The spectrum of neuropsychiatric symptoms in patients with early untreated Parkinson's disease

Traditional Chinese exercises for the treatment of neuropsychiatric symptoms in Parkinson's disease: A systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the efficacy of traditional Chinese exercises (TCEs) for neuropsychiatric symptoms (NPSs) in patients with Parkinson's disease.

METHODS

A comprehensive literature search was performed across eight databases, including PubMed, Cochrane Library, Embase, Web of Science (WoS), SinoMed, China National Knowledge Infrastructure (CNKI), China Science and Technology Periodical Database (VIP), and Wanfang Database, covering studies published from their inception up to April 23, 2024. The search focused on identifying randomized controlled trials (RCTs) assessing the effectiveness of TCEs for NPSs in PD patients. The authors independently performed literature screening and data extraction. Meta-analysis was executed employing Review Manager V.5.3 software, and Stata 17.0 was used to detect publication bias and perform sensitivity analysis. GRADEpro GDT was used to grade the certainty of each outcome evidence.

RESULTS

Eighteen studies involving 937 participants were included. The meta-analysis showed significant improvements in depression-related scales (standardized mean difference (SMD) = -1.30, 95 % confidence interval (CI): -2.10 to -0.49, p = 0.002), anxiety-related scales (SMD = -1.11, 95 %CI: -2.14 to -0.08, p = 0.03), sleep disorder-related scales (SMD = -0.71, 95 %CI: -0.99 to -0.43, p < 0.00001), and cognition-related scales (SMD = 0.91, 95 %CI: 0.44-1.38, p = 0.0001). Quality of life also improved (SMD = -1.35, 95 % CI: -2.38 to -0.31, p = 0.01; SMD = 0.99, 95 % CI: 0.54-1.43, p < 0.0001). Subgroup analyses grounded in the duration of the intervention suggested that interventions lasting up to 12 weeks showed more significant anti-depression and anti-anxiety effects while those lasting beyond 12 weeks demonstrated greater improvements in sleep quality and cognitive function. Additionally, subgroup analyses based on the type of intervention revealed that both using TCEs alone and the combination of TCEs with conventional medications showed greater effects on anti-depression and cognitive function, while the latter yield more significant anti-anxiety effects. However, no statistical significance was found for fatigue-related scales. The clinical trials included in this review also lacked a thorough description of the randomization process, and only a small proportion reported adequate allocation concealment procedures, raising concerns about potential selection bias. Moreover, owing to the inherent characteristics of TCEs, blinding both participants and practitioners is challenging, which may result in performance bias. Additionally, the absence of blinding could allow assessors' subjective influences to affect the outcomes, leading to detection bias. The overall quality of the evidence, as assessed according to the GRADE criteria, was rated as very low or low for most of outcomes.

CONCLUSIONS

The findings indicated that the use of TCEs may have potential to alleviate the severity of NPSs including depression, anxiety, sleep disorders, and enhance cognition function and overall quality of life in PD patients. Nevertheless, given the limited number of studies and their methodologic issues such as the absence of blinding, along with the small sample sizes, significant heterogeneity across these primary studies, careful interpretation of the results is warranted. More high-quality research with larger sample sizes, including double-blind studies or those employing an active control group involving exercises such as walking, ought to be carried out to validate the above findings and strengthen the evidence base.

REGISTRATION

PROSPERO: CRD42024540164.

Understanding disrupted motivation in Parkinson's disease through a value-based decision-making lens

Neurobehavioural disturbances such as loss of motivation have profound effects on the lives of many people living with Parkinson's disease (PD), as well as other brain disorders. The field of decision-making neuroscience, underpinned by a plethora of work across species, provides an important framework within which to investigate apathy in clinical populations. Here we review how changes in a number of different processes underlying value-based decision making may lead to the common phenotype of apathy in PD. The application of computational models to probe both behaviour and neurophysiology show promise in elucidating these cognitive processes crucial for motivated behaviour. However, observations from the clinical management of PD demand an expanded view of this relationship, which we aim to delineate. Ultimately, effective treatment of apathy may depend on identifying the pattern in which decision making and related mechanisms have been disrupted in individuals living with PD.

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.

Unilateral and Bilateral Subthalamic Deep Brain Stimulation Differently Favour Apathy in Parkinson's Disease

The link between subthalamic nucleus deep brain stimulation (STN-DBS) and apathy in patients with Parkinson's disease (PD) remains a controversial topic. The literature is mixed and the most supported explanation is the reduction of dopaminergic treatment. Yet a body of clinical and experimental evidences suggest that STN-DBS itself can also promote apathy in certain patients. However, the parameters accounting for apathy heterogeneity in stimulated patients along with the mechanisms underlying apathy induced by STN-DBS remain to be investigated. Whether bilateral and unilateral STN-DBS have the same influence on apathy is for instance unknown. We previously and separately showed in patients and rodents that bilateral STN-DBS can promote apathy per se. Here, we compare the effect of bilateral versus unilateral STN-DBS both in patients and in rodents. We conducted a clinical follow-up of patients with Parkinson's disease undergoing unilateral or bilateral STN-DBS and assessing apathy 3 months before and after STN-DBS. In parallel, we applied chronic and uninterrupted unilateral or bilateral DBS in rodents and extract longitudinal motivational changes with a battery of behavioural tests. While bilateral STN-DBS promotes apathy in patients and induces a loss of motivation in rodents, we found that unilateral STN-DBS did not exert such an effect both in patients and in rats. These data show that bilateral but not unilateral STN-DBS promotes apathy. This not only substantiate the induction of neuropsychiatric effects by STN-DBS but also suggest that this might be circumvented if STN-DBS is applied unilaterally instead of bilaterally.

Study on the mechanism of gut microbiota in the pathogenetic interaction between depression and Parkinson 's disease

Depression and Parkinson's disease share pathogenetic characteristics, meaning that they can impact each other and exacerbate their respective progression. From a pathogenetic perspective, depression can develop into Parkinson's disease and is a precursor symptom of Parkinson's disease; Parkinson's disease is also often accompanied by depression. From a pharmacological perspective, the use of antidepressants increases the risk of developing Parkinson's disease, and therapeutic medications for Parkinson's disease can exacerbate symptoms of depression. Therefore, identifying how Parkinson's disease and depression impact each other in their development is key to formulating preventive measures and targeted treatment. One commonality in the pathogenesis of depression and Parkinson's disease are alterations in the gut microbiota, with mechanisms interacting in neural, immune inflammatory, and neuroendocrine pathways. This paper reviews the role of gut microbiota in the pathogenesis of depression and Parkinson's disease; conducts a study of the relationship between both conditions and medication; and suggests that dysregulated gut microbiota may be a key factor in explaining the relationship between Parkinson's disease and depression. Finally, on the basis of these findings, this article hopes to provide suggestions that new ideas for the prevention and treatment of depression and Parkinson's disease.

Shared and distinct cortical morphometric alterations in five neuropsychiatric symptoms of Parkinson's disease

Neuropsychiatric symptoms (including anxiety, depression, apathy, impulse-compulsive behaviors and hallucinations) are among the most common non-motor features of Parkinson's disease. Whether these symptoms should be considered as a direct consequence of the pathophysiologic mechanisms of Parkinson's disease is controversial. Morphometric similarity network analysis and epicenter mapping approach were performed on T1-weighted images of 505 patients with Parkinson's disease and 167 age- and sex-matched healthy participants from Parkinson's Progression Markers Initiative database to reveal the commonalities and specificities of distinct neuropsychiatric symptoms. Abnormal cortical co-alteration pattern in patients with neuropsychiatric symptoms was in somatomotor, vision and frontoparietal regions, with epicenters in somatomotor regions. Apathy, impulse-compulsive behaviors and hallucinations shares structural abnormalities in somatomotor and vision regions, with epicenters in somatomotor regions. In contrast, the cortical abnormalities and epicenters of anxiety and depression were prominent in the default mode network regions. By embedding each symptom within their co-alteration space, we observed a cluster composed of apathy, impulse-compulsive behaviors and hallucinations, while anxiety and depression remained separate. Our findings indicate different structural mechanisms underlie the occurrence and progression of different neuropsychiatric symptoms. Based upon these results, we propose that apathy, impulse-compulsive behaviors and hallucinations are directly related to damage of motor circuit, while anxiety and depression may be the combination effects of primary pathophysiology of Parkinson's disease and psychosocial causes.

Physical Violence and Aggression in Parkinson's Disease: A Systematic Review

BACKGROUND

Physical violence and aggression (PVA), defined as behaviors with the potential to cause bodily injury, are unfortunate risks in the management of all-cause neurodegenerative dementias. While dementia in Parkinson's disease (PD) may not be evident for many years after clinical onset, neuropsychiatric disturbances occur at all stages of the disease. At issue is whether PVA in PD is associated with clinical factors that can be targets for prevention and management in the absence of a prevailing dementia syndrome.

OBJECTIVE

This systematic review examined the extent to which PVA in PD without dementia is a clinically significant concern and whether it is associated with factors that could warrant proactive management.

METHODS

A systematic search of 9 electronic databases used MeSH headings and equivalent terms for PD, aggression, and violence. Eligible manuscripts were original articles that were published in peer-reviewed journals and reported on adults with PD in the awake state with PVA as possible outcomes. Extracted data included study design, PD ascertainment methods and characteristics, PVA assessment methods, subject demographics, psychiatric and medical comorbidities, and pertinent results. Inciting and confounding factors were extracted from case reports. Quality assessment tools were applied in accordance with the study design (e.g., observational, qualitative, or case report).

RESULTS

The search identified 10 manuscripts: 2 observational quantitative studies (total n with PD = 545), 1 qualitative study (n with PD = 20), and 7 case reports (n = 7). The observational studies suggested that PVA is less common than other neuropsychiatric disturbances, but heterogeneous methods and quality concerns prevented further conclusions. In the case reports, all patients were male, and most were early onset. In 6 of the reports, PVA occurred in the context of bilateral subthalamic nucleus deep brain stimulation.

CONCLUSIONS

PVA, while relatively rare in PD, can be a significant management issue that is associated with select premorbid characteristics and antiparkinsonian motor treatments. As PVA may be under-reported, further understanding of its frequency, causes, risk factors, and outcomes would benefit from its systematic assessment, ideally using self-report and informant-based questionnaires.

Cross-Sectional and Longitudinal Association of Clinical and Neurocognitive Factors With Apathy in Patients With Parkinson Disease

BACKGROUND AND OBJECTIVES

A robust understanding of the natural history of apathy in Parkinson disease (PD) is foundational for developing effective clinical management tools. However, large longitudinal studies are lacking while the literature is inconsistent about even cross-sectional associations. We aimed to determine the longitudinal predictors of apathy development in a large cohort of people with PD and its cross-sectional associations and trajectories over time, using sophisticated Bayesian modeling techniques.

METHODS

People with PD followed up in the longitudinal New Zealand Parkinson's progression project were included. Apathy was defined using the neuropsychiatric inventory subscale ≥4, and analyses were also repeated using a less stringent cutoff of ≥1. Both MoCA and comprehensive neuropsychological testing were used as appropriate to the model. Depression was assessed using the hospital anxiety and depression scale. Cross-sectional Bayesian regressions were conducted, and a multistate predictive model was used to identify factors that predict the initial onset of apathy in nonapathetic PD, while also accounting for the competing risk of death. The relationship between apathy presence and mortality was also investigated.

RESULTS

Three hundred forty-six people with PD followed up for up to 14 years across a total of 1,392 sessions were included. Apathy occurrence did not vary significantly across the disease course (disease duration odds ratio [OR] = 0.55, [95% CI 0.28-1.12], affecting approximately 11% or 22% of people at any time depending on the NPI cutoff used. Its presence was associated with a significantly higher risk of death after controlling for all other factors (hazard ratio [HR] = 2.92 [1.50-5.66]). Lower cognition, higher depression levels, and greater motor severity predicted apathy development in those without motivational deficits (HR [cognition] = 0.66 [0.48-0.90], HR [depression] = 1.45 [1.04-2.02], HR [motor severity] = 1.37 [1.01-1.86]). Cognition and depression were also associated with apathy cross-sectionally, along with male sex and possibly lower dopaminergic therapy level, but apathy still occurred across the full spectrum of each variable (OR [cognition] = 0.58 [0.44-0.76], OR [depression] = 1.43 [1.04-1.97], OR [female sex] = 0.45 [0.22-0.92], and OR [levodopa equivalent dose] = 0.78 [0.59-1.04].

DISCUSSION

Apathy occurs across the PD time course and is associated with higher mortality. Depressive symptoms and cognitive impairment in particular predict its future development in those with normal motivation.

The role of dog therapy in clinical recovery and improving quality of life: a randomized, controlled trial

BACKGROUND

Any illness places a significant burden on patients, including deterioration in quality of life. Animal assisted therapy may be helpful in the rehabilitation process and in the treatment of patients to alleviate this phenomenon.

METHODS

A randomized, controlled research was conducted in 2019 and 2020 in a rehabilitation center in Budapest. In our study, the control and experimental groups received the same therapy, but the rehabilitation treatment of the intervention group was complemented by dog therapy. Patients were evaluated by means of the short form Beck Depression Inventory, State-Trait Anxiety Inventory, Illness Intrusiveness Ratings Scale, Visual Analog Scale for pain and the WHO-5 Well-being Index. For statistical analysis paired T-test and ANCOVA was performed.

RESULTS

58 participants in both groups took part in the research. Results confirm that both groups showed statistically significant improvement in all outcome measures, except for depression symptoms in dog therapy group. Quality of life of the participants improved significantly, their pain and anxiety levels were significantly reduced, they felt significantly less burdened by the disease in their daily lives. Therapeutic-dog sessions had a large effect on patients' quality of life and anxiety.

CONCLUSIONS

There is a strong case for animal assisted therapy as a complementary therapy in the rehabilitation program, and it is proposed that consideration should be given to the application of this method on a larger scale within health care. The study was retrospectively registered at ISRCTN Registry (registration number: ISRCTN10208787) on 15/03/2022.

White Matter Microstructural Underpinnings of Mild Behavioral Impairment in Parkinson's Disease

BACKGROUND

Patients with Parkinson's disease (PD) experience changes in behavior, personality, and cognition that can manifest even in the initial stages of the disease. Previous studies have suggested that mild behavioral impairment (MBI) should be considered an early marker of cognitive decline. However, the precise neurostructural underpinnings of MBI in early- to mid-stage PD remain poorly understood.

OBJECTIVE

The aim was to explore the changes in white matter microstructure linked to MBI and mild cognitive impairment (MCI) in early- to mid-stage PD using diffusion magnetic resonance imaging (dMRI).

METHODS

A total of 91 PD patients and 36 healthy participants were recruited and underwent anatomical MRI and dMRI, a comprehensive neuropsychological battery, and the completion of the Mild Behavioral Impairment-Checklist. Metrics of white matter integrity included tissue fractional anisotropy (FAt) and radial diffusivity (RDt), free water (FW), and fixel-based apparent fiber density (AFD).

RESULTS

The connection between the left amygdala and the putamen was disrupted when comparing PD patients with MBI (PD-MBI) to PD-non-MBI, as evidenced by increased RDt (η2 = 0.09, P = 0.004) and both decreased AFD (η2 = 0.05, P = 0.048) and FAt (η2 = 0.12, P = 0.014). Compared to controls, PD patients with both MBI and MCI demonstrated increased FW for the connection between the left orbitofrontal gyrus (OrG) and the hippocampus (η2 = 0.22, P = 0.008), augmented RDt between the right OrG and the amygdala (η2 = 0.14, P = 0.008), and increased RDt (η2 = 0.25, P = 0.028) with decreased AFD (η2 = 0.10, P = 0.046) between the right OrG and the caudate nucleus.

CONCLUSION

MBI is associated with abnormal microstructure of connections involving the orbitofrontal cortex, putamen, and amygdala. To our knowledge, this is the first assessment of the white matter microstructure in PD-MBI using dMRI. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

On the Optimal Diagnosis and the Evolving Role of Pimavanserin in Parkinson's Disease Psychosis

Parkinson's disease (PD) is associated with the development of psychosis (PDP), including hallucinations and delusions, in more than half of the patient population. Optimal PD management must therefore involve considerations about both motor and non-motor symptoms. Often, clinicians fail to diagnosis psychosis in patients with PD and, when it is recognized, treat it suboptimally, despite the availability of multiple interventions. In this paper, we provide a summary of the current guidelines and clinical evidence for treating PDP with antipsychotics. We also provide recommendations for diagnosis and follow-up. Finally, an updated treatment algorithm for PDP that incorporates the use of pimavanserin, the only US FDA-approved drug for the treatment of PDP, was developed by extrapolating from a limited evidence base to bridge to clinical practice using expert opinion and experience. Because pimavanserin is only approved for the treatment of PDP in the US, in other parts of the world other recommendations and algorithms must be considered.

Predictive factors of post-operative apathy in patients with diffuse frontal gliomas undergoing awake brain mapping

Patients with diffuse frontal gliomas often present with post-operative apathy after tumour removal. However, the association between apathy and tumour removal of gliomas from the frontal lobe remains unknown. This study aimed to investigate the factors influencing post-operative apathy after tumour removal in patients with diffuse frontal gliomas. We compared the demographics and clinical characteristics of patients with and without post-operative apathy in a cohort of 54 patients who underwent awake brain mapping for frontal gliomas. The frequency of clinical parameters such as left-sided involvement, high-grade tumour types (WHO grades III, IV), main tumour location in the anterior cingulate gyrus (ACC) and/or dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) was significantly greater in the apathetic group compared to the non-apathetic group. The apathetic group scored significantly lower on neuropsychological assessments such as the Letter Fluency Test among the Word Fluency Tests than the non-pathetic group (p = .000). Moreover, the scores of Parts 3, and 3-1 of the Stroop test were significantly lower in the apathetic group than those in the non-apathetic group (p = .023, .027, respectively). Multivariate model analysis revealed that the appearance of post-operative apathy was significantly related to side of the of lesion [left vs. right, hazard ratio (HR) = 8.00, 95% confidence interval (CI) = 1.36-46.96, p = .021], location of the main tumour in the frontal lobe (ACC/DLPFC/OFC vs. others, HR = 7.99, 95% CI = 2.16-29.59, p = .002), and the Letter Fluency Test (HR = .37, 95% CI = .15-.90, p = .028). Post-operative apathy is significantly associated with ACC and/or DLPFC and OFC in the left hemisphere of diffuse frontal gliomas. Apathy in frontal gliomas is correlated with a decline in the Letter Fluency Test scores. Therefore, this instrument is a potential predictor of post-operative apathy in patients with diffuse frontal gliomas undergoing awake brain mapping.

Pramipexole restores behavioral inhibition in highly impulsive rats through a paradoxical modulation of frontostriatal networks

Impulse control disorders (ICDs), a wide spectrum of maladaptive behaviors which includes pathological gambling, hypersexuality and compulsive buying, have been recently suggested to be triggered or aggravated by treatments with dopamine D2/3 receptor agonists, such as pramipexole (PPX). Despite evidence showing that impulsivity is associated with functional alterations in corticostriatal networks, the neural basis of the exacerbation of impulsivity by PPX has not been elucidated. Here we used a hotspot analysis to assess the functional recruitment of several corticostriatal structures by PPX in male rats identified as highly (HI), moderately impulsive (MI) or with low levels of impulsivity (LI) in the 5-choice serial reaction time task (5-CSRTT). PPX dramatically reduced impulsivity in HI rats. Assessment of the expression pattern of the two immediate early genes C-fos and Zif268 by in situ hybridization subsequently revealed that PPX resulted in a decrease in Zif268 mRNA levels in different striatal regions of both LI and HI rats accompanied by a high impulsivity specific reduction of Zif268 mRNA levels in prelimbic and cingulate cortices. PPX also decreased C-fos mRNA levels in all striatal regions of LI rats, but only in the dorsolateral striatum and nucleus accumbens core (NAc Core) of HI rats. Structural equation modeling further suggested that the anti-impulsive effect of PPX was mainly attributable to the specific downregulation of Zif268 mRNA in the NAc Core. Altogether, our results show that PPX restores impulse control in highly impulsive rats by modulation of limbic frontostriatal circuits.

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.

Parkinson's disease psychosis management: an evidence based, experience informed, pragmatic approach

INTRODUCTION

Psychotic symptoms in people with Parkinson's disease (PD) have attracted increasing. Recommendations on treating psychosis often fail to take into account what psychotic symptoms require treatment, which has been complicated by the increasing number of reports documenting the frequency of 'minor' hallucinations.

AREAS COVERED

This article focuses both on the phenomenology of psychotic symptoms and their management.

EXPERT OPINION

Understanding the nature and implications of the types of psychotic symptoms in PD is the key to proper treatment. Evidence and experience-based data on the effect of anti-psychotic medications will be reviewed and how the various clinical settings should determine the treatment approach. The evidence base consists of all reported blinded trials recorded in PubMed and the experience-based studies are those chosen by the author from PubMed as illustrative. Specific recommendations for the treatment of psychosis will be listed for specific situations. Pimavanserin is the first-line choice for mild symptoms; quetiapine for symptoms that require improvement in a short period and clozapine for urgent problems or those which fail the other approaches.

A general clinical overview of the non-motor symptoms in Parkinson's disease: Neuropsychiatric symptoms

The heterogeneity of non-motor features observed in people with Parkinson's disease (PD) is often dominated by one or more symptoms belonging to the neuropsychiatric spectrum, such as cognitive impairment, psychosis, depression, anxiety, and apathy. Due to their high prevalence in people with PD (PwP) and their occurrence in every stage of the disease, from the prodromal to the advanced stage, it is not surprising that PD can be conceptualised as a complex neuropsychiatric disorder. Despite progress in understanding the pathophysiological mechanisms underlying the neuropsychiatric signs and symptoms in PD, and better identification and diagnosis of these symptoms, effective treatments are still a major unmet need. The impact of these symptoms on the quality of life of PwP and caregivers, as well as their contribution to the overall non-motor symptom burden can be greater than that of motor symptoms and require a personalised, holistic approach. In this chapter, we provide a general clinical overview of the major neuropsychiatric symptoms of PD.

The effect of animal-assisted interventions on the course of neurological diseases: a systematic review

BACKGROUND

In our experience, working with a therapy animal strengthens endurance, maintains motivation, provides a sense of achievement, and boosts overall mental resilience. The aims of this work were to summarize the results of quantitative research on the possibilities of animal-assisted intervention (AAI) among people with neurodegenerative and cerebrovascular diseases and to attempt to assess the effects of animal-assisted interventions in an objective manner and to find supporting evidence based on published literature.

METHODS

Our target groups are people diagnosed with Parkinson's disease, multiple sclerosis, or stroke. A systematic search of relevant articles was conducted by two independent researchers in April 2021 and August 2023. The search for studies was conducted using PubMed, Google Scholar, Web of Science, Scopus, and Ovid databases, specifying keywords and search criteria. The qualitative evaluation of the research reports was conducted by four independent researchers, using the Newcastle-Ottawa Quality Assessment Form.

RESULTS

According to the scientific criteria and based on the Newcastle-Ottawa Quality Assessment Form, thirteen publications met the search criteria, out of which 9 publications were rated good and 4 publications were rated poor. Evaluating the publications we found evidence that AAI had a measurable impact on participants, as their physical and mental health status significantly improved; however, mental health improvement was more prominent.

CONCLUSIONS

By developing evidence-based research methodology and standardized research settings, AAI could be measured effectively as part of health care practice. This would bring significant benefits to the rehabilitation of patients in need.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021255776.

Magnetic Resonance Imaging Biomarkers of Punding in Parkinson's Disease

Punding is a rare condition triggered by dopaminergic therapy in Parkinson's disease (PD), characterized by a complex, excessive, repetitive, and purposeless abnormal movement, and its pathogenesis remains unclear. We aimed to assess the brain structure alterations related to punding by using multipametric magnetic resonance imaging (MRI). Thirty-eight PD patients (19 with punding and 19 without punding) from the Parkinson's Progression Marker Initiative (PPMI) were included in this study. Cortical thickness was assessed with FreeSurfer, and the integrity of white matter fiber tracts and network topologies were analyzed by using FMRIB Software Library (FSL) and Pipeline for Analyzing braiN Diffusion imAges (PANDA). PD patients with punding showed a higher apathy score and more severe cortical atrophy in the left superior parietal, right inferior parietal, and right superior frontal gyrus, and worse integrity of the right cingulum cingulate tract compared to those without punding. On the other hand, no significant difference in structural network topologies was detected between the two groups. These data suggest that the specific area of destruction may be an MRI biomarker of punding risk, and these findings may have important implications for understanding the neural mechanisms of punding in PD.

Association of Neuropsychiatric Symptom Profiles With Cognitive Decline in Patients With Parkinson Disease and Mild Cognitive Impairment

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS) are closely associated with cognitive decline in patients with Parkinson disease (PD). We investigated which profiles of NPS are associated with the risk of dementia in PD with mild cognitive impairment (PD-MCI).

METHODS

We retrospectively assessed 338 patients with PD-MCI from a single tertiary hospital, who underwent neuropsychological tests and a neuropsychiatric inventory (NPI) questionnaire. We conducted a factor analysis of the dichotomized presence of 12 NPI symptoms, yielding 3 NPI factors: factor 1, mood symptoms; factor 2, hyperactivity-related symptoms; and factor 3, psychotic symptoms. Factor analysis of the severity of NPI symptoms also identified similar NPI factors. The neuropsychiatric correlates of NPI factors were evaluated using general linear models for cognitive tests. Subsequently, we evaluated the hazard ratio (HR) of NPI factors on conversion to dementia.

RESULTS

A higher prevalence factor 1 score was associated with lower scores in the verbal memory (β = -0.15; 95% CI -0.24 to -0.06; p = 0.001) and executive domains (β = -0.16; 95% CI -0.28 to -0.04; p = 0.007), whereas higher severity factor 2 scores were associated with lower scores in the naming (β = -0.16; 95% CI -0.28 to -0.03; p = 0.012), visuospatial (β = -0.24; 95% CI -0.41 to -0.07; p = 0.005), and verbal memory domains (β = -0.15; 95% CI -0.24 to -0.05; p = 0.005). A higher severity factor 3 score was associated with lower scores in the visuospatial domain (β = -0.25; 95% CI -0.46 to -0.07; p = 0.007). Cox regression models demonstrated that the risk of dementia was increased in those with higher prevalence factor 1 (HR = 1.48, 95% CI 1.17-1.88, p = 0.001) and factor 2 scores (HR = 1.27, 95% CI 1.07-1.51, p = 0.007) and severity factor 3 score (HR = 1.52, 95% CI 1.29-1.80, p < 0.001) after adjusting for age, sex, education, disease duration, scores for cognition and parkinsonism, and levodopa equivalent dose.

DISCUSSION

This study demonstrated that a higher burden of NPS is associated with dementia conversion in patients with PD-MCI.

Neuropsychiatric features of Parkinson's disease in the era prior to the use of dopaminergic therapies

BACKGROUND

Psychosis in Parkinson's disease includes hallucinations and delusions. Other non-psychotic neuropsychiatric features include depression, anxiety and apathy. There is currently controversy over whether psychosis in Parkinson's is an intrinsic part of the disorder or the result of dopaminergic medications. This study aimed to examine a historical cohort of individuals with Parkinson's prior to the use of dopaminergic therapy to assess the prevalence of psychotic and other neuropsychiatric features.

METHODS

The case notes of patients with Parkinson's disease admitted to the National Hospital for Neurology and Neurosurgery, London between 1924 and 1946 were examined. Demographic and clinical variables were extracted along with any neuropsychiatric features. Cases meeting criteria for encephalitis lethargica were excluded.

RESULTS

115 cases of individuals with Parkinson's disease were identified. 58 (41.7%) were female. Mean age was 54.0 (SD 9.6) years and mean time since Parkinson's diagnosis was 5.3 (SD 5.7) years. No individuals met criteria for encephalitis lethargica. No cases of hallucinations or delusions were reported. There was one case of an illusion in a patient who was using anticholinergic medication. Other neuropsychiatric features reported were sleep disorder (present in 10, 8.7%), depression (8, 7.0%), memory impairment (5, 4.3%), impulsivity (4, 3.5%), bradyphrenia (4, 3.5%), impaired attention (3, 2.6%), anxiety (1, 0.9%), fatigue (1, 0.9%) and apathy (1, 0.9%).

CONCLUSIONS

Prior to the use of dopaminergic therapies, patients with Parkinson's disease admitted to hospital rarely, if ever, reported psychotic symptoms, although other neuropsychiatric symptoms were more prevalent. The main limitation is that a lack of systematic enquiry about psychotic symptoms may have resulted in underreporting.

Dimensions of apathy in Parkinson's disease

INTRODUCTION

Apathy is one of the most common neuropsychiatric manifestations in Parkinson's disease (PD). Recent proposals consider apathy as a multidimensional construct, which can manifest in behavioral, cognitive, emotional, and/or social dimensions. Apathy also overlaps conceptually and clinically with other non-motor comorbidities, particularly depression. Whether all of these dimensions are applicable to the apathetic syndrome experienced by people with PD is unclear. In the present study, we investigated the multidimensional pattern of apathy associated with PD, using the recently developed Apathy Motivation Index (AMI) which probes behavioral, emotional, and social apathy dimensions. We then examined the relationship between these dimensions and other features of PD commonly associated with apathy, including depression, anxiety, cognition, and motor state.

METHODS

A total of 211 participants were identified from the New Zealand Brain Research Institute (NZBRI) longitudinal PD cohort. One hundred eight patients and 45 controls completed the AMI, administered as an online questionnaire, and additional assessments including neuropsychiatric, neuropsychological, and motor scores. The pattern of dimensional apathy in PD was assessed using a repeated-measured analysis of variance, while simple linear regressions were performed to evaluate relationships between these dimensions and other variables.

RESULTS

We found a significant interaction between group (PD versus control) and apathy subscale, driven mainly by higher levels of social and behavioral-but not emotional-apathy in those with PD. This result was strikingly similar to a previous study investigating social apathy in PD. Distinct patterns of dimensional apathy were associated with depression and anxiety, with social and behavioral apathy positively associated with depression, and emotional apathy negatively associated with anxiety.

CONCLUSION

This work provides further evidence for a distinct pattern of apathy in people with PD in which deficits manifest in some-but not all-dimensions of motivated behavior. It emphasizes the importance of considering apathy as a multidimensional construct in clinical and research settings.

Neurobiology of depression in Parkinson's disease: Insights into epidemiology, molecular mechanisms and treatment strategies

Parkinson's disease (PD) is characterized mainly by motor dysfunctions due to the progressive loss of dopaminergic neurons. However, PD patients experience a multitude of debilitating non-motor symptoms, including depression, which may have deleteriously detrimental effects on life. Depression is multifactorial and exhibits a bimodal progression in PD, but its underlying molecular mechanisms are poorly understood. Studies demonstrating the pathophysiology of depression in PD and the specific treatment strategies for depression-like symptoms in PD patients are largely lacking, often underrated, under-recognized and, consequently, inadequately/under-treated. Nevertheless, reports suggest that the incidence of depression is approximately 20-30% of PD patients and may precede the onset of motor symptoms. Diagnosing depression in PD becomes difficult due to the clinical overlap in symptomatology between the two diseases, and the nigrostriatal dysfunction alone is insufficient to explain depressive symptoms in PD. Therefore, the current study provides an overview of the molecular mechanisms underlying the development of depression in PD and new insights into developing current antidepressant strategies to treat depression in PD. This review will identify and understand the molecular pathological mechanisms of depression in PD that will fundamentally help tailoring therapeutic interventions for depressive symptoms in PD.

Comprehensive Evaluation of Psychotic Features and Their Clinical Correlates in Early Parkinson's Disease

BACKGROUND

Some reports suggest that psychotic features may occur in the early stages of Parkinson's disease (PD), but sensitive tools have not been utilized.

OBJECTIVE

The aim was to evaluate the presence of psychotic symptoms using detailed scales and to assess the association with clinical characteristics.

METHODS

Healthy controls and patients within three years of PD onset were recruited. Participants were examined for psychotic symptoms using two different instruments: the Comprehensive Assessment of At-Risk Mental States (CAARMS) and a 10 question PD specific psychosis severity scale (10PDQ). In the PD group, medication use, motor and non-motor symptoms were documented.

RESULTS

Based on CAARMS and 10PDQ scales, psychotic features were present in 39% (27/70) of patients and 4% (3/74) of controls. The prevalence of passage hallucinations and illusions was significantly higher in PD compared to the control group. The presence of PD-associated psychotic features was not significantly affected by medication, motor severity or global cognitive status. Higher prevalence of overall non-motor manifestations, REM sleep behavior disorder (RBD) and depressive symptoms was significantly associated with the manifestation of psychotic features in PD [(adjusted OR:1.3; 95% CI:1.1-1.6; p = 0.003), (adjusted OR:1.3; 95% CI:1.0-1.6; p = 0.023), and (adjusted OR:1.2; 95% CI:1.0-1.4;p = 0.026)].

CONCLUSIONS

Psychotic phenomena mainly of minor nature are highly common in early PD. Cumulative non-motor symptoms, RBD and depressive features are associated with the presence of psychotic symptoms in this non-demented, early-stage PD population. More studies are needed to clarify the mechanisms that contribute to the onset of psychotic features in early PD.

Laterality in Parkinson's disease: A neuropsychological review

Laterality of motor symptom onset in Parkinson's disease is both well-known and under-appreciated. Treatment of disorders that have asymmetric pathological features, such as stroke and epilepsy, demonstrate the importance of incorporating hemispheric lateralization and specialization into therapy and care planning. These practices could theoretically extend to Parkinson's disease, providing increased diagnostic accuracy and improved treatment outcomes. Additionally, while motor symptoms have generally received the majority of attention, non-motor features (e.g., autonomic dysfunction) also decrease quality of life and are influenced by asymmetrical neurodegeneration. Due to the laterality of cognitive and behavioral processes in the two brain hemispheres, analysis of hemibody side of onset can potentially give insight into expected symptom profile of the patient and allow for increased predictive accuracy of disease progression and outcome, thus opening the door to personalized and improved therapy in treating Parkinson's disease patients. This review discusses motor and non-motor symptoms (namely autonomic, sensory, emotional, and cognitive dysfunction) of Parkinson's disease in respect to hemispheric lateralization from a theoretical perspective in hopes of providing a framework for future research and personalized treatment.

Early identification of subjective cognitive functional decline among patients with Parkinson's disease: a longitudinal pilot study

Practical methods for early identification of Parkinson's disease (PD) mild cognitive impairment (PD-MCI) through changes in real-life daily functioning are scarce. The aim of the study was to examine whether the cognitive functional (CF) feature, comprising of seven self-reported Movement Disorder Society's (MDS) Unified Parkinson's Disease Rating Scale (UPDRS) items, predicts PD patients' cognitive functional status after a year. We conducted a 1-year follow-up of 34 PD patients (50-78 year; 70.6% men) suspected of MCI using the following measures: the MDS-UPDRS, UPDRS-CF feature, Beck Depression Inventory (BDI), Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT), Parkinson's Disease Cognitive Functional Rating Scale (PD-CFRS), and Daily Living Questionnaire (DLQ). The first and second UPDRS-CF feature scores, and additional measures at the 1-year follow-up significantly correlated. Hierarchical regression revealed that the initial MoCA, TMT, and BDI scores predicted the second UPDRS-CF, and the first UPDRS-CF predicted 31% of the second PD-CFRS score variance. Depression moderated the relationship between the first UPDRS-CF score and the DLQ Part A. These results suggest practical, self-reported, daily functional markers for identifying gradual decline in PD patients. They consider the patients' heterogeneity, underlying cognitive pathology, and implications on daily functioning, health, and well-being.

Ellagic acid activates the Keap1-Nrf2-ARE signaling pathway in improving Parkinson's disease: A review

Parkinson's disease (PD) is a familiar neurodegenerative disease, accompanied by motor retardation, static tremor, memory decline and dementia. Heredity, environment, age and oxidative stress have been suggested as key factors in the instigation of PD. The Keap1-Nrf2-ARE signaling is one of the most significant anti- oxidative stress (OS) pathways. The Keap1 is a negative regulator of the Nrf2. The Keap1-Nrf2-ARE pathway can induce cell oxidation resistance and reduce nerve injury to treat neurodegenerative diseases. Ellagic acid (EA) can inhibit the Keap1 to accumulate the Nrf2 in the nucleus, and act on the ARE to produce target proteins, which in turn may alleviate the impact of OS on neuronal cells of PD. This review analyzes the structure and physiological role of EA, along with the structure, composition and functions of the Keap1-Nrf2-ARE signaling pathway. We further expound on the mechanism of ellagic acid in its activation of the Keap1-Nrf2-ARE signaling pathway, as well as the relationship between EA in impairing the TLR4/Myd88/NF-κB and Nrf2 pathways. Ellagic acid has the potentiality of improving PD by activating the Keap1-Nrf2-ARE signaling pathway and scavenging free radicals.

Neuroimaging Biomarkers in a Patient With Probable Psychiatric-Onset Prodromal Dementia With Lewy Bodies

OBJECTIVES

Psychiatric-onset prodromal dementia with Lewy bodies (DLBs) is a recently proposed clinical entity characterized by psychiatric presentation that may predate clinical dementia by many years. It is not yet clear how to identify patients with prominent late-onset psychiatric symptoms who may have underlying Lewy body disease. In this article, we describe how neuroimaging can assist in the identification of this condition.

METHODS

A 77-year-old man presented with late-onset psychosis. He underwent an extensive clinical and neuropsychological evaluation. These included brain MRI with arterial spin labeling (ASL) which quantifies perfusion. [123I] FP-CIT SPECT and I-metaiodobenzylguanidine scintigraphy assessed striatal dopaminergic and cardiac adrenergic integrity, respectively.

RESULTS

Clinical evaluation revealed a history of REM sleep behavior disorder and parkinsonism induced by antipsychotics. The patient's cognitive function was normal. Conventional MRI showed parieto-occipital atrophy, and posterior hypoperfusion was revealed by ASL-MRI. Of note, the "cingulate island sign" was present. [123I]FP-CIT SPECT and I-metaiodobenzylguanidine endorsed the suspicion of α-synucleinopathy. The patient fulfils the recently proposed key features of psychiatric-onset prodromal DLB.

DISCUSSION

Prodromal DLB is an emerging concept. Biomarkers have not been yet established. We propose that nuclear imaging and advanced MRI technics showing posterior hypoperfusion and the presence of the "cingulate island sign" could be promising biomarker candidates.

Depressive symptoms before and after Parkinson’s diagnosis—A longitudinal analysis

Background

Depression is common in Parkinson’s disease (PD). It is however unclear when and how depressive symptoms develop and progress in the course of PD development.

Objective

To assess how depressive symptoms evolve in PD, using repeated measures.

Methods

In 2994 older adults, ages 70–79 years, depressive symptoms were assessed 8 times over 11 years using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). For each PD patient at each time point, we calculated the difference between CESD-10 score and its expected value estimated based on data from individuals without PD, and then realigned the time scale in reference to the year of PD diagnosis. We examined longitudinal changes in CESD-10 scores before and after PD diagnosis using a joint modeling approach to account for competing risks of non-participation and death.

Results

A total of 79 PD patients were identified at enrollment or during the follow-up, with repeatedly assessed depressive symptom data up to 9 years before and after PD diagnosis. We found a monotonic trend of increasing CESD-10 score in PD patients throughout the observational period (p = 0.002). The observed scores became higher than expected approximately 7 years before PD diagnosis and significantly different 1 year before PD diagnosis.

Conclusions

Increasing depressive symptomatology appears to precede PD diagnosis by a few years.

Early Parkinson's Disease Phenotypes Tailored by Personality, Behavior, and Motor Symptoms

BACKGROUND

Previous studies described a parkinsonian personality characterized as rigid, introverted, and cautious; however, little is known about personality traits in de novo Parkinson's disease (PD) patients and their relationships with motor and neuropsychiatric symptoms.

OBJECTIVE

To investigate personality in de novo PD and explore its relationship with PD symptoms.

METHODS

Using Cloninger's biosocial model, we assessed personality in 193 de novo PD patients. Motor and non-motor symptoms were measured using several validated scales. Cluster analysis was conducted to investigate the interrelationship of personality traits, motor, and non-motor symptoms.

RESULTS

PD patients showed low novelty seeking, high harm avoidance, and normal reward dependence and persistence scores. Harm avoidance was positively correlated with the severity of depression, anxiety, and apathy (rs = [0.435, 0.676], p < 0.001) and negatively correlated with quality of life (rs = -0.492, p < 0.001). Novelty seeking, reward dependence, and persistence were negatively correlated with apathy (rs = [-0.274, -0.375], p < 0.001). Classification of patients according to personality and PD symptoms revealed 3 distinct clusters: i) neuropsychiatric phenotype (with high harm avoidance and low novelty seeking, hypodopaminergic neuropsychiatric symptoms and higher impulsivity), ii) motor phenotype (with low novelty seeking and higher motor severity), iii) benign phenotype (with low harm avoidance and high novelty seeking, reward dependence, and persistence traits clustered with lower symptoms severity and low impulsivity).

CONCLUSION

Personality in early PD patients allows us to recognize 3 patients' phenotypes. Identification of such subgroups may help to better understand their natural history. Their longitudinal follow-up will allow confirming whether some personality features might influence disease evolution and treatment.

Apathy and impulsiveness in Parkinson disease: Two faces of the same coin?

Apathy and impulsiveness are 2 common non-motor symptoms in Parkinson disease that could occur in different periods or simultaneously. Apathy and impulsiveness could be interpreted as opposite extremes of a spectrum of motivated behavior dependent on dopaminergic dysfunction, in which, impulsivity, is a result of a hyperdopaminergic state, whereas apathy is viewed as a hypodopaminergic. The study aimed to investigate the presence of impulsiveness and other neuropsychiatric symptoms in Parkinson disease patients with apathy symptoms. Eighty-one patients with Parkinson disease were enrolled in this retrospective study. All subjects were evaluated by the Italian version of the Dimensional Apathy Scale and the Barratt Impulsiveness Scale-version 11, to assess, respectively, apathy and impulsiveness; they were divided into 2 groups (apathy and no apathy). All patients were administered also with questionnaires assessing depressive and anxious symptoms. Statistical analyses showed relevant results. In no-apathy group, education was a significant predictor on impulsiveness (attentional and motor) and apathy (executive and emotional); depression was a significant predictor on planning impulsivity and apathy. This study aimed to consider the importance of apathy and impulsivity in Parkinson disease. Although these are considered as opposite extremes of a spectrum of motivated behavior dependent on dopaminergic dysfunction, these can also occur separately. Moreover, several variables could represent important predictors of apathy and impulsiveness, such as depression. Future investigations should deepen the role of other demographics and psychological variables.

A Randomized Clinical Trial to Evaluate the Effects of Safinamide on Apathetic Non-demented Patients With Parkinson's Disease

Background

Apathy is highly prevalent and disabling in Parkinson's disease (PD). Pharmacological options for its management lack sufficient evidence.

Objective

We studied the effects of safinamide on apathy in PD.

Methods

Prospective, 24-week, two-site, randomized, double-blind, placebo-controlled, parallel-group exploratory study in non-demented PD on stable dopaminergic therapy randomized 1:1 to adjunct safinamide (50 mg/day for 2 weeks and 100 mg/day for 22 weeks) or placebo. The primary endpoint was the mean change from baseline to week 24 on the Apathy Scale (AS) total score. Secondary endpoints included changes in cognition, activities of daily living, motor scores, the impression of change, and safety and tolerability measures.

Results

In total, 30 participants (active treatment = 15; placebo = 15; 80% showing clinically significant apathetic symptoms according to the AS) were enrolled, and included in the intention-to-treat analysis. Change in AS (ANOVA) showed a trend to significance [p = 0.059] mediated by a more marked decrease in AS score with safinamide (−7.5 ± 6.9) than with placebo (−2.8 ± 5.7). Post-hoc analysis (paired t-test) showed a significant positive change in the AS score between 12-week and 24-week [p = 0.001] only in the active group. No significant or trend changes were found for any of the secondary outcome variables. Adverse events were few and only mild in both treatment groups.

Conclusions

Safinamide was safe and well-tolerated, but failed to provide evidence of improved apathy. The positive trend observed in the post-hoc analyses deserves to be studied in depth in larger studies.

Trial Registration

EudraCT 2017-003254-17.

Histamine H3 receptor antagonists - Roles in neurological and endocrine diseases and diabetes mellitus

Human histamine H3 receptor (H3R) was initially described in the brain of rat in 1983 and cloned in 1999. It can be found in the human brain and functions as a regulator of histamine synthesis and release. H3 receptors are predominantly resident in the presynaptic region of neurons containing histamine, where they modulate the synthesis and release of histamine (autoreceptor) or other neurotransmitters such as dopamine, norepinephrine, gamma-aminobutyric acid (GABA), glutamate, acetylcholine and serotonin (all heteroreceptors). The human histamine H3 receptor has twenty isoforms of which eight are functional. H3 receptor expression is seen in the cerebral cortex, neurons of the basal ganglia and hippocampus, which are important for process of cognition, sleep and homoeostatic regulation. In addition, histamine H3R antagonists stimulate insulin release, through inducing the release of acetylcholine and cause significant reduction in total body weight and triglycerides in obese subjects by causing a feeling of satiety in the hypothalamus. The ability of histamine H3R antagonist to reduce diabetes-induced hyperglycaemia is comparable to that of metformin. It is reasonable therefore, to claim that H3 receptor antagonists may play an important role in the therapy of disorders of cognition, the ability to sleep, oxidative stress, inflammation and anomaly of glucose homoeostasis. A large number of H3R antagonists are being developed by pharmaceutical companies and university research centres. As examples of these new drugs, this review will discuss a number of drugs, including the first histamine H3R receptor antagonist produced.

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.

The 3-Item "Apathy" Subscale Within the GDS-15 Is Not Supported in De Novo Parkinson's Disease Patients: Analysis of the PPMI Cohort

This study examined individual components of the Geriatric Depression Scale-15 (GDS-15) to determine whether the 3-item Withdrawal-Apathy-Lack of Vigor (WAV) subscale, which has been validated in older adults and advanced Parkinson's disease (PD), was applicable to newly diagnosed patients with PD. Baseline Parkinson's Progression Markers Initiative (PPMI) data (n = 345), including GDS-15 and Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) depression, apathy, and anxiety scores, were examined. Data reduction techniques (i.e., principal components, confirmatory factor analyses) were used. Model fit was poor for the previously identified GDS-15 factor structures. Via principal components analysis, 5 components were identified, none of which reflected the 3-item WAV subscale previously reported in the literature. Internal consistency of the GDS-15 was acceptable, as was the internal consistency for the largest component (labeled "Dysphoria"). All 5 components significantly correlated with the MDS-UPDRS depression, apathy, and anxiety items. Model fit was fair for the "Dysphoria" factor only. Overall, the 3-item WAV factor reported in previous literature was not supported in this sample of de novo PD patients.

Bidirectional Correlations Between Dopaminergic Function and Motivation in Parkinson's Disease

OBJECTIVE

To test the hypothesis that striatal dopamine function influences motivational alterations in Parkinson disease (PD), we compared vesicular monoamine transporter 2 (VMAT2) and dopamine transporter (DaT) imaging data in PD patients with impulse control disorders (ICDs), apathy, or neither.

METHODS

We extracted striatal binding ratios (SBR) from VMAT2 PET imaging (18F-AV133) and DaTscans from the Parkinson's Progression Markers Initiative (PPMI) multicenter observational study. Apathy and ICDs were assessed using the Movement Disorders Society-revised Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP), respectively. We used analysis of variance (ANOVA) and log-linear mixed-effects (LME) regression to model SBRs with neurobehavioral metrics.

RESULTS

Among 23 participants (mean age 62.7 years, mean disease duration 1.8 years) with VMAT2 imaging data, 5 had apathy, 5 had an ICD, and 13 had neither. ANOVA indicated strong groupwise differences in VMAT2 binding in right anterior putamen [F(2,20) = 16.2, p < 0.0001), right posterior putamen [F(2,20) = 16.9, p < 0.0001), and right caudate [F(2,20) = 6.8, p = 0.006)]. Post-hoc tests and repeated-measures analysis with LME regression also supported right striatal VMAT2 elevation in the ICD group and reduction in the apathy group relative to the group with neither ICD nor apathy. DaT did not exhibit similar correlations, but normalizing VMAT2 with DaT SBR strengthened bidirectional correlations with ICD (high VMAT2/DaT) and apathy (low VMAT2/DaT) in all striatal regions bilaterally.

CONCLUSIONS

Our findings constitute preliminary evidence that striatal presynaptic dopaminergic function helps describe the neurobiological basis of motivational dysregulation in PD, from high in ICDs to low in apathy.

Apathy as a Treatment Target in Alzheimer's Disease: Implications for Clinical Trials

Apathy is one of the most prevalent, stable and persistent neuropsychiatric symptom across the neurocognitive disorders spectrum. Recent advances in understanding of phenomenology, neurobiology and intervention trials highlight apathy as an important target for clinical intervention. We conducted a comprehensive review and critical evaluation of recent advances to determine the evidence-based suggestions for future trial designs. This review focused on 4 key areas: 1) pre-dementia states; 2) assessment; 3) mechanisms/biomarkers and 4) treatment/intervention efficacy. Considerable progress has been made in understanding apathy as a treatment target and appreciating pharmacological and non-pharmacological apathy treatment interventions. Areas requiring greater investigation include: diagnostic procedures, symptom measurement, understanding the biological mechanisms/biomarkers of apathy, and a well-formed approach to the development of treatment strategies. A better understanding of the subdomains and biological mechanisms of apathy will advance apathy as a treatment target for clinical trials.

High frequency of psychosis in late-stage Parkinsońs disease

•

55.4% of late-stage Parkinsońs disease (LSPD) patients have psychotic symptoms.

•

72.5% of LSPD patients present a comorbid psychiatric diagnosis.

•

Clinical diagnostic interview increases detection of psychosis.

Background

Psychosis is a frequent non-motor symptom in Parkinson’s disease (PD). Estimates of the frequency of Parkinsońs disease psychosis (PDP) vary widely. Knowledge about the frequency and phenomenology of psychosis in late-stage (LS) PD patients is limited.

This study aimed to determine the frequency of psychosis in LSPD patients through clinical diagnostic interview (CDI) (gold standard), according to NINDS/NIMH diagnostic criteria for PDP. The secondary objectives were to characterize the phenomenology, to test selected instruments and assess their adequacy in comparison to CDI, and to assess the psychiatric comorbidities.

Methods

A cross-sectional study including LSPD patients (patients with ≥ 7 years from symptoms 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. Each patient was interviewed by a psychiatrist who performed a CDI.

Results

92 LSPD patients were included. 55.4% experienced psychotic symptoms according to NINDS/NIMH diagnostic criteria for PDP. Hallucinations were present in 94.1% and delusions in 29.4% of the psychotic patients. Visual hallucinations were the most common (88.23%) psychotic symptom. 72.5% of LSPD patients with psychotic symptoms had at least one comorbid psychiatric diagnosis. Lower frequency of psychosis was found when the assessment was performed only through selected instruments rather than CDI.

Conclusions

A high frequency (55.4%) of psychotic symptoms and comorbid psychiatric (72.5%) diagnosis were found in LSPD patients. The use of CDI, in addition to structured scales may increase the sensitivity of detecting psychotic symptoms.

Frequency and Characteristics of Psychosis in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Psychotic symptoms are highly frequent in Parkinson's disease (PD) patients and are associated with poor prognosis. They include hallucinations, delusions, and minor psychotic phenomena, including sense of presence, passage hallucinations, and illusions.

OBJECTIVE

To evaluate the frequency of psychosis in PD patients.

METHODS

A systematic review and meta-analysis of clinical trials, prospective and retrospective cohort studies, case-control studies, and cross-sectional studies reporting the frequency of psychosis, hallucinations, and delusions in PD.

RESULTS

Electronic database search wielded 3536 articles, an additional 91 were identified through citation chaining. Of these, 163 were fully inspected, 57 removed, and 106 included as relevant for neuropsychiatric events frequency, with 32 meeting our inclusion criteria (psychosis and/or specific psychotic phenomena). The pooled frequency of psychosis was 20.7% (95% CI 14.5 to 28.6; I2 = 94%, 15 studies; combined n = 2919). None of the pre-defined meta-regressions or subgroup analyses were statistically significant or helped explain the statistical heterogeneity. The pooled frequency of any form of hallucination was 21.6% (95% CI 14.7 to 30.6; I2 = 95%; 18 studies; combined n = 3161). Duration of PD at baseline and mean baseline Hoehn & Yahr stage helped explain the statistical heterogeneity in the meta-analysis of hallucinations.

CONCLUSION

Based on the available evidence, around a fifth of PD patients experience psychosis or hallucinations. The risk of developing hallucinations is likely moderated by the disease duration, Hoehn & Yahr stage, and the cognitive status.

Dopamine D3 Receptors: A Potential Target to Treat Motivational Deficits in Parkinson's Disease

Parkinson's disease (PD), which is traditionally viewed as a motor disorder involving the degeneration of dopaminergic (DA) neurons, has recently been identified as a quintessential neuropsychiatric condition. Indeed, a plethora of non-motor symptoms may occur in PD, including apathy. Apathy can be defined as a lack of motivation or a deficit of goal-directed behaviors and results in a pathological decrease of self-initiated voluntary behavior. Apathy in PD appears to fluctuate with the DA state of the patients, suggesting a critical role of DA neurotransmission in the pathophysiology of this neuropsychiatric syndrome. Using a lesion-based approach, we developed a rodent model which exhibits specific alteration in the preparatory component of motivational processes, reminiscent to apathy in PD. We found a selective decrease of DA D₃ receptors (D₃R) expression in the dorsal striatum of lesioned rats. Next, we showed that inhibition of D₃R neurotransmission in non-lesioned animals was sufficient to reproduce the motivational deficit observed in our model. Interestingly, we also found that pharmacologically targeting D₃R efficiently reversed the motivational deficit induced by the lesion. Our findings, among other recent data, suggest a critical role of D₃R in parkinsonian apathy and highlight this receptor as a promising target for treating motivational deficits.

Validity and Reliability of the Persian Version of Parkinson's Disease Sleep Scale-2

OBJECTIVE

Sleep problems are nonmotor symptoms in Parkinson's disease that should be carefully evaluated for better management and treatment. Parkinson's Disease Sleep Scale (PDSS-2) is one of the most reliable tools for measuring sleep difficulties in people with Parkinson's disease. This study investigated the psychometric properties of the Persian version of PDSS-2.

METHODS

Four hundred and fifty-six people with Parkinson's disease with a mean age ±standard deviation of 60.7 ± 11.3 years were engaged in this study. Acceptability was assessed by floor and ceiling effects. Dimensionality was measured by exploratory factor analysis. The convergent validity of PDSS-2 with the Hospital Anxiety and Depression Scale (HADS) was assessed. Internal consistency and test-retest reliability were assessed with Cronbach's alpha and intraclass correlation coefficient (ICC), respectively.

RESULTS

No noticeable ceiling and floor effect was detected. The dimensionality analysis showed three factors. A high correlation was obtained between PDSS-2 and HADS (anxiety subscale). Excellent internal consistency with α = 0.94, and good test-retest reliability with ICC = 0.89 were obtained.

CONCLUSION

This study showed that the Persian version of Parkinson's Disease Sleep Scale has acceptable validity and reliability for measuring sleep disturbances in people with Parkinson's disease.

Effort Mobilization and Healthy Aging

Healthy aging is in part dependent upon people's willingness and ability to mobilize the effort necessary to support behaviors that promote health and well-being. People may have the best information relating to health along with the best intentions to stay healthy (e.g., health-related goals), but positive outcomes will ultimately be dependent upon them actually investing the necessary effort toward using this information to achieve their goals. In addition, the influences on effort mobilization may vary as a function of physical, psychological, and social changes experienced by the individual across the life span. Building on the overall theme of this special issue, we explore the relationships between motivation, effort mobilization, and healthy aging. We begin by characterizing the relationship between motivation and effort, and identify the factors that influence effort mobilization. We then consider the factors associated specifically with aging that may influence effort mobilization (e.g., changes in cardiovascular and neural mechanisms) and, ultimately, the health and well-being of older adults. Finally, distinguishing between those influential factors that are modifiable versus intractable, we identify ways to structure situations and beliefs to optimize mobilization in support of healthy aging.

Predicting Neuropsychiatric Symptoms of Parkinson's Disease with Measures of Striatal Dopaminergic Deficiency

BACKGROUND

The role of nigrostriatal dopaminergic neurons degeneration is well established in the pathophysiology of Parkinson's disease. However, it is unclear if and how the degeneration of the dopamine pathways affects the manifestation of the neuropsychiatric symptoms (NPS) of Parkinson's Disease (PD). Dopamine transporter (DAT) imaging, a technique to measure the reduction in dopamine transporters is increasingly used as a tool in the diagnosis of PD.

METHODS

In this study, we examine if the baseline dopamine transporter density in the striatum measured by the Striatal Binding Ratio (SBR) is associated with the longitudinal onset and/or progression of NPS in PD as measured by part 1 of Movement Disorder Society - Unified Parkinson's Disease Rating Scale, over four years. Data of patients with PD and an abnormal screening present on 123I-ioflupane single-proton emission computed tomography were obtained from Parkinson's Progression Markers Initiative (PPMI) database. Latent Growth Modeling (LGM), a statistical technique that can model the change over time while considering the variability in the rate of change at the individual level, was used to examine the progression of NPS over time.

RESULTS

The results indicate the SBR did not correlate with the baseline NPS but did correlate with the rate of change of NPS (p<0.001) over the next four years, even after eliminating age-related variance, which can be a significant confounding factor.

CONCLUSION

In conclusion, this study showed gradual worsening in NPS in patients with Parkinson's disease, which inversely correlates with the density of the dopamine transporters as measured by SBR at baseline.

Knowledge domain and emerging trends in visual hallucination research: A scientometric analysis

BACKGROUND

Visual hallucination (VH) refers to a spontaneous visual perception without corresponding external stimuli and often occurs in ophthalmological and neuropsychiatric disorders. It is associated with poor quality of life, and increased patient hospitalization and nursing home admission. To date, a scientometric analysis of research on VH is lacking.

AIM

To objectively summarize the features of VH research and gain insights into the emerging trends in research on VH.

METHODS

CiteSpace V was used in this article. Publication outputs, document types, geographic distributions, co-authorship status, research hotspots, and co-citation status were analyzed. A total of 2176 original articles and 465 reviews were included in the database downloaded from the Web of Science Core Collection. We selected the top 50 most cited or occurring articles or items to create a visualized network with a 1-year interval. In the document co-citation analysis stage, we performed clustering analysis on co-cited references, and log likelihood tests were used to name the clusters.

RESULTS

The results showed that most publications can be classified into neurology, sports, and ophthalmology studies. In addition, North America, Europe, Asia and Australia published the most documents. Some well-known authors have always had a leading role in this field; meanwhile, new authors keep emerging. A relatively stable cooperation has been formed among many authors. Furthermore, neuropsychiatric symptom and functional connectivity are the top hotspots. Research on VH in dementia with Lewy bodies and Parkinson’s disease (PD) have received much attention. Studies on VH in PD are likely to be the new emerging trends in the future, especially the mechanisms of VH.

CONCLUSION

Research on VH has formed a complete system. More large-scale clinical and in-depth basic research are required to better understand the mechanisms underlying VH, which will contribute to our understanding of the pathophysiology and therapeutic options for VH.

Present and Future of Parkinson's Disease in Spain: PARKINSON-2030 Delphi Project

Parkinson's disease (PD) is a chronic progressive and irreversible disease and the second most common neurodegenerative disease worldwide. In Spain, it affects around 120.000-150.000 individuals, and its prevalence is estimated to increase in the future. PD has a great impact on patients' and caregivers' lives and also entails a substantial socioeconomic burden. The aim of the present study was to examine the current situation and the 10-year PD forecast for Spain in order to optimize and design future management strategies. This study was performed using the modified Delphi method to try to obtain a consensus among a panel of movement disorders experts. According to the panel, future PD management will improve diagnostic capacity and follow-up, it will include multidisciplinary teams, and innovative treatments will be developed. The expansion of new technologies and studies on biomarkers will have an impact on future PD management, leading to more accurate diagnoses, prognoses, and individualized therapies. However, the socio-economic impact of the disease will continue to be significant by 2030, especially for patients in advanced stages. This study highlighted the unmet needs in diagnosis and treatment and how crucial it is to establish recommendations for future diagnostic and therapeutic management of PD.

Recent advances in the pathology of prodromal non-motor symptoms olfactory deficit and depression in Parkinson's disease: clues to early diagnosis and effective treatment

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by movement dysfunction due to selective degeneration of dopaminergic neurons in the substantia nigra pars compacta. Non-motor symptoms of PD (e.g., sensory dysfunction, sleep disturbance, constipation, neuropsychiatric symptoms) precede motor symptoms, appear at all stages, and impact the quality of life, but they frequently go unrecognized and remain untreated. Even when identified, traditional dopamine replacement therapies have little effect. We discuss here the pathology of two PD-associated non-motor symptoms: olfactory dysfunction and depression. Olfactory dysfunction is one of the earliest non-motor symptoms in PD and predates the onset of motor symptoms. It is accompanied by early deposition of Lewy pathology and neurotransmitter alterations. Because of the correlation between olfactory dysfunction and an increased risk of progression to PD, olfactory testing can potentially be a specific diagnostic marker of PD in the prodromal stage. Depression is a prevalent PD-associated symptom and is often associated with reduced quality of life. Although the pathophysiology of depression in PD is unclear, studies suggest a causal relationship with abnormal neurotransmission and abnormal adult neurogenesis. Here, we summarize recent progress in the pathology of the non-motor symptoms of PD, aiming to provide better guidance for its effective management.

[The handling of psychotropics in diseases of central nervous system]

Psychiatric signs and symptoms occur frequently in individuals with central nervous system diseases. Inadequately treated, these comorbid conditions affect patient rehabilitation, compliance with treatment and quality of life. Their management poses a major challenge given the variable efficacy and safety profiles of available psychotropic drugs and increased risk of drug interaction. This review aims to summarize the existing literature on the prescription of psychotropic drugs for management of psychiatric disorders among persons with central nervous system's diseases.

Distinct neural circuits are associated with subclinical neuropsychiatric symptoms in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) can present with neuropsychiatric symptoms (here, anxiety, depression, and apathy) at any stage of the disease. We investigated the neural correlates of subclinical neuropsychiatric symptoms in relation to motor and cognitive symptoms in a high-functioning PD cohort.

METHODS

Brain morphometry of the cognitively intact, early-stage (Hoehn & Yahr 2) PD group (n = 48) was compared to matched controls (n = 37). Whole-brain, pairwise, resting-state functional connectivity measures were correlated with neuropsychiatric symptom, motor exam, and global cognitive scores of the PD group.

RESULTS

Factor analysis of highly collinear anxiety, depression, and apathy scores revealed a single principal component (i.e., composite neuropsychiatric symptom score) explaining 71.6% of variance. There was no collinearity between the neuropsychiatric, motor, and cognitive scores. Compared to controls, PD group showed only subcortical changes including amygdala and nucleus accumbens atrophy, and greater pallidal volume. Reduced functional connectivity in the limbic cortical-striatal circuits and increased functional connectivity between the cerebellum and occipito-temporal regions were associated with a more impaired neuropsychiatric profile. This functional connectivity pattern was distinct from those associated with motor deficits and global cognitive functioning. The individual components of the neuropsychiatric symptoms also exhibited unique connectivity patterns.

LIMITATIONS

Patients were scanned in "on-medication" state only and a control group with similar neuropsychiatric symptoms was not included.

CONCLUSION

Abnormal functional connectivity of distinct neural circuits is present even at the subclinical stage of neuropsychiatric symptoms in PD. Neuropsychiatric phenotyping is important and may facilitate early interventions to "reorganize" these circuits and delay/prevent clinical symptom onset.

Evolution of Apathy in Early Parkinson's Disease: A 4-Years Prospective Cohort Study

Objective: We investigated the prevalence, evolution, associated factors, and risk factors of apathy in a cohort of patients with early-stage Parkinson's disease (PD), who underwent a 4-years prospective follow-up. Methods: This study included 188 patients with PD (baseline disease duration <3 years) who underwent an annual evaluation using the Lille Apathy Rating Scale (LARS). Based on the cut-off value of -21 observed on the LARS, patients were categorized as PD with and without apathy. The generalized estimating equations (GEE) model was utilized to determine the factors associated with apathy, and the Cox proportional-hazards regression model was used to determine the predictors of apathy. Results: Apathy increased from a baseline rate of 18.6-28.8% after 4 years; notably, this rate was not persistent across patients' visits. The LARS score was independently associated with the male sex (B 8.131, p = 0.009), low Frontal Assessment Battery (FAB) scores (B 0.567, p = 0.011), low attention scores on the Montreal Cognitive Assessment (MOCA) test (B 0.217, p = 0.026), high Hamilton Depression Rating Scale (HDRS) scores (B 1.362, p < 0.001), high Unified Parkinson's Disease Rating Scale (UPDRS) part III scores (B 1.147, p < 0.001), and prolonged follow-up time (B 1.785, p = 0.048). A high HDRS score was the only predictor of apathy in PD [hazard ratio (HR) 1.043, p = 0.026]. Conclusions: The risk of apathy is higher in men with progressive PD accompanied by disease-specific motor and non-motor symptoms. Depression during early-stage PD is a primary risk factor for apathy in PD.

Physical Activity Improves Anxiety and Apathy in Early Parkinson's Disease: A Longitudinal Follow-Up Study

Objective: In a prospective study, we investigated the association between physical activity and various motor, non-motor outcomes, and quality of life in early Parkinson's disease (PD) participants in the PD Longitudinal Singapore Study.

Background: Prospective studies that examined the association between physical activity and motor and non-motor domains in early PD are lacking.

Methods: 121 PD participants were followed-up prospectively to evaluate the association of physical activity with various symptom domains. The Physical Activity Scale for the Elderly (PASE) was used to measure physical activity annually. PD-related symptoms were categorized by motor, non-motor, and quality of life measures. Multivariate regression with gain score analysis was performed to understand the association of baseline PASE scores with the change of each variable at 1-year follow-up.

Results: Higher baseline PASE scores (greater activity) were associated with a younger age, lower MDS-UPDRS motor scores, a smaller levodopa equivalent daily dose, better attention and memory scores, and better QoL. Activity scores in early PD declined on follow-up. Multivariate analysis revealed higher baseline physical activity to be associated with decreased anxiety and apathy scores at 1-year follow-up, after adjusting for demographic variables and medications.

Conclusion: We demonstrated that higher baseline physical activity was associated with improved anxiety and apathy symptoms in early PD over a 1-year period.

Schizotypy in Parkinson's disease predicts dopamine-associated psychosis

Psychosis is the most common neuropsychiatric side-effect of dopaminergic therapy in Parkinson’s disease (PD). It is still unknown which factors determine individual proneness to psychotic symptoms. Schizotypy is a multifaceted personality trait related to psychosis-proneness and dopaminergic neurotransmission in healthy subjects. We investigated whether (1) PD patients exhibit lower schizotypy than controls and (2) dopamine-related neuropsychiatric side-effects can be predicted by higher schizotypy. In this cross-sectional study, we used the Oxford-Liverpool Inventory of Feelings and Experiences in 56 PD patients (12 women, mean ± sd age: 61 ± 11 years) receiving their usual dopaminergic medication and 32 age-matched healthy controls (n = 32; 18 women, mean ± sd age: 57 ± 6 years). We further compared schizotypy scores of patients with (n = 18, 32.1%) and without previously experienced psychosis. We found that patients exhibited lower schizotypy than controls. Further, patients with a history of psychosis exhibited higher schizotypy than patients without these symptoms. Using an information theoretic measure and a machine learning approach, we show that schizotypy yields the greatest predictive value for dopamine-associated hallucinations compared to other patient characteristics and disease related factors. Our results indicate an overlap between neural networks associated with schizotypy and the pathophysiology of PD and a relationship between schizotypy and psychotic side-effects of dopaminergic medication.