Parkinson's disease: the quintessential neuropsychiatric disorder

Healthcare resource utilization patterns among patients with Parkinson's disease psychosis and dementia: analysis of US Medicare beneficiaries treated with pimavanserin versus other-atypical antipsychotics or versus quetiapine

BACKGROUND

Pimavanserin (PIM) is the only FDA approved atypical antipsychotic treatment (AAP) for hallucinations and delusions associated with Parkinson's disease psychosis (PDP) among patients with or without coexisting dementia; however, Other-AAPs (i.e. quetiapine (QUE), risperidone, olanzapine, aripiprazole) are commonly prescribed off-label. Healthcare resource utilization (HCRU) patterns among patients with PDP and coexisting dementia (PDP+D) who newly initiate PIM versus (vs.) Other-AAPs (i.e. other AAP-mix) or QUE in real-world settings is limited.

METHODS

A retrospective analysis of Parts A, B, and D claims from the 100% Medicare sample from 04/01/15 to 12/31/21 was conducted. AAP-naïve patients with PDP+D who initiated ≥12-month continuous monotherapy with PIM vs. Other-AAPs or vs. QUE during 04/01/16-12/31/20 were propensity score matched 1:1 on thirty-one variables (age, sex, race, region and 27 Elixhauser comorbidity characteristics). Adjusted log binomial regressions compared all-cause HCRU [(e.g. inpatient hospitalizations and by hospitalization-type [short-term stays (ST-stays), long-term stays (LT-stays), skilled nursing facility stays (SNF-stays)], and emergency room (ER) visits] risk between cohorts.

RESULTS

Of the 5,932 patients with PDP+D, matched cohorts (n = 1,294 in each) on continuous- monotherapy of PIM vs. Other-AAPs or QUE had similar demographics and comorbidities. Adjusted regression results showed those who initiated PIM vs. Other-AAPs had significantly lower relative risk (RR) of ≥1 all-cause inpatient hospitalizations (RR = 0.88, 95% CI: 0.80-0.97), ST-stays (RR = 0.86, 95% CI: 0.77-0.95), SNF-stays (RR = 0.79, 95% CI: 0.68-0.92), and ER visits (RR = 0.89, 95% CI: 0.84-0.94). PIM vs. QUE also experienced significantly lower RR for ≥1 all-cause IP hospitalizations (RR = 0.88, 95% CI: 0.80-0.96), ST-stays (RR = 0.85, 95% CI: 0.77-0.95), SNF-stays (RR = 0.81, 95% CI: 0.70-0.94), and ER visits (RR = 0.88, 95% CI: 0.83-0.94).

CONCLUSIONS

Patients initiating PIM-monotherapy for PDP+D experienced 12% lower all-cause inpatient hospitalizations vs. Other-AAPs or QUE. These results are consistent with prior real-world research in PDP with or without dementia.

CBT for psychosis in Parkinson's disease: A framework for how and why

Psychosis is a serious comorbidity to Parkinson's disease associated with high levels of distress and disability but access to effective treatments remain limited, leading to high rates of emergency hospitalization. Here, we propose a new framework for how cognitive behavioural therapy (CBT) may be used to treat Parkinson's disease psychosis. We note specific adaptions, including aims that focus on reducing distress and disability and extending quality of life; tailored psychoeducation; assessment and formulation that additionally includes disease course, medication effects and side-effects, and Parkinson's specific social factors; addressing anxiety and depression alongside cognitive appraisals for the types of psychotic symptoms more common in Parkinson's disease; appropriate reality testing sensitive to disease progression; and trigger monitoring and management for hallucinations and delusions that carefully distinguishes this from avoidant coping. We review preliminary case study-level evidence for the successful use of CBT for Parkinson's disease psychosis and suggest a road map for its formal evaluation before integration into evidence-based healthcare.

Psychiatric and cognitive symptoms of Parkinson's disease: A life's tale

INTRODUCTION

Neuropsychiatric symptoms are highly prevalent in Parkinson's disease (PD) and significantly affect the quality of life of patients and their significant others. The aim of this work is to describe typical neuropsychiatric symptoms and their treatment.

METHODS

This is a narrative opinion paper, illustrated by a fictional case report. The most common neuropsychiatric symptoms such as depressive symptoms, anxiety, apathy, psychotic symptoms, impulse control disorders, as well as cognitive impairment are discussed in the context of prodromal stage, early stage, fluctuations stage, post-surgical intervention, and late stage of PD.

RESULTS

Multiple factors such as pathophysiology, dopaminergic medication, deep brain stimulation, personality traits and individual life circumstances influence neuropsychiatric symptoms. Since the complexity and causes of neuropsychiatric symptoms can change, management strategies have to be adapted and individualised throughout the disease trajectory.

DISCUSSION

Recognising neuropsychiatric symptoms within the framework of the disease stage and identifying their potential causes is pivotal to provide adequate interventions.

Potential Risk Factors for Psychosis in Parkinson's Disease: A Review of Cohort and Case-Control Studies

BACKGROUND

Among neuropsychiatric sequelae of Parkinson's disease (PD), psychosis may have the most adverse impacts on prognosis and quality of life.

OBJECTIVES

To summarize and critically review the literature on potential risk factors for psychosis in PD, with particular focus on potentially modifiable risk factors.

METHODS

We conducted a literature review using PubMed and EMBASE. We included articles if: (1) the study population was comprised of patients with PD, (2) the presence of psychosis was systematically ascertained through clinician diagnosis, clinical outcome assessments and/or administrative data, and (3) potential risk factors were examined prior to the onset of psychosis.

RESULTS

Twenty-six studies (15 prospective cohort, 10 retrospective cohort, 1 retrospective case-control) of 21 patient cohorts (n = 15,535 unique patients) were included in the review. Ten studies included minor phenomena in their definition of psychosis. The most consistent potential risk factors for psychosis were sleep disturbances, particularly rapid eye movement sleep behavior disorder and autonomic dysfunction. Potentially modifiable risk factors for psychosis included excessive daytime sleepiness and exposure to anticholinergic medications and levodopa. Possible biomarkers for psychosis in PD included reduced striatal dopamine transporter binding on imaging and mutations in the GBA gene.

CONCLUSIONS

Several studies have identified potentially modifiable risk factors for the development of psychosis in PD. Future studies should utilize consistent, validated definitions of psychosis and focus on increasing understanding of, and developing interventions for, potentially modifiable risk factors for psychosis in patients with PD.

Proteome-Wide Association Study for Finding Druggable Targets in Progression and Onset of Parkinson's Disease

OBJECTIVE

To identify and validate causal protein targets that may serve as potential therapeutic interventions for both the onset and progression of Parkinson's disease (PD) through integrative proteomic and genetic analyses.

METHOD

We utilized large-scale plasma and brain protein quantitative trait loci (pQTL) datasets from the deCODE Health study and the Religious Orders Study/Rush Memory and Aging Project (ROS/MAP), respectively. Proteome-wide association studies (PWAS) were conducted using the OTTERS framework for plasma proteins and the FUSION tool for brain proteins, examining associations with PD onset and three progression phenotypes: composite, motor, and cognitive. Significant protein associations (FDR-corrected p < 0.05) from PWAS were further validated using summary-based Mendelian randomization (SMR), colocalization analyses, and reverse Mendelian randomization (MR) to establish causality. Phenome-wide Mendelian randomization (PheW-MR) was performed to assess potential side effects across 679 disease traits when targeting these proteins to reduce PD-related phenotype risk by 20%. Additionally, we conducted cellular distribution-based clustering using gene expression data from the Allen Brain Atlas (ABA) to explore the distribution of key proteins across brain regions, constructed protein-protein interaction (PPI) networks via the STRING database to explore interactions among proteins, and evaluated the druggability of identified targets using the DrugBank database to identify opportunities for drug repurposing.

RESULT

Our analyses identified 25 candidate proteins associated with PD phenotypes, including 16 plasma proteins linked to PD progression (10 cognitive, 4 motor, and 3 composite) and 9 plasma proteins associated with PD onset. Notably, GPNMB was implicated in both plasma and brain tissues for PD onset. PheW-MR revealed predominantly beneficial side effects for the identified targets, with 83.7% of associations indicating positive outcomes and 16.3% indicating adverse effects. Cellular clustering categorized candidate targets into three distinct expression profiles across brain cell types using ABA. PPI network analysis highlighted one key interaction cluster among the proteins for PD cognitive progression and PD onset. Druggability assessment revealed 15 out of 25 proteins had repurposing opportunities for PD treatment.

CONCLUSION

We have identified 25 causal protein targets associated with the onset and progression of PD, providing new insights into the research and development of treatment strategies for PD.

Parkinson's Disease and Caregiving Roles, Demands, and Support Needs and Experiences: A Scoping Review

Background and Objectives: A public health priority is the increasing number of persons with Parkinson's disease (PwP), and the need to provide them with support. We sought to synthesize the experiences of relatives or friends-family caregivers-who provide such support. Eligibility Criteria: This study was a scoping literature review modeled by the PRISMA guidelines. The articles for this review fit the following inclusion criteria: (1) studies including the perspective of caregivers of PwP, (2) studies conducted in the United States, and (3) studies conducted between January 2019 to January 2024. Sources of Evidence: Articles were identified by searching the PubMed, EBSCO, and Ovid databases between January 2019 and January 2024. The search terms included the following: (Parkinson's disease) AND (caregiver OR caregiving OR carer). Results: A total of 31 articles were included. Most of the included articles are descriptive (n = 26), including quantitative (n = 17), qualitative (n = 7), and mixed-methods studies (n = 2). Gender, race, and ethnicity were not consistently reported. Findings across studies demonstrated common roles of caregiving (e.g., assistance with personal care), extensive physical and mental health strains, social isolation, and work and financial strain. Benefit-finding was also evident among caregivers including a goal of securing the PwP dignity and comfort as the disease progressed. The studies of this review provide perspectives on benefits and challenges of caregiving in this context and caregiver resources. Conclusions: Future studies need to improve racial and gender-related diversity and address caregiver strain and health.

[Schizophrenic spectrum disorders and Parkinson's disease]

The case demonstrated the difficulties of differential diagnosis and selection of therapy in patients with Parkinson's disease and schizophrenic spectrum disorders. A clinical case of a 45-year-old male with a 10-year history of paranoid schizophrenia, with hallucinatory paranoid attacks and a steady increase in negative symptoms in the form of apato-abulic defect, is presented. The use of antipsychotics was associated with neuroleptic parkinsonism, well responding to therapy, and reduced when the patient discontinued antipsychotic therapy. However, after 10 years of schizophrenia, Parkinson's syndrome manifested without neuroleptics; the antipsychotic therapy led to a sharp deterioration in motor status. A neurologist specializing in extrapyramidal disorders made the following diagnosis: Parkinson's disease, mixed form, Hoehn and Yahr stage 2. According to the neurologist's recommendation, typical neuroleptics were replaced with quetiapine, and levodopa was added to therapy. During treatment, the parkinsonism symptoms significantly decreased without an increase in psychotic symptoms. The clinical case illustrates the challenges in diagnosing Parkinson's disease in a patient with schizophrenia and the complexity of treating such comorbidities. When managing such patients, close collaboration between psychiatrists and neurologists is necessary to make an accurate diagnosis and select the optimal therapy. The introduction of the multidisciplinarity principle will make it possible to achieve the fastest diagnosis and selection of balanced therapy in this category of patients.

The Comprehensive Anxiety and Parkinson's Scale (CAPS): co-development and initial validation of the long (CAPS-54) and short (CAPS-24) versions

PURPOSE

Anxiety is a prevalent symptom of Parkinson's disease, but is often under-recognised and challenging to characterise. The present study aimed to develop a comprehensive new scale that characterised the specific and nuanced experience of anxiety in people living with Parkinson's disease. A shortened version of the scale was also developed. The psychometric properties of both versions of the scale were assessed for reliability and validity.

METHODS

Secondary analyses were conducted on data from 254 people with Parkinson's disease and anxiety collected in a modified Nominal Group Technique ranking survey. Secondary analyses included exploratory factor analysis, reliability and validity analyses, and confirmatory factor analysis.

RESULTS

A standardised scale of anxiety and Parkinson's disease, in its long Comprehensive Anxiety and Parkinson's Scale - 54 (CAPS-54) and short versions (CAPS-24), was developed. Reliability and validity analyses of the scales demonstrated excellent factorial and internal consistency, as well as good convergent validity.

CONCLUSIONS

The CAP Scales offer researchers and clinicians a more comprehensive means of assessing the experience of anxiety in the context of Parkinson's disease than is currently available. Initial validation of the scales is promising. Future validation and identification of clinical boundaries with an independent sample is recommended.

Electrode Location and Domain-Specific Cognitive Change Following Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease

BACKGROUND AND OBJECTIVES

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease (PD) motor symptoms. DBS is also associated with postoperative cognitive change in some patients. Previous studies found associations between medial active electrode contacts and overall cognitive decline. Our current aim is to determine the relationship between active electrode contact location and domain-specific cognitive changes.

METHODS

A single-institution retrospective cohort study was conducted in patients with PD who underwent subthalamic nucleus (STN) DBS from August 05, 2010, to February 22, 2021, and received preoperative and postoperative neuropsychological testing. Standardized norm-referenced test z-scores were categorized into attention, executive function, language, verbal memory, and visuospatial domains. SD change scores were averaged to create domain-specific change scores. We identified anterior commissure/posterior commissure coordinates of active electrode contacts in atlas space. We evaluated differences in active electrode contact location between patients with a domain score decrease of at least 1 SD and less than 1 SD. We performed multiple variable linear regression controlling for age, sex, education, time from surgery to postoperative neuropsychological testing (follow-up duration), disease duration, preoperative unified Parkinson's disease rating scale off medication scores, and preoperative memory scores to determine the relationship between active electrode contact location and domain change.

RESULTS

A total of 83 patients (male: n = 60, 72.3%) were included with a mean age of 63.6 ± 8.3 years, median disease duration of 9.0 [6.0, 11.5] years, and median follow-up duration of 8.0 [7.0, 11.0] months. More superior active electrode contact location in the left STN (P = .002) and higher preoperative memory scores (P < .0001) were associated with worsening memory. Active electrode contact location was not associated with change in other domains.

CONCLUSION

In patients with PD who underwent STN DBS, we found an association between superior active electrode contacts in the left STN and verbal memory decline. Our study increases understanding of factors associated with cognitive change after DBS and may help inform postoperative programming.

Clinically established early Parkinson's disease patients do not show impaired use of priors in conditions of perceptual uncertainty

The ability to use past learned experiences to guide decisions is an important component of adaptive behavior, especially when decision-making is performed under time pressure or when perceptual information is unreliable. Previous studies using visual discrimination tasks have shown that this prior-informed decision-making ability is impaired in Parkinson's disease (PD), but the mechanisms underlying this deficit and the precise impact of dopaminergic denervation within cortico-basal circuits remain unclear. To shed light on this problem, we evaluated prior-informed decision-making under various conditions of perceptual uncertainty in a sample of 13 clinically established early PD patients, and compared behavioral performance with healthy control (HC) subjects matched in age, sex and education. PD patients and HC subjects performed a random dot motion task in which they had to decide the net direction (leftward vs. rightward) of a field of moving dots and communicate their choices through manual button presses. We manipulated prior knowledge by modulating the probability of occurrence of leftward vs. rightward motion stimuli between blocks of trials, and by explicitly giving these probabilities to subjects at the beginning of each block. We further manipulated stimulus discriminability by varying the proportion of dots moving coherently in the signal direction and speed-accuracy instructions. PD patients used choice probabilities to guide perceptual decisions in both speed and accuracy conditions, and their performance did not significantly differ from that of HC subjects. An additional analysis of the data with the diffusion decision model confirmed this conclusion. These results suggest that the impaired use of priors during visual discrimination observed at more advanced stages of PD is independent of dopaminergic denervation, though additional studies with larger sample sizes are needed to more firmly establish this conclusion.

A Cognitive-Behavioral Model of Apathy in Parkinson's Disease

Apathy is recognized to be a common, disabling syndrome that occurs across a range of psychiatric and neurological conditions, including Parkinson's disease. It can have a significant impact on quality of life, both for people affected and those around them. Currently, there are no established, evidence-based treatments for this debilitating syndrome. Assessment and treatment have been complicated by overlaps with depression and anhedonia, as well as a lack of understanding of the underlying mechanisms. Emerging lines of evidence conceptualize apathy as a reduction of motivation associated with disordered effort-based decision-making and dysfunction of distinct neural circuitry between the basal ganglia and medial prefrontal cortex. Here, we introduce a novel cognitive-behavioral framework that can inform a clinician's conceptualization and treatment of apathy, using cognitive-behavioral therapy (CBT) techniques. We focus on people with Parkinson's disease in our model, but our approach is transdiagnostic and can be applied to other conditions. It considers both individual targets for therapy as well as maintenance and intervention at a systemic level. The generalizability and parsimony of the framework provides a structured assessment and formulation of apathy, while also allowing clinicians to remain sensitive to other neuropsychiatric symptoms that can occur alongside apathy, such as depression and anxiety.

The potential of arts therapies in Parkinson's disease rehabilitation: A comprehensive review

BACKGROUND AND PURPOSE

Parkinson's disease (PD) causes a decline in motor function, cognitive decline, and impacts the mental health of patients. Due to the high cost and side effects of conventional treatments, the medical community has begun to explore safer and more cost-effective alternative therapies. In this context, arts therapies have gained increasing attention as innovative treatments. This review plans to explore the role and potential of various arts therapies in the rehabilitation of PD patients by analyzing existing literature and case studies.

METHODS

This review comprehensively searched the literature in several databases, including PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure, to assess the effectiveness of different arts therapies in the rehabilitation of patients with PD.

RESULTS

From 3440 articles screened, 16 met the inclusion criteria. These studies included a variety of therapies, including music, meditation, yoga, art, dance, theatre, video games and play therapy. These different types of arts therapies had a positive impact on the motor, psychological and cognitive rehabilitation of PD patients, respectively.

CONCLUSION

The existing literature highlights the great potential of arts therapies in the rehabilitation of people with PD, further confirming the efficacy of arts therapies in enhancing the motor, psychological and cognitive rehabilitation process of people with PD. In addition, this review identifies research gaps in the use of color therapy in PD rehabilitation and highlights the need for further exploration of various arts therapies modalities.

Development and validation of the DBS-PS (Deep Brain Stimulation-Perception Scale): Assessing parkinsonian patients' expectations to prevent post-operative disappointment?

BACKGROUND

Recent literature suggests that taking into consideration and evaluating preoperative expectations of Parkinson's disease (PD) patients candidates to deep brain stimulation (DBS), can contribute to treatment effectiveness. However, few validated instruments investigating preoperative expectations are available. We present the development and validation of the DBS-PS (Deep Brain Stimulation - Perception Scale).

METHODS

The DBS-PS is an 11 questions self-administered scale, with answers rated on a 10-point Likert scale (1 completely false, 10 completely true). Items were generated on the basis of patient's interviews analyzed by an expert group and reached consensus. The scale is divided into three domains: expectations for PD, expectations for social-life and leisure, expectations for intimate life. Exploratory factor analysis (EFA) completed by item response theory (IRT) analysis was conducted to validate the theoretical structure of the DBS-PS.

RESULTS

64 PD patients aged 59.18 (SD = 5.74) years with PD diagnosed since 9.36 (SD = 4.09) years completed the DBS-PS preoperatively. EFA confirmed a 3 factors scale structure (eigenvalue >1) explaining 69% of variance (factor 1: 43%; factor 2: 17%; factor 3: 9%). Reliability (Cronbach's α: 0.714 for factor 1, 0.781 for factor 2, 0.889 for factor 3) and discriminant validity (Pearson coefficient r < 0.50) were satisfactory. IRT showed good model fit, preserved unidimensionality, but some local dependences were observed.

CONCLUSION

The DBS-PS shows satisfactory psychometric properties. It is easy to administer in routine practice with preoperative PD patients. It constitutes an interesting basis for cognitive restructuring before neurosurgery, by highlighting dysfunctional cognitions and measuring the benefits of cognitive restructuring therapy.

Reward and Punishment Learning as Predictors of Cognitive Behavioral Therapy Response in Parkinson's Disease Comorbid with Clinical Depression

Depression is highly comorbid among individuals with Parkinson's Disease (PD), who often experience unique challenges to accessing and benefitting from empirically supported interventions like Cognitive Behavioral Therapy (CBT). Given the role of reward processing in both depression and PD, this study analyzed a subset (N = 25) of participants who participated in a pilot telemedicine intervention of PD-informed CBT, and also completed a Reward- and Punishment-Learning Task (RPLT) at baseline. At the conclusion of CBT, participants were categorized into treatment responders (n = 14) and non-responders (n = 11). Responders learned more optimally from negative rather than positive feedback on the RPLT, while this pattern was reversed in non-responders. Computational modeling suggested group differences in learning rate to negative feedback may drive the observed differences. Overall, the results suggest that a within-subject bias for punishment-based learning might help to predict response to CBT intervention for depression in those with PD.Plain Language Summary Performance on a Computerized Task may predict which Parkinson's Disease Patients benefit from Cognitive Behavioral Treatment of Clinical DepressionWhy was the study done? Clinical depression regularly arises in individuals with Parkinson's Disease (PD) due to the neurobiological changes with the onset and progression of the disease as well as the unique psychosocial difficulties associated with living with a chronic condition. Nonetheless, psychiatric disorders among individuals with PD are often underdiagnosed and likewise undertreated for a variety of reasons. The results of our study have implications about how to improve the accuracy and specificity of mental health treatment recommendations in the future to maximize benefits for individuals with PD, who often face additional barriers to accessing quality mental health treatment.What did the researchers do? We explored whether performance on a computerized task called the Reward- and Punishment-Learning Task (RPLT) helped to predict response to Cognitive Behavioral Therapy (CBT) for depression better than other predictors identified in previous studies. Twenty-five individuals with PD and clinical depression that completed a 10-week telehealth CBT program were assessed for: Demographics (Age, gender, etc.); Clinical information (PD duration, mental health diagnoses, levels of anxiety/depression, etc.); Neurocognitive performance (Memory, processing speed, impulse control, etc.); and RPLT performance.What did the researchers find? A total of 14 participants significantly benefitted from CBT treatment while 11 did not significantly benefit from treatment.There were no differences before treatment in the demographics, clinical information, and neurocognitive performance of those participants who ended up benefitting from the treatment versus those who did not.There were, however, differences before treatment in RPLT performance so that those individuals that benefitted from CBT seemed to learn better from negative feedback.What do the findings mean? Our results suggest that the CBT program benefitted those PD patients with clinical depression that seemed to overall learn best from avoiding punishment rather than obtaining reward which was targeted in CBT by focusing on increasing engagement in rewarding activities. The Reward- and Punishment-Learning Task hence may be a useful tool to help predict treatment response and provide more individualized recommendations on how to best maximize the benefits of psychotherapy for individuals with PD that may struggle to connect to mental health care. Caution is recommended about interpretating these results beyond this study as the overall number of participants was small and the data for this study were collected as part of a previous study so there was no opportunity to include additional measurements of interest.

Continuous and Unconstrained Tremor Monitoring in Parkinson's Disease Using Supervised Machine Learning and Wearable Sensors

Background

Accurately assessing the severity and frequency of fluctuating motor symptoms is important at all stages of Parkinson's disease management. Contrarily to time-consuming clinical testing or patient self-reporting with uncertain reliability, recordings with wearable sensors show promise as a tool for continuously and objectively assessing PD symptoms. While wearables-based clinical assessments during standardised and scripted tasks have been successfully implemented, assessments during unconstrained activity remain a challenge.

Methods

We developed and implemented a supervised machine learning algorithm, trained and tested on tremor scores. We evaluated the algorithm on a 67-hour database comprising sensor data and clinical tremor scores for 24 Parkinson patients at four extremities for periods of about 3 hours. A random 25% subset of the labelled samples was used as test data, the remainder as training data. Based on features extracted from the sensor data, a Support Vector Machine was trained to predict tremor severity. Due to the inherent imbalance in tremor scores, we applied dataset rebalancing techniques.

Results

Our classifier demonstrated robust performance in detecting tremor events with a sensitivity of 0.90 on the test-portion of the resampled dataset. The overall classification accuracy was high at 0.88.

Conclusion

We implemented an accurate classifier for tremor monitoring in free-living environments that can be trained even with modestly sized and imbalanced datasets. This advancement offers significant clinical value in continuously monitoring Parkinson's disease symptoms beyond the hospital setting, paving the way for personalized management of PD, timely therapeutic adjustments, and improved patient quality of life.

Theta frequency deep brain stimulation in the subthalamic nucleus improves working memory in Parkinson's disease

Most research in Parkinson's disease focuses on improving motor symptoms. Yet, up to 80% of patients present with non-motor symptoms that often have a large impact on patients' quality of life. Impairment in working memory, a fundamental cognitive process, is common in Parkinson's disease. While deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor symptoms in Parkinson's disease, its impact on cognitive functions is less well studied. Here, we examine the effect of DBS in the theta, beta, low and high gamma frequency on working memory in 20 Parkinson's disease patients with bilateral STN-DBS. A linear mixed effects model demonstrates that STN-DBS in the theta frequency improves working memory performance. This effect is frequency-specific and was absent for beta and gamma frequency stimulation. Further, this effect is specific to cognitive performance, as theta frequency DBS did not affect motor function. A non-parametric cluster-based permutation analysis of whole-brain normative structural connectivity shows that working memory enhancement by theta frequency stimulation is associated with higher connectivity between the stimulated subthalamic area and the right middle frontal gyrus. Again, this association is frequency- and task-specific. These findings highlight the potential of theta frequency STN-DBS as a targeted intervention to improve working memory in patients with Parkinson's disease.

Deciphering the molecular pathways underlying dopaminergic neuronal damage in Parkinson's disease associated with SARS-CoV-2 infection

BACKGROUND

The COVID-19 pandemic caused by SARS-CoV-2 has led to significant global morbidity and mortality, with potential neurological consequences, such as Parkinson's disease (PD). However, the underlying mechanisms remain elusive.

METHODS

To address this critical question, we conducted an in-depth transcriptome analysis of dopaminergic (DA) neurons in both COVID-19 and PD patients. We identified common pathways and differentially expressed genes (DEGs), performed enrichment analysis, constructed protein‒protein interaction networks and gene regulatory networks, and employed machine learning methods to develop disease diagnosis and progression prediction models. To further substantiate our findings, we performed validation of hub genes using a single-cell sequencing dataset encompassing DA neurons from PD patients, as well as transcriptome sequencing of DA neurons from a mouse model of MPTP(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced PD. Furthermore, a drug-protein interaction network was also created.

RESULTS

We gained detailed insights into biological functions and signaling pathways, including ion transport and synaptic signaling pathways. CD38 was identified as a potential key biomarker. Disease diagnosis and progression prediction models were specifically tailored for PD. Molecular docking simulations and molecular dynamics simulations were employed to predict potential therapeutic drugs, revealing that genistein holds significant promise for exerting dual therapeutic effects on both PD and COVID-19.

CONCLUSIONS

Our study provides innovative strategies for advancing PD-related research and treatment in the context of the ongoing COVID-19 pandemic by elucidating the common pathogenesis between COVID-19 and PD in DA neurons.

The effects of rivastigmine on neuropsychiatric symptoms in the early stages of Parkinson's disease: A systematic review

BACKGROUND AND PURPOSE

Neuropsychiatric symptoms including depression, apathy and psychosis occur frequently in patients with Parkinson's disease. A subgroup of patients develop cognitive impairment, which may increase the risk of falls due to reduced attention. The acetylcholinesterase inhibitor rivastigmine is beneficial in Parkinson's disease dementia, but whether the use of rivastigmine is effective earlier in the disease course is unclear. The aim of this systematic review was to assess the evidence for rivastigmine in the treatment of neuropsychiatric symptoms in Parkinson's disease without dementia.

METHODS

Embase, Medline, PsychINFO, Cochrane CENTRAL, NGLC, National Institute for Health and Care Excellence Evidence and medRxiv.org were searched for studies with terms relating to population (Parkinson's disease) and intervention (rivastigmine). Of 1922 references identified, 358 were duplications. Following title and abstract review, 1331 articles were excluded. After full-text review, nine articles remained.

RESULTS

Outcomes were heterogenous, therefore, the results are presented in narrative form. The articles included six randomized controlled trials, two open-label trials and one case series. Outcome measures included: time to develop psychosis; frequency of rapid eye movement sleep behaviour disorder (RBD) episodes; apathy; gait variability; falls; cognitive ability; Neuropsychiatric Inventory score; and regional spontaneous brain activity.

CONCLUSIONS

There is evidence that rivastigmine is beneficial for RBD and apathy in Parkinson's disease patients without dementia. There is high level evidence that rivastigmine reduces falls, which may be due to improved attention. The impact of rivastigmine on psychotic symptoms is less clear, but is supported by current theoretical models which involve acetylcholine dysfunction in the generation of visual hallucinations in Parkinson's disease.

Investigating the association between a history of depression and biomarkers of Alzheimer's disease, cerebrovascular disease, and neurodegeneration in patients with dementia

The association between depression and dementia, particularly Alzheimer's disease (AD) and cerebrovascular disease (CVD), remains an active area of research. This study aimed to investigate the relationship between a history of depression and biomarkers of AD and CVD in patients with dementia in a clinical setting. A total of 126 patients from the University Health Network (UHN) Memory Clinic with comprehensive clinical evaluations, including neuropsychological testing and medical examinations, were included. Lumbar puncture was performed to collect cerebrospinal fluid (CSF) for biomarker analysis, and brain magnetic resonance imaging (MRI) scans were obtained to assess white matter hyperintensity (WMH) burden. The presence of depression was determined through medical records. The study findings did not reveal significant differences between participants with and without a history of depression in terms of AD biomarkers, WMH burden, neurofilament light chain levels, cognitive scores, age of symptom onset, disease duration, or vascular risk scores. Logistic regression analysis did not indicate a meaningful predictive value of these variables for depression status. This clinical study contributes to our understanding regarding the association between depression and AD/CVD biomarkers in patients with cognitive impairment. Further research is needed to elucidate the complex relationship between depression and dementia and to explore the potential mechanisms linking depression, AD, and CVD.

Psychosocial interventions affecting global perceptions of control in people with Parkinson's disease: a scoping review

PURPOSE

Perceived control is an important construct for the psychological well-being of people affected by chronic conditions, and higher perceived control is associated with better outcomes. Psychosocial interventions have been trialled in these populations to improve both global and specific perceptions of control. However, most interventions involving people with Parkinson's have focused on single-domain forms of control, while those addressing global perceived control are yet to be reviewed. This study aimed to identify and map the types of psychosocial interventions in individuals with Parkinson's which have included forms of global perceived control as an outcome.

MATERIALS AND METHODS

Scoping review based on a search across MEDLINE, PsycINFO, CINAHL, Academic Search Ultimate.

RESULTS

From an initial return of 4388 citations, 12 citations were eventually included. These consisted of 8 quantitative and 4 qualitative studies, and covered 4 overarching categories of psychosocial interventions. Mixed results were found for cognitive, educational, and physical interventions, while a randomised controlled trial on mindfulness-based lifestyle programme showed more preliminary positive evidence.

CONCLUSIONS

Further rigorous research is required on the topic to build on these preliminary findings. In the meantime, clinicians may need to consider programmes which proved effective with populations similar to people with Parkinson's.IMPLICATIONS FOR REHABILITATIONPerceived control is a psychological construct important for people with chronic illnesses, which can be targeted by psychosocial interventions.This article reviewed psychosocial interventions targeting global forms of perceived control in Parkinson's.Mixed results were reported for the cognitive, educational, and physical interventions identified, while a randomised controlled trial on a mindfulness-based lifestyle programme showed more promising evidence.In the meantime, clinicians may need to consider programmes found to be effective with people with similar conditions to Parkinson's.

Alterations in cortical volume and complexity in Parkinson's disease with depression

AIMS

The aim of this study is to investigate differences in gray matter volume and cortical complexity between Parkinson's disease with depression (PDD) patients and Parkinson's disease without depression (PDND) patients.

METHODS

A total of 41 PDND patients, 36 PDD patients, and 38 healthy controls (HC) were recruited and analyzed by Voxel-based morphometry (VBM) and surface-based morphometry (SBM). Differences in gray matter volume and cortical complexity were compared using the one-way analysis of variance (ANOVA) and correlated with the Hamilton Depression Scale-17 (HAMD-17) scores.

RESULTS

PDD patients exhibited significant cortical atrophy in various regions, including bilateral medial parietal-occipital-temporal lobes, right dorsolateral temporal lobes, bilateral parahippocampal gyrus, and bilateral hippocampus, compared to HC and PDND groups. A negative correlation between the GMV of left precuneus and HAMD-17 scores in the PDD group tended to be significant (r = -0.318, p = 0.059). Decreased gyrification index was observed in the bilateral insular and dorsolateral temporal cortex. However, there were no significant differences found in fractal dimension and sulcal depth.

CONCLUSION

Our research shows extensive cortical structural changes in the insular cortex, parietal-occipital-temporal lobes, and hippocampal regions in PDD. This provides a morphological perspective for understanding the pathophysiological mechanism underlying depression in Parkinson's disease.

Structural connectivity from DTI to predict mild cognitive impairment in de novo Parkinson's disease

BACKGROUND

Early detection of Parkinson's disease (PD) patients at high risk for mild cognitive impairment (MCI) can help with timely intervention. White matter structural connectivity is considered an early and sensitive indicator of neurodegenerative disease.

OBJECTIVES

To investigate whether baseline white matter structural connectivity features from diffusion tensor imaging (DTI) of de novo PD patients can help predict PD-MCI conversion at an individual level using machine learning methods.

METHODS

We included 90 de novo PD patients who underwent DTI and 3D T1-weighted imaging. Elastic net-based feature consensus ranking (ENFCR) was used with 1000 random training sets to select clinical and structural connectivity features. Linear discrimination analysis (LDA), support vector machine (SVM), K-nearest neighbor (KNN) and naïve Bayes (NB) classifiers were trained based on features selected more than 500 times. The area under the ROC curve (AUC), accuracy (ACC), sensitivity (SEN) and specificity (SPE) were used to evaluate model performance.

RESULTS

A total of 57 PD patients were classified as PD-MCI nonconverters, and 33 PD patients were classified as PD-MCI converters. The models trained with clinical data showed moderate performance (AUC range: 0.62-0.68; ACC range: 0.63-0.77; SEN range: 0.45-0.66; SPE range: 0.64-0.84). Models trained with structural connectivity (AUC range, 0.81-0.84; ACC range, 0.75-0.86; SEN range, 0.77-0.91; SPE range, 0.71-0.88) performed similar to models that were trained with both clinical and structural connectivity data (AUC range, 0.81-0.85; ACC range, 0.74-0.85; SEN range, 0.79-0.91; SPE range, 0.70-0.89).

CONCLUSIONS

Baseline white matter structural connectivity from DTI is helpful in predicting future MCI conversion in de novo PD patients.

Imbalanced motivated behaviors according to motor sign asymmetry in drug-naïve Parkinson's disease

Few studies have considered the influence of motor sign asymmetry on motivated behaviors in de novo drug-naïve Parkinson's disease (PD). We tested whether motor sign asymmetry could be associated with different motivated behavior patterns in de novo drug-naïve PD. We performed a cross-sectional study in 128 de novo drug-naïve PD patients and used the Ardouin Scale of Behavior in Parkinson's disease (ASBPD) to assess a set of motivated behaviors. We assessed motor asymmetry based on (i) side of motor onset and (ii) MDS-UPDRS motor score, then we compared right hemibody Parkinson's disease to left hemibody Parkinson's disease. According to the MDS-UPDRS motor score, patients with de novo right hemibody PD had significantly lower frequency of approach behaviors (p = 0.031), including nocturnal hyperactivity (p = 0.040), eating behavior (p = 0.040), creativity (p = 0.040), and excess of motivation (p = 0.017) than patients with de novo left hemibody PD. Patients with de novo left hemibody PD did not significantly differ from those with de novo right hemibody PD regarding avoidance behaviors including apathy, anxiety and depression. Our findings suggest that motor sign asymmetry may be associated with an imbalance between motivated behaviors in de novo drug-naïve Parkinson's disease.

Cortical gyrification pattern of depression in Parkinson's disease: a neuroimaging marker for disease severity?

Background

Although the study of the neuroanatomical correlates of depression in Parkinson's Disease (PD) is gaining increasing interest, up to now the cortical gyrification pattern of PD-related depression has not been reported. This study was conducted to investigate the local gyrification index (LGI) in PD patients with depression, and its associations with the severity of depression.

Methods

LGI values, as measured using FreeSurfer software, were compared between 59 depressed PD (dPD), 27 non-depressed PD (ndPD) patients and 43 healthy controls. The values were also compared between ndPD and mild-depressed PD (mi-dPD), moderate-depressed PD (mo-dPD) and severe-depressed PD (se-dPD) patients as sub-group analyses. Furthermore, we evaluated the correlation between LGI values and depressive symptom scores within dPD group.

Results

Compared to ndPD, the dPD patients exhibited decreased LGI in the left parietal, the right superior-frontal, posterior cingulate and paracentral regions, and the LGI values within these areas negatively correlated with the severity of depression. Specially, reduced gyrification was observed in mo-dPD and involving a larger region in se-dPD, but not in mi-dPD group.

Conclusion

The present study demonstrated that cortical gyrification is decreased within specific brain regions among PD patients with versus without depression, and those changes were associated with the severity of depression. Our findings suggested that cortical gyrification might be a potential neuroimaging marker for the severity of depression in patients with PD.

Incremental health care resource utilization and costs associated among patients with Parkinson's disease psychosis and incident dementia: An analysis of medicare beneficiaries

BACKGROUND

Real-world evidence examining the incremental health care resource use (HCRU) and cost burden of incident dementia among patients with Parkinson's disease psychosis (PDP) are needed within the United States (US).

OBJECTIVES

To compare HCRU and cost burden between PDP patients with incident dementia (PDP + D) versus without incident dementia (PDP).

METHODS

A retrospective analysis of inpatient (Part A), outpatient (Part B), and prescription drug (Part D) claims from the 100% Medicare sample was conducted to compare PDP + D patients versus PDP patients between 01/01/14-12/31/18. Patients with a diagnosis of dementia, psychosis, secondary parkinsonism, or other psychotic disorders, during 12-month pre-index were excluded. Patients in both groups were matched using 1:1 propensity score matching (PSM) methodology using 31 variables (age, sex, race, region and 27 Elixhauser comorbidity characteristics). Differences in 12-month post-index HCRU rates and mean per patient per year (PPPY) costs for all-cause inpatient (IP) hospitalizations, and by type of IP stay (i.e., short-term [ST-stay], skilled nursing facility [SNF-stay] and long-term [LT-stay]) were analyzed via logistic and gamma log-link regression models.

RESULTS

Of the 12,484 patients who met our study criteria, 1855 PSM-matched cohorts were identified. Mean age, gender, and comorbidities were similar in PSM groups. Approximately, 50.3% with PDP + D reported ≥1 all-cause IP hospitalizations versus 36.0% with PDP (p < 0.05) during 12-month follow-up. Specifically, all-cause ST-stay, SNF-stay, and LT-stay among PDP + D versus PDP patients were: 45.2% versus 35.7%, 28.3% versus 15.7%, and 8.5% versus 6.0% (p < 0.05), respectively. Psychiatric-related ST-stay, SNF-stay, and LT-stay among PDP + D versus PDP patients were: 12.3% versus 9.0%, 7.5% versus 3.4%, and 2.4% versus 1.2% (p < 0.05), respectively. Mean PPPY all-cause IP hospitalization costs for PDP + D patients versus PDP patients was $17,891 (±29,882) versus $11,599 (±$25,247) (p < 0.05).

CONCLUSIONS

Patients with PDP + D experience significantly higher all-cause and psychiatric-related IP hospitalizations, including ST-stays, LT stays, and SNF stays. They also had 54% greater mean PPPY IP hospitalization costs versus PDP patients.

Lewy Body Dementia: An Overview of Promising Therapeutics

PURPOSE OF REVIEW

Lewy body dementia (LBD) encompasses dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). This article will emphasize potential disease-modifying therapies as well as investigative symptomatic treatments for non-motor symptoms including cognitive impairment and psychosis that can present a tremendous burden to patients with LBD and their caregivers.

RECENT FINDINGS

We review 11 prospective disease-modifying therapies (DMT) including four with phase 2 data (neflamapimod, nilotinib, bosutinib, and E2027); four with some limited data in symptomatic populations including phase 1, open-label, registry, or cohort data (vodabatinib, ambroxol, clenbuterol, and terazosin); and three with phase 1 data in healthy populations (Anle138b, fosgonimeton, and CT1812). We also appraise four symptomatic therapies for cognitive impairment, but due to safety and efficacy concerns, only NYX-458 remains under active investigation. Of symptomatic therapies for psychosis recently investigated, pimavanserin shows promise in LBD, but studies of nelotanserin have been suspended. Although the discovery of novel symptomatic and disease-modifying therapeutics remains a significant challenge, recently published and upcoming trials signify promising strides toward that aim.

Uncovering the neurophysiology of mood, motivation and behavioral symptoms in Parkinson's disease through intracranial recordings

Neuropsychiatric mood and motivation symptoms (depression, anxiety, apathy, impulse control disorders) in Parkinson's disease (PD) are highly disabling, difficult to treat and exacerbated by current medications and deep brain stimulation therapies. High-resolution intracranial recording techniques have the potential to undercover the network dysfunction and cognitive processes that drive these symptoms, towards a principled re-tuning of circuits. We highlight intracranial recording as a valuable tool for mapping and desegregating neural networks and their contribution to mood, motivation and behavioral symptoms, via the ability to dissect multiplexed overlapping spatial and temporal neural components. This technique can be powerfully combined with behavioral paradigms and emerging computational techniques to model underlying latent behavioral states. We review the literature of intracranial recording studies investigating mood, motivation and behavioral symptomatology with reference to 1) emotional processing, 2) executive control 3) subjective valuation (reward & cost evaluation) 4) motor control and 5) learning and updating. This reveals associations between different frequency specific network activities and underlying cognitive processes of reward decision making and action control. If validated, these signals represent potential computational biomarkers of motivational and behavioural states and could lead to principled therapy development for mood, motivation and behavioral symptoms in PD.

Comparative Efficacy, Safety, and Acceptability of Pimavanserin and Other Atypical Antipsychotics for Parkinson's Disease Psychosis: Systematic Review and Network Meta-Analysis

BACKGROUND

The current comparative efficacy, safety, and acceptability of atypical antipsychotics (AAPs) in treating Parkinson's Disease Psychosis (PDP) are not entirely understood.

OBJECTIVE

To evaluate comparative efficacy, safety, and acceptability of AAPs in patients with PDP.

METHODS

We conducted a systematic review and a network meta-analysis to compare the efficacy, safety, and acceptability of pimavanserin, quetiapine, olanzapine, clozapine, ziprasidone, and risperidone. We estimated relative standardized mean differences (SMDs) for continuous outcomes and odds ratios (OR) for binary outcomes, with their respective 95% confidence intervals (CIs).

RESULTS

We included 19 unique studies evaluating AAPs in a total of 1,242 persons with PDP. Based on Clinical Global Impression Scale for Severity, pimavanserin (SMD, -4.81; 95% CI, -5.39, -4.24) and clozapine (SMD, -4.25; 95% CI, -5.24, -3.26) significantly improved symptoms compared with placebo. Also, compared to placebo, pimavanserin (OR, 1.16; 95% CI, 1.07, 1.24) significantly improved psychotic symptoms based on Scale for Assessment of Positive Symptoms for Parkinson's Disease Psychosis/Hallucinations and Delusions scores. In comparison to placebo, clozapine (SMD, -0.69; 95% CI, -1.35, -0.02), pimavanserin (SMD, -0.01; 95% CI, -0.56, 0.53), and quetiapine (SMD, 0.00; 95% CI, -0.68, 0.69) did not impair motor function per Unified Parkinson's Disease Rating scale. Based on Mini-Mental State Examination scale, quetiapine (SMD, 0.60; 95% CI, 0.07, 1.14) significantly impaired cognition compared to placebo.

CONCLUSIONS

In patients with PDP, pimavanserin and clozapine demonstrated significant improvement in psychosis without affecting motor function. With quetiapine being associated with a significant decline in cognition and despite not impairing motor function, our findings suggest that it should be avoided in patients with PDP and reduced cognitive abilities.

Genetic Insights into the Molecular Pathophysiology of Depression in Parkinson's Disease

Background and Objectives: Parkinson's disease (PD) is a clinically heterogeneous disorder with poorly understood pathological contributing factors. Depression presents one of the most frequent non-motor PD manifestations, and several genetic polymorphisms have been suggested that could affect the depression risk in PD. Therefore, in this review we have collected recent studies addressing the role of genetic factors in the development of depression in PD, aiming to gain insights into its molecular pathobiology and enable the future development of targeted and effective treatment strategies. Materials and Methods: we have searched PubMed and Scopus databases for peer-reviewed research articles published in English (pre-clinical and clinical studies as well as relevant reviews and meta-analyses) investigating the genetic architecture and pathophysiology of PD depression. Results: in particular, polymorphisms in genes related to the serotoninergic pathway (sodium-dependent serotonin transporter gene, SLC6A4, tryptophan hydrolase-2 gene, TPH2), dopamine metabolism and neurotransmission (dopamine receptor D3 gene, DRD3, aldehyde dehydrogenase 2 gene, ALDH2), neurotrophic factors (brain-derived neurotrophic factor gene, BDNF), endocannabinoid system (cannabinoid receptor gene, CNR1), circadian rhythm (thyrotroph embryonic factor gene, TEF), the sodium-dependent neutral amino acid transporter B(0)AT2 gene, SLC6A15), and PARK16 genetic locus were detected as altering susceptibility to depression among PD patients. However, polymorphisms in the dopamine transporter gene (SLC6A3), monoamine oxidase A (MAOA) and B (MAOB) genes, catechol-O-methyltransferase gene (COMT), CRY1, and CRY2 have not been related to PD depression. Conclusions: the specific mechanisms underlying the potential role of genetic diversity in PD depression are still under investigation, however, there is evidence that they may involve neurotransmitter imbalance, mitochondrial impairment, oxidative stress, and neuroinflammation, as well as the dysregulation of neurotrophic factors and their downstream signaling pathways.

Apathy in Parkinson's Disease: Clinical Patterns and Neurobiological Basis

Apathy is commonly defined as a loss of motivation leading to a reduction in goal-directed behaviors. This multidimensional syndrome, which includes cognitive, emotional and behavioral components, is one of the most prevalent neuropsychiatric features of Parkinson's disease (PD). It has been established that the prevalence of apathy increases as PD progresses. However, the pathophysiology and anatomic substrate of this syndrome remain unclear. Apathy seems to be underpinned by impaired anatomical structures that link the prefrontal cortex with the limbic system. It can be encountered in the prodromal stage of the disease and in fluctuating PD patients receiving bilateral chronic subthalamic nucleus stimulation. In these stages, apathy may be considered as a disorder of motivation that embodies amotivational behavioral syndrome, is underpinned by combined dopaminergic and serotonergic denervation and is dopa-responsive. In contrast, in advanced PD patients, apathy may be considered as cognitive apathy that announces cognitive decline and PD dementia, is underpinned by diffuse neurotransmitter system dysfunction and Lewy pathology spreading and is no longer dopa-responsive. In this review, we discuss the clinical patterns of apathy and their treatment, the neurobiological basis of apathy, the potential role of the anatomical structures involved and the pathways in motivational and cognitive apathy.

Unintended impacts of a national antipsychotic reduction initiative among nursing facility residents with and without Alzheimer's disease

BACKGROUND

In July 2012, the Centers for Medicare & Medicaid services launched an antipsychotic reduction initiative (ARI) to improve care for nursing facility residents with Alzheimer's disease and related dementias (ADRD). We examined the impact of this policy on antipsychotic and psychotropic medication (PM) utilization and diagnosis patterns in long-stay nursing facility residents with ADRD and other conditions in which antipsychotics are indicated.

METHODS

Using an 80% sample of fee-for-service Medicare beneficiaries with Part D, we conducted a retrospective cohort study of nursing facility residents with ADRD, bipolar disorder, psychosis, Parkinson's disease, and residents exempt from the policy due to diagnoses of schizophrenia, Tourette syndrome, and/or Huntington's disease. We used interrupted time-series analyses to compare changes in diagnoses, antipsychotic use, and PM utilization before (January 1, 2011-June 30, 2012) and after (July 1, 2012-September 30, 2015) ARI implementation.

RESULTS

We identified 874,487 long-stay nursing facility residents with a diagnosis of ADRD (n = 358,518), exempt (n = 92,859), bipolar (n = 128,298), psychosis (n = 93,402), and Parkinson's disease (n = 80,211). In all cohorts, antipsychotic use declined prior to the ARI; upon policy implementation, antipsychotic use reductions were sustained throughout the study period, including statistically significant ARI-associated accelerated declines in all cohorts. PM changes varied by cohort, with ARI-associated increases in non-benzodiazepine sedatives and/or muscle relaxants noted in ADRD, psychosis, and Parkinson's cohorts. Although anticonvulsant use increased throughout the study period in all groups, with the exception of the bipolar cohort, these increases were not associated with ARI implementation. Findings are minimally explained by increased post-ARI membership in the psychosis and Parkinson's cohorts.

CONCLUSIONS

Our study documents antipsychotic use significantly declined in non-ADRD clinical and exempt cohorts, where such reductions may not be clinically warranted. Furthermore, ARI-associated compensatory increases in PMs do not offset these reductions. Changes in PM utilization and diagnostic make-up of residents using PMs require further investigation to assess the potential for adverse clinical and economic outcomes.

A scoping review of neurodegenerative manifestations in explainable digital phenotyping

Neurologists nowadays no longer view neurodegenerative diseases, like Parkinson's and Alzheimer's disease, as single entities, but rather as a spectrum of multifaceted symptoms with heterogeneous progression courses and treatment responses. The definition of the naturalistic behavioral repertoire of early neurodegenerative manifestations is still elusive, impeding early diagnosis and intervention. Central to this view is the role of artificial intelligence (AI) in reinforcing the depth of phenotypic information, thereby supporting the paradigm shift to precision medicine and personalized healthcare. This suggestion advocates the definition of disease subtypes in a new biomarker-supported nosology framework, yet without empirical consensus on standardization, reliability and interpretability. Although the well-defined neurodegenerative processes, linked to a triad of motor and non-motor preclinical symptoms, are detected by clinical intuition, we undertake an unbiased data-driven approach to identify different patterns of neuropathology distribution based on the naturalistic behavior data inherent to populations in-the-wild. We appraise the role of remote technologies in the definition of digital phenotyping specific to brain-, body- and social-level neurodegenerative subtle symptoms, emphasizing inter- and intra-patient variability powered by deep learning. As such, the present review endeavors to exploit digital technologies and AI to create disease-specific phenotypic explanations, facilitating the understanding of neurodegenerative diseases as "bio-psycho-social" conditions. Not only does this translational effort within explainable digital phenotyping foster the understanding of disease-induced traits, but it also enhances diagnostic and, eventually, treatment personalization.

Role of hippocampal subfields in neurodegenerative disease progression analyzed with a multi-scale attention-based network

BACKGROUND AND OBJECTIVE

Both Alzheimer's disease (AD) and Parkinson's disease (PD) are progressive neurodegenerative diseases. Early identification is very important for the prevention and intervention of their progress. Hippocampus plays a crucial role in cognition, in which there are correlations between atrophy of Hippocampal subfields and cognitive impairment in neurodegenerative diseases. Exploring biomarkers in the prediction of early cognitive impairment in AD and PD is significant for understanding the progress of neurodegenerative diseases.

METHODS

A multi-scale attention-based deep learning method is proposed to perform computer-aided diagnosis for neurodegenerative disease based on Hippocampal subfields. First, the two dimensional (2D) Hippocampal Mapping Image (HMI) is constructed and used as input of three branches of the following network. Second, the multi-scale module and attention module are integrated into the 2D residual network to improve the diversity of the extracted features and capture significance of various voxels for classification. Finally, the role of Hippocampal subfields in the progression of different neurodegenerative diseases is analyzed using the proposed method.

RESULTS

Classification experiments between normal control (NC), mild cognitive impairment (MCI), AD, PD with normal cognition (PD-NC) and PD with mild cognitive impairment (PD-MCI) are carried out using the proposed method. Experimental results show that subfields subiculum, presubiculum, CA1, and molecular layer are strongly correlated with cognitive impairment in AD and MCI, subfields GC-DG and fimbria are sensitive in detecting early stage of cognitive impairment in MCI, subfields CA3, CA4, GC-DG, and CA1 show significant atrophy in PD. For exploring the role of Hippocampal subfields in PD cognitive impairment, we find that left parasubiculum, left HATA and left presubiculum could be important biomarkers for predicting conversion from PD-NC to PD-MCI.

CONCLUSION

The proposed multi-scale attention-based network can effectively discover the correlation between subfields and neurodegenerative diseases. Experimental results are consistent with previous clinical studies, which will be useful for further exploring the role of Hippocampal subfields in neurodegenerative disease progression.

Depression in Major Neurodegenerative Diseases and Strokes: A Critical Review of Similarities and Differences among Neurological Disorders

Depression and anxiety are highly prevalent in most neurological disorders and can have a major impact on the patient's disability and quality of life. However, mostly due to the heterogeneity of symptoms and the complexity of the underlying comorbidities, depression can be difficult to diagnose, resulting in limited recognition and in undertreatment. The early detection and treatment of depression simultaneously with the neurological disorder is key to avoiding deterioration and further disability. Although the neurologist should be able to identify and treat depression initially, a neuropsychiatry team should be available for severe cases and those who are unresponsive to treatment. Neurologists should be also aware that in neurodegenerative diseases, such as Alzheimer's or Parkinson's, different depression symptoms could develop at different stages of the disease. The treatment options for depression in neurological diseases include drugs, cognitive-behavioral therapy, and somatic interventions, among others, but often, the evidence-based efficacy is limited and the results are highly variable. Here, we review recent research on the diagnosis and treatment of depression in the context of Alzheimer's disease, Parkinson's disease, and strokes, with the aim of identifying common approaches and solutions for its initial management by the neurologist.

Non-Motor Symptoms of Parkinson's Disease: The Neurobiology of Early Psychiatric and Cognitive Dysfunction

Parkinson's disease (PD) is a progressive neurodegenerative disorder that has been recognized for over 200 years by its clinically dominant motor system impairment. There are prominent non-motor symptoms as well, and among these, psychiatric symptoms of depression and anxiety and cognitive impairment are common and can appear earlier than motor symptoms. Although the neurobiology underlying these particular PD-associated non-motor symptoms is not completely understood, the identification of PARK genes that contribute to hereditary and sporadic PD has enabled genetic models in animals that, in turn, have fostered ever deepening analyses of cells, synapses, circuits, and behaviors relevant to non-motor psychiatric and cognitive symptoms of human PD. Moreover, while it has long been recognized that inflammation is a prominent component of PD, recent studies demonstrate that brain-immune signaling crosstalk has significant modulatory effects on brain cell and synaptic function in the context of psychiatric symptoms. This review provides a focused update on such progress in understanding the neurobiology of PD-related non-motor psychiatric and cognitive symptoms.

Spatial Transcriptome Profiling of Mouse Hippocampal Single Cell Microzone in Parkinson's Disease

The hippocampus is an important part of the limbic system in the human brain that has essential roles in spatial navigation and cognitive functions. It is still unknown how gene expression changes in single-cell in different spatial locations of the hippocampus of Parkinson's disease. The purpose of this study was to analyze the gene expression features of single cells in different spatial locations of mouse hippocampus, and to explore the effects of gene expression regulation on learning and memory mechanisms. Here, we obtained 74 single-cell samples from different spatial locations in a mouse hippocampus through microdissection technology, and used single-cell RNA-sequencing and spatial transcriptome sequencing to visualize and quantify the single-cell transcriptome features of tissue sections. The results of differential expression analysis showed that the expression of Sv2b, Neurod6, Grp and Stk32b genes in a hippocampus single cell at different locations was significantly different, and the marker genes of CA1, CA3 and DG subregions were identified. The results of gene function enrichment analysis showed that the up-regulated differentially expressed genes Tubb2a, Eno1, Atp2b1, Plk2, Map4, Pex5l, Fibcd1 and Pdzd2 were mainly involved in neuron to neuron synapse, vesicle-mediated transport in synapse, calcium signaling pathway and neurodegenerative disease pathways, thus affecting learning and memory function. It revealed the transcriptome profile and heterogeneity of spatially located cells in the hippocampus of PD for the first time, and demonstrated that the impaired learning and memory ability of PD was affected by the synergistic effect of CA1 and CA3 subregions neuron genes. These results are crucial for understanding the pathological mechanism of the Parkinson's disease and making precise treatment plans.

Protective Effects of Currants (Vitis vinifera) on Corticolimbic Serotoninergic Alterations and Anxiety-like Comorbidity in a Rat Model of Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of nigral dopaminergic neurons. Increasing evidence supports that PD is not simply a motor disorder but a systemic disease leading to motor and non-motor symptoms, including memory loss and neuropsychiatric conditions, with poor management of the non-motor deficits by the existing dopaminergic medication. Oxidative stress is considered a contributing factor for nigrostriatal degeneration, while antioxidant/anti-inflammatory properties of natural phyto-polyphenols have been suggested to have beneficial effects. The present study aimed to determine the contribution of monoaminergic neurotransmission on the anxiety-like phenotype in a rat rotenone PD model and evaluate the possible neuroprotective effects of black Corinthian currant, Vitis vinifera, consisting of antioxidant polyphenols. Rotenone-treated rats showed anxiety-like behavior and exploratory deficits, accompanied by changes in 5-HT, SERT and β₂-ARs expression in the prefrontal cortices, hippocampus and basolateral amygdala. Importantly, the motor and non-motor behavior, as well as 5-HT, SERT and β₂-ARs expression patterns of the PD-like phenotype were partially recovered by a supplementary diet with currants. Overall, our results suggest that the neuroprotective effects of Corinthian currants in rotenone-induced anxiety-like behavior may be mediated via corticolimbic serotonergic transmission.

From cradle to grave: neurogenesis, neuroregeneration and neurodegeneration in Alzheimer's and Parkinson's diseases

Two of the most common neurodegenerative disorders - Alzheimer's and Parkinson's diseases - are characterized by synaptic dysfunction and degeneration that culminate in neuronal loss due to abnormal protein accumulation. The intracellular aggregation of hyper-phosphorylated tau and the extracellular aggregation of amyloid beta plaques form the basis of Alzheimer's disease pathology. The major hallmark of Parkinson's disease is the loss of dopaminergic neurons in the substantia nigra pars compacta, following the formation of Lewy bodies, which consists primarily of alpha-synuclein aggregates. However, the discrete mechanisms that contribute to neurodegeneration in these disorders are still poorly understood. Both neuronal loss and impaired adult neurogenesis have been reported in animal models of these disorders. Yet these findings remain subject to frequent debate due to a lack of conclusive evidence in post mortem brain tissue from human patients. While some publications provide significant findings related to axonal regeneration in Alzheimer's and Parkinson's diseases, they also highlight the limitations and obstacles to the development of neuroregenerative therapies. In this review, we summarize in vitro and in vivo findings related to neurogenesis, neuroregeneration and neurodegeneration in the context of Alzheimer's and Parkinson's diseases.

Management of psychiatric and cognitive complications in Parkinson's disease

Neuropsychiatric symptoms (NPSs) such as affective disorders, psychosis, behavioral changes, and cognitive impairment are common in Parkinson's disease (PD). However, NPSs remain under-recognized and under-treated, often leading to adverse outcomes. Their epidemiology, presentation, risk factors, neural substrate, and management strategies are incompletely understood. While psychological and psychosocial factors may contribute, hallmark PD neuropathophysiological changes, plus the associations between exposure to dopaminergic medications and occurrence of some symptoms, suggest a neurobiological basis for many NPSs. A range of psychotropic medications, psychotherapeutic techniques, stimulation therapies, and other non-pharmacological treatments have been studied, are used clinically, and are beneficial for managing NPSs in PD. Appropriate management of NPSs is critical for comprehensive PD care, from recognizing their presentations and timing throughout the disease course, to the incorporation of different therapeutic strategies (ie, pharmacological and non-pharmacological) that utilize a multidisciplinary approach.

High frequency of Depressive Disorders and Suicidal Phenomena in Late-Stage Parkinson´s Disease - A Cross-Sectional Study

BACKGROUND

Depressive disorders (DD) are widely recognized as one of the most frequent neuropsychiatric disorders in Parkinson´s disease. Patients with late-stage Parkinson´s disease (LSPD) continue to be a neglected population, and little is known about DD frequency in LSPD.

OBJECTIVES

To determine the frequency of DD in LSPD patients through a clinical diagnostic interview (CDI) and according to diagnostic DSM- 5 criteria. Secondary objectives were to determine the predictive ability of depressive scales to detect DD, to identify potential predictors of DD in LSPD and, to evaluate suicidal phenomena in LSPD.

METHODS

A cross-sectional study including LSPD patients (≥7 years from symptom onset and Hoehn and Yahr scale score >3 or a Schwab and England scale score <50% in the ON condition) was conducted. Patients were subjected to psychiatric, neurological, and neuropsychological evaluations. Six depression scales were applied.

RESULTS

92 LSPD patients were included. 59.78% of LSPD patients had a current diagnosis of DD according to CDI, 38.04% patients had a diagnosis of major depressive disorder, and 21.72% non-major depressive disorder. Suicidal ideation was present in 36.96% of patients. All applied scales were able to detect depressive disorders.

CONCLUSIONS

More than half of LSPD patients met DD diagnostic criteria and over one-third were diagnosed with major depressive disorder. Overall, the LSPD population seem to have a unique clinical phenotype regarding the frequency and features of DD, whose early identification and treatment could improve the quality of life of patients and caregivers.

Using gait robotics to improve symptoms of Parkinson's disease: an open-label, pilot randomized controlled trial

BACKGROUND

People with Parkinson's Disease (PD) have difficulty participating in exercise.

AIM

The primary objective of this pilot randomized controlled trial (RCT) was to determine if 8 weeks (2x per week) of bilateral exoskeleton (Exo) exercise results in positive changes in cognition and participation in adults with PD compared to exercising without an exoskeleton (Nxo) or wait-list control (Con).

DESIGN

Open-label, parallel, pilot randomized controlled trial.

SETTING

Neurorehabilitation clinic in a large urban center.

POPULATION

Adults 50-85 years old with a confirmed diagnosis of PD.

METHODS

Eight weeks of twice-weekly combined aerobic, strength and mobility exercise or wait-list control. Participants were randomly assigned to exercise with no exoskeleton (Nxo), exercise with the exoskeleton (Exo), or waitlist control (Con). Primary endpoints were change in cognitive function (SCOPA-COG) and mood. Secondary endpoints were change in gait speed, six-minute walk test (6MWT), freezing of gait, balance, and PD-specific health and quality of life outcomes. Safety endpoint was analysis of adverse events (AE).

RESULTS

Forty participated in the trial (Exo, N.=13; Nxo, N.=14; Con, N.=13). Significant improvement in the Memory & Learning domain of the SCOPA-COG (P=0.014) and 6MWT (P=0.008) were detected for the Exo group compared to the Nxo and/or Con group. No other statistically significant between-groups effects were found. There were no serious or unanticipated AE.

CONCLUSIONS

Functional exercise with a low-profile overground exoskeleton showed promising results for improving memory and gait endurance in people with PD across HY stages I-IV.

CLINICAL REHABILITATION IMPACT

Exoskeletons can improve participation in high-intensity exercise.

Changes in non-motor symptoms in patients with Parkinson's disease following COVID-19 pandemic restrictions: A systematic review

This review discussed the effects of the impact of the Coronavirus Disease 2019 (COVID-19) pandemic on the psychological wellbeing of people with Parkinson's disease (PD) focusing specifically on depressive symptoms, anxiety levels, sleep, and quality of life (QoL). Together with motor symptoms, psychological symptoms are common and disabling conditions in the clinical course of PD becoming a relevant topic as a result of the lockdown measure due to alter their everyday life. We searched on PubMed online electronic databases for English articles published between January 2020 and 31 December 2021. Twenty-eight relevant studies were found and included in the review. Heterogeneous data emerged from the topics analyzed. Overall, data from depression studies showed significant depressive symptoms if the patient was analyzed longitudinally or vs. a control group consisting in healthy subjects, while these differences become minimal when the control group is a family member. Differently, in most of the studies reviewed there is no evidence of a statistically significant impact on anxiety disorders, nor on the quality of sleep. Conversely, PD patients showed a statistically significant negative impact of QoL compared with control groups or other neurological conditions. Although these findings must be interpreted carefully in the light of the studies' limitations, both in methodology and design, collectively our review showed that COVID-19 pandemic has had negative effects on the mental health of people with PD, due to disruption of healthcare services, loss of usual activities and supports and reduction in physical activity.

Spiritual care for the management of Parkinson's disease: Where we are and how far can we go

An increasing number of studies have investigated the neural networks and brain regions activated by different aspects of religious faith or spiritual practice. The extent to which religiousness and spirituality are dependent on the integrity of neural circuits is a question unique to neurological illnesses. Several studies have reported that neural networks and brain areas represent the various components of religious faith or spiritual activity in recent decades. In addition to research in healthy people, another strategy is to observe if neurological abnormalities caused by stroke, tumour, brain damage, or degenerative sickness are accompanied by an alteration in religiosity or spirituality. Similarly, Parkinson's disease (PD), an ailment characterized by dopaminergic neuron malfunction, has been utilized to explore the role of dopaminergic networks in the practice, experience, and maintenance of religious or spiritual beliefs. Case-control and priming studies have demonstrated a decline in spirituality and religion in people with PD due to dopaminergic degeneration. These studies could not adequately control for confounding variables and lacked methodological rigour. Using qualitative and quantitative assessments, a mixed-method approach might shed additional light on putative religious beliefs alterations in PD. In the current review paper, we discussed the recent research on the impact of PD on spiritual beliefs and spirituality.

The Impact of Telemedicine on Parkinson's Care during the COVID-19 Pandemic: An Italian Online Survey

Traditionally, medical care and research in Parkinson’s disease (PD) have been conducted through in-person visit. The recent Coronavirus Disease 2019 (COVID-19) pandemic has profoundly impacted the delivery of in-person clinical care. We conducted an online survey to investigate the impact of COVID-19 on access to telehealth care, interviewing both PD patients and neurologists. Survey responses were collected from 1 March to 31 May 2021 through an anonymous, self-reported questionnaire, on the ‘Qualtrics’ platform. In total, 197 patients and 42 neurologists completed the survey. In our sample, 37.56% of PD patients and 88.10% of neurologists reported having used alternatives to in-person visits, while 13.70% of PD patients and 40.48% of neurologists used telemedicine. Data showed that respondents were generally satisfied with the use of telemedicine during the COVID-19 pandemic. The relational dimension between patient and neurologist seems to be the factor that most positively affected the telemedicine experience, contributing greatly to a more patient-centred care. Current findings suggest the need to improve the access to telehealth services for patients with PD. The technology has the potential to improve the care of frail patients, especially when availability of face-to-face visits is limited.

Depression in Patients with Parkinson's Disease: Current Understanding of its Neurobiology and Implications for Treatment

Depression is one of the most frequent and burdensome non-motor symptoms in Parkinson’s disease (PD), across all stages. Even when its severity is mild, PD depression has a great impact on quality of life for these patients and their caregivers. Accordingly, accurate diagnosis, supported by validated scales, identification of risk factors, and recognition of motor and non-motor symptoms comorbid to depression are critical to understanding the neurobiology of depression, which in turn determines the effectiveness of dopaminergic drugs, antidepressants and non-pharmacological interventions. Recent advances using in vivo functional and structural imaging demonstrate that PD depression is underpinned by dysfunction of limbic networks and monoaminergic systems, depending on the stage of PD and its associated symptoms, including apathy, anxiety, rapid eye movement sleep behavior disorder (RBD), cognitive impairment and dementia. In particular, the evolution of serotonergic, noradrenergic, and dopaminergic dysfunction and abnormalities of limbic circuits across time, involving the anterior cingulate and orbitofrontal cortices, amygdala, thalamus and ventral striatum, help to delineate the variable expression of depression in patients with prodromal, early and advanced PD. Evidence is accumulating to support the use of dual serotonin and noradrenaline reuptake inhibitors (desipramine, nortriptyline, venlafaxine) in patients with PD and moderate to severe depression, while selective serotonin reuptake inhibitors, repetitive transcranial magnetic stimulation and cognitive behavioral therapy may also be considered. In all patients, recent findings advocate that optimization of dopamine replacement therapy and evaluation of deep brain stimulation of the subthalamic nucleus to improve motor symptoms represents an important first step, in addition to physical activity. Overall, this review indicates that increasing understanding of neurobiological changes help to implement a roadmap of tailored interventions for patients with PD and depression, depending on the stage and comorbid symptoms underlying PD subtypes and their prognosis.

Bipolar Spectrum disorders in Parkinson's disease: a systematic evaluation

OBJECTIVE

Psychiatric disorders are very common in patients affected by Parkinson's disease (PD). However, comorbidity with Bipolar Spectrum disorders is understudied. The aim of this study is to explore the clinical correlates of PD associated with Bipolar Spectrum disorders.

METHODS

One hundred PD patients were screened for psychiatric comorbidities, cognitive profile, motor, and non-motor symptoms. The sample was divided into three groups: PD-patients with Bipolar Spectrum disorders (bipolar disorder type I, type II, and spontaneous or induced hypomania; N = 32), PD-patients with others psychiatric comorbidities (N = 39), PD-patients without psychiatric comorbidities (N = 29). Clinical features were compared among the groups using analysis of variance and chi-square test. A logistic regression was performed to evaluate the association between Bipolar Spectrum disorders and early onset of PD (≤50 years) controlling for lifetime antipsychotic use.

RESULTS

In comparison with PD patients with and without other psychiatric comorbidity, subjects affected by Bipolar Spectrum disorders were younger, showed more frequently an early onset PD, reported more involuntary movements and a higher rate of impulse control disorders and compulsive behaviors. No differences were observed in indexes of exposure to dopamine agonist treatments. The early onset of PD was predicted by Bipolar Spectrum comorbidity, independently from lifetime antipsychotic use.

CONCLUSION

Bipolar Spectrum disorders are common in early onset PD. The presence of bipolar comorbidity could identify a particular subtype of PD, showing higher rates of neurological and psychiatric complications and deserving further investigation.

Path analysis of biomarkers for cognitive decline in early Parkinson’s disease

Clinical and biochemical diversity of Parkinson’s disease (PD) and numerous demographic, clinical, and pathological measures influencing cognitive function and its decline in PD create problems with the determination of effects of individual measures on cognition in PD. This is particularly the case where these measures significantly interrelate with each other producing intricate networks of direct and indirect effects on cognition. Here, we use generalized structural equation modelling (GSEM) to identify and characterize significant paths for direct and indirect effects of 14 baseline measures on global cognition in PD at baseline and at 4 years later. We consider 269 drug-naïve participants from the Parkinson’s Progression Marker Initiative database, diagnosed with idiopathic PD and observed for at least 4 years after baseline. Two GSEM networks are derived, highlighting the possibility of at least two different molecular pathways or two different PD sub-types, with either CSF p-tau181 or amyloid beta (1–42) being the primary protein variables potentially driving progression of cognitive decline. The models provide insights into the interrelations between the 14 baseline variables, and determined their total effects on cognition in early PD. High CSF amyloid concentrations (> 500 pg/ml) are associated with nearly full protection against cognitive decline in early PD in the whole range of baseline age between 40 and 80 years, and irrespectively of whether p-tau181 or amyloid beta (1–42) are considered as the primary protein variables. The total effect of depression on cognition is shown to be strongly amplified by PD, but not at the time of diagnosis or at prodromal stages. CSF p-tau181 protein could not be a reliable indicator of cognitive decline because of its significantly heterogeneous effects on cognition. The outcomes will enable better understanding of the roles of the clinical and pathological measures and their mutual effects on cognition in early PD.

Psychiatric, Motor, and Autonomic Effects of Bifrontal ECT in Depressed Parkinson's Disease Patients

OBJECTIVE

Depressive symptoms are a source of significant morbidity in Parkinson's disease (PD). Electroconvulsive therapy (ECT) is a promising treatment for depression in PD (dPD); however, data remain limited, including data on optimal electrode placement. In this retrospective study, the investigators aimed to characterize the effects of bifrontal ECT for dPD on psychiatric and motor symptoms, as well as autonomic response.

METHODS

Clinical data were retrieved from a university-affiliated ECT service in Vancouver, British Columbia, for patients with dPD receiving bifrontal ECT between 2014 and 2018. Clinical Global Impression (depressive symptoms) and Unified Parkinson's Disease Rating Scale (motor symptoms) scores and cardiovascular measurements during ECT, as well as doses of dopaminergic medications, were recorded.

RESULTS

Eight patients met criteria for inclusion. Six patients (75%) met response criteria for improvement of depressive symptoms, including 83% of patients who completed a full ECT course. Five patients went on to receive maintenance ECT, with only one patient relapsing by the 1-year follow-up (20%). For patients with motor scales reported, 60% showed a clinically significant improvement in motor symptoms. Among patients who completed ECT, a reduction in the median dopaminergic medication dose was also observed (-350 mg). Two patients discontinued ECT as a result of tolerability concerns. Participants demonstrated a relatively typical pattern of autonomic response to ECT, with low incidence of bradycardic events.

CONCLUSIONS

The results provide preliminary evidence of the benefit of bifrontal ECT in dPD for both depressive and motor symptoms. The autonomic data suggest that most patients with dPD respond in a typical physiological manner to ECT stimulus; however, further investigation is needed.