Cognitive and neuroanatomical correlates of neuropsychiatric symptoms in Parkinson's disease: A systematic review

Classification of Parkinson's disease with and without dopaminergic deficiency based on non-motor symptoms and structural neuroimaging

The presence of non-motor symptoms (NMS) such as olfactive deficit or neuropsychiatric symptoms has been associated with the diagnosis of Parkinson's Disease (PD). NMS are also associated with different brain structural features underlying distinctive processes in PD. NMS has been poorly studied in patients with a PD-like clinical profile, showing Scans Without Evidence of Dopaminergic Deficit (SWEDD). This study proposes to compare classification models differentiating PD, SWEDD and Healthy Controls (HC) based on NMS and neurostructural factors. 683 participants (382 PD diagnosed in the last 2 years, 48 with SWEDD, 170 HC) from the PPMI dataset were compared based on available assessments. Each participant underwent an olfactive, neuropsychiatric and sleep assessment, and a 3T MRI. Brain volumes were extracted and standardized from each MRI. Classifications were based on logistic regressions using 5-fold cross-validation models combining different NMS and MRI data and determining their involvement in differentiation between patient subgroups (PD vs. SWEDD) or between patients and HC. NMS were significant factors in PD vs. SWEDD, PD vs. HC and SWEDD vs. HC classifiers, when considered alone or in combination with MRI data. No classification models were significantly different from chance based-on MRI, nor more accurate combining NMS and MRI when compared with models based on NMS only. These results highlight the importance of NMS in differentiating between PD and SWEDD, PD and HC, SWEDD and HC. However, classical imaging data such as cortical and subcortical volumetry seems insufficient to improve these classifications. Other imaging features such as connectivity could also be studied.

Clinical and cognitive features associated with psychosis in Parkinson's disease: a longitudinal study

Background

Parkinson's disease psychosis (PDPsy) is associated with increased nursing home placement and mortality and is closely linked with cognitive dysfunction.

Objective

Assess the clinical and cognitive features associated with PDPsy in patients without dementia.

Methods

We prospectively recruited people with Parkinson's disease (PwP) without dementia for a 3-year, longitudinal study at an outpatient movement disorders clinic. Participants completed annual visits involving assessment of motor and non-motor symptoms including neuropsychological testing. PDPsy was defined as the recurring presence of visual illusions, sense of presence, hallucinations, or delusions for at least 1 month. Using generalized estimating equations, we conducted two sets of analyses to separately assess the clinical and the cognitive predictors of PDPsy.

Results

We enrolled 105 participants. At baseline, mean age was 67.8 (SD = 8.0), median disease duration was 4.9 years (IQR: 3.4-7.7), and mean MoCA was 24.8 (SD = 2.3). Prevalence of PDPsy increased over 3 years from 31% (n = 32) to 39% (n = 26). Forty-five participants (43%) experienced PDPsy. Visual illusions were most common (70%, n = 84), followed by hallucinations (58.3%, n = 70). In multivariate analysis, of the clinical variables, only depressive symptoms [OR 1.09, 95% CI: (1.03, 1.16), p = 0.004] increased the odds of PDPsy; of the cognitive variables, only Trail Making Test B-A scores [OR 1.43, 95% CI: (1.06, 1.93), p = 0.018] significantly increased the odds of PDPsy.

Conclusions

In PwP without dementia, depressive symptoms were associated with increased risk of PDPsy. Executive/attentional dysfunction was also associated with PDPsy and may mark the transition from isolated minor hallucinations to more complex psychotic symptoms.

Functional and connectivity correlates associated with Parkinson's disease psychosis: a systematic review

Neural underpinnings of Parkinson's disease psychosis remain unclear to this day with relatively few studies and reviews available. Using a systematic review approach, here, we aimed to qualitatively synthesize evidence from studies investigating Parkinson's psychosis-specific alterations in brain structure, function or chemistry using different neuroimaging modalities. PubMed, Web of Science and Embase databases were searched for functional MRI (task-based and resting state), diffusion tensor imaging, PET and single-photon emission computed tomography studies comparing Parkinson's disease psychosis patients with Parkinson's patients without psychosis. We report findings from 29 studies (514 Parkinson's psychosis patients, mean age ± SD = 67.92 ± 4.37 years; 51.36% males; 853 Parkinson's patients, mean age ± SD = 66.75 ± 4.19 years; 55.81% males). Qualitative synthesis revealed widespread patterns of altered brain function across task-based and resting-state functional MRI studies in Parkinson's psychosis patients compared with Parkinson's patients without psychosis. Similarly, white matter abnormalities were reported in parietal, temporal and occipital regions. Hypo-metabolism and reduced dopamine transporter binding were also reported whole brain and in sub-cortical areas. This suggests extensive alterations affecting regions involved in high-order visual processing and attentional networks.

Neuropsychiatric symptoms and brain morphology in patients with mild cognitive impairment, cerebrovascular disease and Parkinson disease: A cross sectional and longitudinal study

OBJECTIVES

Neuropsychiatric symptoms (NPS) increase risk of developing dementia and are linked to various neurodegenerative conditions, including mild cognitive impairment (MCI due to Alzheimer's disease [AD]), cerebrovascular disease (CVD), and Parkinson's disease (PD). We explored the structural neural correlates of NPS cross-sectionally and longitudinally across various neurodegenerative diagnoses.

METHODS

The study included individuals with MCI due to AD, (n = 74), CVD (n = 143), and PD (n = 137) at baseline, and at 2-years follow-up (MCI due to AD, n = 37, CVD n = 103, and PD n = 84). We assessed the severity of NPS using the Neuropsychiatric Inventory Questionnaire. For brain structure we included cortical thickness and subcortical volume of predefined regions of interest associated with corticolimbic and frontal-executive circuits.

RESULTS

Cross-sectional analysis revealed significant negative correlations between appetite with both circuits in the MCI and CVD groups, while apathy was associated with these circuits in both the MCI and PD groups. Longitudinally, changes in apathy scores in the MCI group were negatively linked to the changes of the frontal-executive circuit. In the CVD group, changes in agitation and nighttime behavior were negatively associated with the corticolimbic and frontal-executive circuits, respectively. In the PD group, changes in disinhibition and apathy were positively associated with the corticolimbic and frontal-executive circuits, respectively.

CONCLUSIONS

The observed correlations suggest that underlying pathological changes in the brain may contribute to alterations in neural activity associated with MBI. Notably, the difference between cross-sectional and longitudinal results indicates the necessity of conducting longitudinal studies for reproducible findings and drawing robust inferences.

Mild Behavioral Impairment in Parkinson's Disease: An Updated Review on the Clinical, Genetic, Neuroanatomical, and Pathophysiological Aspects

Neuropsychiatric symptoms (NPS), including depression, anxiety, apathy, visual hallucinations, and impulse control disorders, are very common during the course of Parkinson's disease (PD), occurring even at the prodromal and premotor stages. Mild behavioral impairment (MBI) represents a recently described neurobehavioral syndrome, characterized by the emergence of persistent and impactful NPS in later life, reflecting arisk of dementia. Accumulating evidence suggests that MBI is highly prevalent in non-demented patients with PD, also being associated with an advanced disease stage, more severe motor deficits, as well as global and multiple-domain cognitive impairment. Neuroimaging studies have revealed that MBI in patients with PD may be related todistinct patterns of brain atrophy, altered neuronal connectivity, and distribution of dopamine transporter (DAT) depletion, shedding more light on its pathophysiological background. Genetic studies in PD patients have also shown that specific single-nucleotide polymorphisms (SNPs) may be associated with MBI, paving the way for future research in this field. In this review, we summarize and critically discuss the emerging evidence on the frequency, associated clinical and genetic factors, as well as neuroanatomical and neurophysiological correlates of MBI in PD, aiming to elucidate the underlying pathophysiology and its potential role as an early "marker" of cognitive decline, particularly in this population. In addition, we aim to identify research gaps, and propose novel relative areas of interest that could aid in our better understanding of the relationship of this newly defined diagnostic entity with PD.

Educational disparities in Brazil may interfere with the cognitive performance of Parkinson's disease patients

The prevalence of cognitive impairment in Parkinson's disease (PD) is about 20% to 60%. The Mini-Mental Status Examination (MMSE) is the most used cognitive screening test.

Objective

To evaluate the influence of clinical and demographic characteristics, specifically the education level, on the MMSE score in PD patients of a northeast Brazilian sample.

Methods

We performed a cross-sectional study of 198 PD patients at a Movement Disorders outpatient clinic in Fortaleza, CE, Brazil. Participants were assessed by detailed clinical history, modified Hoehn and Yahr staging (HY), geriatric depression scale (GDS) and MMSE.

Results

We found that 68% of patients had MMSE scores below the Brazilian thresholds, which were based in Brucki et al. study (2003). There was a statistically significant difference in the bivariate analysis between educational level and cut-off classification for MMSE. More years of formal schooling were associated with more patients scoring below threshold. We found that 75%, 68.8%, and 79.7% of individuals with more than 11, 9 to 11, and 4 to 8 years of formal schooling, respectively, were below the suggested Brazilian Brucki's threshold. GDS and age were negatively correlated with total MMSE and all its domains. There was no correlation between disease duration and MMSE. Subjects with hallucinations had lower scores.

Conclusion

Most of the sample had lower performance according to Brazilian thresholds, but there was no control group and no neuropsychological test in this study. Further studies in northeast Brazil are needed to review MMSE cut-off values.

Investigating affective neuropsychiatric symptoms in rodent models of Parkinson's disease

Affective neuropsychiatric disorders such as depression, anxiety and apathy are among the most frequent non-motor symptoms observed in people with Parkinson's disease (PD). These conditions often emerge during the prodromal phase of the disease and are generally considered to result from neurodegenerative processes in meso-corticolimbic structures, occurring in parallel to the loss of nigrostriatal dopaminergic neurons. Depression, anxiety, and apathy are often treated with conventional medications, including selective serotonin reuptake inhibitors, tricyclic antidepressants, and dopaminergic agonists. The ability of these pharmacological interventions to consistently counteract such neuropsychiatric symptoms in PD is still relatively limited and the development of reliable experimental models represents an important tool to identify more effective treatments. This chapter provides information on rodent models of PD utilized to study these affective neuropsychiatric symptoms. Neurotoxin-based and genetic models are discussed, together with the main behavioral tests utilized to identify depression- and anxiety-like behaviors, anhedonia, and apathy. The ability of various therapeutic approaches to counteract the symptoms observed in the various models is also reviewed.

White matter hyperintensities and smaller cortical thickness are associated with neuropsychiatric symptoms in neurodegenerative and cerebrovascular diseases

BACKGROUND

Neuropsychiatric symptoms (NPS) are a core feature of most neurodegenerative and cerebrovascular diseases. White matter hyperintensities and brain atrophy have been implicated in NPS. We aimed to investigate the relative contribution of white matter hyperintensities and cortical thickness to NPS in participants across neurodegenerative and cerebrovascular diseases.

METHODS

Five hundred thirteen participants with one of these conditions, i.e. Alzheimer's Disease/Mild Cognitive Impairment, Amyotrophic Lateral Sclerosis, Frontotemporal Dementia, Parkinson's Disease, or Cerebrovascular Disease, were included in the study. NPS were assessed using the Neuropsychiatric Inventory - Questionnaire and grouped into hyperactivity, psychotic, affective, and apathy subsyndromes. White matter hyperintensities were quantified using a semi-automatic segmentation technique and FreeSurfer cortical thickness was used to measure regional grey matter loss.

RESULTS

Although NPS were frequent across the five disease groups, participants with frontotemporal dementia had the highest frequency of hyperactivity, apathy, and affective subsyndromes compared to other groups, whilst psychotic subsyndrome was high in both frontotemporal dementia and Parkinson's disease. Results from univariate and multivariate results showed that various predictors were associated with neuropsychiatric subsyndromes, especially cortical thickness in the inferior frontal, cingulate, and insula regions, sex(female), global cognition, and basal ganglia-thalamus white matter hyperintensities.

CONCLUSIONS

In participants with neurodegenerative and cerebrovascular diseases, our results suggest that smaller cortical thickness and white matter hyperintensity burden in several cortical-subcortical structures may contribute to the development of NPS. Further studies investigating the mechanisms that determine the progression of NPS in various neurodegenerative and cerebrovascular diseases are needed.

Independent effect of cardiometabolic syndromes and depression on dementia in Parkinson's disease: A 12-year longitudinal follow-up study of a nationwide cohort

BACKGROUND

We aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. Furthermore, we explored the effect of each cardiometabolic syndrome and depression on the incidence of PDD.

METHODS

Using data from the Korean National Health Insurance Service, 79,622 patients with de novo Parkinson's disease (PD) aged ≥40 years between January 2002 and December 2010 were followed to December 2019. We analyzed the incidence of PDD according to age at PD diagnosis and disease duration. To determine cardiometabolic syndromes and depression that affected PDD, we used Fine and Gray competing regression after controlling for age and sex.

RESULTS

During the 12.5-year follow-up period, the incidence of PDD increased with age at PD diagnosis (0.81-45.31 per 1000 person-years among those aged 40-44 and over 80 years, respectively) and longer disease duration (22.68 per 1000 person-years in 1-2 years to 34.16 per 1000 person-years in 15-16 years). Hypertension (subdistribution hazard ratio [SHR] = 1.11; 95% confidence interval [CI] 1.07-1.16), diabetes (SHR = 1.09; 95% CI 1.05-1.14), dyslipidemia (SHR = 1.15; 95% CI 1.11-1.20), and depression (SHR = 1.36; 95% CI 1.30-1.41) independently increased the risk for PDD.

CONCLUSIONS

Our findings provide insights into cardiometabolic syndromes as modifiable risk factors for incident PDD. Furthermore, our results will help in designing public health policies with respect to controlling cardiometabolic syndromes and depression to prevent incident PDD in patients with PD.

Grey matter volume loss in Parkinson's disease psychosis and its relationship with serotonergic gene expression: A meta-analysis

BACKGROUND

Neuroanatomical alterations underlying psychosis in Parkinson's Disease (PDP) remain unclear. We carried out a meta-analysis of MRI studies investigating the neural correlates of PDP and examined its relation with dopaminergic and serotonergic receptor gene expression.

METHODS

PubMed, Web of Science and Embase were searched for MRI studies (k studies = 10) of PDP compared to PD patients without psychosis (PDnP). Seed-based d Mapping with Permutation of Subject Images and multiple linear regression analyses was used to examine the relationship between pooled estimates of grey matter volume (GMV) loss in PDP and D1/D2 and 5-HT1a/5-HT2a receptor gene expression estimates from Allen Human Brain Atlas.

RESULTS

We observed lower grey matter volume in parietal-temporo-occipital regions (PDP n = 211, PDnP, n = 298). GMV loss in PDP was associated with local expression of 5-HT1a (b = 0.109, p = 0.012) and 5-HT2a receptors (b= -0.106, p = 0.002) but not dopaminergic receptors.

CONCLUSION

Widespread GMV loss in the parieto-temporo-occipital regions may underlie PDP. Association between grey matter volume and local expression of serotonergic receptor genes may suggest a role for serotonergic receptors in PDP.

Longitudinal cognitive changes in patients with early Parkinson's disease and neuropsychiatric symptoms

AIMS

In this study, we aimed to investigate the effect of neuropsychiatric symptoms (NPS) on the rate of cognitive decline for both global cognition and specific cognitive domains in a cohort of patients from the Parkinson's Progression Markers Initiative (PPMI).

METHOD

Prospectively longitudinal data were obtained from the PPMI cohort. NPS, including depression, anxiety, apathy, psychosis, impulse control disorders (ICDs), and cognition ability, were evaluated by a series of questionnaires. Linear mixed-effects models were used to investigate the relationship between NPS and the rate of cognitive decline. Generalized estimating equations (GEEs) were used to investigate the relationship between NPS and the occurrence of mild cognitive impairment (MCI).

RESULTS

In total, 423 patients with Parkinson's disease (PD) were recruited at baseline and 395, 378, 366, 346, and 315 participants were followed up at 1, 2, 3, 4, and 5 years, respectively. Depression, anxiety, apathy, and psychosis were associated with global cognitive decline. Except for those with ICDs, patients with psychosis, depression, anxiety, and apathy were more likely to meet the criteria for MCI. Patients with depression and anxiety showed a progressive decline in four major cognitive domains. Apathy and ICDs were separately associated with a progressive decline in processing speed-attention and memory, respectively.

CONCLUSIONS

Neuropsychiatric symptoms, including psychosis, depression, anxiety, and apathy, could be used to predict future cognitive decline in patients with PD.

Distinguishing apathy from depression: A review differentiating the behavioral, neuroanatomic, and treatment-related aspects of apathy from depression in neurocognitive disorders

OBJECTIVES

This narrative review describes the clinical features of apathy and depression in individuals with neurocognitive disorders (NCDs), with the goal of differentiating the two syndromes on the basis of clinical presentation, diagnostic criteria, neuropathological features, and contrasting responses to treatments.

METHODS

Literature was identified using PubMed, with search terms to capture medical conditions of interest; additional references were also included based on our collective experience and knowledge of the literature.

RESULTS

Evidence from current literature supports the distinction between the two disorders; apathy and depression occur with varying prevalence in individuals with NCDs, pose different risks of progression to dementia, and have distinct, if overlapping, neurobiological underpinnings. Although apathy is a distinct neuropsychiatric syndrome, distinguishing apathy from depression can be challenging, as both conditions may occur concurrently and share several overlapping features. Apathy is associated with unfavorable outcomes, especially those with neurodegenerative etiologies (e.g., Alzheimer's disease) and is associated with an increased burden for both patients and caregivers. Diagnosing apathy is important not only to serve as the basis for appropriate treatment, but also for the development of novel targeted interventions for this condition. Although there are currently no approved pharmacologic treatments for apathy, the research described in this review supports apathy as a distinct neuropsychiatric condition that warrants specific treatments aimed at alleviating patient disability.

CONCLUSIONS

Despite differences between these disorders, both apathy and depression pose significant challenges to patients, their families, and caregivers; better diagnostics are needed to develop more tailored treatment and support.

Non-visual hallucinations in Parkinson's disease: a systematic review

BACKGROUND

Non-visual hallucinations in Parkinson's disease (PD) can be prevalent and distressing. Most existing research has however, focused on visual hallucinations as well as related risk factors. The current study thus conducted a systematic review to collate existing evidence on non-visual hallucinations in PD, focusing on their prevalence, phenomenology, and clinical-cognitive correlates.

METHODS

Ninety-one relevant studies were included from a systematic search across PsycINFO APA, PubMed, and Web of Science, for peer-reviewed publications in the English language, from 1970 to the present. These comprised a mix of case (30 studies; n = 56) and group design (62 studies; n = 7346) studies, divided into three somewhat overlapping collections to address our three research foci.

RESULTS

Prevalence estimates for hallucinations were: auditory 1.5-72.0%, olfactory 1.6-21.0%, somatic-tactile 0.4-22.5%, gustatory 1.0-15.0%, and sensed presence 0.9-73.3%. Phenomenological inquiries revealed descriptions of vivid, consuming events replete with elaborate detail, adversely affecting PD patients in different ways. Overt experiences of multisensory hallucinations were also highly variable (0.4-80%) but exceedingly common, reported by almost half of the 45 included prevalence studies. There was some evidence for modality-specific hallucination predictors, but this was largely tentative, pending robust replication.

CONCLUSIONS

Marked prevalence figures coupled with phenomenological descriptions implicating distress denote that non-visual and multisensory hallucinations in PD are of clinical significance. More direct research and clinical attention need to be devoted to the study and management of such hallucinatory experiences.

Treatment for cognitive and neuropsychiatric non-motor symptoms in Parkinson's disease: current evidence and future perspectives

INTRODUCTION

Non-motor symptoms (NMS) affect patients with Parkinson's disease (PD) from the prodromal to the advanced stages. NMS phenotypes greatly vary and have a huge impact on patients' and caregivers' quality of life (QoL). The management of cognitive and neuropsychiatric NMS remains an unmet need.

AREAS COVERED

The authors, herein, review the dopaminergic and non-dopaminergic pathogenesis, clinical features, assessment, and pharmacological and non-pharmacological treatments of cognitive and neuropsychiatric NMS in PD. They discuss the current evidence and report the findings of an overview of ongoing trials on pharmacological and selected non-pharmacological strategies.

EXPERT OPINION

The treatment of cognitive and neuropsychiatric NMS in PD is poorly explored, and therapeutic options are unsatisfactory. Pharmacological treatment of cognitive NMS is based on symptomatic active principles used in Alzheimer's disease. Dopamine agonists, selective serotonin, and serotonin-norepinephrine reuptake inhibitors have some evidence on PD-related depression. Clozapine, quetiapine, and pimavanserin may be considered for psychosis in PD. Evidence on the treatment of other neuropsychiatric NMS is limited or lacking. Addressing pathophysiological and clinical issues, which hamper solid evidence on the treatment of cognitive and neuropsychiatric NMS, may reduce the impact on QoL for PD patients and their caregivers.

Systematic review of data-driven cognitive subtypes in Parkinson disease

BACKGROUND AND PURPOSE

Recent application of the mild cognitive impairment concept to Parkinson disease (PD) has proven valuable in identifying patients at risk of dementia. However, it has sparked controversy regarding the existence of cognitive subtypes. The present review evaluates the current literature pertaining to data-driven subtypes of cognition in PD.

METHODS

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, systematic literature searches for peer-reviewed articles on the topic of cognitive subtyping in PD were performed.

RESULTS

Twenty-two relevant articles were identified in the systematic search. Subtype structures showed either a spectrum of severity or specific domains of impairment. Domain-specific subtypes included amnestic/nonamnestic, memory/executive, and frontal/posterior dichotomies, as well as more complex structures with less definitive groupings. Preliminary longitudinal evidence showed some differences in cognitive progression among subtypes. Neuroimaging evidence provided insight into distinct patterns of brain alterations among subtypes.

CONCLUSIONS

Recurring phenotypes in the literature suggest strong clinical relevance of certain cognitive subtypes in PD. Although the current literature is limited, it raises critical questions about the utility of data-driven methods in cognitive research. The results encourage further integration of neuroimaging research to define the latent neural mechanisms behind divergent subtypes. Although there is no consensus, there appears to be growing consistency and inherent value in identifying cognitive subtypes in PD.

Characterization of Early Stage Parkinson's Disease From Resting-State fMRI Data Using a Long Short-Term Memory Network

Parkinson's disease (PD) is a common and complex neurodegenerative disorder with five stages on the Hoehn and Yahr scaling. Characterizing brain function alterations with progression of early stage disease would support accurate disease staging, development of new therapies, and objective monitoring of disease progression or treatment response. Functional magnetic resonance imaging (fMRI) is a promising tool in revealing functional connectivity (FC) differences and developing biomarkers in PD. While fMRI and FC data have been utilized for diagnosis of PD through application of machine learning approaches such as support vector machine and logistic regression, the characterization of FC changes in early-stage PD has not been investigated. Given the complexity and non-linearity of fMRI data, we propose the use of a long short-term memory (LSTM) network to distinguish the early stages of PD and understand related functional brain changes. The study included 84 subjects (56 in stage 2 and 28 in stage 1) from the Parkinson's Progression Markers Initiative (PPMI), the largest-available public PD dataset. Under a repeated 10-fold stratified cross-validation, the LSTM model reached an accuracy of 71.63%, 13.52% higher than the best traditional machine learning method and 11.56% higher than a CNN model, indicating significantly better robustness and accuracy compared with other machine learning classifiers. Finally, we used the learned LSTM model weights to select the top brain regions that contributed to model prediction and performed FC analyses to characterize functional changes with disease stage and motor impairment to gain better insight into the brain mechanisms of PD.

Affective disorders and сognitive impairment in the early stages of Parkinson's disease

Parkinson's disease (BP) is the second most important age-related neurodegenerative disease in developed societies after Alzheimer's disease with a prevalence of 41 per 100,000 in the fourth decade of life to more than 1900 per 100,000 people over 80 years old. Parkinson's disease (BP) is the second most important age-related neidgenerative disease in developed societies after Alzheimer's disease with a prevalence of 41 per 100,000 in the fourth decade of life to more than 1900 per 100,000 people over 80 years old. Neurodegeneration associated with Parkinson's disease is likely to occur over several decades before the appearance of motor symptoms. Affective and cognitive some of the most frequent non-engine manifestations of BP diseases that can lead to a variety of adverse outcomes

Disrupted reward processing in Parkinson's disease and its relationship with dopamine state and neuropsychiatric syndromes: a systematic review and meta-analysis

BACKGROUND

Neuropsychiatric symptoms are common in Parkinson's disease (PD) and predict poorer outcomes. Reward processing dysfunction is a candidate mechanism for the development of psychiatric symptoms including depression and impulse control disorders (ICDs). We aimed to determine whether reward processing is impaired in PD and its relationship with neuropsychiatric syndromes and dopamine replacement therapy.

METHODS

The Ovid MEDLINE/PubMed, Embase and PsycInfo databases were searched for articles published up to 5 November 2020. Studies reporting reward processing task performance by patients with PD and healthy controls were included. Summary statistics comparing reward processing between groups were converted to standardised mean difference (SMD) scores and meta-analysed using a random effects model.

RESULTS

We identified 55 studies containing 2578 participants (1638 PD and 940 healthy controls). Studies assessing three subcomponent categories of reward processing tasks were included: option valuation (n=12), reinforcement learning (n=37) and reward response vigour (n=6). Across all studies, patients with PD on medication exhibited a small-to-medium impairment versus healthy controls (SMD=0.34; 95% CI 0.14 to 0.53), with greater impairments observed off dopaminergic medication in within-subjects designs (SMD=0.43, 95% CI 0.29 to 0.57). Within-subjects subcomponent analysis revealed impaired processing off medication on option valuation (SMD=0.57, 95% CI 0.39 to 0.75) and reward response vigour (SMD=0.36, 95% CI 0.13 to 0.59) tasks. However, the opposite applied for reinforcement learning, which relative to healthy controls was impaired on-medication (SMD=0.45, 95% CI 0.25 to 0.65) but not off-medication (SMD=0.28, 95% CI -0.03 to 0.59). ICD was the only neuropsychiatric syndrome with sufficient studies (n=13) for meta-analysis, but no significant impairment was identified compared tonon-ICD patients (SMD=-0.02, 95% CI -0.43 to 0.39).

CONCLUSION

Reward processing disruption in PD differs according to subcomponent and dopamine medication state, and warrants further study as a potential treatment target and mechanism underlying associated neuropsychiatric syndromes.

Cognitive dysfunction and neuropsychiatric aspects of Parkinson's disease

Movement abnormalities, by definition, and cognitive changes, to varying extents, affect every patient with Parkinson's disease (PD) and are attributed to the underlying neurodegenerative disease. Various psychiatric disorders occur in most patients at some point over the course of PD, including in the prodromal phase. Even though psychiatric disturbances tend to aggravate motor and cognitive deficits, they are under-recognized and under-treated, and the role of the underlying neurological disease is often minimized. To provide an integrated approach to understanding neuropsychiatric aspects of PD, this chapter reviews how cognitive changes in PD relate to the common psychiatric disturbances in PD along with the prevalence, phenomenology, pathophysiology, and treatment of each.

Patients with depression in the early stages of Parkinson's disease: A cross-sectional observational study

Background. Depression is one of the most maladaptive manifestations of Parkinson's disease (PD). The relationship between depression and motor, cognitive, and other affective disorders in the early stages of PD remains debatable. Aim. To assess the frequency and severity of depression, to clarify the features of motor, affective disorders, and cognitive functions in patients with depression in the early stages of PD. Materials and methods. We observed 61 patients diagnosed with PD at stages III according to the HoehnYahr scale. The average age was 62.29.6 years, the average duration of PD was 2.51.6 years. Data were analyzed using the Unified PD Scale, the Beck Depression Inventory, the Apathy Scale, the Spielberger Anxiety Inventory, the PD Cognitive Assessment Scale (SCOPA-COG), the digital character substitution test (the symbolsnumbers test), the Montreal the Cognitive Function Assessment Scale (MoCA), the number-to-letter combination test, the Stroop test. Results. Symptoms of depression were detected in 48 (79%) patients with PD; 20 (33%) patients had subdepression, 24 (39%) had moderate and severe depression, and 4 (7%) had severe depression. In patients at stage I PD according to HoehnYahr, the frequency of moderate depression was 28%, at stage II (moderate and severe) 45%, and severe 10%. Patients with depression were characterized by a greater severity of motor symptoms, disturbances in daily activities, anxiety, apathy, as well as a decrease in executive cognitive functions. An inverse correlation was noted between the duration of depressive symptoms and deterioration in performance on tests to assess attention and control cognitive functions. Conclusion. Depression is a characteristic feature of the early stages of PD. Its frequency and severity increase from stage I to stage II of PD. Depression can be considered as an indicator of a more severe course of the disease, the progression of impairments in controlling cognitive functions. The possibility of assessing the prognosis of the course of the disease additionally substantiates the need to diagnose depression in patients with PD in the early stages of the disease.

Current concepts in treating mild cognitive impairment in Parkinson's disease

Impairment in various aspects of cognition is recognized as an important non-motor symptom of Parkinson's disease (PD). Mild cognitive impairment in PD (PD-MCI) is common in non-demented PD patients and is often associated with severity of motor symptoms, disease duration and increasing age. Further, PD-MCI can have a significant negative effect on performance of daily life activities and may be a harbinger of development of PD dementia. Thus, there is significant interest in developing therapeutic strategies to ameliorate cognitive deficits in PD and improve cognitive functioning of PD patients. However, due to significant questions that remain regarding the pathophysiology of cognitive dysfunction in PD, remediation of cognitive dysfunction in PD has proven difficult. In this paper, we will focus on PD-MCI and will review some of the current therapeutic approaches being taken to try to improve cognitive functioning in patients with PD-MCI.

Advanced brain ageing in Parkinson's disease is related to disease duration and individual impairment

Machine learning can reliably predict individual age from MRI data, revealing that patients with neurodegenerative disorders show an elevated biological age. A surprising gap in the literature, however, pertains to Parkinson's disease. Here, we evaluate brain age in two cohorts of Parkinson's patients and investigated the relationship between individual brain age and clinical characteristics. We assessed 372 patients with idiopathic Parkinson's disease, newly diagnosed cases from the Parkinson's Progression Marker Initiative database and a more chronic local sample, as well as age- and sex-matched healthy controls. Following morphometric preprocessing and atlas-based compression, individual brain age was predicted using a multivariate machine learning model trained on an independent, multi-site reference sample. Across cohorts, healthy controls were well predicted with a mean error of 4.4 years. In turn, Parkinson's patients showed a significant (controlling for age, gender and site) increase in brain age of ∼3 years. While this effect was already present in the newly diagnosed sample, advanced biological age was significantly related to disease duration as well as worse cognitive and motor impairment. While biological age is increased in patients with Parkinson's disease, the effect is at the lower end of what is found for other neurological and psychiatric disorders. We argue that this may reflect a heterochronicity between forebrain atrophy and small but behaviourally salient midbrain pathology. Finally, we point to the need to disentangle physiological ageing trajectories, lifestyle effects and core pathological changes.

A bidirectional relationship between anxiety, depression and gastrointestinal symptoms in Parkinson's disease

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Gastrointestinal (GI) and mood symptoms are common in Parkinson’s disease.

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Depression and anxiety are bidirectional risk factors for GI distress.

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Association between GI and mood symptoms may reflect disrupted Gut-Brain axis.

Introduction

Anxiety, depression and gastrointestinal (GI) symptoms are common non-motor symptoms in Parkinson’s disease (PD). Past studies provide evidence of a disrupted microbiome-gut-brain axis in PD, which is associated with certain motor and non-motor symptoms in PD. Additionally, there is evidence of a bidirectional association between mental health and gut health among individuals with GI disorders. The current study examined the bidirectional association between GI symptoms and anxiety/depression among individuals newly diagnosed with PD.

Methods

We conducted a secondary data analysis of the Parkinson’s Progression Markers Initiative. This included 487 individuals newly diagnosed with PD and followed for up to 5 years. Participants completed questionnaires of anxiety, depression and GI symptoms (Scales for Outcomes in Parkinson’s Disease Autonomic; SCOPA-AUT) at each annual visit. Multilevel models examined the bidirectional-lagged relationship between GI symptoms and anxiety/depression.

Results

Models provided evidence for a bidirectional relationship between GI symptoms and anxiety/depression. Specifically, more severe GI symptoms predicted more severe anxious/depressive symptoms within the same year and at the following year. There was also evidence of the inverse directionality, meaning that more severe anxiety/depression predicted more severe GI symptoms concurrently and in the following year.

Discussion

Findings provide preliminary evidence for a cyclical relationship among gut health and mental health in PD. Future studies are needed to examine if the microbiome-gut-brain axis plays a mechanistic role.

Structural network topology and microstructural alterations of the anterior insula associate with cognitive and affective impairment in Parkinson's disease

The aim of the current study was to assess the structural centrality and microstructural integrity of the cortical hubs of the salience network, the anterior insular cortex (AIC) subregions and anterior cingulate cortex (ACC), and their relationship to cognitive and affective impairment in PD. MRI of 53 PD patients and 15 age-matched controls included 3D-T1 for anatomical registration, and diffusion tensor imaging for probabilistic tractography. Network topological measures of eigenvector and betweenness centrality were calculated for ventral (vAI) and dorsal (dAI) AIC. Microstructural tract integrity between vAI, dAI and the ACC was quantified with fractional anisotrophy (FA) and mean diffusivity (MD). Structural integrity and connectivity were related to cognitive and affective scores. The dAI had significantly higher eigenvector centrality in PD than controls (p < 0.01), associated with higher depression scores (left dAI only, r_s = 0.28, p < 0.05). Tracts between dAI and ACC showed lower FA and higher MD in PD (p < 0.05), and associated with lower semantic fluency, working memory and executive functioning, and higher anxiety scores (range 0.002 < p < 0.05). This study provides evidence for clinically relevant structural damage to the cortical hubs of the salience network in PD, possibly due to extensive local neuropathology and loss of interconnecting AIC-ACC tracts.

Arithmetic Errors in Financial Contexts in Parkinson's Disease

Research on dyscalculia in neurodegenerative diseases is still scarce, despite high impact on patients' independence and activities of daily living function. Most studies address Alzheimer's Disease; however, patients with Parkinson's Disease (PD) also have a higher risk for cognitive impairment while the relation to arithmetic deficits in financial contexts has rarely been studied. Therefore, the current exploratory study investigates deficits in two simple arithmetic tasks in financial contexts administered within the Clinical Dementia Rating in a sample of 100 PD patients. Patients were classified as cognitively normal (PD-NC) or mildly impaired (PD-MCI) according to Level I consensus criteria, and assessed using a comprehensive neuropsychological test battery, neurological motor examination, and sociodemographic and clinical questionnaires. In total, 18% showed arithmetic deficits: they were predominately female, had longer disease duration, more impaired global cognition, but minor signs of depression compared to PD patients without arithmetic deficits. When correcting for clinical and sociodemographic confounders, greater impairments in attention and visuo-spatial/constructional domains predicted occurrence of arithmetic deficits. The type of deficit did not seem to be arbitrary but seemed to involve impaired place × value processing frequently. Our results argue for the importance of further systematic investigations of arithmetic deficits in PD with sensitive tests to confirm the results of our exploratory study that a specific subgroup of PD patients present themselves with dyscalculia.

Statistically Defined Parkinson's Disease Executive and Memory Cognitive Phenotypes: Demographic, Behavioral, and Structural Neuroimaging Comparisons

BACKGROUND

Some individuals with Parkinson's disease (PD) experience working memory and inhibitory difficulties, others learning and memory difficulties, while some only minimal to no cognitive deficits for many years.

OBJECTIVE

To statistically derive PD executive and memory phenotypes, and compare PD phenotypes on disease and demographic variables, vascular risk factors, and specific neuroimaging variables with known associations to executive and memory function relative to non-PD peers.

METHODS

Non-demented individuals with PD (n = 116) and non-PD peers (n = 62) were recruited to complete neuropsychology measures, blood draw, and structural magnetic resonance imaging. Tests representing the cognitive domains of interest (4 executive function, 3 memory) were included in a k-means cluster analysis comprised of the PD participants. Resulting clusters were compared demographic and disease-related variables, vascular risk markers, gray/white regions of interest, and white matter connectivity between known regions involved in executive and memory functions (dorsolateral prefrontal cortices to caudate nuclei; entorhinal cortices to hippocampi).

RESULTS

Clusters showed: 1) PD Executive, n = 25; 2) PD Memory, n = 35; 3) PD Cognitively Well; n = 56. Even after disease variable corrections, PD Executive had less subcortical gray matter, white matter, and fewer bilateral dorsolateral-prefrontal cortex to caudate nucleus connections; PD Memory showed bilaterally reduced entorhinal-hippocampal connections. PD Cognitively Well showed only reduced putamen volume and right entorhinal cortex to hippocampi connections relative to non-PD peers. Groups did not statistically differ on cortical integrity measures or cerebrovascular disease markers.

CONCLUSION

PD cognitive phenotypes showed different structural gray and white matter patterns. We discuss data relative to phenotype demographics, cognitive patterns, and structural brain profiles.

Improving Mood and Cognitive Symptoms in Huntington's Disease With Cariprazine Treatment

In Huntington's disease (HD), the main clinical symptoms include depression, apathy, cognitive deficits, motor deficiencies and involuntary movements. Cognitive, mood and behavioral changes may precede motor symptoms by up to 15 years. The treatment of these diverse symptoms is challenging. Tetrabenazine and deutetrabenazine are the only medications specifically approved for Huntington's chorea, but they do not affect the non-motor symptoms. For these, antidepressants, antipsychotics, and benzodiazepines have demonstrated benefit in some cases and can be used off-label. These drugs, due to sedative side effects, may negatively influence cognition. Sixteen patients having HD received a 12-week off-label cariprazine (CAR) treatment (1.5-3 mg/day). Cognitive performance and behavioral changes were measured by the Addenbrooke Cognitive Examination (ACE) test, the Cognitive and Behavioral part of the Unified Huntington's Disease Rating Scale (UHDRS), and the Beck Depression Inventory (BDI). Mixed model for repeated measures was fitted to the data, with terms of visit, baseline (BL) and their interaction. Cariprazine treatment resulted in the following changes from BL to week 12, respectively: the mean score of BDI decreased from 17.7 ± 10.7 to 10.0 ± 10.7 (p <0.0097), while the Behavioral Assessment score of the UHDRS decreased from 54.9 ± 11.3 to 32.5 ± 15.4 (p < 0.0001); ACE score increased from 75.1 ± 11.0 to 89.0 ± 9.3 (p < 0.0001); Cognitive Verbal Fluency score from 6.2 ± 2.5 to 7.7 ± 2.7 (p < 0.0103); Symbol Digit Test from 9.2 ± 6.9 to 12.3 ± 8.9 (p < 0.0009). Mild akathisia was the most frequent side effect, presenting in 2 out of 16 patients (12.5%). We conclude that CAR had a positive effect on depressive mood, apathy and cognitive functions in patients with early stage of HD. Based on the neurobiological basis of these symptoms, CAR can improve the dopamine imbalance of the prefrontal cortex. This draws attention to the transdiagnostic approach which supports the further understanding of the similar symptomatology of different neuropsychiatric disorders and helps to identify new indications of pharmaceutical compounds.

The impact of Lee Silverman Voice Treatment (LSVT LOUD®) on voice, communication, and participation: Findings from a prospective, longitudinal study

BACKGROUND

Lee Silverman Voice Treatment (LSVT LOUD®), an intensive 4-week program of voice therapy, is regarded as the most well-researched, efficacious treatment for hypokinetic dysarthria in individuals with Parkinson's disease (PD). Although numerous studies have published acoustic and perceptual findings, there is comparatively little information about the impact of LSVT LOUD® on functional communication outcomes.

METHODS

This prospective, longitudinal study investigated the impact of treatment on daily communication in 25 individuals with PD. Three validated communication measures (the Voice Handicap Index, the Communicative Effectiveness Scale, and the Communicative Participation Item Bank) were given before and after treatment and again 4-8 weeks and 3-6 months following treatment. Communication partners were also asked to rate communication effectiveness at all four timepoints.

RESULTS

Significant improvements were found for all three self-reported scales which remained above baseline across all post-treatment timepoints. In addition, self-reported communicative effectiveness was significantly correlated with the assessments of communication partners. Particular benefits were reported for more complex communicative activities such as asking questions, giving detailed information, communicating in noisy situations, and speaking in groups.

CONCLUSIONS

Overall, the findings suggested that LSVT LOUD® promotes an increased sense of personal control over the communication difficulties resulting from PD by decreasing voice handicap and improving communication effectiveness and communicative participation. For individuals with PD, LSVT LOUD® may reduce the risk of social isolation by improving communication and facilitating social participation.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) describe the impact of PD on voice and communication, (2) discuss how these characteristics may be associated with more global measures of functional communication and particularly communicative participation, (3) explain which aspects of functional communication were affected by LSVT LOUD® as assessed by study participants and their communication partners.

Diagnosis, treatment and management of apathy in Parkinson's disease: a scoping review

OBJECTIVE

To conduct a scoping review of the literature on apathy in Parkinson's disease (PD), to better understand how apathy in Parkinson's disease is diagnosed, treated and managed.

METHODS

MEDLINE, Embase, PsycINFO, CINAHL, Cochrane Central Register of Control Trials and Cochrane Database of Systematic Reviews were searched to 17 May 2017. An updated review was run from 17 May 2017 to 28 January 2019. The grey literature was searched using the CADTH Grey Matters tool. Original peer-reviewed research was included if it included individuals with PD and apathy. Non-original data was only included if it was in the form of meta-analysis. All information regarding diagnosis, treatment and management of PD was extracted. Citation screening and extraction were performed in duplicate.

RESULTS

From 11 375 citations, 362 articles were included in the final review. The majority of included studies focussed on prevalence, with few studies examining treatment. Twenty screening tools for apathy were identified. Fifty per cent of treatment studies were randomised control trials (RCTs). RCTs applied treatment methods including: exercise, mindfulness, rotigotine (Neupro) transdermal patch and rivastigmine (Exelon).

CONCLUSIONS

This review identified a large body of literature describing current knowledge on diagnosing, treating and managing apathy in PD. Future research should aim to detect an ideal screening tool for apathy in PD, to identify the best treatment options for apathy and the variety of comorbidities it may present with and finally aim to better understand postoperative apathy in those with deep brain stimulation.

Depression Comorbid With Stroke, Traumatic Brain Injury, Parkinson's Disease, and Multiple Sclerosis: Diagnosis and Treatment

Depression is common among patients with neurologic disorders, and it has long been considered more difficult to treat than depression in the general population. In this review, the authors consider challenges in the diagnosis and treatment of depression among patients with stroke, traumatic brain injury, Parkinson's disease, and multiple sclerosis. For each disorder, the authors discuss the epidemiology and time course of depression as well as review the physiologic and psychological etiologies of depression. In addition, for each disorder, they review screening tools and diagnostic considerations, including differential diagnosis; discuss etiological factors, both neurobiological and psychological; and assess evidence for various depression treatments, including pharmacologic, psychosocial, and neuromodulatory therapies. The evidence suggests that depression is common among patients with neurologic disorders and that it is crucial for general psychiatrists to provide treatment for this population.

Mild cognitive impairment, psychiatric symptoms, and executive functioning in patients with Parkinson's disease

OBJECTIVE

Mild cognitive impairment (MCI) and psychiatric symptoms (anxiety, depression, and apathy) are common in Parkinson's disease (PD). While studies have supported the association between psychiatric symptoms and cognitive performance in PD, it is unclear if the magnitude of link between psychiatric symptoms and cognitive health is stronger by MCI status. The purpose of this study was to examine the association between cognitive performance and psychiatric symptoms in PD and whether MCI status moderates this association.

METHODS/DESIGN

Participants (N = 187) completed a comprehensive neuropsychological assessment that included measures of attention, language, executive function (EF), visuospatial ability, episodic memory, and psychiatric symptoms. Participants were classified as PD-MCI (N = 73) or PD-normal cognition (NC; N = 114). Linear regression analyses were conducted to examine the association between psychiatric symptoms and cognitive performance and the moderating effect of PD-MCI status.

RESULTS

There were no differences in mean psychiatric symptoms between PD-MCI and PD-NC. Psychiatric symptoms were predominantly associated with worse EF. The magnitude of the association between anxiety and worse EF was larger in participants with PD-MCI compared with PD-NC. A multivariable regression analysis examining the independent contributions of each symptom demonstrated the most robust association between EF and anxiety.

CONCLUSIONS

Symptoms of anxiety, depression, and apathy are associated with worse executive functioning in individuals with PD. PD-MCI may be important in moderating the association between cognitive performance, specifically anxiety, and EF. Factors that promote cognitive resilience may serve as key therapeutic modalities in managing neuropsychiatric symptoms in PD.

The effect of aging, Parkinson's disease, and exogenous dopamine on the neural response associated with auditory regularity processing

Processing regular patterns in auditory scenes is important for navigating complex environments. Electroencephalography studies find enhancement of sustained brain activity, correlating with the emergence of a regular pattern in sounds. How aging, aging-related diseases such as Parkinson's disease (PD), and treatment of PD with dopaminergic therapy affect this fundamental function remain unknown. We addressed this knowledge gap. Healthy younger and older adults and patients with PD listened to sounds that contained or were devoid of regular patterns. Healthy older adults and patients with PD were tested twice-off and on dopaminergic medication, in counterbalanced order. Regularity-evoked, sustained electroencephalography activity was reduced in older, compared with younger adults. Patients with PD and older controls evidenced comparable attenuation of the sustained response. Dopaminergic therapy further weakened the sustained response in both older controls and patients with PD. These findings suggest that fundamental regularity processing is impacted by aging but not specifically by PD. The finding that dopaminergic therapy attenuates rather than improves the sustained response coheres with the dopamine overdose response and is in line with previous findings that regularity processing implicates brain regions receiving dopamine from the ventral tegmental area that is relatively spared in PD and normal aging.

Nosology and Phenomenology of Psychosis in Movement Disorders

BACKGROUND

Psychotic symptoms, such as delusions and hallucinations, are part of the clinical picture of several conditions presenting movement disorders. Phenomenology and epidemiology of psychosis in Parkinson's disease have received wide attention; however, the presence of psychosis in other movement disorders is, comparatively, less well known.

OBJECTIVES

To review psychotic symptoms present in different movement disorders.

METHODS

A comprehensive and structured literature search was performed to identify and analyze data on patients with movement disorders and comorbid psychosis.

RESULTS

In monogenic parkinsonisms, such as PARK-GBA, PARK-LRRK2, and PARK-SNCA, visual hallucinations related to dopamine replacement therapy are frequent as well as are delusions in PARK-LRRK2 and PARK-SNCA, but not in PARK-GBA. Different types of delusions and hallucinations are found in Huntington's disease and other choreic disorders. In Tourette's syndrome, paranoid delusions as well as visual, olfactory, and auditory hallucinations have been described, which usually develop after an average of 10 years of disease. Delusions in ataxias are more frequent in ATX-TBP, ATX-ATN1, and ATX-ATXN3, whereas it is rare in Friedreich's ataxia. Psychosis is also a prominent and frequent clinical feature in Fahr's disease, Wilson's disease, neurodegeneration with brain iron accumulation, and some lysosomal storage disorders, whereas it is uncommon in atypical parkinsonisms and dystonia. Psychosis usually occurs at late disease stages, but may appear as onset symptoms of the disease, especially in Wilson's disease, Huntington's disease, late-onset Tays-Sachs, and Niemann-Pick.

CONCLUSION

Psychosis is a frequent comorbidity in most hyper- and hypokinetic movement disorders. Appropriate recognition is relevant both in the early and late disease stages.

Depressive symptoms precede cognitive impairment in de novo Parkinson's disease patients: Analysis of the PPMI cohort

INTRODUCTION

Nonmotor symptoms, including depression, anxiety, apathy, and cognitive dysfunction, are common in Parkinson's disease (PD). Although a link between mood symptoms and cognitive impairment in PD has been theorized vis-à-vis striatal dopamine depletion, studies have been inconsistent regarding the relationship between mood symptoms and cognitive function. Inconsistencies may reflect the cross-sectional nature of previous studies. The current study examined the bidirectional longitudinal relationship between mood and cognition.

METHOD

Data were obtained from 310 individuals newly diagnosed with PD, who were followed up to 4 years (baseline, 1st, 2nd, 3rd, and 4th annual follow-ups). Apathy, anxiety, depressive symptoms, motor severity, and neurocognitive functioning were assessed at each annual assessment. The longitudinal relationship between apathy, anxiety, depressive symptoms, and cognition was analyzed with multilevel models.

RESULTS

Over the 4-year period, more severe depressive symptoms were related to worse performance on tasks of processing speed, verbal learning, and verbal delayed recall. Additionally, there was a significant Depression × Time interaction, suggesting that individuals with more severe depressive symptoms experience more rapid declines in global cognitive functioning and verbal learning. Apathy and anxiety were not significantly related to performance in any cognitive test. Lagged models revealed that changes in depression precede declines in working memory, verbal learning, delayed verbal recall, and global cognition.

CONCLUSION

Findings suggest depressive symptoms may be a harbinger for future cognitive decline among individuals with PD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Effects of Cognitive Performance and Affective Status on Fatigue in Parkinson's Disease

Background

Fatigue is a common non-motor symptom in Parkinson's disease (PD) and is typically assessed via self-reported questionnaires such as the Parkinson's Fatigue Scale (PFS). The PFS captures the presence of subjective experience of physical fatigue as well as its impact on daily functioning.

Objectives

We aimed to investigate whether different variables (cognition, neuropsychiatric symptoms, disease-related measures) are associated with the experience of physical fatigue in comparison to fatigue affecting daily functioning.

Method

Sixty-two non-demented PD patients were evaluated through questionnaires assessing fatigue, daytime sleepiness, apathy, depression, anxiety, and cognition. Items of fatigue were classified and summarized into two index variables measuring either the subjective experience of physical fatigue or the impact of fatigue on daily functioning. Linear regression with a stepwise elimination procedure was conducted to select the significant predictors for each index variable separately.

Results

Subjective experience of physical fatigue (Model 1; r² = 0.46; p <0.01) was significantly associated with higher levels of depression (b =0.07; p <0.01), anxiety (b =0.03; p <0.05), and lower performances in verbal episodic memory (b =-0.16; p <0.05). Fatigue affecting daily functioning (Model 2; r² = 0.44; p <0.05) was significantly related to higher levels of depression (b = 0.07; p < 0.01), anxiety (b = 0.03; p > 0.05), and lower motor functioning (b = 0.01; p = 0.05).

Conclusions

In conclusion, our work supports associations between fatigue and other neuropsychiatric symptoms in PD and extends prior work suggesting that motor disturbances are specifically linked to fatigue-related impairment of daily functioning, but not to the subjective experience of physical fatigue.

Detecting Apathy in Individuals with Parkinson's Disease: A Systematic Review

BACKGROUND

Individuals experiencing apathy in Parkinson's disease (PD) have a lack of emotion and motivation. Apathy often overlaps with comorbidities such as depression, and is sometimes difficult to detect.

OBJECTIVE

To examine diagnostic accuracy of apathy-screening tools compared with a gold standard (clinician diagnosis) among adult outpatients with PD.

METHODS

A systematic review was conducted. Six research databases were searched to May 23, 2018. Diagnostic accuracy measures, including sensitivity and specificity were gathered.

RESULTS

1,007 full-text articles were reviewed with seven full-text articles included. The gold standard was considered a clinician diagnosis as apathy is not defined in the DSM/ICD. Diagnostic accuracy measures were reported for the Lille Apathy Rating Scale (LARS) both informant- and observer-rated, Unified Parkinson's Disease Rating Scale (UPDRS), Apathy Scale (AS), Apathy Evaluation Scale (AES), Non-Motor Symptoms Questionnaire (NMS-Q), and Dimensional Apathy Scale (DAS). The AES had the best reported sensitivity and specificity values, both 90%. The AS had the highest reported specificity at 100%, with 66% sensitivity. Pooled prevalence of apathy was 29.1% (95% CI 21.5%-36.6%).

CONCLUSIONS

While 18 screening tools exist to screen for apathy in PD, only six have been validated against clinician diagnosis. The AES had the highest reported sensitivity and specificity and is a brief, easy to use tool. The AS was designed specifically for use in PD populations and has the highest reported specificity. Future research should focus on the development of an accepted gold standard, to further understand accuracy measures of all available apathy screening tools.

Mild behavioral impairment is linked to worse cognition and brain atrophy in Parkinson disease

OBJECTIVE

To evaluate the associations of mild behavioral impairment (MBI) with cognitive deficits and patterns of gray matter changes in Parkinson disease (PD).

METHODS

Sixty patients with PD without dementia and 29 healthy controls underwent a cognitive neuropsychological evaluation and structural MRI scan. MBI was evaluated with the MBI Checklist (MBI-C), a rating scale designed to elicit emergent neuropsychiatric symptoms in accordance with MBI criteria. We divided the patients with PD into 2 groups: 1 group with high MBI-C scores (PD-MBI) and the other with low MBI-C scores (PD-noMBI).

RESULTS

Among 60 patients with PD, 20 were categorized as having PD-MBI (33.33%). In healthy controls, no participants met the MBI cut-point threshold. The PD-MBI group had significantly lower Montreal Cognitive Assessment and z scores in all 5 domains and the global score compared to healthy controls and those with PD-noMBI. In addition, all cognitive domains except language and global cognition negatively correlated with the MBI-C total score in all patients with PD. For cortical structures, the PD-MBI group revealed middle temporal cortex thinning and decreased volume compared with the PD-noMBI group, and decreased volume in this area negatively correlated with the MBI-C total score.

CONCLUSIONS

The impaired cognitive function over all domains and atrophy in the temporal area in the PD-MBI group are in line with posterior cortical circuit deficits in PD, which have been associated with a faster rate of progression to dementia. These initial results suggest that MBI might be an early and important marker for incident cognitive decline and dementia in patients with PD.

Usual walking and obstacle avoidance are influenced by depressive and anxiety symptoms in patients with Parkinson's disease

AIM

The aim of the present study was to analyze the association of depressive and anxiety symptoms with usual walking and obstacle avoidance in patients with Parkinson's disease.

METHODS

Patients were divided into three groups: without depressive and anxiety symptoms (n = 28); depressive symptoms only (n = 15); and depressive and anxiety symptoms (n = 19). Symptoms of depression and anxiety were evaluated by the Hospital Anxiety and Depression scale. Participants walked across a pathway in two experimental conditions: usual walking and obstacle avoidance. Kinematic data were recorded using an optoelectronic three-dimensional system.

RESULTS

During usual walking, the depressive and anxiety symptoms group presented shorter stride length and longer double support phase compared with the without depressive and anxiety symptoms group, and lower velocity than the without depressive and anxiety symptoms and depressive symptoms groups. During the approach phase of obstacle avoidance, the depressive and anxiety symptoms group decreased the stride length and velocity, whereas the without depressive and anxiety symptoms and depressive symptoms groups did not modulate these parameters. The depressive and anxiety symptoms group also showed shorter step length and velocity, longer step duration, and wider step width during obstacle crossing. Additionally, the depressive and anxiety symptoms group presented shorter foot-to-obstacle horizontal distances, and lower horizontal mean velocities during obstacle crossing. Partial correlation analyses showed that both depressive and anxiety symptoms were associated with spatiotemporal gait parameters.

CONCLUSION

Combined symptoms of depression and anxiety are associated with walking impairments in patients with Parkinson's disease in both usual walking and obstacle avoidance. Geriatr Gerontol Int 2019; 19: 868-873.

Comparison of Quantitative Electroencephalogram During Sleep in Depressed and Non-Depressed Patients with Parkinson's Disease

BACKGROUND Depression is one of the most important factors affecting quality of life in Parkinson's patients. Most research on Parkinson's disease with depression has focused on neuroimaging, and there have been few quantitative electroencephalogram studies. Sleep is a biomarker for depression; therefore, the aim of this study was to identify differences in quantitative electroencephalograms during sleep in depressed and non-depressed patients with Parkinson's disease. MATERIAL AND METHODS We assessed 38 Parkinson's disease patients (26 depressed patients, 12 non-depressed patients) and 20 normal subjects using the Geriatric Depressive Scale for Depressive Symptoms and quantitative electroencephalogram analysis of amplitude of different frequency bands in different sleep stages using Met-lab software and Fast Fourier Transformation. RESULTS Non-rapid eye moment 2 and the Frontal 4 Electrode amplitude in the delta and theta ranges were progressively and significantly greater in the depressed-Parkinson's disease group (p<0.05) than in the control group. In the depressed Parkinson's disease group, from the comparison of non-rapid eye moment 2 and rapid eye moment, in Frontal 4 the amplitude in the delta ranges of non-rapid eye moment 2 was greater than in the non-depressed group, and in Central 3, Central 4, Occipital 1, and Occipital 2, the amplitudes in the beta ranges of rapid eye moment were greater (p<0.05) than in the non-depressed group. CONCLUSIONS The higher amplitude in theta in frontal areas in NREM2 and the higher amplitude in beta in parietal and occipital lobe areas in REM relative to NREM2 were significantly different in depressed and non-depressed patients with Parkinson's disease.

Measuring executive dysfunction in Parkinson's disease: Reliability and validity of the Spanish version of Frontal Assessment Battery (FAB-E)

Background

Deficits in executive functions (EFs) are frequently detected in patients with Parkinson’s disease (PD). The Frontal Assessment Battery (FAB) is a screening test for assessing EFs although it has not been so far adapted and validated in Spain. We evaluated the reliability and validity of the Spanish version of the FAB (FAB-E) in PD patients.

Materials and methods

Our study included 54 healthy subjects and 67 PD patients. Cognitive assessment of participants was conducted using the FAB-E, Mini-Mental State Examination (MMSE), Trail Making Test (TMT), Revised-Barcelona Test (RBT) and Executive Interview (EXIT-25). Internal consistency, intra- and test-retest reliabilities, concurrent and discriminant validity of the FAB-E were examined. To evaluate the influence of cognitive dysfunction in PD on the performance of the FAB-E, we also classified the PD patients into groups according to their cognitive status as measured by the MMSE using published criteria to identify cognitive deficits in PD.

Results

The FAB-E showed good internal consistency (α = 0.751). The intraclass correlation coefficients (ranging from 0.559 to 0.891) and Spearman correlations (from 0.494 to 0.864) of the FAB-E subtests indicated a good-strong reliability. The total and subtest scores generally showed a good concurrent validity, except for the prehension behaviour item of the FAB-E and the Interference and Go/no-go tasks of the EXIT-25 that presented low estimates. Excluding the prehension behaviour subtest, the performance of the FAB-E was higher in the control group than in PD patients. Cognitive dysfunction in PD patients also indicated significant poorer FAB-E scores excepting the motor and prehension behaviour subtests. Discriminant analysis determined a cut-off of 14.5 was optimal to differentiate healthy subjects from PD patients. Moreover, a cut-off <12.5 allocated satisfactorily those PD patients with cognitive impairment (MMSE<26) and scores <11.5 classified suitably those PD patients with dementia (MMSE<24).

Conclusion

The FAB-E is an accurate tool for evaluating EFs in patients with PD and can provide useful information for distinguishing PD patients with and without cognitive dysfunction at a bedside assessment.

Interaction Between Neuropsychiatric Symptoms and Cognitive Performance in Parkinson's Disease: What Do Clinical and Neuroimaging Studies Tell Us?

PURPOSE OF REVIEW

Parkinson's disease was studied for a long time from the prism of a motor impairment. Recent advances have outlined the importance of cognitive and neuropsychiatric symptoms (NPS) in the PD equation. This review concentrates on the present possibilities of using neuroimaging techniques in order to quantify the cognitive performance and NPS in PD patients.

RECENT FINDINGS

Mild cognitive impairment as well as many NPS have been acknowledged as important criteria for assessing the quality of life in patients with Parkinson's disease and have been shown as potential factors in predicting further evolution of PD from a clinical perspective. Some NPS strongly influence cognition (depression, REM sleep behavior disorder), while others are less specifically associated with it (impulse control disorders). Neuroimaging techniques reported specific structural, functional, and metabolic brain changes that might be specific for each NPS type. Recent neuroimaging advances report a strong interrelation between NPS and cognitive performance in PD. A special place for consideration is given to REM sleep behavior disorder, depression, and hallucinations. Nevertheless, some studies report distinct results, outlining that the neuroimaging acquisition and analysis techniques still have limitations and also likely represent the complexity of the manifestation of NPS in PD.

Repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex to alleviate depression and cognitive impairment associated with Parkinson's disease: A review and clinical implications

The rapid methodological development and growing availability of neuromodulation techniques have spurred myriad studies investigating their clinical effectiveness. Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) has in many instances been proven to exert antidepressant-like effects superior to placebo and equivalent to standard psychopharmacological treatment. Due to the similar neuroanatomy and neurophysiology of executive and affective control processes, rTMS to the DLPFC may be able to address multiple issues simultaneously. This review pools available literature on the therapeutic usage of rTMS on non-motor symptoms of Parkinson's disease associated with the DLPFC (i.e. mood disturbance and cognitive impairment). To the best of the author's knowledge, it is one of the few available of its' kind, up to this date. Most studies included in the review found beneficial effects of high frequency prefrontal rTMS on PD-related depression. In regard to the usability of rTMS to alleviate cognitive impairment associated with PD, definitive claims are yet to be established.

Association of MRI Measurements with Cognitive Outcomes After STN-DBS in Parkinson's Disease

Objectives

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for improving the motor symptoms of Parkinson's disease (PD). Overall, cognitive function remains stable after STN-DBS in most patients. However, cognitive decline, specifically in the verbal fluency domain, is seen in a subset of STN-DBS patients. Currently, predictors of cognitive decline in PD patients treated with STN-DBS are not well known. Thus, identification of presurgical predictors might provide an important clinical tool for better risk-to-benefit assessment. This study explores whether whole brain white matter lesion (WML) volume, or hippocampal and forebrain volumes, measured quantitatively on MRI, are associated with cognitive changes following STN-DBS in PD patients.

Methods

We conducted a retrospective study using presurgical, and ≥ 6-month postsurgical neuropsychological (NP) evaluation scores from 43 PD patients with STN-DBS. Mean pre/post NP test scores for measures of executive function, attention, verbal fluency, memory, and visuospatial function were analyzed and correlated with WML volume, and brain volumetric data.

Results

Although cognitive measures of verbal fluency, executive function, attention, memory, and visuospatial function showed declines following STN-DBS, we observed limited evidence that white matter lesion burden or cortical atrophy contributed to cognitive change following STN-DBS.

Conclusions

These results suggest that post-STN-DBS cognitive changes may be unrelated to presurgical WML burden and presence of cortical atrophy.

Characteristics of apathy in treatment-naïve patients with Parkinson's disease

INTRODUCTION

Although apathy is a common psychiatric symptom of Parkinson's disease (PD), there are many unknown aspects of its pathology. This study aimed to investigate the characteristics of apathy in treatment-naïve patients with early-stage PD.

METHODS

Fifty treatment-naïve patients with early-stage PD were divided into 1 of 2 groups-apathetic or non-apathetic-based on Starkstein Apathy Scale (AS) scores. Cognitive function, depressive symptoms, olfactory function, and motor severity were compared between the two groups using validated assessment scales. Multiple linear regression was performed to assess the association between AS scores and clinical parameters.

RESULTS

Apathy (AS score ≥16) was observed in 13 (26%) patients. Assessment scale scores (Beck Depression Inventory-Second Edition [p < .004]; modified Hoehn & Yahr stage [p = .039]; Unified Parkinson's Disease Rating Scale part III [p < .001]) were significantly higher in apathetic patients than in non-apathetic patients. Significant association between these scale scores and AS score was also evident (all p ≤ .001). There were no significant differences in the test scores derived from several other validated scales.

CONCLUSION

Apathy was observed in 26% of treatment-naïve patients with early-stage PD. Significant association between apathy and motor severity was found, suggesting that dysfunction of the dopaminergic pathway is involved in the pathology of apathy.

Factors associated with depression in patients with Parkinson's disease A multicenter study in Lima, Peru

The diagnosis and treatment of depression in patients with Parkinson's disease (PD) is inadequate, often contributing to a reduced quality of life, rapid disease progression, higher cognitive impairment, and an increased burden of care for family members of patients with PD.

OBJECTIVE

To determine the factors associated with depression in PD and to examine the frequency of depressive symptoms among patients with PD.

METHODS

This study was an observational, analytical, multicenter study of a cross-sectional cohort, conducted between July 2016 and May 2017. PD patients were recruited from neurology clinics in Lima, Peru. All statistical analyses were performed using descriptive statistics. Bivariate and multivariate logistic regression analyses were calculated using STATA.

RESULTS

Out of 124 patients (average age: 68.7 years; 58% males) included in the study 60.5% (75/124) presented with symptoms of depression; only 20% (25/124) received antidepressants. Factors associated with depression in PD included: unemployment, falls, freezing of gait, involuntary movements micrographia, stooped posture, hyposmia, movement disorders in sleep, rapid disease progression, and the use of MAOIs. Furthermore, statistically significant differences were found in disease duration, UPDRS and MMSE scores, Hoehn and Yahr (HY) stage, and length of time taking L-dopa between PD patients with and without depressive symptoms.

CONCLUSION

Factors associated with depressive symptoms in patients with PD were hyposmia, rapid progression of the disease, the use of L-dopa, and use of MAOIs. The frequency of depressive symptoms in patients with PD is high; early diagnosis and prompt treatment are needed to improve their quality of life and the family environment.