which included the Mini-Mental State Examination, the Mattis Dementia Rating Scale (MDRS), the Trail Making Test (TMT) parts A and B, in addition to language and memory skills assessment. Neuropsychiatric and daily functioning features were also evaluated. Spearman correlation analyses were used to evaluate the association between the scores obtained in the cognitive scales and demographic/clinical variables.

RESULTS

 Although none of the participants had a formal diagnosis of dementia, 50% presented some degree of cognitive impairment when considering the results of the MDRS. Of note, a noticeable number of patients was not able to complete the full neuropsychological assessment. The TMT part B was the most difficult task, being completed by only 22 participants (54%). As expected, the greater the educational level, the better the performance on the cognitive tests. Better motor function was also associated with better scores in cognition.

CONCLUSIONS

 Adopting strict inclusion/exclusion criteria and a comprehensive clinical evaluation, we found remarkable limitations for the MDS recommendations when individuals with low educational levels are considered. A revision of the current guidelines is necessary considering differences among populations, especially related to formal education.

Correspondence of the Boston Naming Test and Multilingual Naming Test in identifying naming impairments in a geriatric cognitive disorders clinic

Confrontation naming measures are commonly used for both diagnostic and clinical research purposes in populations of known or suspected neurodegenerative disorders. The Boston Naming Test (BNT) is the most widely used measure of confrontation naming but has been criticized for outdated and culturally biased content. A new naming measure, the Multilingual Naming Test (MiNT), has been developed that may address these limitations, but research regarding its validity and diagnostic performance relative to existing instruments is limited. The current study examined how the BNT and MiNT performed in a sample of older adults evaluated in an interprofessional memory disorders clinic. Eighty-six individuals (50.0% women) met the inclusion criteria and were included in the study. The average age of participants was 74.2 years (SD = 7.7), and the average education was 16.7 years (SD = 2.5). Most participants were non-Hispanic White (94.2%), and the remaining participants were Hispanic or Black. All participants completed a comprehensive evaluation in English and were administered both the BNT and the MiNT. The strength of agreement as indexed by CCC (.67) was modest for the sample as a whole. Eighty-seven-point five percent classification agreement for impaired vs. normal naming performance was obtained. Eleven cases showed disagreement between BNT and MiNT classification of impairment, with seven of these being borderline score cases. Overall, the results suggest that the MiNT performs similarly at the identification of naming impairments as the BNT, though performance may diverge across different diagnostic groups and may be influenced by age.

Using gait robotics to improve symptoms of Parkinson's disease: an open-label, pilot randomized controlled trial

BACKGROUND

People with Parkinson's Disease (PD) have difficulty participating in exercise.

AIM

The primary objective of this pilot randomized controlled trial (RCT) was to determine if 8 weeks (2x per week) of bilateral exoskeleton (Exo) exercise results in positive changes in cognition and participation in adults with PD compared to exercising without an exoskeleton (Nxo) or wait-list control (Con).

DESIGN

Open-label, parallel, pilot randomized controlled trial.

SETTING

Neurorehabilitation clinic in a large urban center.

POPULATION

Adults 50-85 years old with a confirmed diagnosis of PD.

METHODS

Eight weeks of twice-weekly combined aerobic, strength and mobility exercise or wait-list control. Participants were randomly assigned to exercise with no exoskeleton (Nxo), exercise with the exoskeleton (Exo), or waitlist control (Con). Primary endpoints were change in cognitive function (SCOPA-COG) and mood. Secondary endpoints were change in gait speed, six-minute walk test (6MWT), freezing of gait, balance, and PD-specific health and quality of life outcomes. Safety endpoint was analysis of adverse events (AE).

RESULTS

Forty participated in the trial (Exo, N.=13; Nxo, N.=14; Con, N.=13). Significant improvement in the Memory & Learning domain of the SCOPA-COG (P=0.014) and 6MWT (P=0.008) were detected for the Exo group compared to the Nxo and/or Con group. No other statistically significant between-groups effects were found. There were no serious or unanticipated AE.

CONCLUSIONS

Functional exercise with a low-profile overground exoskeleton showed promising results for improving memory and gait endurance in people with PD across HY stages I-IV.

CLINICAL REHABILITATION IMPACT

Exoskeletons can improve participation in high-intensity exercise.

Cognitive control in Parkinson's disease

Cognitive control is the ability to act according to plan. Problems with cognitive control are a primary symptom and a major decrement of quality of life in Parkinson's disease (PD). Individuals with PD have problems with seemingly different controlled processes (e.g., task switching, impulsivity, gait disturbance, apathetic motivation). We review how these varied processes all rely upon disease-related alteration of common neural substrates, particularly due to dopaminergic imbalance. A comprehensive understanding of the neural systems underlying cognitive control will hopefully lead to more concise and reliable explanations of distributed deficits. However, high levels of clinical heterogeneity and medication-invariant control deficiencies suggest the need for increasingly detailed elaboration of the neural systems underlying control in PD.

An initial exploration of the convergent and ecological validity of the UDS 3.0 neuropsychological battery in Parkinson's Disease

OBJECTIVE

The Uniform Data Set 3.0 neuropsychological battery (UDS3NB) is well developed for research with Alzheimer's disease and related dementias, and may serve as a common set of measures of cognitive decline across neurodegenerative diseases. However, the battery has not been formally assessed in persons with Parkinson's disease (PD). The current research provides initial information on the convergent and ecological validity of the UDS3NB in individuals with PD.

METHODS

Participants included 75 individuals diagnosed with PD from the Arizona Study of Aging and Neurodegenerative Disorders. Clinical dementia ratings, administered independently from the cognitive measures, identified individuals as having normal cognition (n = 38), Mild Cognitive Impairment (MCI; n = 25) and dementia (n = 12). UDS3NB measures were compared between these groups, and correlations between UDS3NB measures, gold standard neuropsychological measures, and informant rated activities of daily living ability (ADL) were evaluated.

RESULTS

At the group-level, UDS3NB scores followed the expected pattern with higher scores in participants with PD but no cognitive diagnosis and lower in those with dementia; scores in the MCI group were between these extremes. Convergent validity was suggested by moderate correlations between UDS specific measures (i.e., Craft story) and measures such as the RAVLT. Ecological validity was suggested by statistically significant correlations between UDS3NB performance and caregiver ratings of ADLs, with speed and executive functioning measures (Trailmaking A; r = -.51, p < .01; Trailmaking B; r = -.51, p < .01) most strongly related to reported daily functioning.

CONCLUSIONS

Findings provide initial support for the convergent and ecological validity of the UDS3NB in individuals with PD. Implications and future directions for this battery are discussed.

Cognitive Correlates of Instrumental Activities of Daily Living Performance in Parkinson Disease Without Dementia

OBJECTIVE

To investigate cognitive correlates of instrumental activities of daily living (IADL) performance among people with Parkinson disease (PD) without dementia.

DESIGN

Cross-sectional.

SETTING

Academic medical center.

PARTICIPANTS

Volunteer sample (N=161) comprising participants with PD without dementia (n=102) and healthy comparison (HC) participants (n=59).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Performance-based assessment of cognitively-demanding IADL (meal preparation, bill paying, shopping, medication management, small home repair), neuropsychological tests (attentional control/flexibility, planning, working memory, memory, crystallized intelligence), and measures of motor function and other characteristics (eg, depressive symptoms).

RESULTS

There were no group differences in neuropsychological test performance (P>.06). The PD group performed more poorly than the HC group on a number of cognitive IADL tasks (P<.04). After accounting for the effects of motor impairment and other disease-related characteristics, neuropsychological test performance accounted for a small but unique portion of the variance in performance of all cognitive IADL combined, meal preparation, shopping, and medication management in the PD group (R 2=4%-13%; P≤.01).

CONCLUSIONS

The PD group had cognitive IADL performance limitations despite being unimpaired on neuropsychological tests. Within PD, neuropsychological test performance accounted for a small but significant portion of the variance in cognitive IADL performance over and above the effects of motor and other impairments. These results support the added value of using performance-based IADL assessments in functional evaluations of individuals with early and mild PD without dementia.

Virtual Reality Functional Capacity Assessment Tool (VRFCAT-SL) in Parkinson's Disease

Background:

Cognitive impairment is common in Parkinson’s disease (PD) and highly associated with loss of independence, caregiver burden, and assisted living placement. The need for cognitive functional capacity tools validated for use in PD clinical and research applications has thus been emphasized in the literature. The Virtual Reality Functional Capacity Assessment Tool (VRFCAT-SL) is a tablet-based instrument that assesses proficiency for performing real world tasks in a highly realistic environment.

Objective:

The present study explored application of the VRFCAT-SL in clinical assessments of patients with PD. Specifically, we examined associations between VRFCAT-SL performance and measures of cognition, motor severity, and self-reported cognitive functioning.

Methods:

The VRFCAT-SL was completed by a sample of 29 PD patients seen in clinic for a comprehensive neuropsychological evaluation. Fifteen patients met Movement Disorders Society Task Force criteria for mild cognitive impairment (PD-MCI); no patients were diagnosed with dementia. Non-parametric correlations between VRFCAT-SL performance and standardized neuropsychological tests and clinical measures were examined.

Results:

VRFCAT-SL performance was moderately associated with global rank on neuropsychological testing and discriminated PD-MCI. Follow-up analyses found completion time was associated with visual memory, sustained attention, and set-switching, while errors were associated with psychomotor inhibition. No clinical or motor measures were associated with VRFCAT-SL performance. Self-report was not associated with VRFCAT-SL or neuropsychological test performance.

Conclusion:

The VRFCAT-SL appears to provide a useful measure of cognitive functional capacity that is not confounded by PD motor symptoms. Future studies will examine utility in PD dementia.

The Effect of Deep Brain Stimulation of the Subthalamic Nucleus on Language Function in Parkinson's Disease: A Systematic Review

Purpose This systematic review focuses on the effect of bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on language function in Parkinson's disease (PD). It fills an important gap in recent reviews by considering other language tasks in addition to verbal fluency. Method We critically and systematically reviewed the literature on studies that investigated the effect of bilateral STN-DBS on language function in PD. All studies included a matched PD control group who were on best medical treatment, with language testing at similar baseline and follow-up intervals as the DBS PD group. Results Thirteen identified studies included a form of a verbal fluency task, seven studies included picture naming, and only two studies included more language-oriented tasks. We found that verbal fluency was negatively affected after DBS, whereas picture naming was unaffected. Studies investigating individual change patterns using reliable change indices showed that individual variability is larger for picture naming than for verbal fluency. Conclusions Verbal fluency is the most frequently investigated aspect of language function. Our analysis showed a pattern of decline in verbal fluency across multiple studies after STN-DBS, whereas picture naming was unaffected. Data on more language-oriented tests in a large DBS sample and best medical treatment control group are sparse. The investigation of language function in PD after DBS requires sensitive language tests (with and without time pressure) and experimental designs as used in the studies reviewed here. Reliable change index statistics are a promising tool for investigating individual differences in performance after DBS. Supplemental Material https://doi.org/10.23641/asha.14794458.

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.

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.

Subclinical affective and cognitive fluctuations in Parkinson's disease: a randomized double-blind double-dummy study of Oral vs. Intrajejunal Levodopa

BACKGROUND

Chronic levodopa treatment in Parkinson's disease (PD) may promote undesirable motor and non-motor fluctuations. Compared to chronic oral levodopa treatment, continuous infusion of levodopa/carbidopa intestinal gel (LCIG) in advanced PD reduces motor fluctuations. However, differences in their effect on acute non-motor changes were not formally demonstrated.

OBJECTIVE

We performed a randomized, double-blind, double-dummy, crossover study to compare acute non-motor changes between intermittent oral immediate-release carbidopa/levodopa (LC-IR) and LCIG.

METHODS

After > 12-h OFF, thirteen PD patients chronically treated with LCIG and without history of non-motor swings, were allocated to receive first, LCIG infusion plus three oral doses of placebo, or placebo infusion plus three oral doses of LC-IR. Over-encapsulated oral medication (LC-IR or placebo) was administered every 2 h. We monitored plasmatic levels of levodopa, motor status (UPDRS-III), mood, anxiety, and frontal functions at baseline (0-h) and hourly after each oral challenge.

RESULTS

Repeated-measures ANOVAs showed significant group by treatment interaction indicating more fluctuations of levodopa plasma levels with LC-IR. No significant interactions were seen in the temporal profile of motor status, anxiety, mood and cognition. However, point-to-point parametric and nonparametric tests showed a significant more marked and more sustained improvement in anxiety scores under LCIG. A significant improvement of mood and verbal fluency was seen a + 3-h only under LCIG.

DISCUSSION

Our sample of advanced PD patients exhibited moderate but significant non-motor fluctuations. LCIG was associated with a more favorable profile of acute affective and cognitive fluctuations that was particularly expressed at the first part of the infusion curve.

ReadySteady intervention to promote physical activity in older adults with Parkinson's disease: Study design and methods

The main motor impairments of gait and balance experienced by people with Parkinson's disease (PD) contribute to a sedentary lifestyle, resulting in poor physical conditioning, loss of functional independence, and reduced quality of life. Despite the known benefits of physical activity in PD, the majority of older adults with PD are insufficiently active. Few studies incorporate behavioral change approaches to promoting physical activity in PD. The main goal of this research is to foster community mobility in older adults with PD by promoting physical activity and improving gait patterns using a theory-based behavioral change intervention. The ReadySteady intervention combines wellness motivation theory with polestriding physical activity, which has been shown to be beneficial for people with PD. The intervention will be tested using a randomized controlled design, including inactive older adults diagnosed with PD. Participants will be randomly assigned the 12-week ReadySteady intervention, 12-week polestriding, and education intervention, or 12-week education intervention. Thirty-six older adults with PD will participate in each of the interventions. Level of physical activity, clinical scores, quantitative measures of gait and balance control, and motivational variables for each intervention will be measured at three time points: pre-intervention, post-intervention (12 weeks), and follow-up (24 weeks). If the intervention is beneficial, it may serve as a sustainable addition to current practice in health promotion efforts serving the PD population.

Cognitive and behavioral assessment in Parkinson's disease

Introduction: Cognitive impairment and behavioral disturbances are common findings in Parkinson's disease (PD). Despite initially being considered late complications of the disease, it is currently accepted that almost all PD patients will exhibit cognitive and behavioral abnormalities from the early and even the premotor stages of the disease. Areas covered: The present review focuses on the cognitive profile of PD, the clinical picture of PD-MCI and dementia in PD (PDD) and the recommended methods for cognitive assessment in this population. The authors also describe the more representative neuropsychiatric alterations and provide an overview of the recommended methods of assessment. Expert opinion: Cognitive and behavioral symptoms are inherent to PD, appear in a vast majority of patients at some point during disease progression and have an enormous impact on health-related quality of life of patients and caregivers. Validated methods of cognitive and behavioral assessment are currently developed and must be used in research and clinical settings.

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.

Impact of Cognitive Profile on Impulse Control Disorders Presence and Severity in Parkinson's Disease

Background: Impulse control disorders (ICDs) and related behaviors are frequent in Parkinson's disease (PD). Mild cognitive impairment (PD-MCI) and dementia (PDD), both characterized by heterogeneous cognitive phenotypes, are also commonly reported in PD. However, the frequency and severity of ICD within PD cognitive states is unknown.

Methods: Three hundred and twenty-six PD patients completed a comprehensive neuropsychological assessment and were classified as PD-MCI, PDD, or without cognitive alterations (PD-NC). The Minnesota impulsive disorders interview was used to ascertain the presence (ICD+) or absence (ICD–) of ICD. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale was used to assess ICD severity. A subsample of 286 patients evaluated with the same cognitive tasks was selected in order to investigate the characteristics of ICD in PD cognitive phenotypes.

Results: ICDs were present in 55% of PD-NC, in 50% of PD-MCI, and in 42% of PDD patients. Frequencies of ICD+ with attentive (ICD+: 20% vs. ICD–: 4%; p = 0.031) and executive impairments (ICD+: 44% vs. ICD–: 30%; p = 0.027) were higher in the PD-MCI and PDD subgroups, respectively. As expected, no differences were observed in the PD-NC. PD-MCI with attentive impairments presented higher percentage of ICD+ with deficits in the Trail Making Test B-A but not in the Digit Span Sequencing task. In PDD, executive failures concerned Similarities task (ICD+: 67%; ICD–: 29%; p = 0.035), with no differences between ICD+ and ICD– in the Stroop task.

Conclusions: Prevalence and severity of ICDs and related behaviors do not differ in PD with different cognitive states. However, ICD+ are more likely to show deficits, respectively in attentive and in executive domains, specifically in the Trail Making Test B-A task for the attention and working memory domain in PD-MCI and in the Similarities task for the executive function domain in PDD. Prospective studies should evaluate if these tests can be used as screening tool for ICDs in PD.

Information processing deficit in older adults with HIV infection: A comparison with Parkinson's disease

OBJECTIVE

Individuals with HIV treated with antiretroviral therapy can expect to reach average life span, making them susceptible to combined disease and aging effects on cognitive and motor functions. Slowed processing speed in HIV is a concern for cognitive and everyday functioning and is sensitive to declines in aging. We hypothesized that information processing (IP) deficits, over and above that expected with normal aging, would occur in older HIV patients similar to those observed in Parkinson's disease (PD) patients, with both conditions affecting frontostriatal pathways.

METHOD

Groups comprised 26 individuals with HIV infection, 29 with mild-to-moderate PD, and 21 healthy controls (C). Speed of IP was assessed with the oral version of the Symbol Digit Modalities Test and the color naming condition of the Golden Stroop Task.

RESULTS

The HIV group was impaired on speed of IP tasks compared with both the C and PD groups. Even after controlling for normal aging effects, older age in the HIV group correlated with IP slowing. Slower IP speed was associated with poorer general cognitive ability and more extrapyramidal motor signs in older HIV-infected individuals.

CONCLUSIONS

The notable effects of impaired IP speed, over and above neurotypical age-related declines, indicate that older HIV-infected individuals may have an enhanced vulnerability for developing nonmotor and motor symptoms despite antiretroviral therapy. Assessing for oral IP speed may provide the unique opportunity to identify early signs of progressive clinical declines in HIV. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Cognitive impairment in Parkinson's disease: a report from a multidisciplinary symposium on unmet needs and future directions to maintain cognitive health

People with Parkinson's disease (PD) and their care partners frequently report cognitive decline as one of their greatest concerns. Mild cognitive impairment affects approximately 20-50% of people with PD, and longitudinal studies reveal dementia in up to 80% of PD. Through the Parkinson's Disease Foundation Community Choice Research Award Program, the PD community identified maintaining cognitive function as one of their major unmet needs. In response, a working group of experts across multiple disciplines was organized to evaluate the unmet needs, current challenges, and future opportunities related to cognitive impairment in PD. Specific conference goals included defining the current state in the field and gaps regarding cognitive issues in PD from patient, care partner, and healthcare professional viewpoints; discussing non-pharmacological interventions to help maintain cognitive function; forming recommendations for what people with PD can do at all disease stages to maintain cognitive health; and proposing ideas for how healthcare professionals can approach cognitive changes in PD. This paper summarizes the discussions of the conference, first by addressing what is currently known about cognitive dysfunction in PD and discussing several non-pharmacological interventions that are often suggested to people with PD. Second, based on the conference discussions, we provide considerations for people with PD for maintaining cognitive health and for healthcare professionals and care partners when working with people with PD experiencing cognitive impairment. Furthermore, we highlight key issues and knowledge gaps that need to be addressed in order to advance research in cognition in PD and improve clinical care.

Cognitive and Neuropsychiatric Features of Early Parkinson's Disease

The clinical definition of Parkinson's disease (PD) is based on cardinal motor features including bradykinesia as well as an additional symptom of tremor, postural instability, or rigidity. Evidence from neuropathological, imaging, and clinical research suggests a premotor, early phase of PD pathology. Further understanding of the earliest biomarkers of PD is crucial for the development of neuroprotective, disease modifying, cognitive, and psychiatric interventions. Recent research has explored early non-motor markers of PD pathology. This issue is especially timely as the International Parkinson and Movement Disorder Society has recently provided a research definition for prodromal PD which includes combinations of prodromal markers and risk factors aimed at identifying target populations for disease-prevention trials. In this review of early PD, we will outline early non-motor symptoms, early cognitive and neuropsychiatric features, neuropsychological assessment strategies, emerging evidence for early biomarkers, and treatment recommendations.

The Role of a Neuropsychologist on a Movement Disorders Deep Brain Stimulation Team

The term movement disorders is misleading in the implication that the symptoms are limited to motor problems. Most movement disorders include a variety of neurobehavioral and neurocognitive symptoms that require neuropsychological expertise. The goal of this paper is to provide a rationale and practical roadmap for neuropsychologists' involvement in a Movement Disorders team with a specific focus on pre-operative deep brain stimulation (DBS) evaluations. Pragmatic recommendations regarding requisite skills, clinical practice, recommendations, communication, and benefits are outlined.

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.

Role of clinical neuropsychology in deep brain stimulation: Review of the literature and considerations for clinicians

Deep Brain Stimulation (DBS) is an effective surgical therapy for several neurological movement disorders. The clinical neuropsychologist has a well-established role in the neuropsychological evaluation and selection of surgical candidates. In this article, we argue that the clinical neuropsychologist's role is much broader, when considered in relation to applied psychologists' core competencies. We consider the role of the clinical neuropsychologist in DBS in relation to: assessment, formulation, evaluation and research, intervention or implementation, and communication. For each competence the relevant evidence-base was reviewed. Clinical neuropsychology has a vital role in presurgical assessment of cognitive functioning and psychological, and emotional and behavioral difficulties. Formulation is central to the selection of surgical candidates and crucial to intervention planning. Clinical neuropsychology has a well-established role in postsurgical assessment of cognitive functioning and psychological, emotional, and behavioral outcomes, which is fundamental to evaluation on an individual and service level. The unique contribution clinical neuropsychology makes to pre- and postsurgical interventions is also highlighted. Finally, we discuss how clinical neuropsychology can promote clear and effective communication with patients and between professionals.

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

INTRODUCTION

The Parkinson's Disease-Cognitive Rating Scale (PD-CRS) is a valid and reliable instrument to screen for and diagnose mild cognitive impairment in PD (PD-MCI) and to monitor potential outcomes in clinical trials. Although this scale shows adequate sensitivity to change in non-demented PD patients, an alternative form (AF) with proven reliability could minimize practice effects associated with repeated testing.

METHODS

We selected PD-CRS/AF items following the criteria proposed in the original PD-CRS. We assessed a prospective sample of 75 non-demented PD patients (normal cognition, n = 50; PD-MCI, n = 25) using both tools, administered on two consecutive days, in a randomized order.

RESULTS

The PD-CRS/AF showed a high internal consistency (Cronbach's α = 0.80). Differences between total mean scores were not significant. Floor/ceiling effects were acceptable. The discriminative power for MCI was high for both tools (area under the curve 0.91; 95% CI, 0.84-0.98 for PD-CRS; 0.88, 95% CI, 0.80-0.96 for PD-CRS/AF). Receiver operating curve analysis showed the optimal cut-off point of the two versions to discriminate PD-MCI from PD-normal cognition was ≤81 (PD-CRS = sensitivity 94%, specificity 73%; PD-CRS/AF = sensitivity 92%, specificity 73%).

CONCLUSIONS

Our results suggest that the PD-CRS/AF is a valid and reliable instrument to complement the original PD-CRS as an analogous tool for serial cognitive testing for PD patients in clinical practice and cognitive trials.

Parkinson's Disease: Cognitive Impairment

Cognitive deficits are important and emerging clinical targets for psychiatrists caring for patients with Parkinson's disease (PD), a neurodegenerative disorder commonly accompanied by mood and psychotic disturbances and identified by its progressive motor abnormalities. Over the course of the disease and across all its stages, virtually every individual with PD experiences some degree of cognitive deficit, ranging from mild cognitive impairment to dementia. Across this spectrum, cognitive impairments affect functioning and quality of life, often more than motor aspects of the disease. Advances in treatments for motor deficits in PD now render the clinical significance of cognitive dysfunction more obvious, including its impact on psychiatric presentations and their treatment. Since cognitive dysfunction is underdetected and undertreated in clinical practice, holistic psychiatric care of PD patients warrants appreciation of the clinical presentation, biopsychosocial features, and treatment of cognitive impairment. Future directions for research and clinical care also discussed.

Validation of the Parkinson's Disease-Cognitive Rating Scale Applying the Movement Disorder Society Task Force Criteria for Dementia Associated with Parkinson's Disease

BACKGROUND

The authors studied the measurement properties of the Parkinson's Disease-Cognitive Rating Scale (PD-CRS) compared with Movement Disorders Society Task Force (MDS-TF) criteria for the diagnosis of dementia in patients with Parkinson's disease.

METHODS

The sample consisted of 223 patients who were diagnosed in accordance with the United Kingdom Parkinson's Disease Society Brain Bank who were assessed with both the MDS-TF and the PD-CRS criteria (in addition to other instruments) without the assessors' knowledge of previous results. Internal consistency was studied (homogeneity of the items and Guttmann's λ values were obtained) in addition to convergent, divergent, and discriminative validity. The receiver operating characteristic curve was obtained, and the cutoff point at which the PD-CRS had the greatest efficiency was analyzed.

RESULTS

The internal consistency was shown to be adequate, with a λ value of 0.821. A floor effect was observed in 4 of the items (Sustained Attention, Working Memory, Immediate Verbal Memory, and Alternating Verbal Fluency), and 1 item showed a ceiling effect (Clock Copying). The scale adequately discriminated patients with and without dementia (Kruskal-Wallis; P ≤ 0.000). The area under the curve was 0.899. With a cutoff score of 62 (from a possible score of 134), the scale achieved 94% sensitivity and 99% specificity.

CONCLUSIONS

The PD-CRS has adequate measurement properties and is a valid tool for studying the presence of dementia in patients with Parkinson's disease.

A novel de novo mutation in ATP1A3 and childhood-onset schizophrenia

We describe a child with onset of command auditory hallucinations and behavioral regression at 6 yr of age in the context of longer standing selective mutism, aggression, and mild motor delays. His genetic evaluation included chromosomal microarray analysis and whole-exome sequencing. Sequencing revealed a previously unreported heterozygous de novo mutation c.385G>A in ATP1A3, predicted to result in a p.V129M amino acid change. This gene codes for a neuron-specific isoform of the catalytic α-subunit of the ATP-dependent transmembrane sodium–potassium pump. Heterozygous mutations in this gene have been reported as causing both sporadic and inherited forms of alternating hemiplegia of childhood and rapid-onset dystonia parkinsonism. We discuss the literature on phenotypes associated with known variants in ATP1A3, examine past functional studies of the role of ATP1A3 in neuronal function, and describe a novel clinical presentation associated with mutation of this gene.

Test-Retest Reliability of Dual-Task Outcome Measures in People With Parkinson Disease

BACKGROUND

Dual-task (DT) training is gaining ground as a physical therapy intervention in people with Parkinson disease (PD). Future studies evaluating the effect of such interventions need reliable outcome measures. To date, the test-retest reliability of DT measures in patients with PD remains largely unknown.

OBJECTIVE

The purpose of this study was to assess the reliability of DT outcome measures in patients with PD.

DESIGN

A repeated-measures design was used.

METHODS

Patients with PD ("on" medication, Mini-Mental State Examination score ≥24) performed 2 cognitive tasks (ie, backward digit span task and auditory Stroop task) and 1 functional task (ie, mobile phone task) in combination with walking. Tasks were assessed at 2 time points (same hour) with an interval of 6 weeks. Test-retest reliability was assessed for gait while performing each secondary task (DT gait) for both cognitive tasks while walking (DT cognitive) and for the functional task while walking (DT functional).

RESULTS

Sixty-two patients with PD (age=39-89 years, Hoehn and Yahr stages II-III) were included in the study. Intraclass correlation coefficients (ICCs) showed excellent reliability for DT gait measures, ranging between .86 and .95 when combined with the digit span task, between .86 and .95 when combined with the auditory Stroop task, and between .72 and .90 when combined with the mobile phone task. The standard error of measurements for DT gait speed varied between 0.06 and 0.08 m/s, leading to minimal detectable changes between 0.16 and 0.22 m/s. With regard to DT cognitive measures, reaction times showed good-to-excellent reliability (digit span task: ICC=.75; auditory Stroop task: ICC=.82).

LIMITATIONS

The results cannot be generalized to patients with advanced disease or to other DT measures.

CONCLUSIONS

In people with PD, DT measures proved to be reliable for use in clinical studies and look promising for use in clinical practice to assess improvements after DT training. Large effects, however, are needed to obtain meaningful effect sizes.

The Diagnostic Accuracy of Parkinson's Disease Mild Cognitive Impairment Battery Using the Movement Disorder Society Task Force Criteria

Background

The aim of the present study was to provide empirical evidence regarding the classification accuracy of the International Parkinson and Movement Disorder Society (MDS) neuropsychological battery (NB) in the determination of Parkinson's disease mild cognitive impairment (PD-MCI).

Methods

The present cross-sectional study included 106 PD patients subjected to PD-MCI classification at Level I and 120 healthy controls (HCs). All HC and PD subjects were then assessed with MDS-NB at Level II and matched according to age and education using different thresholds (1.5 and 2.0 standard deviations [SDs] below average).

Results

We found that Level I and II resulted in different classifications of PD-MCI status. Detection thresholds of -1.5 SD and -2.0 SDs at Level II had also a significant impact on the discriminative validity of all measures in the MDS neuropsychological battery, based on area under the curve analyses. Overall, semantic fluency showed the highest potential in all comparisons not only between PD-MCI and HC, but also between PD-MCI and PD with no deficit (PD-ND).

Conclusions

Our results show that the battery at Level II is applicable and that some measures, such as semantic fluency, have high discriminative validity in the detection of PD-MCI versus PD-ND and HCs.

The Penn Parkinson's Daily Activities Questionnaire-15: Psychometric properties of a brief assessment of cognitive instrumental activities of daily living in Parkinson's disease

INTRODUCTION

To describe the psychometric properties of the Penn Parkinson's Daily Activities Questionnaire-15 (PDAQ-15), a 15-item measure of cognitive instrumental activities of daily living for Parkinson's disease (PD) patients derived from the original 50-item PDAQ.

METHODS

PDAQ-15 items were chosen by expert consensus. Knowledgeable informants of PD participants (n = 161) completed the PDAQ-15. Knowledgeable informants were defined as an individual having regular contact with the PD participant. PD participants were assigned a diagnosis of normal cognition, mild cognitive impairment, or dementia based on expert consensus.

RESULTS

PDAQ-15 scores correlated strongly with global cognition (Dementia Rating Scale-2, r = 0.71, p < 0.001) and a performance-based functional measure (Direct Assessment of Functional Status, r = 0.83; p < 0.001). PDAQ-15 scores accurately discriminated between non-demented PD participants (normal cognition/mild cognitive impairment) and PD with dementia (ROC curve area = 0.91), participants with and without any cognitive impairment (normal cognition versus mild cognitive impairment/dementia, ROC curve area = 0.85) and between participants with mild cognitive impairment and dementia (ROC curve area = 0.84).

CONCLUSIONS

The PDAQ-15 shows good discriminant validity across cognitive stages, correlates highly with global cognitive performance, and appears suitable to assess daily cognitive functioning in PD.

Parkinson's Disease--Cognitive Functional Rating Scale across different conditions and degrees of cognitive impairment

BACKGROUND/AIMS

The Parkinson's Disease--Cognitive Functional Rating Scale (PD-CFRS) was designed to avoid motor biases in capturing the functional impact of cognitive impairment in Parkinson's disease (PD). Its performance capturing functional impairment in other conditions leading to cognitive dysfunction is unknown. We compare it with non-specific Instrumental Activities of Daily Living scales.

METHODS

Two hundred consecutive patients diagnosed in a community hospital with mild cognitive impairment (MCI) [31 MCI-amnestic; 33 MCI-multi-domain; 33 PD-MCI] and dementia [35 Alzheimer's disease; 34 vascular dementia; 34 PD with dementia] were assessed on the PD-CFRS, the Blessed Dementia Scale (BDS), the Clinical Dementia Rating--Sum of Boxes (CDR-SOB), and given a comprehensive cognitive assessment. Diagnostic accuracy and optimal cut-off scores were calculated for the PD-CFRS and compared with each functional measure.

RESULTS

The PD-CFRS presented high concurrent validity and significant correlation with both BDS and CDR-SOB, and cognitive scores offering a similar discrimination accuracy to non-specific scales [PD-CFRS ≥ 9 (sensitivity= 0.94; specificity = 0.95)]. No changes appear in cut-off scores when excluding PD patients. Effect size analysis indicated no relevant interference with PD-CFRS scores between the principal cognitive subgroups.

DISCUSSION

The findings extend the clinimetric properties of the PD-CFRS and indicate it as an adequate instrument to capture the full spectrum of functional consequences of cognitive decline in the community.

Clinical validity of the Mattis Dementia Rating Scale in differentiating mild cognitive impairment in Parkinson's disease and normative data

BACKGROUND/AIMS

The aim of the present study was to provide normative data and determine the validity of the Czech version of the Mattis Dementia Rating Scale 2 (czDRS-2) in screening for mild cognitive impairment in Parkinson's disease (PD-MCI) based on the Movement Disorder Society (MDS) Level II criteria.

METHODS

For validation purposes, 41 healthy controls (HC), 46 patients with PD-NI (Parkinson's disease, no impairment) and 41 patients with PD-MCI (all groups assessed by the MDS Level II criteria for PD-MCI) were matched according to age and education.

RESULTS

With screening and diagnostic cutoff scores determined at ≤139 points, the czDRS-2 showed a sensitivity of 78% and a specificity of 88% in the detection of PD-MCI versus HC and a sensitivity of 78% and a specificity of 76% in the detection of PD-MCI versus PD-NI. The AUC (95% confidence interval) for the czDRS-2 was 84% (75-93) and 82% (73-91), respectively. We report percentile values for 286 subjects from the Czech population stratified by education level.

CONCLUSION

Our results show that the czDRS-2 is a valid instrument at Level I for screening PD-MCI and support its construct validity and diagnostic equivalence in a cross-cultural setting.

Therapeutic development paths for cognitive impairment in Parkinson's disease: report of a regulatory roundtable

Cognitive impairment is a common occurrence in Parkinson's disease (PD), although the severity and specific presentation varies across patients. Initial deficits, including mild cognitive impairment (PD-MCI), may remain stable or in many cases, may progress over variable lengths of time to Parkinson's disease dementia (PDD). As there are currently no marketed treatments for milder forms of cognitive impairment, an opportunity exists to define the path for therapeutic development in this area. In the absence of a well-defined path for the approval of therapies that target PD-MCI, pharmaceutical companies are unlikely to pursue this indication. In order to move forward and improve the quality of life for PD patients, it is imperative for the field to have consensus on the definition of PD-MCI, the best instruments to measure cognitive decline, and a strategy for future clinical trials.

Development and initial testing of the Penn Parkinson's Daily Activities Questionnaire

OBJECTIVE

The aim of this work was to describe the development and psychometric analysis of the Penn Parkinson's Daily Activities Questionnaire. The questionnaire is an item response theory-based tool for rating cognitive instrumental activities of daily living in PD.

METHODS

Candidate items for the Penn Parkinson's Daily Activities Questionnaire were developed through literature review and focus groups of patients and knowledgeable informants. Item selection and calibration of item-response theory parameters were performed using responses from a cohort of PD patients and knowledgeable informants (n = 388). In independent cohorts of PD patients and knowledgeable informants, assessments of test-retest reliability (n = 50), and construct validity (n = 68) of the questionnaire were subsequently performed. Construct validity was assessed by correlating questionnaire scores with measures of motor function, cognition, an existing activities of daily living measure, and directly observed daily function.

RESULTS

Fifty items were retained in the final questionnaire item bank. Items were excluded owing to redundancy, difficult reading level, and when item-response theory parameters could not be calculated. Test-retest reliability was high (intraclass correlation coefficient = 0.97; P < 0.001). The questionnaire correlated strongly with cognition (r = 0.68; P < 0.001) and directly observed daily function (r = 0.87; P < 0.001), but not with motor impairment (r = 0.08; P = 0.53). The questionnaire score accurately discriminated between PD patients with and without dementia (receiver operating characteristic curve = 0.91; 95% confidence interval: 0.85-0.97).

CONCLUSIONS

The Penn Parkinson's Daily Activities Questionnaire shows strong evidence of reliability and validity. Item response theory-based psychometric analysis suggests that this questionnaire can discriminate across a range of daily functions.