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Background: Visual hallucinations are common in patients with Parkinson's disease and represent probably the major independent predictor for cognitive deterioration and nursing home placement., Objective: To investigate if treatment of minor visual hallucinations in Parkinson's disease with rivastigmine delays the progression to psychosis., Methods: A multicenter, randomized, double-blind, placebo-controlled trial was conducted which aimed to recruit 168 patients with Parkinson's disease reporting minor visual hallucinations 4 weeks before it. Important exclusion criteria were Parkinson's disease dementia, current delirium, and treatment with antipsychotics or drugs that have significant anti-cholinergic side effects. Subjects were randomized to rivastigmine capsules, 3-6 mg twice a day, or placebo for 24 months. The primary outcome was the time to Parkinson's disease psychosis, which was defined as the need to start with antipsychotics., Results: The trial was stopped prematurely because of slow recruitment. Ninety-one patients were randomized: 46 patients were assigned to rivastigmine and 45 patients to placebo. No effect of rivastigmine could be demonstrated on the transition time to psychosis or dementia during the 24-month follow-up period. After 6 months of study treatment, cognition, mood, motor performance, and non-motor performance did not differ significantly between the rivastigmine-group and the placebo-group., Conclusions: Because the study was terminated early, it was insufficiently powered to properly evaluate the primary outcome. The limited data of the study favor a wait and see approach instead of early treatment with rivastigmine in PD patients with minor VH., (© 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Background: The International Parkinson and Movement Disorders Society criteria for mild cognitive impairment in PD need validation. The objectives of this present study were to evaluate prognostic validity of level I (abbreviated) International Parkinson and Movement Disorders Society mild cognitive impairment in PD criteria for development of PD dementia and compared them with level II (comprehensive) criteria., Methods: We analyzed data from 8 international studies (1045 patients) from our consortium that included baseline data on demographics, motor signs, depression, detailed neuropsychological testing, and longitudinal follow-up for conversion to Parkinson's disease dementia. Survival analysis evaluated their contribution to the hazard of Parkinson's disease dementia., Results: Level I mild cognitive impairment in PD, increasing age, male sex, and severity of PD motor signs independently increased the hazard of Parkinson's disease dementia. Level I and level II mild cognitive impairment in PD classification had similar discriminative ability with respect to the time to Parkinson's disease dementia., Conclusions: Level I mild cognitive impairment in PD classification independently contributes to the hazard of Parkinson's disease dementia. This finding supports the prognostic validity of the abbreviated mild cognitive impairment in PD criteria. © 2019 International Parkinson and Movement Disorder Society., (© 2019 International Parkinson and Movement Disorder Society.)

Background: Numerous neuropsychological tests and test versions are used in Parkinson's disease research, but their relative capacity to detect mild cognitive deficits and their comparability across studies are unknown. The objective of this study was to identify neuropsychological tests that consistently detect cognitive decline in PD across studies., Methods: Data from 30 normed neuropsychological tests across 20 international studies in up to 2908 nondemented PD patients were analyzed. A subset of 17 tests was administered to up to 1247 healthy controls. A 2-step meta-analytic approach using standardized scores compared performance in PD with normative data., Results: Pooled estimates of the differences between PD and site-specific healthy controls identified significant cognitive deficits in PD patients on 14 test scores across 5 commonly assessed cognitive domains (attention or working memory, executive, language, memory, and visuospatial abilities), but healthy control performance was statistically above average on 7 of these tests. Analyses based on published norms only, as opposed to direct assessment of healthy controls, showed high between-study variability that could not be accounted for and led to inconclusive results., Conclusions: Normed neuropsychological tests across multiple cognitive domains consistently detect cognitive deficits in PD when compared with site-specific healthy control performance, but relative PD performance was significantly affected by the inclusion and type of healthy controls versus the use of published norms only. Additional research is needed to identify a cognitive battery that can be administered in multisite international studies and that is sensitive to cognitive decline, responsive to therapeutic interventions, and superior to individual cognitive tests. © 2018 International Parkinson and Movement Disorder Society., (© 2018 International Parkinson and Movement Disorder Society.)

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., (© 2017 International Parkinson and Movement Disorder Society.)

Objective: To evaluate the possible influence of electrode trajectories penetrating the caudate nucleus (CN) on cognitive outcomes in deep brain stimulation (DBS) surgery for Parkinson's disease (PD)., Background: It is currently unclear how mandatory CN avoidance during trajectory planning is., Design/methods: Electrode trajectories were determined to be inside, outside, or in border region of the CN. Pre- and postoperative neuropsychological tests of each trajectory group were compared in order to evaluate possible differences in cognitive outcomes 12 months after bilateral STN DBS., Results: One hundred six electrode tracks in 53 patients were evaluated. Bilateral penetration of the CN occurred in 15 (28%) patients, while unilateral penetration occurred in 28 (53%). In 19 (36%) patients tracks were located in the border region of the CN. There was no electrode penetration of the CN in 10 (19%) patients. No difference in cognitive outcomes was found between the different groups., Conclusion: Cognitive outcome was not influenced by DBS electrode tracks penetrating the CN. It is both feasible and sensible to avoid electrode tracks through the CN when possible, considering its function and anatomical position. However, penetration of the CN can be considered without major concerns regarding cognitive decline when this facilitates optimal trajectory planning due to specific individual anatomical variations., (© 2018 The Author(s) Published by S. Karger AG, Basel.)

Background: The International Parkinson and Movement Disorder Society criteria for mild cognitive impairment in PD were recently formulated., Objectives: The aim of this international study was to evaluate the predictive validity of the comprehensive (level II) version of these criteria by assessment of their contribution to the hazard of PD dementia., Methods: Individual patient data were selected from four separate studies on cognition in PD that provided information on demographics, motor examination, depression, neuropsychological examination suitable for application of level II criteria, and longitudinal follow-up for conversion to dementia. Survival analysis evaluated the predictive value of level II criteria for cognitive decline toward dementia as expressed by the relative hazard of dementia., Results: A total of 467 patients were included. The analyses showed a clear contribution of impairment according to level II mild cognitive impairment criteria, age, and severity of PD motor symptoms to the hazard of dementia. There was a trend of increasing hazard of dementia with declining neuropsychological performance., Conclusions: This is the first large international study evaluating the predictive validity of level II mild cognitive impairment criteria for PD. The results showed a clear and unique contribution of classification according to level II criteria to the hazard of PD dementia. This finding supports their predictive validity and shows that they contribute important new information on the hazard of dementia, beyond known demographic and PD-specific factors of influence. © 2017 International Parkinson and Movement Disorder Society., (© 2017 International Parkinson and Movement Disorder Society.)

Background: Effects on non-motor symptoms, mainly cognitive and psychiatric side effects, could influence the decision for either globus pallidus pars interna (GPi) or subthalamic nucleus (STN) deep brain stimulation (DBS) for patients with Parkinson's disease (PD)., Objective: 1) To compare cognitive and psychiatric outcomes 3 years after GPi DBS versus STN DBS, and 2) to report on occurrence of suicidal ideation, psychiatric diagnoses, social functioning, and marital satisfaction 3 years after DBS., Methods: Patients were randomized to receive GPi DBS (n = 65) or STN DBS (n = 63). Standardized assessments were performed at baseline, 1 year, and 3 years. We used linear mixed model analyses to investigate between-group differences on the Mattis Dementia Rating Scale (MDRS), neuropsychological tests, and psychiatric questionnaires 3 years after DBS., Results: Eighty-seven patients (68%) completed at least one neuropsychological test after 3 years. No significant between-group differences were found on the MDRS (p = 0.61), neuropsychological tests (p-values between 0.17 and 0.87), and psychiatric questionnaires (p-values between 0.23 and 0.88) 3 years after DBS. The Mini International Neuropsychiatric Interview did not indicate a substantial number of psychiatric diagnoses after 3 years. Social functioning and marital satisfaction were comparable in both groups., Conclusions: Three years after GPi DBS and STN DBS no pronounced between-group differences on measures of cognitive and psychiatric functioning could be demonstrated. Overall, cognitive and psychiatric outcome 3 years after DBS do not provide a clear direction for clinicians when considering which of these two surgical targets to choose., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To develop a prognostic model to predict disease outcomes in individual patients with Parkinson disease (PD) and perform an external validation study in an independent cohort., Methods: Model development was done in the Comorbidity and Aging in Rehabilitation Patients: The Influence on Activities (CARPA) cohort (Netherlands). External validation was performed using the Cambridgeshire Parkinson's Incidence from GP to Neurologist (CamPaIGN) cohort (UK). Both are longitudinal incident cohort studies that prospectively followed up patients with PD from the time of diagnosis. A composite outcome measure was made in which patients were classified as having an unfavorable prognosis when they had postural instability or dementia at the 5-year assessment (or at the last assessment before loss to follow-up), or had died before this time. The final model was derived with a backward selection strategy from candidate predictor variables that were measured at baseline., Results: In the resulting model, higher patient age, higher Unified Parkinson's Disease Rating Scale motor examination axial score, and a lower animal fluency score were all associated with a higher probability of an unfavorable outcome. External validation confirmed good discriminative ability between favorable and unfavorable outcomes with an area under the receiver operating characteristic curve of 0.85 (95% confidence interval 0.77-0.93) and a well-calibrated model with a calibration slope of 1.13 and no significant lack of fit (Hosmer-Lemeshow test: p = 0.39)., Conclusion: We constructed a model that allows individual patient prognostication at 5 years from diagnosis, using a small set of predictor variables that can easily be obtained by clinicians or research nurses., (© 2016 American Academy of Neurology.)

Background: The aim of this study was to assess psychiatric and social outcome 12 months after bilateral deep brain stimulation (DBS) of the globus pallidus pars interna (GPi) and subthalamic nucleus (STN) for advanced Parkinson's disease (PD)., Methods: We randomly assigned patients to receive GPi DBS (n = 65) or STN DBS (n = 63). Standardized psychiatric and social questionnaires were assessed at baseline and after 12 months., Results: No differences were found between GPi DBS and STN DBS on psychiatric evaluation. Within-group comparisons showed small but statistically significant changes on several measures in both groups. Descriptive statistics indicated slight changes in social functioning. Marital satisfaction of patients and partners remained relatively stable after GPi and STN DBS., Conclusions: We found neither differences in psychiatric and social outcome between GPi DBS and STN DBS nor any relevant within-group differences. The decision for GPi DBS or STN DBS cannot be based on expected psychiatric or social effects., (© 2015 International Parkinson and Movement Disorder Society.)

Objective: To compare motor symptoms, cognition, mood, and behavior 3 years after deep brain stimulation (DBS) of the globus pallidus pars interna (GPi) and subthalamic nucleus (STN) in advanced Parkinson disease (PD)., Methods: Patients with PD eligible for DBS were randomized to bilateral GPi DBS and bilateral STN DBS (1:1). The primary outcome measures were (1) improvement in motor symptoms in off-drug phase measured with the Unified Parkinson Disease Rating Scale (UPDRS) and (2) a composite score for cognitive, mood, and behavioral effects, and inability to complete follow-up at 36 months after surgery., Results: Of the 128 patients enrolled, 90 were able to complete the 3-year follow-up. We found significantly more improvement of motor symptoms after STN DBS (median [interquartile range (IQR)] at 3 years, GPi 33 [23-41], STN 28 [20-36], p = 0.04). No between-group differences were observed on the composite score (GPi 83%, STN 86%). Secondary outcomes showed larger improvement in off-drug functioning in the AMC Linear Disability Scale score after STN DBS (mean ± SD, GPi 65.2 ± 20.1, STN 72.6 ± 18.0, p = 0.05). Medication was reduced more after STN DBS (median levodopa equivalent dose [IQR] at 3 years, GPi 1,060 [657-1,860], STN 605 [411-875], p < 0.001). No differences in adverse effects were recorded, apart from more reoperations to a different target after GPi DBS (GPi n = 8, STN n = 1)., Conclusions: Off-drug phase motor symptoms and functioning improve more after STN DBS than after GPi DBS. No between-group differences were observed on a composite score for cognition, mood, and behavior, and the inability to participate in follow-up., Classification of Evidence: This study provides Class II evidence that STN DBS provides more off-phase motor improvement than GPi DBS, but with a similar risk for cognitive, mood, and behavioral complications., (© 2016 American Academy of Neurology.)

Objective: To assess the neuropsychological outcome 12 months after bilateral deep brain stimulation (DBS) of the globus pallidus pars interna (GPi) or subthalamic nucleus (STN) for advanced Parkinson disease., Methods: We randomly assigned patients to receive either GPi DBS or STN DBS. Standardized neuropsychological tests were performed at baseline and after 12 months. Patients and study assessors were masked to treatment allocation., Results: Univariate analysis of change scores indicated group differences on Stroop word reading and Stroop color naming (confidence interval [CI] 1.9-10.0 and 2.1-8.8), on Trail Making Test B (CI 0.5-10.3), and on Wechsler Adult Intelligence Scale similarities (CI -0.01 to 1.5), with STN DBS showing greater negative change than GPi DBS. No differences were found between GPi DBS and STN DBS on the other neuropsychological tests. Older age and better semantic fluency at baseline predicted cognitive decline after DBS., Conclusions: We found no clinically significant differences in neuropsychological outcome between GPi DBS and STN DBS. No satisfactory explanation is available for the predictive value of baseline semantic fluency for cognitive decline., Classification of Evidence: This study provides Class I evidence that there is no large difference in neuropsychological outcome between GPi DBS and STN DBS after 12 months. The study lacks the precision to exclude a moderate difference in outcomes., (© 2015 American Academy of Neurology.)

Objective: To assess the ability of neurophysiologic markers in conjunction with cognitive assessment to improve prediction of progression to dementia in Parkinson disease (PD)., Methods: Baseline cognitive assessments and magnetoencephalographic recordings from 63 prospectively included PD patients without dementia were analyzed in relation to PD-related dementia (PDD) conversion over a 7-year period. We computed Cox proportional hazard models to assess the risk of converting to dementia conveyed by cognitive and neurophysiologic markers in individual as well as combined risk factor analyses., Results: Nineteen patients (30.2%) developed dementia. Baseline cognitive performance and neurophysiologic markers each individually predicted conversion to PDD. Of the cognitive test battery, performance on a posterior (pattern recognition memory score < median; hazard ratio (HR) 6.80; p = 0.001) and a fronto-executive (spatial span score < median; HR 4.41; p = 0.006) task most strongly predicted dementia conversion. Of the neurophysiologic markers, beta power < median was the strongest PDD predictor (HR 5.21; p = 0.004), followed by peak frequency < median (HR 3.97; p = 0.016) and theta power > median (HR 2.82; p = 0.037). In combination, baseline cognitive performance and neurophysiologic measures had even stronger predictive value, with the combination of impaired fronto-executive task performance and low beta power being associated with the highest dementia risk (both risk factors vs none: HR 27.3; p < 0.001)., Conclusions: Combining neurophysiologic markers with cognitive assessment can substantially improve dementia risk profiling in PD, providing potential benefits for clinical care as well as for the future development of therapeutic strategies.

Dementia in Parkinson's disease (PD) is a serious health issue and a major concern for many patients. In most cases mild cognitive impairment (MCI) is considered a transitional stage between normal cognitive functioning and dementia which is of potential importance in the early identification of patients at risk for dementia. Recently, the Movement Disorder Society (MDS) proposed diagnostic criteria for MCI in PD (PD-MCI). These criteria comprise two operationalizations: Level I (based on an abbreviated assessment) and Level II (based on comprehensive neuropsychological evaluation permitting MCI subtyping). These criteria need to be validated. This paper describes a project aiming to validate the MDS PD-MCI criteria by pooling and analyzing cross-sectional and longitudinal neuropsychological databases comprising ≥5,500 PD patients and ≥1,700 controls. After applying the MDS PD-MCI Level I and Level II criteria, rates of conversion to PD-dementia and predictive variables for conversion to PD-dementia will be established. This study will also assist in identifying whether revisions of the PD-MCI criteria are required.

Cognitive change is frequently observed in patients with Parkinson's disease (PD). However, the exact profile and extent of cognitive impairments remain unclear due to the clinical heterogeneity of PD and methodological issues in many previous studies. In this study, we aimed to examine the severity, frequency, and profile of cognitive changes in newly diagnosed PD patients over 5 years. At baseline and after 3 and 5 years, a hospital-based sample of PD patients (n = 59) and healthy controls (n = 40) were given neuropsychological tests covering six cognitive domains. Patients showed greater decline over time than healthy controls on all cognitive domains, except for attention. The profile of decline showed that psychomotor speed and memory were most affected. At the individual level 53% of the patients showed more cognitive decline than controls. Age at onset and memory impairment at baseline predicted cognitive decline. Cognitive functions in PD patients show greater decline in most domains than in healthy elderly over the course of 5 years. Due to selection bias as a result of attrition, the actual degree of decline may be greater than reported here.

Objective: In Parkinson disease (PD), the rate of clinical progression is highly variable. To date, there are conflicting findings concerning the prognostic factors influencing the rate of progression. Methodologic issues such as the use of selected patients from therapeutic trials, and short durations of follow-up probably underlie this problem. We therefore designed a prospective follow-up study of a cohort of newly diagnosed patients with PD., Methods: A cohort of 129 patients with newly diagnosed PD was assessed at baseline, and 1, 2, 3, and 5 years later. The rate of progression and its prognostic factors on the level of motor impairments, disability, and quality of life were investigated using linear mixed-model analysis., Results: Annual increase of motor impairments measured with the Unified Parkinson's Disease Rating Scale-Motor Examination was estimated to be 2.46 points (95% confidence interval: 2.05-2.88). The main determinants of faster increase of motor impairments were male sex and cognitive dysfunction at the time of diagnosis. The main determinants of faster increase of disability were higher age at onset, cognitive dysfunction, and the presence of levodopa-nonresponsive motor symptoms at the time of diagnosis. No clinically relevant determinants were found for the decrease in quality of life., Conclusion: This study shows the importance of nondopaminergic symptoms at the time of diagnosis, because these symptoms are the main determinants of increased disability in the first 5 years of the disease.

Background: Patients with advanced Parkinson's disease often have rapid swings between mobility and immobility, and many respond unsatisfactorily to adjustments in pharmacological treatment. We assessed whether globus pallidus pars interna (GPi) deep brain stimulation (DBS) gives greater functional improvement than does subthalamic nucleus (STN) DBS., Methods: We recruited patients from five centres in the Netherlands who were aged 18 years or older, had idiopathic Parkinson's disease, and had, despite optimum pharmacological treatment, at least one of the following symptoms: severe response fluctuations, dyskinesias, painful dystonias, or bradykinesia. By use of a computer-generated randomisation sequence, we randomly assigned patients to receive either GPi DBS or STN DBS (1:1), applying a minimisation procedure according to drug use (levodopa equivalent dose <1000 mg vs ≥1000 mg) and treatment centre. Patients and study assessors (but not those who assessed adverse events) were masked to treatment allocation. We had two primary outcomes: functional health as measured by the weighted Academic Medical Center Linear Disability Scale (ALDS; weighted by time spent in the off phase and on phase) and a composite score for cognitive, mood, and behavioural effects up to 1 year after surgery. Secondary outcomes were symptom scales, activities of daily living scales, a quality-of-life questionnaire, the occurrence of adverse events, and drug use. We used the intention-to-treat principle for all analyses. This trial is registered with www.controlled-trials.com, number ISRCTN85542074., Findings: Between Feb 1, 2007, and March 29, 2011, we enrolled 128 patients, assigning 65 to GPi DBS and 63 to STN DBS. We found no statistically significant difference in either of our primary outcomes: mean change in weighted ALDS (3·0 [SD 14·5] in the GPi group vs 7·7 [23·2] in the STN group; p=0·28) and the number of patients with cognitive, mood, and behavioural side-effects (36 [58%] of 62 patients in the GPi group vs 35 [56%] of 63 patients in the STN group; p=0·94). Secondary outcomes showed larger improvements in off-drug phase in the STN group compared with the GPi group in the mean change in unified Parkinson's disease rating scale motor examination scores (20·3 [16·3] vs 11·4 [16·1]; p=0·03), the mean change in ALDS scores (20·3 [27·1] vs 11·8 [18·9]; p=0·04), and medication (mean levodopa equivalent drug reduction: 546 [SD 561] vs 208 [521]; p=0·01). We recorded no difference in the occurrence of adverse events between the two groups. Other secondary endpoints showed no difference between the groups., Interpretation: Although there was no difference in our primary outcomes, our findings suggest that STN could be the preferred target for DBS in patients with advanced Parkinson's disease., Funding: Stichting Internationaal Parkinson Fonds, Prinses Beatrix Fonds, and Parkinson Vereniging., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Mild cognitive impairment is common in nondemented Parkinson's disease (PD) patients and may be a harbinger of dementia. In view of its importance, the Movement Disorder Society commissioned a task force to delineate diagnostic criteria for mild cognitive impairment in PD. The proposed diagnostic criteria are based on a literature review and expert consensus. This article provides guidelines to characterize the clinical syndrome and methods for its diagnosis. The criteria will require validation, and possibly refinement, as additional research improves our understanding of the epidemiology, presentation, neurobiology, assessment, and long-term course of this clinical syndrome. These diagnostic criteria will support future research efforts to identify at the earliest stage those PD patients at increased risk of progressive cognitive decline and dementia who may benefit from clinical interventions at a predementia stage., (Copyright © 2012 Movement Disorder Society.)

Objective: To find predictors of cognitive decline and quality of life 1&emsp14;year after bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's disease (PD)., Methods: A total of 105 patients were evaluated with a comprehensive neuropsychological assessment before and 12 months after surgery. A control group of 40 PD patients was included to control for effects of repeated testing and disease progression. The authors determined individual changes in cognition, mood and quality of life using a statistical method that controls for multiple comparisons, and performed logistic regression analyses to assess predictors of cognitive changes and quality of life., Results: 12 months after surgery, the improvement in motor function was 41% (Unified Parkinson's Disease Rating Scale Part 3 score in off). The STN group showed a large improvement in quality of life compared with the control group (Cohen d=0.9). At the individual level, 32% (95% CI 22 to 40) of the STN group showed a substantial improvement in quality of life. 36% (95% CI 27 to 46) of the STN patients showed a profile of cognitive decline compared with the control group. Mood improved in 16 STN patients and declined in 16 subjects. Impaired attention, advanced age and a low l-dopa response at baseline predicted cognitive decline, whereas a high l-dopa response at baseline predicted an improvement in quality of life. Postoperative decrease in dopaminergic medication was not related to cognitive decline., Conclusions: STN DBS improves quality of life. However, a profile of cognitive decline can be found in a significant number of patients. l-dopa response, age and attention at baseline are predictors of cognitive and psychosocial outcome.

Objective: To determine progression and prognostic factors of progression rate of motor impairment, disability, and quality of life (QoL) in patients with newly diagnosed Parkinson's disease., Methods: A group of 126 patients with newly diagnosed PD recruited from outpatient clinics participated in this 3-year prospective cohort study. Motor impairment was rated with the Unified Parkinson Disease Rating Scale Motor-Examination. Disability was rated using the Schwab and England Activities of Daily Living Scale, the AMC Linear Disability Score. QoL was assessed with the Parkinson's Disease Quality of Life questionnaire. Linear mixed model analyses were conducted to identify determinants of progression rate of motor impairment, disability, and poor QoL., Results: Motor impairment progressed with 3 points per year. There was a slight progression of disability and QoL during 3 years of follow-up. Female sex was a prognostic factor for slower progression of motor impairment and QoL. Older age at onset showed to prognosticate faster progression of disability and impaired QoL. Furthermore, independent of follow-up time, older age at onset was associated with worse motor impairment; nondopaminergic reactive symptoms (Axial impairment) were associated with more disability and poorer QoL; comorbidity showed relation with disability and QoL but to a lesser extent; self-reported mood symptoms were associated with poorer QoL; and disease duration correlated with motor impairment., Conclusions: Motor impairment, disability, and QoL of newly diagnosed Parkinson patients show progression in the first 3 years. Older age at onset predicts worse progression rate of disability and impaired QoL over time. Female sex predicts slower progression of motor impairment and less decline of QoL., (Copyright © 2011 Movement Disorder Society.)

Cognitive dysfunction is one of the most incapacitating non-motor symptoms of Parkinson's disease (PD). Some cognitive deficits are thought to be related to abnormal dopamine homeostasis. The latter is influenced by catechol-O-methyltransferase (COMT), an enzyme that degrades dopamine. Previous research suggests a relationship between the COMT val158met functional polymorphism (SNP) and measures of executive function. We evaluated this hypothesis in a cohort of PD patients with an extensive neuropsychological test battery. Cognitive assessment and COMT genotyping were performed in 153 early PD patients from outpatient clinics general hospitals in the Netherlands. Our results do not support a direct effect of COMT val158met genotype on performance on neuropsychological measures of attention and executive function, but they suggest that genotype may interact with dopaminergic medication use to influence cognitive ability., (© 2010 Movement Disorder Society.)

Music has the potential to evoke strong emotions and plays a significant role in the lives of many people. Music might therefore be an ideal medium to assess emotion recognition. We investigated emotion recognition in music in 20 patients with idiopathic Parkinson's disease (PD) and 20 matched healthy volunteers. The role of cognitive dysfunction and other disease characteristics in emotion recognition was also evaluated. We used 32 musical excerpts that expressed happiness, sadness, fear or anger. PD patients were impaired in recognizing fear and anger in music. Fear recognition was associated with executive functions in PD patients and in healthy controls, but the emotion recognition impairments of PD patients persisted after adjusting for executive functioning. We found no differences in the recognition of happy or sad music. Emotion recognition was not related to depressive symptoms, disease duration or severity of motor symptoms. We conclude that PD patients are impaired in recognizing complex emotions in music. Although this impairment is related to executive dysfunction, our findings most likely reflect an additional primary deficit in emotional processing., (2010 Elsevier Inc. All rights reserved.)

This controlled prospective study examined the evolution and predictors of cognitive decline in Parkinson's disease (PD). Consecutive patients diagnosed at baseline with PD (n = 89), established PD (EPD) patients (n = 52) with a mean disease duration of 6.5 years, and healthy control subjects (n = 64) underwent extensive neuropsychological assessment twice, approximately 3 years apart. A standardized regression-based method, normative data, and multivariate normative comparisons were used to assess the cognitive course of PD. Cognitive performance of newly diagnosed patients decreased significantly over time, particularly on measures of psychomotor speed and attention and to a lesser extent on tests of memory, visuospatial skills, and executive functions. About 50% of the patients showed cognitive decline and 9% developed dementia. Similar results were observed in EPD patients. None of the baseline features predicted cognitive change in newly diagnosed patients, whereas age at disease onset and axial impairment (postural and gait disorders) contributed to decline in established patients. We conclude that within few years after diagnosis, PD patients show faster rate of cognitive decline than matched healthy subjects, particularly in domains of attention and psychomotor speed. Selection bias probably led to underestimation of the true extent of cognitive decline in established patients.

A meta-analysis was conducted on 25 longitudinal studies involving 901 initially non-demented Parkinson's disease (PD) patients to examine the magnitude of decline across multiple cognitive domains associated with disease progression. Pooled effect sizes reflecting the standardized difference between baseline and follow-up neuropsychological performance were calculated for 8 cognitive domains using a random-effects model. Relatively small effect sizes were found across all cognitive domains (d = .00 - .40). During a mean follow-up interval of 29 months, significant declines were detected in global cognitive ability (d = .40), visuoconstructive skills (d = .32), and memory (d = .29). Age showed a significant relation with decline in global cognitive ability and memory. Lower educational level was associated with greater decline in all cognitive domains. Studies with longer follow-up intervals yielded larger effect sizes for global cognitive ability. In non-demented PD patients, changes in cognitive functions over time appear to be modest. Educational level, age, and length of the follow-up interval are likely to affect the magnitude of decline in several domains. Methodological flaws, such as selection bias and uncontrolled practice effects, may have caused underestimation of the true extent of decline.

In neuropsychological evaluations and single case research generally a number of tests are administered, since the interest is not in a single, but in multiple characteristics of a patient. The typical problem is to decide whether or not a patient is different from normal controls with respect to one or more of these characteristics. Consideration of each characteristic separately entails an increased risk of a false positive decision (a wrongful decision that the patient is abnormal, or a type 1 error). From a statistical point of view this calls for a multivariate analysis. In this paper, we propose two approaches to perform normative comparisons for such multivariate data: Bonferroni corrected univariate comparisons and a multivariate comparison. Both approaches allow for the testing of unidirectional (two-sided) as well as directional (one-sided) hypothesis, i.e. the hypothesis that a patient deviates in a negative sense from the norm. Monte Carlo simulations were performed to check if the type I error of both approaches is adequately controlled, and to investigate the power of both approaches to detect deviation from the norm. The results indicate that the type I error rate of both approaches is correct, even in small samples. The results also indicate that the power is higher for the univariate approach if the normative sample size is very small (i.e. just exceeds the number of tests administered). In larger samples, the multivariate comparison has in general increased power. We illustrate both approaches with a clinical example of patients with Parkinson disease, who received deep brain stimulation to alleviate motor symptoms, and who were neuropsychologically evaluated to detect possible cognitive side effects.

Objective: To determine the frequency and pattern of cognitive dysfunction in patients with newly diagnosed Parkinson disease (PD) and to identify its demographic and clinical correlates., Methods: A cohort of 115 consecutive patients with newly diagnosed PD and 70 healthy controls underwent a comprehensive neuropsychological assessment including tests of psychomotor speed, attention, language, memory, executive and visuospatial functions, as well as measures of affective status. Patients also received quantitative ratings of motor symptom severity and functional status. Neuropsychological performance of PD patients was compared with that of healthy controls and with available normative data. Independent demographic and clinical predictors of cognitive impairment were identified with multiple logistic regression analysis., Results: Relative to controls, PD patients performed significantly worse on most cognitive measures. However, further analysis revealed that group differences in cognitive performance could mainly be explained by measures of immediate memory and executive function. Comparison with normative data showed that impairments were most frequent on measures of executive function, memory and psychomotor speed. In all, 24% of PD patients (4% of controls) displayed defective performance on at least three neuropsychological tests and were classified as cognitively impaired. Late onset of disease was an independent predictor of cognitive dysfunction in PD., Conclusion: Cognitive impairments are common even in newly diagnosed Parkinson disease patients, with deficits being most prominent in the domains of memory and executive functions. Older age at disease onset is likely to be an important determinant of cognitive dysfunction in Parkinson disease.

Objective: To compare the cognitive and behavioural effects of unilateral pallidotomy and bilateral subthalamic nucleus (STN) stimulation., Methods: After baseline examination 34 patients were randomly assigned to unilateral pallidotomy (4 left-sided, 10 right-sided) or bilateral STN stimulation (n = 20). At baseline and six and twelve months after surgery we administered neuropsychological tests of language, memory, visuospatial function, mental speed and executive functions. Also a depression rating scale, and self and proxy ratings of memory and dysexecutive symptoms were administered., Results: Six months after surgery, the STN group and the pallidotomy group differed significantly in change from baseline in number of errors on two tests of executive functioning. After 12 months the STN group reported less positive affect compared with baseline than the pallidotomy group. One patient in the STN group showed an overall cognitive deterioration due to complications., Conclusions: Although we need larger groups to draw firm conclusions, our results suggest that bilateral STN stimulation has slightly more negative effects on executive functioning than unilateral pallidotomy.