Movement Disorder Society Task Force Research Articles

Mapping brain morphology to cognitive deficits: a study on PD-CRS scores in Parkinson's disease with mild cognitive impairment.

The Parkinson's Disease-Cognitive Rating Scale (PD-CRS) is a widely used tool for detecting mild cognitive impairment (MCI) in Parkinson's Disease (PD) patients, however, the neuroanatomical underpinnings of this test's outcomes require clarification. This study aims to: (a) investigate cortical volume (CVol) and cortical thickness (CTh) disparities between PD patients exhibiting mild cognitive impairment (PD-MCI) and those with preserved cognitive abilities (PD-IC); and (b) identify the structural correlates in magnetic resonance imaging (MRI) of overall PD-CRS performance, including its subtest scores, within a non-demented PD cohort. This study involved 51 PD patients with Hoehn & Yahr stages I-II, categorized into two groups: PD-IC (n = 36) and PD-MCI (n = 15). Cognitive screening evaluations utilized the PD-CRS and the Montreal Cognitive Assessment (MoCA). PD-MCI classification adhered to the Movement Disorder Society Task Force criteria, incorporating extensive neuropsychological assessments. The interrelation between brain morphology and cognitive performance was determined using FreeSurfer. Vertex-wise analysis of the entire brain demonstrated a notable reduction in CVol within a 2,934 mm2 cluster, encompassing parietal and temporal regions, in the PD-MCI group relative to the PD-IC group. Lower PD-CRS total scores correlated with decreased CVol in the middle frontal, superior temporal, inferior parietal, and cingulate cortices. The PD-CRS subtests for Sustained Attention and Clock Drawing were associated with cortical thinning in distinct regions: the Clock Drawing subtest correlated with changes in the parietal lobe, insula, and superior temporal cortex morphology; while the PD-CRS frontal-subcortical scores presented positive correlations with CTh in the transverse temporal, medial orbitofrontal, superior temporal, precuneus, fusiform, and supramarginal regions. Additionally, PD-CRS subtests for Semantic and Alternating verbal fluency were linked to CTh changes in orbitofrontal, temporal, fusiform, insula, and precentral regions. PD-CRS performance mirrors neuroanatomical changes across extensive fronto-temporo-parietal areas, covering both lateral and medial cortical surfaces, in PD patients without dementia. The observed changes in CVol and CTh associated with this cognitive screening tool suggest their potential as surrogate markers for cognitive decline in PD. These findings warrant further exploration and validation in multicenter studies involving independent patient cohorts.

Anticipating Tomorrow: Tailoring Parkinson's Symptomatic Therapy Using Predictors of Outcome.

Although research into Parkinson's disease (PD) subtypes and outcome predictions has continued to advance, recommendations for using outcome prediction to guide current treatment decisions remain sparse. To provide expert opinion-based recommendations for individually tailored PD symptomatic treatment based on knowledge of risk prediction and subtypes. Using a modified Delphi approach, members of the Movement Disorders Society (MDS) Task Force on PD subtypes generated a series of general recommendations around the question: "Using what you know about genetic/biological/clinical subtypes (or any individual-level predictors of outcome), what advice would you give for selecting symptomatic treatments for an individual patient now, based on what their subtype or individual characteristics predict about their future disease course?" After four iterations and revisions, those recommendations with over 75% endorsement were adopted. A total of 19 recommendations were endorsed by a group of 13 panelists. The recommendations primarily centered around two themes: (1) incorporating future risk of cognitive impairment into current treatment plans; and (2) identifying future symptom clusters that might be forestalled with a single medication. These recommendations provide clinicians with a framework for integrating future outcomes into patient-specific treatment choices. They are not prescriptive guidelines, but adaptable suggestions, which should be tailored to each individual. They are to be considered as a first step of a process that will continue to evolve as additional stakeholders provide new insights and as new information becomes available. As individualized risk prediction advances, the path to better tailored treatment regimens will become clearer.

4 Compensatory Functional Activation During Motion Discrimination in Parkinson’s Disease

Objective:PD patients commonly exhibit executive dysfunction early in the disease course which may or may not predict further cognitive decline over time. Early emergence of visuospatial and memory impairments, in contrast, are more consistent predictors of an evolving dementia syndrome. Most prior studies using fMRI have focused on mechanisms of executive dysfunction and have demonstrated that PD patients exhibit hyperactivation that is dependent on the degree of cognitive impairment, suggestive of compensatory strategies. No study has evaluated whether PD patients with normal cognition (PD-NC) and PD patients with Mild Cognitive Impairment (PD-MCI) exhibit compensatory activation patterns during visuospatial task performance.Participants and Methods:10 PD-NC, 12 PD-MCI, and 14 age and sex-matched healthy controls (HC) participated in the study. PD participants were diagnosed with MCI based on the Movement Disorders Society Task Force, Level II assessment (comprehensive assessment). Functional magnetic resonance imaging (fMRI) was performed during a motion discrimination task that required participants to identify the direction of horizontal global coherent motion embedded within dynamic visual noise under Low and High coherence conditions. Behavioral accuracy and functional activation were evaluated using 3 * 2 analyses of covariance (ANCOVAs) (group [HC, PD-NC, PD-MCI] * Coherence [High vs. Low]) accounting for age, sex, and education. Analyses were performed in R (v4.1.2(Team, 2013)).Results:PD-MCI (0.702± 0.269) patients exhibited significantly lower accuracy on the motion discrimination task than HC (0.853 ± 0.241; p = 0.033) and PD-NC (0.880 ± 0.208; p =0.039). A Group * Coherence interaction was identified in which several regions, including orbitofrontal, posterior parietal and occipital cortex, showed increased activation during High relative to Low coherence trials in the PD patient groups but not in the HC group. HC showed default mode deactivation and frontal-parietal activation during Low relative to High coherence trials that was not evident in the patient groups.Conclusions:PD-MCI patients exhibited worse visuospatial performance on a motion discrimination task than PD-NC and HC participants and exhibited hyperactivation of the posterior parietal and occipital regions during motion discrimination, suggesting possible compensatory activation.

5 Midbrain Degeneration and Cognition in Parkinson’s Disease

Objective:Neuromelanin imaging is an emerging biomarker for PD as it captures degeneration of the midbrain, a process which is associated with the motor symptoms of the disease. Currently, it is unknown whether this degeneration also contributes to cognitive dysfunction in PD beyond dysfunction associated with fronto-subcortical systems, as quantitative examination of substantia nigra (SN) degeneration could not be studied until recently.In the current study, we examine whether neuromelanin signal is associated with broader cognitive dysfunction in PD patients with varying degrees of cognitive impairment: PD with normal cognition (PD-NC), PD with mild cognitive impairment (PD-MCI), and healthy controls (HC).Participants and Methods:11 PD-NC, 16 PD-MCI and 14 age and sex-matched healthy controls (HC) participated in the study. PD participants were diagnosed with MCI based on the Movement Disorders Society Task force, Level II assessment (comprehensive assessment). In addition, all participants underwent an MRI scan that included a T1-weighted sequence and a neuromelanin-sensitive (NM-MRI) sequence. Contrast-to-noise-ratio of the substantia nigra pars compacta (SNc) was calculated and a distribution-corrected z-score was used to identify the number of extrema voxels for each individual, suggestive of the number of voxels that have exhibited significant degeneration (extrema_count). An analysis of covariance (ANCOVA) was used to evaluate group differences between HC, PD-NC, and PD-MCI in the extrema_count accounting for age, sex, and education. A multiple regression for each cognitive variable with extrema_count as the dependent variable adjusting for age, sex, and education were conducted.Results:A significant main effect of group (F(2, 33) = 33.548 ; p < 0.001) indicated that PD-NC (21.55 ± 12.57) and PD-MCI (43.64 ± 32.84) patients exhibited significantly greater extrema_counts relative to HC (3.36 ± 3.61; both p < 0.001). Regression results indicated that higher extrema_counts were associated with worse cognitive performance across cognitive domains, including working memory (Digit Span Backward; R2 = .357, F(1,20) = 5.295, p = .032), (Hopkins Verbal Learning Test - Revised, Trials 1 to 3; R2 = .432, F(1,20) = 5.819, p = .026).Conclusions:PD patients (PD-NC and PD-MCI) exhibited decreased neuromelanin in the SNc relative to healthy controls, confirming the ability of the NM-MRI sequence to differentiate PD from HC. There was no significant difference in SNc neuromelanin levels between PD-NC patients and PD-MCI patients, however, this is likely due to the small sample size. In addition, significant SNc degeneration was associated with worse cognitive performances in tasks associated with working memory and executive functioning. These results warrant further examination of the role of SN in PD patients with differing levels of cognitive impairment.

25 Delayed Cerebrovascular Response in Parkinson's Disease

Objective:Cardiovascular risk factors and white matter hyperintensities predict the progression and severity of cognitive symptoms in PD. While controversial, emerging evidence suggests that cerebrovascular dysfunction is an etiological driver of protein aggregation in neurodegenerative conditions, highlighting a need to understand how cerebrovascular function impacts cognitive function in PD. MRI cerebrovascular reactivity (CVR) paradigms provide an opportunity to measure the ability of the cerebral vessels to dilate or constrict in response to challenges. The current study evaluates whether whole brain CVR measures, degree of response (fit) and delay differ in PD with normal cognition (PD-NC) and PD with mild cognitive impairment (PD-MCI) relative to healthy controls (HC). Additionally, we evaluate if these metrics are associated with cognitive performance.Participants and Methods:8 PD-NC, 11 PD-MCI and 11 age and sex-matched healthy controls (HC) participated in the study. PD participants were diagnosed with MCI based on the Movement Disorders Society Task force, Level II assessment (comprehensive assessment). Participants were asked to inhale gas enriched in CO2 to elicit a vasodilatory response while undergoing bold oxygen level-dependent magnetic resonance image (MRI). Whole brain fit to an end-tidal CO2 regressor and delay were used to quantify CVR in each participant. An analysis of covariance (ANCOVA) was used to evaluate group differences between HC, PD-NC, and PD-MCI in the whole brain fit and delay CVR measures accounting for age, sex, and education. Multiple regressions were conducted for each cognitive variable with whole brain fit and delay as the dependent variables adjusting for age, sex, and education.Results:A significant main effect of group was observed for whole brain CVR latency (F(2, 23) = 4.227; p = 0.027). Post hoc tests were not significant, though indicated a trend that PD-NC (18.14 ±1.94) and PD-MCI (18.15 ± 1.55) patients exhibited longer delays relative to HC (15.84 ± 2.37). Regression results indicated limited relationships between CVR measures and cognitive functioning.Conclusions:PD patients (PD-NC and PD-MCI) exhibited longer CVR delays relative to HC, suggesting a delayed vasodilatory response in PD. Examination of the association between CVR metrics and cognition were not significant, though these results should be interpreted with caution given the small sample size.

Validation of the Arabic version of Parkinson's Disease Sleep Scale-Revised Version (PDSS-2)

ObjectivesParkinson's disease sleep scale (PDSS) was recommended by the Movement Disorder Society task force for screening and grading the severity of sleep problems in Parkinson's disease (PD). This work aimed to examine the validity and reliability of an Arabic version of PDSS-2. MethodsThis cross-sectional study was carried out on 133 patients fulfilling diagnostic criteria for PD. The patients were clinically assessed using the following scales: Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), modified Hoehn and Yahr Scale (H&Y), non-motor symptoms scale (NMSS), Beck Depression Inventory (BDI), and Pittsburgh Sleep Quality Index (PSQI). PDSS-2 scale was translated according to approved translation standards into Arabic and back-translated into English. Patients were asked to respond based on their experience in the last week. ResultsThe mean PDSS2 score for the included PD patients was 17±10. Cronbach's α coefficient value was 0.89, indicating good internal consistency. Most items showed high item-total correlation; the lowest was 0.375, considered higher than the conventional cut-off of 0.3. Test-retest reliability showed good agreement (ICC: 0.848). The exploratory factor analysis showed that items had been loaded over four factors. Total PDSS-2 score was positively correlated to age, disease duration, modified H&Y scale, MDS-UPDRS, NMSS, BDI, and global PSQI score. A cut-off point of 13 could differentiate poor sleepers from good sleepers with 91% sensitivity and 70% specificity (AUC 0.893, P<0.001). ConclusionThe Arabic version of PDSS-2 has appropriate validity and can be reliably used for assessing sleep-related problems in Arabic-speaking patients with PD.

Quantitative sleep electroencephalogram and cognitive performance in Parkinson's disease with and without rapid eye movement sleep behavior disorder.

Parkinson's disease (PD) patients with REM sleep behavior disorder (RBD) are at greater risk for cognitive decline and RBD has been associated with alterations in sleep-related EEG oscillations. This study evaluates differences in sleep quantitative EEG (qEEG) and cognition in PD participants with (PD-RBD) and without RBD (PD-no-RBD). In this cross-sectional study, polysomnography (PSG)-derived qEEG and a comprehensive level II neuropsychological assessment were compared between PD-RBD (n = 21) and PD-no-RBD (n = 31). Following artifact rejection, qEEG analysis was performed in the frontal and central leads. Measures included Scalp-slow wave (SW) density, spindle density, morphological properties of SW and sleep spindles, SW-spindle phase-amplitude coupling, and spectral power analysis in NREM and REM. The neurocognitive battery had at least two tests per domain, covering five cognitive domains as recommended by the Movement Disorders Society Task Force for PD-MCI diagnosis. Differences in qEEG features and cognitive performance were compared between the two groups. Stepwise linear regression was performed to evaluate predictors of cognitive performance. Multiple comparisons were corrected using the Benjamini-Hochberg method. Spindle density and SW-spindle co-occurrence percent were lower in participants with PD-RBD compared to PD-no-RBD. The PD-RBD group also demonstrated higher theta spectral power during REM. Sleep spindles and years of education, but not RBD, were predictors of cognitive performance. PD participants with RBD have alterations in sleep-related qEEG compared to PD participants without RBD. Although PD-RBD participants had worse cognitive performance compared to PD-no-RBD, regression models suggest that lower sleep spindle density, rather than presence of RBD, predicts worse comprehensive cognitive score. Future studies should include longitudinal evaluation to determine whether sleep-related qEEG alterations are associated with more rapid cognitive decline in PD-RBD.

Prevalence of neurocognitive disorder in Huntington's disease using the Enroll-HD dataset.

Cognitive decline in Huntington's disease (HD) begins early in the disease course, however the reported prevalence and severity of cognitive impairment varies based on diagnostic approach. A Movement Disorders Society Task Force recently endorsed the use of standardized DSM-5-based criteria to diagnose neurocognitive disorder (NCD) in Huntington's disease. To determine the prevalence and severity of cognitive impairment across different stages of HD by applying NCD criteria (mild and major) to participant data from the Enroll-HD database. Enroll-HD participants were triaged into either premanifest (preHD), manifest or control groups. PreHD was further dichotomized into preHD near or preHD far based on predicted time to diagnosis using the scaled CAG-age product score (CAPs). Embedded cognitive performance and functional independence measures were used to determine prevalence of NCD (mild and major) for all groups. Prevalence of NCD-mild was 25.2%-38.4% for manifest HD, 22.8%-47.3% for preHD near, 11.5%-25.1% for preHD far, and 8.8%-19.1% for controls. Prevalence of NCD-major was 21.1%-57.7% for manifest HD, 0.5%-16.3% for preHD near, 0.0%-4.5% for preHD far, and 0.0%-3.0% for controls. The prevalence of NCD in HD is elevated in preHD and demonstrates a sharp rise prior to diagnosis. In manifest HD, the vast majority of participants meet criteria for NCD. These findings are important for optimizing clinical care and/or anticipating the need for supportive services.

Global assessment, cognitive profile, and characteristics of mild cognitive impairment in Parkinson's disease.

Cognitive deficits are evident throughout the course of Parkinson's disease (PD), with 24% of patients experiencing subtle cognitive disturbances at the time of diagnosis, and with up to 80% of patients developing PD dementia (PDD) at advanced stages of the disease PD patients with mild cognitive impairment (MCI), an at-risk phenotype of PDD, present with heterogeneous clinical characteristics that complicate the management of PD. This study aims to examine the characteristics of PD-MCI by using the Movement Disorder Society (MDS) diagnostic criteria and evaluate the validity of global cognitive scales in identifying PD-MCI. Seventy-nine (79) PD patients completed neuropsychological assessments and a comprehensive cognitive battery. PD-MCI was classified according to the level 2 MDS task force criteria. Mini-Mental State Examination (sMMSE), Montreal Cognitive Assessment (MoCA) and Parkinson's Disease Cognitive Rating Scale (PDCRS) were examined against a level 2 dichotomised PD-MCI diagnosis. Characteristics of PD-MCI were evaluated using logistic regression analysis. Twenty-seven patients met criteria for PD-MCI (34%). The MoCA and PDCRS demonstrated high validity to screen for PD-MCI. Impairments in multiple cognitive domains were observed in 77.8% of PD-MCI patients. There were significantly more males in the PD-MCI group compared to PD patients without MCI (p<0.01). PD patients with MCI exhibited impairments in the attention/working memory, executive function and memory domains. Heterogeneous cognitive characteristics in PD warrant further investigation into specific cognitive subtypes to advance understanding and effective evaluation of PD-MCI.

The Phase 2, Randomized, Placebo-controlled PRECEDENT Trial of SAGE-718 in Patients With Parkinson's Disease Cognitive Impairment: Clinical Trial in Progress (P2-11.005)

<h3>Objective:</h3> The randomized, placebo-controlled PRECEDENT Study is designed to evaluate the efficacy, safety, and tolerability of SAGE-718 as a potential treatment for cognitive impairment due to Parkinson’s disease (PD). <h3>Background:</h3> PD is a multisystem disorder with diverse clinical features, including neuropsychiatric symptoms and non-motor manifestations alongside motor symptomatology. Cognitive impairment, a common non-motor symptom of PD, contributes to poor functional outcomes, loss of independence, and increased risk of dementia. A significant unmet need exists for effective and well-tolerated pharmacotherapies that address cognitive impairment due to PD. Positive modulation of NMDA receptors may improve cognitive deficits. SAGE-718, an investigational NMDA receptor positive allosteric modulator, has been associated with improved cognitive performance in patients with PD and other neurodegenerative diseases. <h3>Design/Methods:</h3> PRECEDENT (NCT05318937) is a Phase 2, randomized, double-blind, placebo-controlled trial that includes a 3-week screening period, a 1-week baseline period, a 6-week treatment period, and a 4-week follow-up period. Approximately 76 patients aged 50–75 years meeting Movement Disorder Society Task Force Criteria for PD Mild Cognitive Impairment with mild-to-moderate motor involvement will be randomized 1:1 to receive either SAGE-718 or placebo once daily for 42 days. The primary endpoint is change from baseline in the Wechsler Adult Intelligence Scale-IV Coding score (a measure of executive functioning) at Day 42. Secondary endpoints include the proportion of patients with treatment-emergent adverse events (TEAEs), severity of TEAEs, and number of patients who withdraw from the study due to TEAEs. Other endpoints include additional assessments of cognitive performance, safety/tolerability, motor symptoms, functioning, and pharmacokinetics. <h3>Results:</h3> PRECEDENT is currently enrolling at sites in the United States. <h3>Conclusions:</h3> PRECEDENT is designed to evaluate the efficacy, safety, and tolerability of SAGE-718 in patients with cognitive impairment due to PD. <b>Disclosure:</b> Dr. Bullock has received personal compensation for serving as an employee of Sage Therapeutics, Inc. . Dr. Bullock has stock in Sage Therapeutics, Inc. Aaron Koenig has received personal compensation for serving as an employee of Sage Therapeutics. Dr. Paumier has nothing to disclose. Ms. Freitag has nothing to disclose. Jeffrey Wald has received personal compensation for serving as an employee of Sage Therapeutics. Jeffrey Wald has received stock or an ownership interest from Sage Thereapeutics. Dr. Park has nothing to disclose. Michael Quirk has received personal compensation for serving as an employee of Sage Therapeutics. Michael Quirk has received stock or an ownership interest from Sage Therapeutics. Jennifer Petrillo, 14951 has received personal compensation for serving as an employee of Sage Therapeutics. Jennifer Petrillo, 14951 has received stock or an ownership interest from Sage Therapeutics. Dr. Doherty has received personal compensation for serving as an employee of Sage Therapeutics. Dr. Doherty has received stock or an ownership interest from Sage Therapeutics.

Pausing before verb production is associated with mild cognitive impairment in Parkinson's disease.

Cognitive dysfunction and communication impairment are common and disabling symptoms in Parkinson's Disease (PD). Action verb deficits occur in PD, but it remains unclear if these impairments are related to motor system dysfunction and/or cognitive decline. The objective of our study was to evaluate relative contributions of cognitive and motor dysfunction to action verb production in naturalistic speech of patients with PD. We proposed that pausing before action-related language is associated with cognitive dysfunction and may serve as a marker of mild cognitive impairment in PD. Participants with PD (n = 92) were asked to describe the Cookie Theft picture. Speech files were transcribed, segmented into utterances, and verbs classified as action or non-action (auxiliary). We measured silent pauses before verbs and before utterances containing verbs of different classes. Cognitive assessment included Montreal Cognitive Assessment (MoCA) and neuropsychological tests to categorize PD participants as normal cognition (PD-NC) or mild cognitive impairment (PD-MCI) based on Movement Disorders Society (MDS) Task Force Tier II criteria. Motor symptoms were assessed using MDS-UPDRS. We performed Wilcoxon rank sum tests to identify differences in pausing between PD-NC and PD-MCI. Logistic regression models using PD-MCI as dependent variables were used to evaluate the association between pause variables and cognitive status. Participants with PD-MCI demonstrated more pausing before and within utterances compared to PD-NC, and the duration of these pauses were correlated with MoCA but not motor severity (MDS-UPDRS). Logistic regression models demonstrated that pauses before action utterances were associated with PD-MCI status, whereas pauses before non-action utterances were not significantly associated with cognitive diagnosis. We characterized pausing patterns in spontaneous speech in PD-MCI, including analysis of pause location with respect to verb class. We identified associations between cognitive status and pausing before utterances containing action verbs. Evaluation of verb-related pauses may be developed into a potentially powerful speech marker tool to detect early cognitive decline in PD and better understand linguistic dysfunction in PD.

Transitional Care for Young People with Movement Disorders: Consensus-Based Recommendations from the MDS Task Force on Pediatrics.

The International Parkinson and Movement Disorders Society (MDS) set up a working group on pediatric movement disorders (MDS Task Force on Pediatrics) to generate recommendations to guide the transition process from pediatrics to adult health care systems in patients with childhood-onset movement disorders. To develop recommendations for transitional care for childhood onset movement disorders, we used a formal consensus development process, using a multi-round, web-based Delphi survey. The Delphi survey was based on the results of the scoping review of the literature and the results of a survey of MDS members on transition practices. Through iterative discussions, we generated the recommendations included in the survey. The MDS Task Force on Pediatrics were the voting members for the Delphi survey. The task force members comprise 23 child and adult neurologists with expertise in the field of movement disorders and from all regions of the world. Fifteen recommendations divided across four different areas were made pertaining to: (1) team composition and structure, (2) planning and readiness, (3) goals of care, and (4) administration and research. All recommendations achieved consensus with a median score of 7 or greater. Recommendations on providing transitional care for patients with childhood onset movement disorders are provided. Nevertheless several challenges remain in the implementation of these recommendations, related to health infrastructure and the distribution of health resources, and the availability of knowledgeable and interested practitioners. Research on the influence of transitional care programs on outcomes in childhood onset movement disorders is much needed.

Psychometric properties and construct validity of the Parkinson's Disease-Cognitive Rating Scale (PD-CRS) in Colombia.

Cognitive impairment is frequent among people living with Parkinson's disease: up to 40% of patients exhibit symptoms of mild cognitive impairment and 25% meet the criteria for dementia. Parkinson's Disease Cognitive Rating Scale (PD-CRS) is one of the recommended scales by the Movement Disorders Society Task Force for level 1 screening of dementia. However, its psychometric properties have not been studied in the Colombian population. A cross-sectional study was conducted on 100 patients with Parkinson's disease diagnosed by a movement disorders neurologist. Patients were evaluated with PD-CRS and MoCA. Principal component analysis was conducted, and then confirmatory factor analysis was implemented through the maximum-likelihood method. Internal consistency was evaluated using Cronbach α. Convergent and divergent validity were also calculated and concurrent validity with the MoCA was assessed. 62% were males. Their median age was 68 years (IQR 57-74) and the median disease duration was 4 years (IQR 2-9). 77% were classified in early stages (Hoehn and Yahr stage ≤ 2), while the MDS-UPDRS part III score was 25 (IQR 15.5-38). In the principal component factor analysis, the pattern matrix unveiled a mnesic and a non-mnesic domain. Confirmatory factor analysis showed similar explanatory capacity (λ ≥ 0.50) for items other than naming (λ = 0.34). Cronbach's α for the full 9-items instrument was 0.74. MoCA and PD-CRS total scores were correlated (ρ = 0.71, p = 0.000). Assuming a cut-off score of 62 points, there is an agreement of 89% with the definition of dementia by MoCA for Colombia (κ = 0.59; p = 0.000). PD-CRS has acceptable psychometric properties for the Colombian population and has significant correlation and agreement with a validated scale (MoCA).

Age Cutoff for Early-Onset Parkinson's Disease: Recommendations from the International Parkinson and Movement Disorder Society Task Force on Early Onset Parkinson's Disease.

Early-onset Parkinson's disease (EOPD)/young-onset Parkinson's disease (YOPD) is defined as Parkinson's disease (PD) with an age at onset (AAO) after age 21 years but before the usual AAO for PD. Consensus is lacking, and the reported maximal age for EOPD/YOPD has varied from 40 to 60 years, leading to a lack of uniformity in published studies and difficulty in harmonization of data. EOPD and YOPD have both been used in the literature, somewhat interchangeably. To define the nomenclature and AAO cutoff for EOPD/YOPD. An extensive review of the literature and task force meetings were conducted. Conclusions were reached by consensus. First, the literature has seen a shift from the use of YOPD toward EOPD. This seems motivated by an attempt to avoid age-related stigmatization of patients. Second, in defining EOPD, 56% of the countries use 50 or 51 years as the cutoff age. Third, the majority of international genetic studies in PD use an age cutoff of younger than 50 years to define EOPD. Fourth, many studies suggest that changes in the estrogen level can affect the predisposition to develop PD, making the average age at menopause of 50 years an important factor to consider when defining EOPD. Fifth, considering the differential impact of the AAO of PD on professional and social life, using 50 years as the upper cutoff for the definition of EOPD seems reasonable. This task force recommends the use of EOPD rather than YOPD. It defines EOPD as PD with AAO after 21 years but before 50 years.

Nomenclature of Genetic Movement Disorders: Recommendations of the International Parkinson and Movement Disorder Society Task Force - An Update.

In 2016, the Movement Disorder Society Task Force for the Nomenclature of Genetic Movement Disorders presented a new system for naming genetically determined movement disorders and provided a criterion-based list of confirmed monogenic movement disorders. Since then, a substantial number of novel disease-causing genes have been described, which warrant classification using this system. In addition, with this update, we further refined the system and propose dissolving the imaging-based categories of Primary Familial Brain Calcification and Neurodegeneration with Brain Iron Accumulation and reclassifying these genetic conditions according to their predominant phenotype. We also introduce the novel category of Mixed Movement Disorders (MxMD), which includes conditions linked to multiple equally prominent movement disorder phenotypes. In this article, we present updated lists of newly confirmed monogenic causes of movement disorders. We found a total of 89 different newly identified genes that warrant a prefix based on our criteria; 6 genes for parkinsonism, 21 for dystonia, 38 for dominant and recessive ataxia, 5 for chorea, 7 for myoclonus, 13 for spastic paraplegia, 3 for paroxysmal movement disorders, and 6 for mixed movement disorder phenotypes; 10 genes were linked to combined phenotypes and have been assigned two new prefixes. The updated lists represent a resource for clinicians and researchers alike and they have also been published on the website of the Task Force for the Nomenclature of Genetic Movement Disorders on the homepage of the International Parkinson and Movement Disorder Society (https://www.movementdisorders.org/MDS/About/Committees--Other-Groups/MDS-Task-Forces/Task-Force-on-Nomenclature-in-Movement-Disorders.htm). © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.

Profile of cognitive impairment in late-stage Parkinson's disease.

IntroductionThe profile of cognitive impairment associated with the late stages of Parkinson's disease (LSPD) is rarely reported. Its characterization is necessary to better understand the cognitive changes that occur as the disease progresses and to better contribute to its management.MethodsIn this cross‐sectional study, we characterized the cognitive profile of LSPD patients using the comprehensive assessment methodology proposed by the International Parkinson and Movement Disorders Society Task Force. The association of clinical and demographic variables with dementia diagnosis was also investigated using binary logistic regression analysis.ResultsEighty‐four LSPD patients were included (age 75.4 ± 6.9; disease duration 16.9 ± 7.5). Fifty‐four (64.3%) were classified as demented and presented a global impairment cognitive profile. In the nondemented group (N = 30), 25 (83.3%) LSPD patients met the diagnostic criteria for mild cognitive impairment, mostly with multiple domain impairment (96.0%) and a heterogeneous profile. Memory was the most frequent and severely impaired cognitive domain in both groups. Disease disability, orientation, complex order comprehension, verbal learning, and visuoconstructive abilities were significantly associated with dementia diagnosis (p < .05).ConclusionsCognitive impairment in multiple domains was common in LSPD patients. The most frequent and prominent deficits were in the memory domain, with a strong interference from attention impairment. Disease disability, orientation, complex order comprehension, verbal learning, and visuoconstructive abilities proved to be important determinants for dementia diagnosis.

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.

Slow Wave Sleep and EEG Delta Spectral Power are Associated with Cognitive Function in Parkinson's Disease.

Cognitive and sleep dysfunction are common non-motor symptoms in Parkinson's disease (PD). Determine the relationship between slow wave sleep (SWS) and cognitive performance in PD. Thirty-two PD participants were evaluated with polysomnography and a comprehensive level II neurocognitive battery, as defined by the Movement Disorders Society Task Force for diagnosis of PD-mild cognitive impairment. Raw scores for each test were transformed into z-scores using normative data. Z-scores were averaged to obtain domain scores, and domain scores were averaged to determine the Composite Cognitive Score (CCS), the primary outcome. Participants were grouped by percent of SWS into High SWS and Low SWS groups and compared on CCS and other outcomes using 2-sided t-tests or Mann-Whitney U. Correlations of cognitive outcomes with sleep architecture and EEG spectral power were performed. Participants in the High SWS group demonstrated better global cognitive function (CCS) (p = 0.01, effect size: r = 0.45). In exploratory analyses, the High SWS group showed better performance in domains of executive function (effect size: Cohen's d = 1.05), language (d = 0.95), and processing speed (d = 1.12). Percentage of SWS was correlated with global cognition and executive function, language, and processing speed. Frontal EEG delta power during N3 was correlated with the CCS and executive function. Cognition was not correlated with subjective sleep quality. Increased SWS and higher delta spectral power are associated with better cognitive performance in PD. This demonstrates the significant relationship between sleep and cognitive function and suggests that interventions to improve sleep might improve cognition in individuals with PD.

Do We Belittle Essential Tremor by Calling It a Syndrome Rather Than a Disease? No.

A task force of the International Parkinson and Movement Disorder Society (MDS) recently published a tremor classification scheme that is based on the nosologic principle of two primary axes for classifying an illness: clinical manifestations (Axis 1) and etiology (Axis 2). An Axis 1 clinical syndrome is a recurring group of clinical symptoms, signs (physical findings), and possibly laboratory results that suggests the presence of at least one underlying Axis 2 etiology. Syndromes must be defined and used consistently to be of value in finding specific etiologies and effective treatments. The MDS task force concluded that essential tremor is a common neurological syndrome that has never been defined consistently by clinicians and researchers. The MDS task force defined essential tremor as a syndrome of bilateral upper limb action tremor of at least 3 years duration, with or without tremor in other locations (e.g., head, voice, or lower limbs), in the absence of other neurological signs (e.g., dystonia, parkinsonism, myoclonus, ataxia, peripheral neuropathy, and cognitive impairment). Deviations from this definition should not be labeled as essential tremor. Patients with additional questionably-abnormal signs or with signs of uncertain relevance to tremor are classified as essential tremor plus. The MDS classification scheme encourages a thorough unbiased phenotyping of patients with tremor, with no assumptions of etiology, pathology, pathophysiology, or relationship to other neurological disorders. The etiologies, pathology, and clinical course of essential tremor are too heterogeneous for this syndrome to be viewed as a disease or a family of diseases.

The Free and Cued Selective Reminding Test in Parkinson's Disease Mild Cognitive Impairment: Discriminative Accuracy and Neural Correlates.

Introduction: Memory alterations are common in Parkinson's disease (PD) patients but the mechanisms involved in these deficits remain poorly understood. The study aims to explore the profile of episodic memory deficits in non-demented early PD patients.Methods: We obtained neurological, cognitive and behavioral data from 114 PD patients and 41 healthy controls (HC). PD participants were grouped as normal cognition (PD-NC) and mild cognitive impairment (PD-MCI) according to the Level II criteria of the Movement Disorders Society Task Force (MDS-TF). We evaluate the performance amongst groups on an episodic memory task using the Free and Cued Selective Reminding Test (FCSRT). Additionally, gray matter volume (GMV) voxel based morphometry, and mean diffusivity (MD) analyses were conducted in a subset of patients to explore the structural brain correlates of FCSRT performance.Results: Performance on all subscores of the FCSRT was significantly worse in PD-MCI than in PD-NC and HC. Delayed total recall (DTR) subscore was the best at differentiating PD-NC from PD-MCI. Using crosstabulation, DTR allowed identification of PD-MCI patients with an accuracy of 80%. Delayed free and cued recall was associated with decreased GMV and increased MD in multiple fronto-temporal and parietal areas.Conclusion: Encoding and retrieval deficits are a main characteristic of PD-MCI and are associated with structural damage in temporal, parietal and prefrontal areas.