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

Preoperative cognitive profile predictive of cognitive decline after subthalamic deep brain stimulation in Parkinson's disease

Cognitive decline represents a severe non-motor symptom of Parkinson's disease (PD) that can significantly reduce the benefits of subthalamic deep brain stimulation (STN DBS). Here, we aimed to describe post-surgery cognitive decline and identify pre-surgery cognitive profile associated with faster decline in STN DBS-treated PD patients. A retrospective observational study of 126 PD patients treated by STN DBS combined with oral dopaminergic therapy followed for 3.54 years on average (SD = 2.32) with repeated assessments of cognition was conducted. Pre-surgery cognitive profile was obtained via a comprehensive neuropsychological examination and data analysed using exploratory factor analysis and Bayesian generalized linear mixed models. On the whole, we observed a mild annual cognitive decline of 0.90 points from a total of 144 points in the Mattis Dementia Rating Scale (95% posterior probability interval [-1.19, -0.62]) with high inter-individual variability. However, true score changes did not reach previously reported reliable change cut-offs. Executive deficit was the only pre-surgery cognitive variable to reliably predict the rate of post-surgery cognitive decline. On the other hand, exploratory analysis of electrode localization did not yield any statistically clear results. Overall, our data and models imply mild gradual average annual post-surgery cognitive decline with high inter-individual variability in STN DBS-treated PD patients. Nonetheless, patients with worse long-term cognitive prognosis can be reliably identified via pre-surgery examination of executive functions. To further increase the utility of our results, we demonstrate how our models can help with disentangling true score changes from measurement error in future studies of post-surgery cognitive changes.

Computerized assessment of executive functioning: Validation of the CNS Vital Signs executive functioning scores in a sample of community-dwelling older adults

Objective: Computerized assessment of cognitive functioning has gained significant popularity over recent years, yet options for clinical assessment of executive functioning (EF) are lacking. One computerized testing platform, CNS Vital Signs (CNS-VS), offers tests designed to measure EF but requires further validation. The goal of the present study was to validate CNS-VS executive scores against standard clinical measures of EF. We also sought to determine whether a modified CNS-VS composite score that included variables purported to measure inhibition, switching, and working memory would outperform the currently available CNS-VS Executive Function Index. Method: A sample of 73 cognitively healthy older adults completed four tests from the Delis-Kaplan Executive Function System, the Digit Span subtest from the Wechsler Adult Intelligence Scale-fourth edition, and three CNS-VS tasks purported to measure inhibition, switching, and working memory. Results: Performances on the CNS-VS tests were predicted by performances on standard paper-and-pencil measures. Although the currently available CNS-VS Executive Function Index predicted unique variance in a well-validated paper-and-pencil EF composite score, our Modified CNS-VS EF composite accounted for unique variance above and beyond the original CNS-VS Executive Function Index, while the reverse was not true. Conclusions: The present results support the construct validity of CNS-VS EF tests but also suggest that modifications to their current composite scores would improve the prediction of EF performance.

Structural and microstructural predictors of cognitive decline in deep brain stimulation of subthalamic nucleus in Parkinson's disease

BACKGROUND AND OBJECTIVES

The intricate relationship between deep brain stimulation (DBS) in Parkinson's disease (PD) and cognitive impairment has lately garnered substantial attention. The presented study evaluated pre-DBS structural and microstructural cerebral patterns as possible predictors of future cognitive decline in PD DBS patients.

METHODS

Pre-DBS MRI data in 72 PD patients were combined with neuropsychological examinations and follow-up for an average of 2.3 years after DBS implantation procedure using a screening cognitive test validated for diagnosis of mild cognitive impairment in PD in a Czech population - Dementia Rating Scale 2.

RESULTS

PD patients who would exhibit post-DBS cognitive decline were found to have, already at the pre-DBS stage, significantly lower cortical thickness and lower microstructural complexity than cognitively stable PD patients. Differences in the regions directly related to cognition as bilateral parietal, insular and cingulate cortices, but also occipital and sensorimotor cortex were detected. Furthermore, hippocampi, putamina, cerebellum and upper brainstem were implicated as well, all despite the absence of pre-DBS differences in cognitive performance and in the position of DBS leads or stimulation parameters between the two groups.

CONCLUSIONS

Our findings indicate that the cognitive decline in the presented PD cohort was not attributable primarily to DBS of the subthalamic nucleus but was associated with a clinically silent structural and microstructural predisposition to future cognitive deterioration present already before the DBS system implantation.

Effects of non-invasive vagus nerve stimulation on clinical symptoms and molecular biomarkers in Parkinson's disease

Non-invasive vagus nerve stimulation (nVNS) is an established neurostimulation therapy used in the treatment of epilepsy, migraine and cluster headache. In this randomized, double-blind, sham-controlled trial we explored the role of nVNS in the treatment of gait and other motor symptoms in Parkinson's disease (PD) patients. In a subgroup of patients, we measured selected neurotrophins, inflammatory markers and markers of oxidative stress in serum. Thirty-three PD patients with freezing of gait (FOG) were randomized to either active nVNS or sham nVNS. After baseline assessments, patients were instructed to deliver six 2  min stimulations (12  min/day) of the active nVNS/sham nVNS device for 1  month at home. Patients were then re-assessed. After a one-month washout period, they were allocated to the alternate treatment arm and the same process was followed. Significant improvements in key gait parameters (speed, stance time and step length) were observed with active nVNS. While serum tumor necrosis factor- α decreased, glutathione and brain-derived neurotrophic factor levels increased significantly (p < 0.05) after active nVNS treatment. Here we present the first evidence of the efficacy and safety of nVNS in the treatment of gait in PD patients, and propose that nVNS can be used as an adjunctive therapy in the management of PD patients, especially those suffering from FOG. Clinical trial registration: identifier ISRCTN14797144.

Cognitive Deficits in Parkinson's Disease Are Associated with Neuronal Dysfunction and Not White Matter Lesions

Background

Cognitive deficits considerably contribute to the patient's burden in Parkinson's disease (PD). While cognitive decline is linked to neuronal dysfunction, the additional role of white matter lesions (WML) is discussed controversially.

Objective

To investigate the influence of WML, in comparison to neuronal dysfunction, on cognitive deficits in PD.

Methods

We prospectively recruited patients with PD who underwent neuropsychological assessment using the Mattis Dementia Rating Scale 2 (DRS-2) or Parkinson Neuropsychometric Dementia Assessment (PANDA) and both MRI and PET with [¹⁸F]fluorodeoxyglucose (FDG). WML-load and PD cognition-related covariance pattern (PDCP) as a measure of neuronal dysfunction were read out. Relationship between cognitive performance and rank-transformed WML was analyzed with linear regression, controlling for the patients' age. PDCP subject scores were investigated likewise and in a second step adjusting for age and WML load.

Results

Inclusion criteria were met by 76 patients with a mean (± SD) age of 63.5 ± 9.0 years and disease duration of 10.7 ± 5.4 years. Neuropsychological testing revealed front executive and parietal deficits and a median DRS-2 score of 137 (range 119-144)/144 and PANDA score of 22 (range 3-30)/30. No association between WML and cognition was observed, whereas PDCP subject scores showed a trend-level negative correlation with the DRS-2 (P = 0.060) as well as a negative correlation with PANDA (P = 0.049) which persisted also after additional correction for WML (P = 0.039).

Conclusion

The present study indicates that microangiopathic WML do not have a relevant impact on neurocognitive performance in PD whereas neuronal dysfunction does.

What does the Dementia Rating Scale-2 measure? The relationship of neuropsychological measures to DRS-2 total and subscale scores in non-demented individuals with Parkinson's disease

OBJECTIVE

The Dementia Rating Scale-2 (DRS-2) is recommended for assessing global cognition in Parkinson's disease (PD) by the Movement Disorder Society. However, empirical evidence is limited regarding the degree to which the DRS-2 corresponds to traditional neurocognitive domains (i.e., construct validity) in PD. Thus, this study aims to determine the construct validity of the DRS-2 in a non-demented sample of PD patients.

METHOD

Patients with PD (n = 359; mean age = 64.50 ± 8.53, education = 14.97 ± 2.73, disease duration = 8.48 ± 4.87, UPDRS Part III motor scale scores = 25.23 ± 10.17) completed the DRS-2 as part of a comprehensive neuropsychological assessment consisting of attention/working memory, executive function, language, delayed recall, and visuoperceptual-spatial skills.Bootstrapped bias-corrected Spearman rho's correlations andhierarchical linear regressions were performed to examine construct validity of DRS-2 total and subscale scores.

RESULTS

Speeded measures of set-shifting, rapid word generation to letter and semantic cues, and simple visuoperceptual skills largely accounted for variance in DRS-2 total scores. Most DRS-2 subscale scores showed weak relationships with theoretically related neuropsychological measures.

CONCLUSIONS

DRS-2 total scores reflect impairment across a range of cognitive domains (i.e., executive, language, and visuoperception), while DRS-2 subscale scores have limited construct validity. Together, the DRS-2 does not appear to have utility beyond screening for global cognition in PD.

The Instrumental Activities of Daily Living in Parkinson’s Disease Patients Treated by Subthalamic Deep Brain Stimulation

Background

Everyday functioning and instrumental activities of daily living (IADL) play a vital role in preserving the quality of life in patients with Parkinson’s disease (PD) after deep brain stimulation of the subthalamic nucleus (STN-DBS).

Objective

The main goal of the current study was to examine IADL change in pre-and post-surgery of the STN-DBS. We also analyzed the influence of the levodopa equivalent daily dose (LEDD) and global cognitive performance (Dementia Rating Scale; DRS-2) as covariates in relation to IADL.

Methods

Thirty-two non-demented PD patients were administered before and after STN-DBS neurosurgery the Penn Parkinson’s Daily Activities Questionnaire (PDAQ; self-report), the DRS-2 and Beck Depression Inventory (BDI-II) to assess IADL change, global cognition, and depression.

Results

We found a positive effect of STN-DBS on IADL in the post-surgery phase. Moreover, lower global cognition and lower LEDD are predictive of lower IADL in both pre-surgery and post-surgery examinations.

Summary/Conclusion

STN-DBS in PD is a safe method for improvement of everyday functioning and IADL. In the post-surgery phase, we show a relation of IADL to the severity of cognitive impairment in PD and to LEDD.

Additional Benefit of Intraoperative Electroacupuncture in Improving Tolerance of Deep Brain Stimulation Surgical Procedure in Parkinsonian Patients

Background: Deep brain stimulation (DBS) is an effective technique to treat patients with advanced Parkinson’s disease. The surgical procedure of DBS implantation is generally performed under local anesthesia due to the need for intraoperative clinical testing. However, this procedure is long (5–7 h on average) and, therefore, the objective that the patient remains co-operative and tolerates the intervention well is a real challenge. Objective: To evaluate the additional benefit of electroacupuncture (EA) performed intraoperatively to improve the comfort of parkinsonian patients during surgical DBS implantation. Methods: This single-center randomized study compared two groups of patients. In the first group, DBS implantation was performed under local anesthesia alone, while the second group received EA in addition. The patients were evaluated preoperatively, during the different stages of the surgery, and 2 days after surgery, using the 9-item Edmonton Symptom Assessment System (ESAS), including a total sum score and physical and emotional subscores. Results: The data of nine patients were analyzed in each group. Although pain and tiredness increased in both groups after placement of the stereotactic frame, the ESAS item “lack of appetite”, as well as the ESAS total score and physical subscore increased after completion of the first burr hole until the end of the surgical procedure in the control group only. ESAS total score and physical subscore were significantly higher at the end of the intervention in the control group compared to the EA group. After the surgical intervention (D2), anxiety and ESAS emotional subscore were improved in both groups, but the feeling of wellbeing improved in the EA group only. Finally, one patient developed delirium during the intervention and none in the EA group. Discussion: This study shows that intraoperative electroacupuncture significantly improves the tolerance of DBS surgery in parkinsonian patients. This easy-to-perform procedure could be fruitfully added in clinical practice.

Multiculturalism: A Challenge for Cognitive Screeners in Parkinson's Disease

BACKGROUND

The Montreal Cognitive Assessment (MoCA) and the Dementia Rating Scale-2 (DRS-2) are recommended screeners for Parkinson's disease mild cognitive impairment (PD-MCI). Cross-cultural studies examining their diagnostic precision have not addressed cultural bias in a multicultural setting.

OBJECTIVES

To compare DRS-2 and MoCA performance between patients born in Canada, the USA, and the UK (Anglosphere group) and immigrant patients born elsewhere (International group). To identify sources of cultural bias by comparing group characteristics, and by assessing the relationships between performance and immigration and socio-development variables. To examine the diagnostic precision of both tools in detecting PD-MCI in each group.

METHODS

We conducted a clinical chart review of advanced PD patients who completed cognitive screeners (MoCA: n = 288, 30% International group; DRS-2: n = 426, 31% International group). All completed a comprehensive neuropsychological assessment to apply Level II PD-MCI diagnostic criteria.

RESULTS

The International group performed worse than the Anglosphere group on the MoCA and DRS-2, and the only variable that accounted for some of the group difference was the Historical Index of Human Development, a societal variable, which fully mediated the group effect on the DRS-2. Diagnostic precision of the MoCA was at chance level in the International group, and was poorer than that of the DRS-II in this group and that of the MoCA in the Anglosphere group, although these were considered poor.

CONCLUSIONS

Our results support the recommendation to exert caution in using cognitive screeners to capture PD-MCI in all patients and particularly with first generation immigrants.

Performance of Mattis dementia rating scale-Chinese version in patients with mild cognitive impairment and Alzheimer's disease

Background

To identify the applicability of the Chinese Version of Mattis Dementia Rating Scale (DRS-CV).

Methods

The DRS-CV was administered to 483 participants, including 136 normal controls, 167 patients with mild cognition impairment (MCI), and 180 patients with Alzheimer’s disease (AD). Receiver Operating Characteristic (ROC) curve was used to evaluate the sensitivity and specificity of the scale.

Results

The scores of DRS-CV were ranked in the order of NC > MCI > mild AD > moderate AD group. Memory was the sensitive function affected at a relatively earlier stage of AD. ROC curve analysis indicated the DRS-CV total score and memory subscale showed excellent sensitivity and specificity in the discrimination between MCI from mild AD and mild AD from moderate AD, but poor sensitivity and specificity in the discrimination between MCI and NC.

Conclusion

The DRS-CV is useful to the early diagnosis and severity of AD, not to the early identification of MCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02173-0.

Meta-Analysis of Cognition in Parkinson's Disease Mild Cognitive Impairment and Dementia Progression

Mild cognitive changes, including executive dysfunction, are seen in Parkinson's Disease (PD). Approximately 30% of individuals with PD develop Parkinson's disease dementia (PDD). Mild cognitive impairment (MCI) has been identified as a transitional state between normal cognition and dementia. Although PD-MCI and its cognitive correlates have been increasingly studied as a risk indicator for development of PDD, investigations into the PD-MCI construct have yielded heterogeneous findings. Thus, a typical PD-MCI cognitive profile remains undefined. The present meta-analysis examined published cross-sectional studies of PD-MCI and cognitively normal PD (PD-CN) groups to provide aggregated effect sizes of group test performance by cognitive domain. Subsequently, longitudinal studies examining PD-MCI to PDD progression were meta-analyzed. Ninety-two cross-sectional articles of PD-MCI vs. PD-CN were included; 5 longitudinal studies of PD-MCI conversion to PDD were included. Random effects meta-analytic models were constructed resulting in effect sizes (Hedges' g) for cognitive domains. Overall performance across all measures produced a large effect size (g = 0.83, 95% CI [0.79, 0.86], t² = 0.18) in cross-sectional analyses, with cognitive screeners producing the largest effect (g = 1.09, 95% CI [1.00, 1.17], t² = 0.19). Longitudinally, overall measures produced a moderate effect (g = 0.47, 95% CI [0.40, 0.53], t² = 0.01), with measures of executive functioning exhibiting the largest effect (g = 0.70, 95% CI [0.51, 0.89], t² = 0.01). Longitudinal effects were made more robust by low heterogeneity. This report provides the first comprehensive meta-analysis of PD-MCI cognitive outcomes and predictors in PD-MCI conversion to PDD. Limitations include heterogeneity of cross-sectional effect sizes and the potential impact of small-study effects. Areas for continued research include visuospatial skills and visual memory in PD-MCI and longitudinal examination of executive dysfunction in PD-MCI.

Decreased emotional creativity and its relationship with cognitive functions in Parkinson's disease: A preliminary study

Patients with Parkinson's disease (PD) suffer from a wide range of non-motor symptoms, including cognitive deficits and impairment of emotional processing. The present study aimed to explore in PD patients compared to healthy adults the relationship between cognitive performance and emotional creativity (EC), defined as a set of cognitive abilities and personality traits related to originality and appropriateness of emotional experience. PD patients (n = 22) and healthy controls (n = 40) underwent a complex neuropsychological assessment and were administrated with the self-reported Emotional Creativity Inventory (ECI) questionnaire. To explore the relationship between cognitive tests and the ECI, a regression analysis was conducted. PD patients and healthy controls differed significantly in the EC component Preparedness as well as in the neuropsychological test battery scores. PD patients showed lower scores in cognitive tests and a lower score in Preparedness compared to healthy adults. The output of the regression analysis showed that the extent to which the neuropsychological tests relate to the ECI components is low.

Effects of a power strength training using elastic resistance exercises on the motor and non-motor symptoms in patients with Parkinson's disease H&Y 1-3: study protocol for a randomised controlled trial (PARK-BAND Study)

INTRODUCTION

Parkinson's disease (PD) is the second most common neurodegenerative disorder in Brazil. Physical activity is a complementary intervention in managing inherent declines associated with the disease like strength, balance, gait, and functionality and benefit health-related outcomes. Here, we report the PARK-BAND Study protocol, which aims to investigate potential benefits of power training using elastic devices in participants with PD. Our intervention will be provided in patients with PD using elastic devices like elastic bands and tubes. Therefore, we used the term Park from Parkinson's disease and band from elastic bands.

METHODS AND ANALYSIS

This randomised single-blind single-centre two-arm parallel, superiority trial will include 50 participants with PD attending the clinical setting. Those who meet the eligibility criteria and provide consent to participate will be randomised in a 1:1 ratio to either the exercise group, which will receive power training programme or the health education group, which will receive the education programme. Randomisation will be performed by permuted block randomisation with a block size of eight. Both groups will receive a 12-week intervention. The exercise group will have two sessions per week and the health education group will have one session per week. Changes from baseline in bradykinesia, as assessed by the Unified Parkinson's Disease Rating Scale motor examination subscore and physical functional performance, will be the primary outcomes. Secondary outcomes include other neurological, neurophysiological and physical variables, as well as the quality of life, depression, cognition, sleep quality and disturbances, assessed before and after interventions. We hypothesise that the exercise group will have greater improvement in primary and secondary outcomes than the health education group.

ETHICS AND DISSEMINATION

The study is approved by the Research Ethics Committee of Hospital Universitário Walter Cantidio and all participants will provide their written informed consent (register number 91075318.1.0000.5045).Trial results will be disseminated via peer reviewed journal articles and conference presentations, reports for organisations involved with PD and for participants.

TRIAL REGISTRATION NUMBER

Registro Brasileiro de Ensaios Clínicos Registry (RBR-5w2sqt); Pre-results.

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.

SERIAL-ORDER recall in working memory across the cognitive spectrum of Parkinson's disease and neuroimaging correlates

We sought to determine if Parkinson's disease (PD) with mild cognitive impairment (MCI) is associated with a greater SERIAL-ORDER (mental manipulation) than ANY-ORDER (auditory span, storage) deficit in working memory (WM). We investigated WM combining neuropsychological measures with the study of brain functional connectivity. A cohort of 160 patients with idiopathic PD, classified as PD-MCI (n = 87) or PD with normal cognition (PD-NC; n = 73), and 70 matched healthy controls were studied. Verbal WM was assessed with the Backward Digit Span Task (BDT; Lamar et al., 2007, Neuropsychologia, 45, 245), measuring SERIAL-ORDER and ANY-ORDER recall. Resting-state MRI data were collected for 15 PD-MCI, 15 PD-NC and 30 controls. Hypothesis-driven seed-based functional connectivity of the dorsolateral prefrontal cortex (DLPFC) was compared between the three groups and correlated with BDT performance. We found the main effect of the test (impairment in SERIAL ORDER > ANY ORDER) and group ((NC = PD-NC) > PD-MCI) in BDT performance that was even more pronounced in SERIAL ORDER when controlling for ANY ORDER variability but not vice versa. Furthermore, PD-MCI compared to other groups were characterized by the functional disconnection between the bilateral DLPFC and the cerebellum. In functional correlations, DLPFC connectivity was positively related to both SERIAL- and ANY-ORDER performance. In conclusion, PD-MCI patients evidenced greater SERIAL-ORDER (manipulation and cognitive control) than ANY-ORDER (storage) working memory impairment than PD-NC and controls with a disrupted DLPFC resting-state connectivity that was also related to the verbal WM performance.

Comparative sensitivity of the MoCA and Mattis Dementia Rating Scale-2 in Parkinson's disease

BACKGROUND

Clinicians and researchers commonly use global cognitive assessments to screen for impairment. Currently there are no published studies directly comparing the sensitivity and specificity of the Montreal Cognitive Assessment and Mattis Dementia Rating Scale-2 in PD. The objective of this study was to identify the relative sensitivity and specificity of the Montreal Cognitive Assessment and Mattis Dementia Rating Scale-2 in PD.

METHODS

The Montreal Cognitive Assessment and Mattis Dementia Rating Scale-2 were administered to training and validation cohorts. Cutoff scores were determined within the training cohort (n = 85) to optimize sensitivity and specificity for cognitive impairment and were applied to an independent validation cohort (n = 521).

RESULTS

The Montreal Cognitive Assessment was consistently sensitive across training and validation cohorts (90.0% and 80.3%, respectively), whereas the Mattis Dementia Rating Scale-2 was not (87.5% and 60.3%, respectively). In individual domains, the Montreal Cognitive Assessment remained sensitive to memory and visuospatial impairments (91.9% and 87.8%, respectively), whereas the Mattis Dementia Rating Scale-2 was sensitive to executive impairments (86.2%).

CONCLUSION

The Montreal Cognitive Assessment and Mattis Dementia Rating Scale-2 demonstrated individual strengths. Future work should focus on developing domain-specific cognitive screening tools for PD. © 2018 International Parkinson and Movement Disorder Society.

Spanish version of the Mattis Dementia Rating Scale-2 for early detection of Alzheimer's disease and mild cognitive impairment

OBJECTIVE

We aimed to analyse the clinical utility of the Mattis Dementia Rating Scale (MDRS-2) for early detection of Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI) in a sample of Spanish older adults.

METHODS

A total of 125 participants (age = 75.12 ± 6.83, years of education =7.08 ± 3.57) were classified in three diagnostic groups: 45 patients with mild AD, 37 with amnestic MCI-single and multiple domain and 43 cognitively healthy controls (HCs). Reliability, criterion validity and diagnostic accuracy of the MDRS-2 (total and subscales) were analysed. The MDRS-2 scores, adjusted by socio-demographic characteristics, were calculated through hierarchical multiple regression analysis.

RESULTS

The global scale had adequate reliability (α = 0.736) and good criterion validity (r = 0.760, p < .001) with the Mini-Mental State Examination. The optimal cut-off point between AD patients and HCs was 124 (sensitivity [Se] = 97% and specificity [Sp] = 95%), whereas 131 (Se = 89%, Sp = 81%) was the optimal cut-off point between MCI and HCs. An optimal cut-off point of 123 had good Se (0.97), but poor Sp (0.56) to differentiate AD and MCI groups. The Memory and Initiation/Perseveration subscales had the highest discriminative capacity between the groups.

CONCLUSIONS

The MDRS-2 is a reliable and valid instrument for the assessment of cognitive impairment in Spanish older adults. In particular, optimal capacity emerged for the detection of early AD and MCI. Copyright © 2017 John Wiley & Sons, Ltd.

A Comparative Study of Tower of London Scoring Systems and Normative Data

Objective

Tower of London (ToL) is a planning ability task that includes multiple versions. The original ToL was developed by Shallice together with two scoring systems (ToL-SS). Another two ToL-SS were proposed by Anderson et al. and Krikorian et al. The purpose of this study is to provide normative data for four ToL-SS and explore the effects of demographic variables on ToL performance. Furthermore, we aimed to determine the discriminative validity of these ToL-SS in clinical samples.

Method

Four groups were included in the study: a normative sample of healthy adults (HC; n = 298); patients with Parkinson's disease with mild cognitive impairment (PD-MCI; n = 52) and without cognitive impairment (PD-ND; n = 57); and patients with schizophrenia (SCH; n = 28). The effects of demographic variables on ToL-SS were examined in the HC group. Between-groups comparisons of ToL-SS were conducted using regression analysis with dummy codes.

Results

All four ToL-SS were not significantly affected by age, whereas the effect of gender and education is not consistent. ToL-SS significantly (p < .05) differentiate HC from PD-MCI and SCH. Cohen's effect size coefficients d range from 0.68 to 1.29. Internal consistency coefficients (Cronbach's α) of ToL-SS range from 0.33 to 0.60.

Conclusions

Despite poor to questionable internal consistency of ToL-SS, the discriminative validity and clinical utility for assessing planning deficits in PD-MCI and SCH are high. This study provides normative standards for all four ToL-SS on an adult population for use in clinical practice.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Human behavioral assessments in current research of Parkinson's disease

Parkinson's disease (PD) is traditionally classified as a movement disorder because patients mainly complain about motor symptoms. Recently, non-motor symptoms of PD have been recognized by clinicians and scientists as early signs of PD, and they are detrimental factors in the quality of life in advanced PD patients. It is crucial to comprehensively understand the essence of behavioral assessments, from the simplest measurement of certain symptoms to complex neuropsychological tasks. We have recently reviewed behavioral assessments in PD research with animal models (Asakawa et al., 2016). As a companion volume, this article will systematically review the behavioral assessments of motor and non-motor PD symptoms of human patients in current research. The major aims of this article are: (1) promoting a comparative understanding of various behavioral assessments in terms of the principle and measuring indexes; (2) addressing the major strengths and weaknesses of these behavioral assessments for a better selection of tasks/tests in order to avoid biased conclusions due to inappropriate assessments; and (3) presenting new concepts regarding the development of wearable devices and mobile internet in future assessments. In conclusion we emphasize the importance of improving the assessments for non-motor symptoms because of their complex and unique mechanisms in human PD brains.