Validating virtual administration of neuropsychological testing in Parkinson disease: a pilot study

COVID-19 has highlighted the need for remote cognitive testing, but the reliability and validity of virtual cognitive testing in Parkinson disease (PD) is unknown. Therefore, we assessed PD participants enrolled in an observational, cognition-focused study with an extensive cognitive battery completed both in-person and via video conference close in time. Data for 35 PD participants with normal cognition to mild dementia were analyzed. Only one test (semantic verbal fluency) demonstrated a difference in score by administration type, with a significantly better score virtually. Only three tests demonstrated good reliability for in-person versus virtual testing, but reliability values for visit 1 versus visit 2 were similarly low overall. Trail Making Test B was successfully administered virtually to only 18 participants due to technical issues. Virtual and in-person cognitive testing generate similar scores at the group level, but with poor to moderate reliability for most tests. Mode of test administration, learning effects, and technical difficulties explained little of the low test-retest reliability, indicating possible significant short-term variability in cognitive performance in PD in general, which has implications for clinical care and research. In-person cognitive testing with a neuropsychologist remains the gold standard, and it remains to be determined if virtual cognitive testing is feasible in PD.

Course of Impulse Control Disorder Symptoms in Parkinson's Disease: Deep Brain Stimulation Versus Medications

Background

The effect of surgery on impulse control disorders (ICDs) remains unclear in Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS).

Objective

To examine changes in ICD symptoms in PD patients undergoing DBS compared to a medication-only control group.

Methods

The study was a 2-center, 12-month, prospective, observational investigation of PD patients undergoing DBS and a control group matched on age, sex, dopamine agonist use, and baseline presence of ICDs. Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) and total levodopa equivalent daily dose (LEDD) were collected at baseline, 3, 6, and 12 months. Linear mixed-effects models assessed changes in mean QUIP-RS score (sum of buying, eating, gambling, and hypersexuality items).

Results

The cohort included 54 participants (DBS = 26, controls = 28), mean (SD) age 64.3 (8.1) and PD duration 8.0 (5.2) years. Mean baseline QUIP-RS was higher in the DBS group at baseline (8.6 (10.7) vs. 5.3 (6.9), P = 0.18). However, scores at 12 months follow-up were nearly identical (6.6 (7.3) vs. 6.0 (6.9) P = 0.79). Predictors of change in QUIP-RS score were baseline QUIP-RS score (β = 0.483, P < 0.001) and time-varying LEDD (β = 0.003, P = 0.02). Eight patients (four in each group) developed de novo ICD symptoms during follow-up, although none met diagnostic criteria for an impulse control disorder.

Conclusions

ICD symptoms (including de novo symptoms) at 12 months follow-up were similar between PD patients undergoing DBS and patients treated with pharmacological therapy only. Monitoring for emergence of ICD symptoms is important in both surgically- and medication-only-treated PD patients.

Validating virtual administration of neuropsychological testing in Parkinson disease: a pilot study

Background COVID-19 has highlighted the need for remote cognitive testing. Virtual testing may lessen burden and can reach a larger patient population. The reliability and validity of virtual cognitive testing in Parkinson disease (PD) is unknown. Objectives To validate neuropsychological tests for virtual administration in PD. Methods Participants enrolled in an observational, cognition-focused study completed a rater-administered cognitive battery in-person and via video conference 3-7 days apart. Order of administration was counterbalanced. Analyses to compare performance by type of administration (virtual versus in-person) included paired t-test, intraclass correlation (ICC) and linear mixed-effects models. Results Data for 35 (62.9% male) PD participants (62.5% normal cognition, 37.5% cognitive impairment) were analyzed. Only the semantic verbal fluency test demonstrated a difference in score by administration type, with a significantly better score when administered virtually (paired t-test p = 0.011 and linear mixed-effects model p = 0.012). Only the Dementia Rating Scale-2, Trails A test and phonemic verbal fluency demonstrated good reliability (ICC value 0.75-0.90) for virtual versus in-person administration, and values for visit 1 versus visit 2 were similarly low overall. Trail making tests were successfully administered virtually to only 18 (51.4%) participants due to technical issues. Conclusions Virtual cognitive testing overall is feasible in PD, and virtual and in-person cognitive testing generate similar scores at the group level, but reliability is poor or moderate for most tests. Given that mode of test administration, learning effects and technical difficulties explained relatively little of the low test-retest reliability observed, there may be significant short-term variability in cognitive performance in PD in general, which has important implications for clinical care and research.

Genetic prediction of impulse control disorders in Parkinson's disease

OBJECTIVE

To develop a clinico-genetic predictor of impulse control disorder (ICD) risk in Parkinson's disease (PD).

METHODS

In 5770 individuals from three PD cohorts (the 23andMe, Inc.; the University of Pennsylvania [UPenn]; and the Parkinson's Progression Markers Initiative [PPMI]), we used a discovery-replication strategy to develop a clinico-genetic predictor for ICD risk. We first performed a Genomewide Association Study (GWAS) for ICDs anytime during PD in 5262 PD individuals from the 23andMe cohort. We then combined newly discovered ICD risk loci with 13 ICD risk loci previously reported in the literature to develop a model predicting ICD in a Training dataset (n = 339, from UPenn and PPMI cohorts). The model was tested in a non-overlapping Test dataset (n = 169, from UPenn and PPMI cohorts) and used to derive a continuous measure, the ICD-risk score (ICD-RS), enriching for PD individuals with ICD (ICD+ PD).

RESULTS

By GWAS, we discovered four new loci associated with ICD at p-values of 4.9e-07 to 1.3e-06_. Our best logistic regression model included seven clinical and two genetic variables, achieving an area under the receiver operating curve for ICD prediction of 0.75 in the Training and 0.72 in the Test dataset. The ICD-RS separated groups of PD individuals with ICD prevalence of nearly 40% (highest risk quartile) versus 7% (lowest risk quartile).

INTERPRETATION

In this multi-cohort, international study, we developed an easily computed clinico-genetic tool, the ICD-RS, that substantially enriches for subgroups of PD at very high versus very low risk for ICD, enabling pharmacogenetic approaches to PD medication selection.

Perfusion Imaging of Fatigue and Time-on-Task Effects in Patients With Parkinson's Disease

Fatigue is a highly prevalent and debilitating non-motor symptom in Parkinson's disease (PD), yet its' neural mechanisms remain poorly understood. Here we combined arterial spin labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) with a sustained mental workload paradigm to examine the neural correlates of fatigue and time-on-task effects in PD patients. Twenty-one PD patients were scanned at rest and during continuous performance of a 20-min psychomotor vigilance test (PVT). Time-on-task effects were measured by the reaction time changes during the PVT and by self-reported fatigue ratings before and after the PVT. PD subjects demonstrated significant time-on-task effects, including progressively slower reaction time on the PVT and increased post-PVT fatigue ratings compared to pre-PVT. Higher levels of general fatigue were associated with larger increases in mental fatigue ratings after the PVT. ASL imaging data showed increased CBF in the right middle frontal gyrus (MFG), bilateral occipital cortex, and right cerebellum during the PVT compared to rest, and decreased CBF in the right MFG at post-task rest compared to pre-task rest. The magnitude of regional CBF changes in the right MFG and right inferior parietal lobe correlated with subjective fatigue rating increases after the PVT task. These results demonstrate the utility of continuous PVT paradigm for future studies of fatigue and cognitive fatigability in patients, and support the key role of the fronto-parietal attention network in mediating fatigue in PD.

Psychometric Properties of the Clinical Dementia Rating Scale Sum of Boxes in Parkinson's Disease

BACKGROUND

A composite measure that assesses both cognitive and functional abilities in Parkinson's disease (PD) would be useful for diagnosing mild cognitive impairment (MCI) and PD dementia (PDD) and as an outcome measure in randomized controlled trials. The Clinical Dementia Rating Scale Sum of Boxes (CDR-SOB) was designed to assess both cognition and basic-instrumental activities of daily living in Alzheimer's disease but has not yet been validated in PD.

OBJECTIVE

To validate the CDR-SOB as a composite cognitive-functional measure for PD patients, as well as to assess its sensitivity to change.

METHODS

The CDR-SOB and a comprehensive cognitive and functional battery was administered to 101 PD patients at baseline (39 normal cognition [NC], 41 MCI and 21 PDD by expert consensus panel), and re-administered to 64 patients after 1-2 years follow-up (32 NC and 32 cognitive impairment [CI] at baseline).

RESULTS

Cross-sectionally, CDR-SOB and domain scores were correlated with corresponding neuropsychological or functional measures and were significantly different between cognitive subgroups both at baseline and at follow-up. In addition, CDR-SOB ROC curves distinguished between normal cognition and dementia with high sensitivity, but did not distinguish well between NC and MCI. Longitudinal changes in the CDR-SOB and domain scores were not significant and were inconsistent in predicting change in commonly-used cognitive and functional tests.

CONCLUSION

The CDR-SOB detects dementia-level cognitive impairment in PD but may not be appropriate for predicting longitudinal combined cognitive-functional changes in patients without significant cognitive impairment at baseline.

Understanding the Lexicon of Fatigue in Parkinson's Disease

Background:

Fatigue in Parkinson’s disease (PD) is multifaceted and associated with reduced quality of life. In turn, the language used by people with PD to describe fatigue is variable and poorly understood. We sought to elucidate the lexicon of fatigue using a qualitative grounded theory approach.

Objective:

The objective of this study was to understand how patients with PD describe fatigue.

Methods:

A pre-study phase of online journaling (Phase 1) provided information regarding topics of importance to patients. Following this, two independent samples of fatigued subjects were studied. Individuals with PD participated in a telephone interview (Phase 2); interview transcripts were analyzed to develop a detailed codebook. To ensure trustworthiness of the findings, an online survey (Phase 3) was administered to individuals with self-reported PD participating in the online study Fox Insight. The survey included the following question: “How do you define fatigue? Please provide your definition in the space below.” The codebook developed from Phase 2 was applied to the Phase 3 responses.

Results:

Fifteen individuals participated in Phase 2 and 413 individuals completed Phase 3. Fatigue was subdivided into three domains: cognitive, emotional, and physical. Nearly all individuals experienced more than one domain of fatigue. The most common themes included tiredness, lack of energy, and negative motivation.

Conclusion:

Fatigue in PD is multidimensional. Questionnaires that only assess the physical impact of fatigue may not be adequate to capture the broad range of experiences of fatigue among people with PD.

0075 Neural Correlates of Cognitive Fatigue in Parkinson Disease

Introduction

Parkinson’s disease (PD) is a common neurodegenerative disease affecting millions of people world-wide. Fatigue is a prevalent and debilitating non-motor symptom in PD. However, the neural correlates underlying cognitive fatigue are poorly understood. Our previous studies suggested that continuous performance of a simple but mentally demanding psychomotor vigilance task (PVT) induced cognitive fatigue, operationalized as subjective exhaustion and time-on-task performance decline. Here we used arterial spin labeling (ASL) perfusion fMRI to investigate regional cerebral blood flow (CBF) changes in PD patients during cognitive fatigue induced by continuous performance of 20-min PVT.

Methods

Twenty-one PD patients completed a 20-min PVT during the ASL scan and two additional 4-min resting-state ASL scans before and after PVT. Reaction times (RTs) and regional CBF changes throughout the PVT as well as during pre- and post-task resting baselines were measured. Cognitive fatigue was analyzed by dividing the entire PVT performance into five quintiles in addition to the immediate measurement of self-rated fatigue before and after PVT.

Results

PD patients demonstrated significantly increased self-reported fatigue ratings after the task (p &lt; 0.05) and progressively slower RTs across quintiles (p &lt; 0.05). Perfusion data showed that the PVT activates the right middle frontal cortex, right inferior parietal lobe, right insula, bilateral occipital cortex, and right cerebellum (FDR corrected). Moreover, the bilateral middle frontal gyri were less active during the post-task rest compared to the pre-task rest.

Conclusion

These results demonstrated that cognitive fatigue has an ongoing effect on brain activity after a period of continuous mental effort and supported the critical role of prefrontal cortex in mediating cognitive fatigue in PD. The findings also suggest the utility of continuous PVT as an appropriate paradigm to induce and examine cognitive fatigue in PD.

Support

Supported in part by Parkinson’s Foundation Translational Research Grant and NIH grants R01-MH107571, R21-AG051981, and P30-NS045839.

The movement disorder society nonmotor rating scale: Initial validation study

BACKGROUND

The Movement Disorder Society-sponsored Nonmotor Rating Scale is an update of the existing Parkinson's disease Nonmotor Symptoms Scale modified to address some limitations in Nonmotor Symptoms Scale scoring, structure, and symptom coverage.

METHODS

PD patients were recruited from movement disorder centers in an international, multicenter study. The Movement Disorder Society Nonmotor Rating Scale, consisting of 13 domains plus a subscale for nonmotor fluctuations, was rater administered, along with the Nonmotor Symptoms Scale and other clinical assessments. Standard reliability and validity testing were conducted.

RESULTS

Four hundred and two PD patients were recruited (mean age ± standard deviation, 67.42 ± 9.96 years; mean age at PD onset ± standard deviation, 59.27 ± 10.67 years; median Hoehn and Yahr stage 2 (interquartile range 2-3). Data quality was satisfactory for all Movement Disorder Society Nonmotor Rating Scale domains except sexual (6.7% missing data). There were no floor or ceiling effects for the Movement Disorder Society Nonmotor Rating Scale and nonmotor fluctuations total score; domains had no ceiling effects, but some floor effects (13.5%-83.5%). The Movement Disorder Society Nonmotor Rating Scale and nonmotor fluctuations total score internal consistency were acceptable (average Cronbach's alpha, 0.66 and 0.84, respectively); interrater reliability was excellent (intraclass correlation coefficient, >0.95); for test-retest reliability, the intraclass correlation coefficient was 0.84 for the Movement Disorder Society Nonmotor Rating Scale and 0.70 for Movement Disorder Society nonmotor fluctuations total score, and precision was excellent for the Movement Disorder Society Nonmotor Rating Scale (standard error of measurement, 25.30) and fair for nonmotor fluctuations (standard error of measurement, 7.06). Correlations between Movement Disorder Society Nonmotor Rating Scale score and the corresponding Nonmotor Symptoms Scale and Movement Disorder Society UPDRS scores were high. There were no significant sex or age effects. The Movement Disorder Society Nonmotor Rating Scale score increased with increasing PD duration, disease severity, and PD medication dose (all P < 0.001).

CONCLUSIONS

The Movement Disorder Society Nonmotor Rating Scale is a valid measure for measuring the burden of a wide range of Nonmotor Rating Scale scores, including nonmotor fluctuations, in PD patients. © 2019 International Parkinson and Movement Disorder Society.

The Neuropsychiatry of Parkinson Disease: A Perfect Storm

Affective disorders, cognitive decline, and psychosis have long been recognized as common in Parkinson disease (PD), and other psychiatric disorders include impulse control disorders, anxiety symptoms, disorders of sleep and wakefulness, and apathy. Psychiatric aspects of PD are associated with numerous adverse outcomes, yet in spite of this and their frequent occurrence, there is incomplete understanding of epidemiology, presentation, risk factors, neural substrate, and management strategies. Psychiatric features are typically multimorbid, and there is great intra- and interindividual variability in presentation. The hallmark neuropathophysiological changes that occur in PD, plus the association between exposure to dopaminergic medications and certain psychiatric disorders, suggest a neurobiological basis for many psychiatric symptoms, although psychological factors are involved as well. There is evidence that psychiatric disorders in PD are still under-recognized and undertreated and although psychotropic medication use is common, controlled studies demonstrating efficacy and tolerability are largely lacking. Future research on neuropsychiatric complications in PD should be oriented toward determining modifiable correlates or risk factors and establishing efficacious and well-tolerated treatment strategies.

Association of Antipsychotic Use With Mortality Risk in Patients With Parkinson Disease

IMPORTANCE

As many as 60% of patients with Parkinson disease (PD) experience psychosis, 80% develop dementia, and the use of antipsychotics (APs) in the population with PD is common. The use of APs by patients with dementia in the general population is associated with increased mortality, but whether this risk extends to patients with PD remains unknown.

OBJECTIVE

To determine whether AP use in patients with PD is associated with increased mortality.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective matched-cohort study used data from a Veterans Health Administration database from fiscal years 1999 to 2010 to examine the risk associated with AP use in a cohort of patients with idiopathic PD and recent stable physical health. The rates of 180-day mortality were compared in 7877 patients initiating AP therapy and 7877 patients who did not initiate AP therapy (matched for age ±2.5 years, sex, race, index year, presence and duration of dementia, PD duration, delirium, hospitalization, Charlson Comorbidity Index, and new nonpsychiatric medications). Data were analyzed from October 19, 2012, to September 21, 2015.

MAIN OUTCOMES AND MEASURES

Mortality rates at 180 days in those patients who initiated AP therapy compared with matched patients who did not use APs. Cox proportional hazards regression models were used with intent-to-treat (ITT) and exposure-only analyses.

RESULTS

The study population included 7877 matched pairs of patients with PD (65 women [0.8%] and 7812 men [99.2%] in each cohort; mean [SD] age, 76.3 [7.7] years for those who initiated AP therapy and 76.4 [7.6] years for those who did not). Antipsychotic use was associated with more than twice the hazard ratio (HR) of death compared with nonuse (ITT HR, 2.35; 95% CI, 2.08-2.66; P < .001). The HR was significantly higher for patients who used typical vs atypical APs (ITT HR, 1.54; 95% CI, 1.24-1.91; P < .001). Among the atypical APs used, HRs relative to nonuse of APs in descending order were 2.79 (95% CI, 1.97-3.96) for olanzapine, 2.46 (95% CI, 1.94-3.12) for risperidone, and 2.16 (95% CI, 1.88-2.48) for quetiapine fumarate.

CONCLUSIONS AND RELEVANCE

Use of APs is associated with a significantly increased mortality risk in patients with PD, after adjusting for measurable confounders. This finding highlights the need for cautious use of APs in patients with PD. Future studies should examine the role of nonpharmacologic strategies in managing psychosis in PD. In addition, new pharmacologic treatments that do not increase mortality in patients with neurodegenerative diseases need to be developed.

Rivastigmine for mild cognitive impairment in Parkinson disease: a placebo-controlled study

Mild cognitive impairment (MCI) in Parkinson's disease (PD) may be associated with subtle functional impairment and worse quality of life. The objective of this study was to determine the efficacy and tolerability of rivastigmine for PD-MCI. Patients with PD-MCI (n = 28) were enrolled in a 24-week, randomized, double-blind, placebo-controlled, crossover, single-site study of the rivastigmine transdermal patch. The primary outcome measure was the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). Secondary outcomes included the Montreal Cognitive Assessment (MoCA), Dementia Rating Scale-2 (DRS-2), Neurotrax computerized cognitive battery, the Everyday Cognition Battery (ECB), and the Parkinson's Disease Questionnaire (PDQ-8). Twenty-six participants (92.9%) completed both study phase assessments, and 23 (82.1%) completed both phases on study medication. The CGIC response rate demonstrated a trend effect in favor of rivastigmine (regression coefficient for interaction term in linear mixed-effects model = 0.44, F[df] = 3.01 [1, 24], P = 0.096). For secondary outcomes, a significant rivastigmine effect on the ECB (regression coefficient = -2.41, F[df] = 5.81 [1, 22.05], P = 0.03) was seen, but no treatment effect was found on any cognitive measures. Trend effects also occurred in favor of rivastigmine on the PDQ-8 (regression coefficient = 4.55, F[df] = 3.93 [1, 14. 79], P = 0.09) and the State Anxiety Inventory (regression coefficient = -1.24, F[df] = 3.17 [1, 33], P = 0.08). Rivastigmine in PD-MCI showed a trend effect for improvements on a global rating of cognition, disease-related health status, and anxiety severity, and significant improvement on a performance-based measure of cognitive abilities. © 2015 International Parkinson and Movement Disorder Society.

Benefit finding and relationship quality in Parkinson's disease: a pilot dyadic analysis of husbands and wives

Parkinson's disease (PD) significantly impacts both patients' and spouses' emotional and physical health. However, despite the importance of social relationships for wellbeing, few studies have examined relationship quality and their correlates in individuals with PD and their partners. Specifically, no known studies have examined the association between benefit finding, or the experience of personal growth and other positive changes in the face of a stressor, and perceived marital quality. To address these gaps in the field, 25 married couples participated in a cross-sectional, pilot study. Patients were veterans diagnosed with idiopathic PD receiving care at the Philadelphia VA Medical Center. Each patient and spouse independently completed self-reported measures of sociodemographics, physical and mental wellbeing, caregiver burden, marital quality, and perceived benefits associated with having PD. Actor-partner interdependence models revealed that, after adjusting for covariates, greater perceived benefits from either having PD or living with a spouse with PD was associated with greater marital quality, both for that individual and their partner. Thus, perceiving positive consequences, such as personal growth, as a result of personally having PD or living with a spouse with PD is related to greater marital quality for both members of the marital dyad. Findings may inform individual and couples-based interventions that address the value of benefit finding and incorporate other techniques of positive reappraisal.

Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale

Impulse control disorders and related disorders (hobbyism-punding and dopamine dysregulation syndrome) occur in 15% to 20% of Parkinson's disease (PD) patients. We assessed the validity and reliability of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS), a rating scale designed to measure severity of symptoms and support a diagnosis of impulse control disorders and related disorders in PD. A convenience sample of PD patients at a movement disorders clinic self-completed the QUIP-RS and were administered a semistructured diagnostic interview by a blinded trained rater to assess discriminant validity for impulse control disorders (n = 104) and related disorders (n = 77). Subsets of patients were assessed to determine interrater reliability (n = 104), retest reliability (n = 63), and responsiveness to change (n = 29). Adequate cutoff points (both sensitivity and specificity values >80% plus acceptable likelihood ratios) were established for each impulse control disorder and hobbyism-punding. Interrater and retest reliability (intraclass correlation coefficient r) were >0.60 for all disorders. Participants in an impulse control disorder treatment study who experienced full (t = 3.65, P = .004) or partial (t = 2.98, P = .01) response demonstrated significant improvement on the rating scale over time, while nonresponders did not (t = 0.12, P = .91). The QUIP-RS appears to be valid and reliable as a rating scale for impulse control disorders and related disorders in PD. Preliminary results suggest that it can be used to support a diagnosis of these disorders, as well as to monitor changes in symptom severity over time.

Patterns and trends in antipsychotic prescribing for Parkinson disease psychosis

BACKGROUND

Antipsychotic (AP) use is common in Parkinson disease (PD), but APs can worsen parkinsonism, evidence for efficacy is limited, and use in patients with dementia increases mortality.

OBJECTIVE

To examine the frequency and characteristics, including changes over time, of AP use in a large cohort of patients with PD.

DESIGN

Using Veterans Affairs data from fiscal year (FY) 2008, rates and predictors of AP prescribing were determined for patients with PD and psychosis stratified by dementia status (N = 2597) and a comparison group of patients with dementia and psychosis without PD (N = 6907). Fiscal year 2008 and FY2002 data were compared to examine changes in AP prescribing over time.

SETTING

Department of Veterans Affairs outpatient facilities.

PARTICIPANTS

Outpatients with PD and psychosis and outpatients without PD with dementia and psychosis, all receiving care at Veterans Affairs facilities in FY2002 and FY2008.

MAIN OUTCOME MEASURE

Antipsychotic prescribing, including overall, class, and specific medications.

RESULTS

In FY2008, 50% of patients with PD having a diagnosis of psychosis were prescribed an AP. Among treated patients, the atypical AP quetiapine was most frequently prescribed (66%), but approximately 30% received high-potency APs. Clozapine was rarely prescribed (<2%). In multivariate models, diagnoses of PD and dementia were associated with AP use. Comparing FY2008 with FY2002, AP use in PD was unchanged, with decreases in risperidone and olanzapine use offset by an increase in quetiapine prescribing and the introduction of aripiprazole.

CONCLUSIONS

Half of the patients with PD and psychosis receive APs, not uncommonly high-potency agents associated with worsening parkinsonism, and frequency of use has been unchanged since the "black box" warning for AP use in patients with dementia was issued. Recent trends are a shift to quetiapine use and the common use of aripiprazole. As psychosis and dementia are frequently comorbid in PD, safety risks associated with AP use in this population need to be assessed.

Olfactory dysfunction is associated with neuropsychiatric manifestations in Parkinson's disease

Hyposmia, psychiatric disorders, and cognitive problems are common nonmotor manifestations in Parkinson's disease, but how they are related remains unclear. We investigated the relationship between olfactory dysfunction and neuropsychiatric manifestations and performed a cross-sectional study of 248 patients at two movement disorders clinics at academic medical centers. Psychiatric measures were the Geriatric Depression Scale-15, Inventory of Depressive Symptomatology, State Anxiety Inventory, Apathy Scale, and Parkinson's Psychosis Rating Scale. Cognitive measures were the Mini-Mental State Examination, Hopkins Verbal Learning Test-Revised, Digit Span, Tower of London-Drexel, and the Stroop Color Word Test. Olfaction was tested with the University of Pennsylvania Smell Identification Test. There was no significant association between olfaction and mood measures, but psychotic symptoms were more common in patients with olfaction scores below the median (30% vs. 12%; P < 0.001). Worse olfaction was associated with poorer memory (Hopkins Verbal Learning Test-Revised delayed recall items: mean [standard deviation], 6.2 [3.2] vs. 8.4 [2.8]; P < 0.001) and executive performance (Tower of London total moves, 52 [38] vs. 34 [21]; P < 0.001). Odor-identification score was a significant predictor of abnormal performance on these cognitive tests after adjustment for age, sex, and disease characteristics in logistic regression models. The relationship between hyposmia, psychosis, and specific cognitive impairments may reflect the anatomic distribution of Lewy pathology and suggests that olfactory dysfunction could be a biomarker of additional extranigral disease. Future prospective studies are warranted to assess whether hyposmia, a very early feature of Parkinson's disease, might be used to predict the appearance of other common nonmotor symptoms.

Patient versus informant reporting of ICD symptoms in Parkinson's disease using the QUIP: validity and variability

Questions exist regarding the validity of patient-reporting of psychiatric symptoms in Parkinson's disease (PD). We assessed observer variability and validity in reporting of impulse control disorder (ICD) symptoms in PD by using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP). PD patients and their informants (71 pairs) completed the QUIP to assess four ICDs (compulsive gambling, buying, sexual behavior, and eating) in patients. Trained raters then administered a diagnostic interview. Sensitivity of the QUIP for a diagnosed ICD was 100% for both patient- and informant-completed instruments, and specificity was 75% for both raters. Approximately 40% of patients without an ICD diagnosis had a positive QUIP, suggesting that many PD patients experience subsyndromal ICD symptoms that require ongoing monitoring. Agreement between patient- and informant-reporting of any ICD behaviors on the QUIP was moderate (kappa=0.408), and for individual ICDs was highest for gambling (kappa=0.550). Overall, a negative QUIP from either the patient or informant rules out the possibility of an ICD, while a positive QUIP requires a follow-up diagnostic interview and ongoing monitoring to determine if symptoms currently are, or in the future become, clinically significant.

Decreased ventral striatal activity with impulse control disorders in Parkinson's disease

A range of impulse control disorders (ICDs) are reported to occur in Parkinson's disease (PD). However, alterations in brain activity at rest and during risk taking occurring with ICDs in PD are not well understood. We used both arterial spin labeling perfusion functional magnetic resonance imaging (fMRI) to directly quantify resting cerebral blood flow (CBF) and blood oxygenation level dependent (BOLD) fMRI to measure neural responses to risk taking during performance on the Balloon Analogue Risk Task (BART). Eighteen PD patients, either with a diagnosis of one or more ICDs (N = 9) or no lifetime ICD history (N = 9), participated. BOLD fMRI data demonstrated that PD patients without an ICD activate the mesocorticolimbic pathway during risk taking. Compared with non-ICD patients, ICD patients demonstrated significantly diminished BOLD activity in the right ventral striatum during risk taking and significantly reduced resting CBF in the right ventral striatum. ICDs in PD are associated with reduced right ventral striatal activity at rest and diminished striatal activation during risk taking, suggesting that a common neural mechanism may underlie ICDs in individuals with PD and those without PD. Thus, treatments for ICDs in non-PD patients warrant consideration in PD patients with ICDs.

Atomoxetine for depression and other neuropsychiatric symptoms in Parkinson disease

OBJECTIVES

Depression and antidepressant use, especially selective serotonin reuptake inhibitors (SSRIs), are common in Parkinson disease (PD). The objective of this clinical trial was to assess the efficacy of atomoxetine, a selective norepinephrine reuptake inhibitor (SNRI), for the treatment of clinically significant depressive symptoms and common comorbid neuropsychiatric symptoms in PD.

METHODS

A total of 55 subjects with PD and an Inventory of Depressive Symptomatology-Clinician (IDS-C) score > or = 22 were randomized to 8 weeks of atomoxetine or placebo treatment (target dosage = 80 mg/day). Depression response (> 50% decrease in IDS-C score or Clinical Global Impression-Improvement [CGI-I] score of 1 or 2) was assessed using intention-to-treat modeling procedures. Secondary outcomes included global cognition, daytime sleepiness, anxiety, apathy, and motor function.

RESULTS

There were no between-groups differences in a priori-defined response rates. Using a more liberal response criterion of > 40% decrease in IDS score from baseline, there was a trend (p = 0.08) favoring atomoxetine. Patients receiving atomoxetine experienced significantly greater improvement in global cognition (p = 0.003) and daytime sleepiness (p = 0.001), and atomoxetine was well-tolerated.

CONCLUSIONS

Atomoxetine treatment was not efficacious for the treatment of clinically significant depressive symptoms in PD, but was associated with improvement in global cognitive performance and daytime sleepiness. Larger studies of SNRIs in PD for disorders of mood, cognition, and wakefulness are appropriate.

CLASSIFICATION OF EVIDENCE

This interventional study provides Class II evidence that atomoxetine (target dosage = 80 mg/day) is not efficacious in improving clinically significant depression in PD.

Mild cognitive impairment is common in Parkinson's disease patients with normal Mini-Mental State Examination (MMSE) scores

PURPOSE

Cognitive impairment occurs in the majority of Parkinson's disease (PD) patients, but little is known about detection of mild cognitive impairment (MCI) in this population. We report on the frequency and characteristics of cognitive deficits in PD patients with intact global cognition based on Mini-Mental State Examination (MMSE) performance.

METHODS

One hundred and six PD patients with normal age- and education-adjusted MMSE scores (mean [SD] score=29.1 [1.1]) were administered standardized neuropsychological tests assessing memory, executive function, and attention. Impairment on a cognitive domain was a low score (i.e., >or=1.5 SD below the published normative mean) on at least two measures or tests (for memory and executive abilities) or a single measure (for attention).

RESULTS

Mild cognitive impairment was found in 29.2% of PD patients, with 17.9% demonstrating single domain and 11.3% multiple domain impairment. Memory and attention impairment were most common (15.1% and 17.0%, respectively), followed by executive impairment (8.5%). Depending on the measure of disease severity chosen, increasing age and disease severity, anti-anxiety medication use, and a suggestion for increasing severity of daytime sleepiness were independent predictors of cognitive impairment.

CONCLUSIONS

Cognitive deficits are common in PD patients with "normal" cognition based on MMSE performance, suggesting that MCI is under-recognized in clinical practice due to routine use of insensitive screening instruments. In contrast with some previous reports, early memory impairment may be as common as either executive or attentional deficits in PD. In addition, psychiatric medication use and daytime sleepiness may be reversible or treatable contributors to cognitive impairment.

Long-term follow-up of impulse control disorders in Parkinson's disease

Recent studies have linked dopamine agonist (DA) usage with the development of impulse control disorders (ICDs) in Parkinson's disease (PD). Little is known about optimal management strategies or the long-term outcomes of affected patients. To report on the clinical interventions and long-term outcomes of PD patients who developed an ICD after DA initiation. Subjects contacted by telephone for a follow-up interview after a mean time period of 29.2 months. They were administered a modified Minnesota Impulse Disorder Interview for compulsive buying, gambling, and sexuality, and also self-rated changes in their ICD symptomatology. Baseline and follow-up dopamine replacement therapy use was recorded and verified by chart review. Of 18 subjects, 15 (83.3%) participated in the follow-up interview. At follow-up, patients were receiving a significantly lower DA levodopa equivalent daily dosage (LEDD) (Z = -3.1, P = 0.002) and a higher daily levodopa dosage (Z = -1.9, P = 0.05), but a similar total LEDD dosage (Z = -0.47, P = 0.64) with no changes in Unified Parkinson's Disease Rating Scale motor score (Z = -1.3, P = 0.19). As part of ICD management, 12 (80.0%) patients discontinued or significantly decreased DA treatment, all of whom experienced full or partial remission of ICD symptoms by self-report, and 10 (83.3%) of whom no longer met diagnostic criteria for an ICD. For PD patients who develop an ICD in the context of DA treatment, discontinuing or significantly decreasing DA exposure, even when offset by an increase in levodopa treatment, is associated with remission of or significant reduction in ICD behaviors without worsening in motor symptoms.