Depression in Parkinson's disease -- a review

Investigation of the nonmotor symptoms in patients with STN-DBS therapy in comparison with those without STN-DBS

The impact of STN-DBS on NMS remains rather as an underestimated topic. Besides, the significance of NMSs in QOL indexes of PD subjects with STN-DBS is unknown. We primarily aimed to evaluate the NMSs and their significance in QOL indexes in PD subjects comparatively with and without STN-DBS therapy. We enrolled all consecutive PD subjects with and without STN-DBS who applied to our movement disorders outpatient clinics between January/2023 and September/2023. We performed comprehensive assessments of the motor and nonmotor features including the clinical scales of Movement Disorder Society-sponsored revision of the MDS-UPDRS, NMSS, HAM-A, HAM-D, and the PDQ-39. Overall, 48 PD subjects with STN-DBS and 161 without STN-DBS treatment were included. The comparative analyses revealed that the sub-scores of the MDS-UPDRS-2, -3 and -4 were higher in the STN-DBS group. However, the MDS-UDPRS-1 and the total scores of the NMSS were similar between groups. Among eight subitems of the NMSS, only, the sub scores of the mood/cognition and the gastrointestinal tract differed. Remarkably, the significant correlations between the scores of the QOL and the NMSS scores in the STN-DBS (-) group, did not persist within the STN-DBS group. Remarkably, the correlations between the NMSS and PQQ-39 disappeared for most of the sub scores within the STN-DBS group. We found indirect evidence regarding the benefit of STN-DBS therapy on NMSs in our cross-sectional study. Besides, we found weaker impact of NMSs in QOL indexes in PD subjects with STN-DBS therapy.

Lower motor performance is linked with poor sleep quality, depressive symptoms, and grey matter volume alterations

Motor performance (MP) is essential for functional independence and well-being, particularly in later life. However, the relationship between behavioural aspects such as sleep quality and depressive symptoms, which contribute to MP, and the underlying structural brain substrates of their interplay remains unclear. This study used three population-based cohorts of younger and older adults (n=1,950) from the Human Connectome Project-Young Adult (HCP-YA), HCP-Aging (HCP-A), and enhanced Nathan Kline Institute-Rockland sample (eNKI-RS). Several canonical correlation analyses were computed within a machine learning framework to assess the associations between each of the three domains (sleep quality, depressive symptoms, grey matter volume (GMV)) and MP. The HCP-YA analyses showed progressively stronger associations between MP and each domain: depressive symptoms (unexpectedly positive, r=0.13, SD=0.06), sleep quality (r=0.17, SD=0.05), and GMV (r=0.19, SD=0.06). Combining sleep and depressive symptoms significantly improved the canonical correlations (r=0.25, SD=0.05), while the addition of GMV exhibited no further increase (r=0.23, SD=0.06). In young adults, better sleep quality, mild depressive symptoms, and GMV of several brain regions were associated with better MP. This was conceptually replicated in young adults from the eNKI-RS cohort. In HCP-Aging, better sleep quality, fewer depressive symptoms, and increased GMV were associated with MP. Robust multivariate associations were observed between sleep quality, depressive symptoms and GMV with MP, as well as age-related variations in these factors. Future studies should further explore these associations and consider interventions targeting sleep and mental health to test the potential effects on MP across the lifespan.

Late-life mood disorder as the initial presentation of progressive supranuclear palsy: A case series

Aim

Progressive supranuclear palsy (PSP) is a rapidly progressive neurodegenerative disorder characterized by Parkinsonism, supranuclear ophthalmoplegia, postural instability, and cognitive impairment.

Patients

This case series describes three patients initially diagnosed with late-life mood disorders (depression and bipolar disorder) who were later diagnosed with PSP because of the development of typical neurological symptoms.

Result

The diagnostic challenge of PSP is highlighted in this case report, particularly in the early stages, when characteristic symptoms may not be present. The importance of considering PSP in the differential diagnosis of late-life mood disorders, especially in the absence of response to standard antidepressant therapy, is also emphasized. The heterogeneity of PSP is described, with various subtypes and atypical variants presenting with different clinical features. The psychiatric symptoms of PSP include apathy, disinhibition, depression, and anxiety, whereas hallucinations and delusions are less frequent. Tau positron emission tomography imaging is discussed as a potential biomarker for atypical PSP.

Conclusion

Early diagnosis and intervention are crucial for improved outcomes in PSP, necessitating further research to enhance the diagnostic and treatment strategies for PSP and other neurodegenerative diseases.

Effects of STN-DBS on cognition and mood in young-onset Parkinson's disease: a two-year follow-up

Background

The effects of subthalamic nucleus deep brain stimulation (STN-DBS) on the cognition and mood of patients with PD are still not uniformly concluded, and young-onset Parkinson's disease (YOPD) is even less explored.

Objective

To observe the effectiveness of STN-DBS on the cognition and mood of YOPD patients.

Methods

A total of 27 subjects, with a mean age at onset of 39.48 ± 6.24 and age at surgery for STN-DBS of 48.44 ± 4.85, were followed up preoperatively and for 2 years postoperatively. Using the Unified Parkinson disease rating scale (UPDRS), H&Y(Hoehn and Yahr stage), 39-Item Parkinson's Disease Questionnaire (PDQ-39), Mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA) to assess motor, cognition, and mood.

Results

At the 2-year follow-up after STN-DBS, YOPD patients showed significant improvements in motor and quality of life (UPDRS III: p < 0.001, PDQ-39: p < 0.001); overall cognition was not significantly different from preoperative (MMSE: p = 0.275, MoCA: p = 0.913), although language function was significantly impaired compared to preoperative (MMSE: p = 0.004, MoCA: p = 0.009); depression and anxiety symptoms also improved significantly (HAMD: p < 0.001, HAMA: p < 0.001) and the depression score correlated significantly with motor (preoperative: r = 0.493, p = 0.009), disease duration (preoperative: r = 0.519, p = 0.006; postoperative: r = 0.406, p = 0.036) and H&Y (preoperative: r = 0.430, p = 0.025; postoperative: r = 0.387, p = 0.046); total anxiety scores were also significantly correlated with motor (preoperative: r = 0.553, p = 0.003; postoperative: r = 0.444, p = 0.020), disease duration (preoperative: r = 0.417, p = 0.031), PDQ-39 (preoperative: r = 0.464, p = 0.015) and H&Y (preoperative: r = 0.440, p = 0.022; postoperative: r = 0.526, p = 0.005).

Conclusion

STN-DBS is a safe and effective treatment for YOPD. The mood improved significantly, and overall cognition was not impaired, were only verbal fluency decreased but did not affect the improvement in quality of life.

Tonic dopamine and biases in value learning linked through a biologically inspired reinforcement learning model

A hallmark of various psychiatric disorders is biased future predictions. Here we examined the mechanisms for biased value learning using reinforcement learning models incorporating recent findings on synaptic plasticity and opponent circuit mechanisms in the basal ganglia. We show that variations in tonic dopamine can alter the balance between learning from positive and negative reward prediction errors, leading to biased value predictions. This bias arises from the sigmoidal shapes of the dose-occupancy curves and distinct affinities of D1- and D2-type dopamine receptors: changes in tonic dopamine differentially alters the slope of the dose-occupancy curves of these receptors, thus sensitivities, at baseline dopamine concentrations. We show that this mechanism can explain biased value learning in both mice and humans and may also contribute to symptoms observed in psychiatric disorders. Our model provides a foundation for understanding the basal ganglia circuit and underscores the significance of tonic dopamine in modulating learning processes.

The pharmacological management of the behavioral aspects of Parkinson's disease: an update

INTRODUCTION

Behavioural symptoms are common manifestations of Parkinson's disease and include depression, anxiety, impulse control disorders, hallucinations, psychosis, and cognitive dysfunction. They remain inadequately addressed in many patients despite their relevance for quality of life and disability. This applies also to impulse control disorders where the most common approach in recent literature is to refrain from using dopamine agonists without consideration about their potential benefit on motor complications.

AREAS COVERED

We conducted a narrative review searching for articles on behavioral symptoms in Parkinson disease and selected those which included involved neurotransmitters such as dopamine, noradrenaline, serotonin, acetylcholine. We specifically focused our search on open-label and randomized double-blind studies and biomarkers which could best characterize these clinical manifestations.

EXPERT OPINION

Management of Parkinson disease behavioural manifestations lacks clear guidelines and standardized protocols beside general suggestions of dose adjustments in dopamine replacement therapy and use of antidepressants or antipsychotic drugs with little consideration of patients' age, sex, comorbidities, and motor status. We suggest a pragmatic approach which includes education of affected patients and caring people, dealing with complex cases by experienced multidisciplinary teams, use of cognitive behavioural therapy, and psychological counselling to complement drug treatment.

A pilot study of machine learning of resting-state EEG and depression in Parkinson's disease

Introduction

Depression is a non-motor symptom of Parkinson's disease (PD). PD-related depression is difficult to diagnose, and the neurophysiological basis is poorly understood. Depression can markedly affect cortical function, which suggests that scalp electroencephalography (EEG) may be able to distinguish depression in PD. We conducted a pilot study of depression and resting-state EEG in PD.

Methods

We recruited 18 PD patients without depression, 18 PD patients with depression, and 12 demographically similar non-PD patients with clinical depression. All patients were on their usual medications. We collected resting-state EEG in all patients and compared cortical brain signal features between patients with and without depression. We used a machine learning algorithm that harnesses the entire power spectrum (linear predictive coding of EEG Algorithm for PD: LEAPD) to distinguish between groups.

Results

We found differences between PD patients with and without depression in the alpha band (8-13 Hz) globally and in the beta (13-30 Hz) and gamma (30-50 Hz) bands in the central electrodes. From two minutes of resting-state EEG, we found that LEAPD-based machine learning could robustly distinguish between PD patients with and without depression with 97 % accuracy and between PD patients with depression and non-PD patients with depression with 100 % accuracy. We verified the robustness of our finding by confirming that the classification accuracy gracefully declines as data are randomly truncated.

Conclusions

Our results suggest that resting-state EEG power spectral analysis has the potential to distinguish depression in PD accurately. We demonstrated the efficacy of the LEAPD algorithm in identifying PD patients with depression from PD patients without depression and controls with depression. Our data provide insight into cortical mechanisms of depression and could lead to novel neurophysiological markers for non-motor symptoms of PD.

SUMOylation and Major Depressive Disorder

Since the discovery of the small ubiquitin-like modifier (SUMO) protein in 1995, SUMOylation has been considered a crucial post-translational modification in diverse cellular functions. In neurons, SUMOylation has various roles ranging from managing synaptic transmitter release to maintaining mitochondrial integrity and determining neuronal health. It has been discovered that neuronal dysfunction is a key factor in the development of major depressive disorder (MDD). PubMed and Google Scholar databases were searched with keywords such as 'SUMO', 'neuronal plasticity', and 'depression' to obtain relevant scientific literature. Here, we provide an overview of recent studies demonstrating the role of SUMOylation in maintaining neuronal function in participants suffering from MDD.

Prodromal depression and subsequent risk of developing Parkinson's disease: a systematic review with meta-analysis

Aim: Parkinson's disease (PD) is a progressive neurological disorder that predominately affects dopaminergic neurons. We believe that this pooling of data will help to better understand the prodromal nature of depression in PD. Materials & methods: We conducted this study in accordance with PRISMA guidelines 2020. Fifteen eligible articles were shortlisted for final analysis. Risk of bias assessment was also conducted Results: The random-effect model revealed that the risk of subsequent Parkinson's disease in patients with prodromal depression was twice as likely (OR, 2.04; 95% CI, 1.02-4.08) as compared with a healthy population. Conclusion: Our meta-analysis concluded that the subsequent risk of PD is significantly higher in patients with depression as compared with healthy individuals.

Depression Level Prediction in People with Parkinson's Disease during the COVID-19 Pandemic

Many recent studies show that the COVID-19 pandemic has been severely affecting the mental wellness of people with Parkinson's disease. In this study, we propose a machine learning-based approach to predict the level of anxiety and depression among participants with Parkinson's disease using surveys conducted before and during the pandemic in order to provide timely intervention. The proposed method successfully predicts one's depression level using automated machine learning with a root mean square error (RMSE) of 2.841. In addition, we performed model importance and feature importance analysis to reduce the number of features from 5,308 to 4 for maximizing the survey completion rate while minimizing the RMSE and computational complexity.

Depression Induced by Chronic Unpredictable Mild Stress Increases Susceptibility to Parkinson's Disease in Mice via Neuroinflammation Mediated by P2X7 Receptor

The relationship between depression and Parkinson's disease (PD) is complicated and still not fully understood. We investigated whether depression increased the susceptibility to PD and whether this resulted from neuroinflammation mediated by purinergic ligand-gated ion channel 7 receptor (P2X7R) of microglia in mice. Depression was induced by a 14-day chronic unpredictable mild stress (CUMS), and PD was induced by 1-day acute injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Before MPTP administration, some mice were given brilliant blue G (BBG), a P2X7R inhibitor. Changes in depression and motor function were assessed by sucrose preference, tail suspension, open field, and rotating rod tests. Differences in P2X7R, caspase-1, NLRP3 inflammasome, interleukin (IL)-1β, tyrosine hydroxylase (TH), and microglial activation among experimental groups were detected by immunofluorescence, immunohistochemistry, western blotting, and ELISA. CUMS-induced depression-like behavior, and MPTP induced PD in mice. CUMS mice had no motor dysfunction, but the dyskinesia and loss of TH-positive neurons in the substantia nigra after MPTP treatment were more serious than with MPTP treatment alone. With behavioral changes, neuroinflammatory markers, such as caspase-1, NLRP3 and IL-1β increased, and microglia were activated as well as expression of P2X7R increased. Additionally, BBG partly reversed the above abnormalities. Summarily, we suggest that CUMS aggravates dyskinesia and death of dopaminergic neurons in an MPTP-PD model via promoting activation of microglia and neuroinflammation, which may be mediated by P2X7R. Inhibition of P2X7R could be a new control strategy for PD associated with depression.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Risk of Dementia in Patients with Depression or Parkinson's Disease: A Retrospective Cohort Study

Background

This study aimed to clarify whether Parkinson's disease (PD) and depression were independent risk factors or with synergic effects in dementia.

Methods

Newly diagnosed PD (n = 1213) patients and control subjects (n = 4852) were selected from the Taiwan National Health Insurance Research Database from January 2001 through December 2008. Follow-up ended in 2011 with an outcome of dementia occurring or not. This cohort was divided into controls with or without depression, PD only, and PD with depression. The incident rate of dementia and hazard ratio (HR) using Cox's regression analysis were calculated for each group.

Results

When compared with controls without depression as HR 1.00, the adjusted HR for dementia was 3.29 (p < 0.001) in the PD only group, 2.77 (p < 0.001) in the PD with depression group, and 1.55 (p=0.024) in the depression only group. The incident rate of dementia was 29.2 (per 1000 person-years) in the PD only group and 13.2 in the PD with depression group. The effect of PD on dementia in the depression group produced a HR of 0.97 (p=0.905).

Conclusions

Parkinson's disease served as a risk factor for dementia. By comparison, depression was not a risk factor for dementia in PD patients, although it did act as a risk factor for dementia.

Depressive symptoms effect subjective sleep quality in Chinese patients with Parkinson's disease

OBJECTIVES

The objective of this paper was aimed to estimate the influence of depressive symptoms on subjective sleep quality in Chinese PD patients.

PATIENTS AND METHODS

A sample of 491 PD patients was collected and studied in the present study. Depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAMD). PD severity was assessed using Hoehn and Yahr (H-Y) staging, and motor symptoms were measured with the Unified PD Rating Scale (UPDRS) part III. The Montreal Cognitive Assessment (MOCA) was used to evaluate the global Cognitive status and PD Sleep Scale (PDSS) was used to quantify sleep quality. Three linear regression models were built to check factors associated with caregiver burden, one for the total sample and two for subgroups stratified by the presence of cognitive disturbance.

RESULTS

In our sample, 29.9% of patients suffer from sleep disturbance. The most frequent depressive symptoms were helplessness (81.5%), depressed mood (57.8%), and general somatic symptoms (55.4%) for entire sample. Patients with cognitive disturbance (n = 274; 55.8% of sample) presented more depressive symptoms than patients without cognitive disturbance. Patients suffer poorer sleep quality when patients experience depression with cognitive disturbance. On linear regression models, the main determinants of subjective quality for the total sample were NMS-depression/anxiety/anhedonia, HAMD-anxiety/somatization, disease severity, age and HAMD-loss of weight. For patients with cognitive disturbance, the significant determinants were NMS-depression/anxiety/anhedonia, HAMD-anxiety/somatization, motor symptoms, HAMD-loss of weight and gender. For patients without cognitive disturbance, the significant determinants were NMS-depression/anxiety/anhedonia, disease severity and HAMD-anxiety/somatization.

CONCLUSION

Depressive symptoms in PD are highly associated with and are determinants of subjective sleep quality, and are more prevalent in patients with cognitive disturbance. Detailed assessment and specific interventions aimed at depression and dementia could alleviate sleep disorder.

The Effect of Different Exercise Modes on Domain-Specific Cognitive Function in Patients Suffering from Parkinson's Disease: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Supervised exercise training alleviates motor symptoms in people with Parkinson's disease (PD). However, the efficacy of exercise to improve nonmotor symptoms such as cognitive function is less well known.

OBJECTIVE

To systematically review evidence on the efficacy of different exercise modes (coordination exercise, resistance exercise, aerobic exercise) on domain-specific cognitive function in patients with PD.

METHODS

Parallel-group randomized controlled trials published before March 2018 were included. Primary outcome measures included global cognitive function and its subdomains, and the Unified Parkinson's Disease Rating Scale was included as a secondary outcome. Methodological quality was assessed using the Physiotherapy Evidence Database scale.

RESULTS

The literature search yielded 2,000 articles, of which 11 met inclusion criteria. 508 patients (mean age 68±4 years) were included with a disease severity from 1 to 4 on the Hoehn & Yahr stage scale. Overall study quality was modest (mean 6±2, range 3-8/10). In 5 trials a significant between-group effect size (ES) was identified for tests of specific cognitive domains, including a positive effect of aerobic exercise on memory (ES = 2.42) and executive function (ES = 1.54), and of combined resistance and coordination exercise on global cognitive function (ES = 1.54). Two trials found a significant ES for coordination exercise (ES = 0.84-1.88), which led to improved executive function compared with that of non-exercising control subjects.

CONCLUSION

All modes of exercise are associated with improved cognitive function in individuals with PD. Aerobic exercise tended to best improve memory; however, a clear effect of exercise mode was not identified.

Damaged Insula Network Contributes to Depression in Parkinson's Disease

BACKGROUND

Depression is common in patients with Parkinson's disease (PD). Our previous studies suggest that depressed PD patients have altered insula structures. It is, however, still unknown whether the altered structures cause disruption of insula functional networks, further contributing to depression in PD.

METHODS

In the present study, 17 depressed PD patients, 17 non-depressed PD patients, and 17 normal controls were enrolled. All subjects went through neurological and psychiatric clinical assessments. Resting-state functional magnetic resonance imaging and seed-based insula functional analyses were performed to examine the insula functional connectivity alterations in PD patients.

RESULTS

We found that compared with normal controls, PD patients exhibited significantly decreased insula functional connectivity widely across the whole brain. Compared with non-depressed PD patients, depressed patients showed further decreased functional connectivity in the middle frontal gyrus and inferior parietal lobe. Furthermore, connectivity between the left anterior insula and middle frontal gyrus was positively correlated with the cognitive scale score.

CONCLUSION

These results suggest that insula networks were severely damaged in PD patients, and that the disrupted connection between the salience network and executive control network might contribute to depression in PD.

Clinical and Therapeutic Challenges when Psychiatric Disorders Occur in Neurological Diseases: A Narrative Review

Background:

Over the course of the 20th century, neurology and psychiatry diverged and became two separate disciplines. Subsequently, the continuous progress of neurosciences confused their boundaries. However, with ‘the splitting’ and ‘the lumping’ approaches, relevant difficulties remain in targeting clinical and therapeutic goals, when psychiatric signs and symptoms co-occur with neurological diseases.

Objective:

The study summarize current evidence on psychiatric signs and symptoms comorbid with neurological diseases, with the aim to provide information on diagnostic problems and available therapeutic options.

Methods:

Finding from searches of publications on ‘PsycInfo’, ‘Medline’, and ‘Science Direct’, from January 1993 to December 2018 (25 years) is summarized in a narrative manner on six main neurological areas: congenital neurological illnesses (n=16), dementias (n=15), basal ganglia diseases (n=30), epilepsy (n=22), strokes/focal brain injuries (n=29), and neurological neoplastic/paraneoplastic diseases (n=15).

Results:

Clinical phenotypes of psychiatric syndromes are frequently described in neurological studies. Little evidence is provided on the most adequate therapeutic approaches.

Conclusion:

Psychiatric syndromes in comorbidity with neurological diseases are heterogeneous and severe; evidence-based treatments are scarce. Despite a model supporting an equal approach between psychiatric and neurological syndromes, psychiatric syndromes in neurological diseases have been described, to a relevant degree, as less important, leading to a hierarchical primate of the neurological manifestations, and thus, in our opinion, limiting the systematic studies on psychopharmacological treatments in this area.

Examining the Reserve Hypothesis in Parkinson's Disease: A Longitudinal Study

BACKGROUND

Whether reserve plays a role in Parkinson's disease (PD) patients has received less attention than in dementia and has been mainly examined in relation with cognitive function.

OBJECTIVE

To investigate whether reserve plays a role in the severity and progression of motor, cognitive, and nonmotor PD symptoms by examining whether education level (proxy of reserve) is associated with baseline performance and rate of progression.

METHODS

We used data from a longitudinal cohort of PD patients (≤5-year disease duration at baseline) annually followed up to 5 years (n = 393; 41% women; mean age = 62.3 years, standard deviation = 10.0; mean disease duration = 2.6 years, standard deviation = 1.5). We examined the relationship of education with time to reach Hoehn and Yahr stage ≥3 using Cox regression and with baseline severity and progression of motor (Movement Disorder Society-Unified Parkinson's Disease Rating Scale parts II and III, gait speed), cognitive (Mini-Mental State Examination), and nonmotor (depression, anxiety, nonmotor symptoms scale, quality of life) symptoms using mixed models.

RESULTS

Education level was not associated with age at onset or diagnosis. Compared with the low-education group, the incidence of Hoehn and Yahr ≥3.0 was 0.42 times lower (95% confidence interval, 0.22-0.82, P = 0.012) in the high-education group. Higher education was associated with better baseline motor function (P < 0.001), but not with the rate of motor decline (P > 0.15). Similar results were observed for cognition. Education was not associated with nonmotor symptoms.

CONCLUSIONS

Higher education is associated with better baseline motor/cognitive function in PD, but not with rate of decline, and with a lower risk of reaching Hoehn and Yahr ≥3 during the follow-up. Our observations are consistent with a passive reserve hypothesis for motor/cognitive symptoms. © 2019 International Parkinson and Movement Disorder Society.

A Stage-Based Approach to Therapy in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disorder that features progressive, disabling motor symptoms, such as bradykinesia, rigidity, and resting tremor. Nevertheless, some non-motor symptoms, including depression, REM sleep behavior disorder, and olfactive impairment, are even earlier features of PD. At later stages, apathy, impulse control disorder, neuropsychiatric disturbances, and cognitive impairment can present, and they often become a heavy burden for both patients and caregivers. Indeed, PD increasingly compromises activities of daily life, even though a high variability in clinical presentation can be observed among people affected. Nowadays, symptomatic drugs and non-pharmaceutical treatments represent the best therapeutic options to improve quality of life in PD patients. The aim of the present review is to provide a practical, stage-based guide to pharmacological management of both motor and non-motor symptoms of PD. Furthermore, warning about drug side effects, contraindications, as well as dosage and methods of administration, are highlighted here, to help the physician in yielding the best therapeutic strategies for each symptom and condition in patients with PD.

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

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

The relationship between temperament and depression in Parkinson's disease patients under dopaminergic treatment

AIM

The risk factors for depressive symptoms in patients with Parkinson's disease (PD) under dopaminergic drug treatment are unclear. In this study, we examined whether some temperament traits are related to the presence of comorbid depression in PD patients, independent of the characteristics of illness and drug treatment.

METHODS

The participants in this study were 74 patients with idiopathic PD who were already treated with stable doses of levodopa or dopamine agonists. Depressive (n = 20) and non-depressive (n = 52) PD patients were assessed by means of the Unified Parkinson's Disease Rating Scale, Beck Depression Inventory, and Temperament Evaluation of Memphis, Pisa, Paris and San Diego Auto-questionnaire. The doses of levodopa and dopamine agonists were converted into levodopa equivalent daily dose.

RESULTS

The duration of treatment in the depressive group was significantly longer than in the non-depressive group (P = 0.03). The depressive patients had significantly higher scores on the Unified Parkinson's Disease Rating Scale than the non-depressive patients. Depressive (P < 0.0001), cyclothymic (P < 0.0001), anxious (P < 0.0001), and irritable (P = 0.02) temperament scores were significantly higher in depressive than in non-depressive patients. Hyperthymia scores were significantly higher in non-depressive patients than in depressive patients (P = 0.01). Logistic regression analysis revealed that depressive temperament traits (P = 0.03) significantly predicted the diagnosis of depression. In contrast, hyperthymic temperament seemed to be associated with the absence of depression (P = 0.006).

CONCLUSION

Our results indicated that the severity of PD and duration of dopaminergic treatment were not predictive of the development of depression in PD patients. Depressive temperament strongly predicted the development of depression in our sample. Hyperthymic temperament seemed to be associated with patients without depression. We suggest that depressive temperament traits seem to be related to depression, while hyperthymic temperament may have a protective role in the risk of depression in PD patients.

Effects of a Group Protocol on Physical Activity and Associated Changes in Mood and Health Locus of Control in Adults with Parkinson Disease and Reduced Mobility

BACKGROUND

Parkinson disease (PD) is a degenerative nervous disorder that affects motor functioning. Although physical activity is beneficial, it often is reduced, and psychosocial issues persist such as low mood and perceptions of loss of control over health.

OBJECTIVE

To determine the extent to which a community-based physical activity/self-regulatory skills intervention affects overall physical activity and changes in psychosocial factors in adults with PD and in adults with reduced mobility without PD.

METHODS

Existing participants (N = 45, mean age = 71 years) of community-based PD group movement classes, who also participated in an individualized 6-session protocol for exercise support that emphasized self-regulation through barriers, completed validated self-report surveys. Participants' mean length of movement class participation was 11.8 months at the time of survey administration.

RESULTS

Mixed-model repeated-measures analysis of variance indicated significant improvements in physical activity, self-regulation, exercise self-efficacy, negative mood, and task social cohesion but not internal health locus of control. Improvement in social cohesion was significantly greater in the PD group (n = 27) than in the non-PD (n = 18) group. Changes in exercise self-efficacy mediated a significant relationship between changes in self-regulation and physical activity. Changes in social cohesion mediated a significant relationship between changes in physical activity and mood. Changes in mood and social cohesion had a reciprocal, mutually reinforcing relationship. For the PD group, length of program involvement predicted vigor change (r = 0.52, p = 0.006).

CONCLUSION

The intervention demonstrated positive effects on physical activity and psychosocial factors in adults with PD and with reduced mobility. Effects on social cohesion were important. Such programming should be considered as an adjunct to traditional medical treatment.

Echogenic alteration in the raphe nuclei measured by transcranial sonography in patients with Parkinson disease and depression

BACKGROUND

Recently, several studies using transcranial sonography (TCS) have demonstrated reduced echogenicity of the mesencephalic midline in unipolar depression and patients with comorbid depression and Parkinson disease (PD). However, there is no consensus on the conclusion that raphe nuclei (RN) hypoechogenicity is associated with depression in PD. The methods used in previous studies lack quantitative and objective indicators to some extent; therefore, the present study used the level of platelet 5-hydroxytryptamine (5-HT) as an objective indicator of depression. Additionally, the reason for the reduced echogenicity of the brainstem raphe is still unclear.

OBJECTIVES

The purpose of the present study was to assess the correlation between alterations in RN echogenicity and depressive symptoms in patients with PD using transcranial sonography (TCS). This information could provide a meaningful clinical reference for the antidiastole between depressive symptoms in PD and unipolar depression in patients with PD in whom depressive symptoms occur before motor symptoms.

METHODS

TCS was performed in patients with PD, patients with PD and depression, patients with depression and no PD, and healthy controls. Using the red nucleus as a reference, the RN was rated from grades 0 to 1 (grade 0: invisible, slightly echogenic, or interrupted RN; grade 1: hyperechogenicity in the RN observed as a continuous line).

RESULTS

The rate of abnormal RN (grade 0) was found to be 16.67% in patients with PD (5/30) and 14.29% in healthy controls (4/28). The presence of abnormal RN was significantly higher (χ = 15.983, P < .05) in patients with depression and PD (40%, 12/30) and in patients with depression only (58.33%, 14/24) than in those without depression and healthy controls. No correlation was found between RN changes and depression severity (P > .05). There were no statistical differences in the concentration of platelet serotonin among the 4 groups (P > .05).

CONCLUSIONS

TCS of the mesencephalic midline may be useful for detecting depression, which is an early symptom of PD. However, further neuropathological studies are needed to understand the principles underlying the use of platelet serotonin as a peripheral biomarker, as well as the connection between PD and depression.

Training working memory updating in Parkinson's disease: A randomised controlled trial

Frontostriatal dysfunction in Parkinson's disease (PD) increases the risk for working memory (WM) impairment and depression, calling for counteractive measures. Computerised cognitive rehabilitation is a promising option, but targeted training protocols are lacking and lab-based training can be demanding due to the repeated visits. This study tested the feasibility and efficacy of home-based computerised training targeting mainly WM updating in PD. Fifty-two cognitively well-preserved PD patients were randomised to a WM training group and an active control group for five weeks of training (three 30-min sessions per week). WM training included three computerised adaptive WM tasks (two updating, one maintenance). The outcomes were examined pre- and post-training with trained and untrained WM tasks, tasks tapping other cognitive domains, and self-ratings of executive functioning and depression. Home-based training was feasible for the patients. The training group improved particularly on the updating training tasks, and showed posttest improvement on untrained WM tasks structurally similar to the trained ones. Moreover, their depression scores decreased compared to the controls. Our study indicates that patients with mild-to-moderate PD can self-administer home-based computerised WM training, and that they yield a similar transfer pattern to untrained WM tasks as has been observed in healthy older adults.

Hope and self-efficacy are associated with better satisfaction with life in people with ALS

The psychological phenotype in amyotrophic lateral sclerosis (ALS) is less negative than in other neurodegenerative diseases, manifested by a lower prevalence of psychopathology, such as anxiety and major depression, and a higher perceived quality of life by patients, irrespective of physical impairment. We hypothesized that positive psychological factors such as hope, optimism, and self-efficacy in people with ALS (PALS) were key determinants of satisfaction with life (SWL), despite physical impairment, and were protective against psychopathology. Forty PALS, at different functional levels, completed objective questionnaires to evaluate psychological factors of hope, optimism, self-efficacy, and SWL. Approximately 41% of the variance in SWL was accounted for by the Agency factor of hope. The results indicated that SWL was significantly correlated to specific positive psychological factors of hope and self-efficacy. Physical impairment was not correlated with positive psychological factors or SWL. These results support the role of hope and self-efficacy in maintaining satisfaction with life in PALS and consideration of these potentially modifiable factors could improve palliative therapy.

Risky decision-making and affective features of impulse control disorders in Parkinson's disease

Impulse control disorders (ICDs) in Parkinson’s disease (PD) are considered dopaminergic treatment side effects. Cognitive and affective factors may increase the risk of ICD in PD. The aim is to investigate risky decision-making and associated cognitive processes in PD patients with ICDs within a four-stage conceptual framework. Relationship between ICDs and affective factors was explored. Thirteen PD patients with ICD (ICD+), 12 PD patients without ICD (ICD−), and 17 healthy controls were recruited. Overall risky decision-making and negative feedback effect were examined with the Balloon Analogue Risk Task (BART). A cognitive battery dissected decision-making processes according to the four-stage conceptual framework. Affective and motivational factors were measured. ANOVA showed no effect of group on overall risky decision-making. However, there was a group × feedback interaction [F (2, 39) = 3.31, p = 0.047]. ICD+, unlike ICD− and healthy controls, failed to reduce risky behaviour following negative feedback. A main effect of group was found for anxiety and depression [F(2, 38) = 8.31, p = 0.001], with higher symptoms in ICD+ vs. healthy controls. Groups did not differ in cognitive outcomes or affective and motivational metrics. ICD+ may show relatively preserved cognitive function, but reduced sensitivity to negative feedback during risky decision-making and higher symptoms of depression and anxiety.

Depression in Parkinson's Disease: The Contribution from Animal Studies

Besides being better known for causing motor impairments, Parkinson's disease (PD) can also cause many nonmotor symptoms, like depression and anxiety, which can cause significant loss of life quality and may not respond to regular drugs treatment. In this review, we discuss the depression in PD, based on data from studies in humans and rodents. Depression frequency seems higher in PD patients than in general population, despite high variation in data due to diagnosis disparities. Development of depression in PD seems more likely to be caused by the nigrostriatal pathway degeneration than as a consequence of the awareness of disease prognostic, and it seems to be related to dopaminergic, noradrenergic, and serotoninergic synapses deficits. The dopaminergic role could be more significant, since it can modulate the release of the others, and its depletion is progressive, due to the degenerative feature of PD. Highly regarded in major depression, serotonin can be depleted in rats after nigrostriatal damage, but data from human patients are more conflicting. Animal studies can help in understanding the neurobiological mechanisms of depression in PD and the pursuit for more effective drugs for its treatment, but they lack the complexity of the disease progression, especially the nondopaminergic degeneration.

Drug induces depression-like phenotypes and alters gene expression profiles in Drosophila

BACKGROUND

Major depressive disorder (MDD) is a severe mental illness that affects more than 350 million people worldwide. However, the molecular mechanisms of depression are currently unclear. Studies suggest that Drosophila and humans have similar depression-like symptoms under pressure. In this research, we choose Drosophila melanogaster as the animal model to explore the molecular mechanisms that trigger depression.

RESULTS

We found that feeding D. melanogaster with the medium containing Levodopa or Chlorpromazine could induce depression-like phenotypes in both behavioral and biochemical biomarkers, including significantly decreased food intake, mating frequency, serotonin (5-HT) concentration, and increased malondialdehyde (MDA) concentration as well as reduced activity of superoxide dismutase (SOD). Moreover, the progeny of Chlorpromazine-treated flies also showed these depression-like features. By RNA-seq technology, we identified 467 genes that were differentially expressed between Chlorpromazine treated (CPZ) and control male flies [fold-change of ≥2 (q-value<5%)]. When comparing CPZ with control flies, 312 genes were upregulated and 155 genes downregulated. Differential expression of genes related to metabolic pathway, Parkinson's disease, Huntington's disease, Alzheimer's disease and lysozyme pathways were observed. Quantitative reverse transcriptase PCR (qRT-PCR) confirmed that 19 genes are differentially expressed in CPZ and control male flies.

CONCLUSIONS

Levodopa, or Chlorpromazine can induce depression-like phenotypes in D. melanogaster regarding changes of appetite and sexual activity, and some key biochemical markers. A total of 467 genes were identified by RNA-seq analysis to have at least a 2-fold-change in expression between CPZ and control flies, including genes involved in metabolism, neurological diseases and lysozyme pathways. Our data provide additional insight into molecular mechanisms underlying depressive disorders in humans and may also contribute to clinical treatment.

[Anxiety and depressive disorders in Parkinson's disease]

This review presents the most recent data of worldwide research on anxiety and depressive disorders in patients with Parkinson's disease. Their characteristics and epidemiology, pathogenetic and clinical features, methods of diagnosis and treatment are presented. Depression occurs in 40-50% of patients with PD, anxiety in 17-43% of patients. Pramipexole, a dopamine agonist, is only one drug recommended for depression treatment. Nortriptyline and desipramine, belonging to the group of tricyclic antidepressants (TCAs), are considered to be possibly effective. There are no clear recommendations for treatment of anxiety. In general, methods of therapy of anxiety and depressive disorders in PD are not well understood which determines the conduct of large-scale studies in the future.

Qigong Exercise May Reduce Serum TNF-α Levels and Improve Sleep in People with Parkinson's Disease: A Pilot Study

Background: Inflammatory cytokine levels are often elevated in people with Parkinson’s disease (PD). People with PD often experience sleep disturbances that significantly impact quality of life. Past studies suggest inflammatory cytokines may be associated with various symptoms of PD. Benefits of Qigong, a mind–body exercise, have been shown in different neurological conditions, but there is still a lack of clinical evidence in the PD population. Methods: Ten people with PD were recruited and randomly assigned into two groups receiving six weeks of Qigong (experimental group) or sham Qigong (control group) intervention. The levels of TNF-α, IL-1β, and IL-6 in subjects’ serum and sleep quality were measured before and after the intervention. Results: After the intervention, the serum level of TNF-α in the experimental group was significantly decreased in all subjects, while the level in the control group showed a trend to increase. Qigong exercise significantly improved sleep quality at night. There was a strong correlation between changes in the level of TNF-α and sleep quality. Conclusion: Qigong exercise decreased TNF-α level in people with PD and helped improve sleep quality. TNF-α may have a potential to influence the sleep quality in people with PD.

Unilateral ultra-brief pulse electroconvulsive therapy for depression in Parkinson's disease

OBJECTIVES

Electroconvulsive therapy (ECT) has demonstrated efficacy in treating core symptoms of Parkinson's disease (PD); however, widespread use of ECT in PD has been limited due to concern over cognitive burden. We investigated the use of a newer ECT technology known to have fewer cognitive side effects (right unilateral [RUL] ultra-brief pulse [UBP]) for the treatment of medically refractory psychiatric dysfunction in PD.

MATERIALS AND METHODS

This open-label pilot study included 6 patients who were assessed in the motoric, cognitive, and neuropsychiatric domains prior to and after RUL UBP ECT. Primary endpoints were changes in total score on the HAM-D-17 and GDS-30 rating scales.

RESULTS

Patients were found to improve in motoric and psychiatric domains following RUL UBP ECT without cognitive side effects, both immediately following ECT and at 1-month follow-up.

CONCLUSIONS

This study demonstrates that RUL UBP ECT is safe, feasible, and potentially efficacious in treating multiple domains of PD, including motor and mood, without clear cognitive side effects.

Recent Advances in Synthesis and Biomedical Applications of Two-Dimensional Transition Metal Dichalcogenide Nanosheets

During recent decades, a giant leap in the development of nanotechnology has been witnessed. Numerous nanomaterials with different dimensions and unprecedented features have been developed and provided unimaginably wide scope to solve the challenging problems in biomedicine, such as cancer diagnosis and therapy. Recently, two-dimensional (2D) transition metal dichalcogenide (TMDC) nanosheets (NSs), including MoS₂ , WS₂ , and etc., have emerged as novel inorganic graphene analogues and attracted tremendous attention due to their unique structures and distinctive properties, and opened up great opportunities for biomedical applications, including ultrasensitive biosensing, biological imaging, drug delivery, cancer therapy, and antibacterial treatment. A comprehensive overview of different synthetic methods of ultrathin 2D TMDC NSs and their state-of-the-art biomedical applications, especially those that have appeared in the past few years, is presented. At the end of this review, the future opportunities and challenges for 2D TMDC NSs in biomedicine are also discussed.

Distinct Subtypes of Apathy Revealed by the Apathy Motivation Index

Apathy is a debilitating but poorly understood disorder characterized by a reduction in motivation. As well as being associated with several brain disorders, apathy is also prevalent in varying degrees in healthy people. Whilst many tools have been developed to assess levels of apathy in clinical disorders, surprisingly there are no measures of apathy suitable for healthy people. Moreover, although apathy is commonly comorbid with symptoms of depression, anhedonia and fatigue, how and why these symptoms are associated is unclear. Here we developed the Apathy-Motivation Index (AMI), a brief self-report index of apathy and motivation. Using exploratory factor analysis (in a sample of 505 people), and then confirmatory analysis (in a different set of 479 individuals), we identified subtypes of apathy in behavioural, social and emotional domains. Latent profile analyses showed four different profiles of apathy that were associated with varying levels of depression, anhedonia and fatigue. The AMI is a novel and reliable measure of individual differences in apathy and might provide a useful means of probing different mechanisms underlying sub-clinical lack of motivation in otherwise healthy individuals. Moreover, associations between apathy and comorbid states may be reflective of problems in different emotional, social and behavioural domains.

Neuropsychiatric manifestations of Parkinson's disease

OBJECTIVE

This clinical update review focuses on the classification and description of common neuropsychiatric manifestations in Parkinson's disease (PD).

METHOD

We conducted a systematic search of the literature using Pubmed and selected the most recent and relevant papers for this review.

RESULTS

Neuropsychiatric manifestations in PD are are very frequent and may arise from an abnormal psychopathological response to the disease, neurobiological changes related to the disease itself, complications of treatments or a combination of all of these.

CONCLUSIONS

Neuropsychiatric symptoms may precede the motor clinical presentation of PD. Early recognition is essential.

Use of Fall-Risk Inducing Drugs in Patients Using Anti-Parkinson Drugs (APD): A Swedish Register-Based Study

Objectives

Many drugs increase the risk of falls in old age. Although persons with Parkinson’s disease (PD) are at increased risk of experiencing falls and fractures, the use of fall-risk inducing drugs (FRIDs) in this population has not previously been investigated. The objective of this study was to investigate the burden of use of FRIDs in older persons treated with anti-Parkinson drugs (APD; used as a proxy for PD), compared to persons without APD.

Methods

We analyzed individual data on age, sex, type of housing and drug use in 1 346 709 persons aged ≥ 65 years in the Swedish Prescribed Drug Register on the date of 30 September 2008. Main outcome measure was the use of FRIDs.

Results

FRIDs were used by 79% of persons with APD and 75% of persons without APD. Persons with APD were more likely to use ≥ 1 FRIDs compared to persons without APD (adjusted OR: 1.09; 95% CI: 1.06-1-12). The association was stronger for concomitant use of ≥ 5 FRIDS (adjusted OR: 1.49; 95% CI: 1.44–1.55).

Conclusions

The high use of FRIDs among persons with APD indicates that these patients may be at increased risk of drug-induced falls. Further studies are needed to investigate how these drugs affect the risk of falling in persons with PD.

Electroacupuncture Alleviates Depressive-Like Symptoms and Modulates BDNF Signaling in 6-Hydroxydopamine Rats

Previous studies have identified the beneficial effects of electroacupuncture (EA) on motor behaviors in Parkinson's disease (PD). However, the role and potential mechanisms of EA in PD-associated depression remain unclear. In the present study, a rat model of PD with unilateral 6-hydroxydopamine (6-OHDA) lesions in the medial forebrain bundle was treated using EA for 4 weeks. We found that 100 Hz EA improved several motor phenotypes. In addition, tyrosine hydroxylase (TH) immunohistochemical analysis showed that EA had a minimal impact on the TH-positive profiles of the ipsilateral ventral tegmental area. Compared with the 6-OHDA group, long-term EA stimulation significantly increased sucrose solution consumption and decreased immobility time in the forced swim test. EA treatment did not alter dopamine, norepinephrine, and serotonin levels in the striatum and hippocampus. Noticeably, EA treatment reversed the 6-OHDA-induced abnormal expression of brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) in the midbrain and hippocampus. These results demonstrate that EA at 100-Hz possesses the ability to improve depressive-like symptoms in PD rats, which is, at least in part, due to the distinct effect of EA on the mesostriatal and mesocorticolimbic dopaminergic pathways. Moreover, BDNF seems to participate in the effect of EA in PD.

Cortical abnormalities in Parkinson's disease patients and relationship to depression: A surface-based morphometry study

Depression is a common occurrence in patients with Parkinson's disease (PD). Brain deficits may be the underlying cause of depression in PD. In the present study, we investigated whether morphometric alterations contribute to depression in PD. Seventeen depressed PD patients, 17 non-depressed PD patients and 45 normal controls were enrolled in the study. All subjects went through neurological and psychiatric clinical assessments. T1 weighted magnetic resonance imaging and surface-based morphometric analyses were performed to examine morphometric abnormalities in PD patients and their relationship to depression. We found that compared with normal controls, PD patients exhibited significantly decreased cortical thickness in the left precentral gyrus and the right postcentral gyrus extending to the middle frontal gyrus. Compared with non-depressed PD patients, depressed patients showed significantly increased cortical areas in the orbitofrontal regions and insula, which may imply white matter atrophy in these areas. The results of orbitofrontal and insula white matter atrophy are consistent with our previous finding that white matter integrity and functional connectivity are damaged in these regions in depressed PD patients, confirming their contribution to depression in PD.

Loss of dopaminergic neurons occurs in the ventral tegmental area and hypothalamus of rats following chronic stress: Possible pathogenetic loci for depression involved in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of dopaminergic (DA) neurons in the nigrostriatal and mesolimbic pathways including ventral tegmental area (VTA). Although several factors for the neuronal loss have been suggested, most of the PD cases are sporadic and idiopathic. In our previous study, we demonstrated the first evidence that solely chronic restraint stress (RS) induced the DA neuronal loss in the substantia nigra (SN). In this study, we further investigated whether chronic stress could affect other major DA systems, VTA and tuberoinfundibular system (TIDA), by using immunohistochemical and in situ hybridization techniques. The present study showed that, in the VTA, tyrosine hydroxylase (TH) immunoreactive neurons decreased by 9.8% at 2nd week, 19.2% at 4th week, 39.5% at 8th week, and 40.6% at 16th week during chronic RS as compared to control. Similarly, in the TIDA, the TH neurons decreased by 10.9% at 2nd week, 38.2% at 4th week, 56.3% at 8th week, and 57.1% at 16th week. The in situ hybridization results consistently demonstrated decreases in Th mRNA expressing cells in the VTA and TIDA in a comparable time dependent manner. Thus, exposure to chronic stress may simultaneously induce multiple neuronal loss of DA systems.

Parkinson's disease: a review of non-motor symptoms

Parkinson's disease (PD) is a neurodegenerative disorder resulting from degeneration of the substantia nigra and the dopaminergic nigrostriatal pathway. Most treatments are geared toward the management and relief of motor symptoms in Parkinson's patients; however, as the disease progresses, various complications can be observed. Non-motor symptoms (NMS) may arise simply from the disease itself and are highly destructive to quality of life. These symptoms include mood disorders, cognitive dysfunction, pain, sensory dysfunction, and dysautonomia. Though it is undisputed that many NMS may appear years or even decades prior to the clinical diagnosis of PD, the focus of this review will be the overt motor phase of the condition. As such, the focus of this paper is to review the major NMS found in PD patients status post-diagnosis, their etiology, as well as treatment options available for the individual NMS.

The Therapeutic Potential of Exercise to Improve Mood, Cognition, and Sleep in Parkinson's Disease

In addition to the classic motor symptoms, Parkinson's disease (PD) is associated with a variety of nonmotor symptoms that significantly reduce quality of life, even in the early stages of the disease. There is an urgent need to develop evidence-based treatments for these symptoms, which include mood disturbances, cognitive dysfunction, and sleep disruption. We focus here on exercise interventions, which have been used to improve mood, cognition, and sleep in healthy older adults and clinical populations, but to date have primarily targeted motor symptoms in PD. We synthesize the existing literature on the benefits of aerobic exercise and strength training on mood, sleep, and cognition as demonstrated in healthy older adults and adults with PD, and suggest that these types of exercise offer a feasible and promising adjunct treatment for mood, cognition, and sleep difficulties in PD. Across stages of the disease, exercise interventions represent a treatment strategy with the unique ability to improve a range of nonmotor symptoms while also alleviating the classic motor symptoms of the disease. Future research in PD should include nonmotor outcomes in exercise trials with the goal of developing evidence-based exercise interventions as a safe, broad-spectrum treatment approach to improve mood, cognition, and sleep for individuals with PD.

Decrease of gene expression of astrocytic 5-HT2B receptors parallels development of depressive phenotype in a mouse model of Parkinson's disease

Astrocytes contribute to pathogenesis of neuropsychiatric disorders, including major depression. Stimulation of astroglial 5-HT2B receptors transactivates epidermal growth factor receptors (EGFRs) and regulates gene expression. Previously we reported that expression of 5-HT2B receptors in cortical astrocytes is down-regulated in animals, which developed anhedonia in response to chronic stress; moreover this down-regulation as well as anhedonia, are reversed by chronic treatment with fluoxetine. In this study we have investigated whether astrocytic 5-HT2B receptor is involved in anhedonia in C57BL/6 mice model of Parkinson' disease (PD) induced by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 days. The MPTP treatment induced anhendonia in 66.7% of animals. The appearance of depressive behavior was accompanied with motor deficiency and decrease of tyrosine hydroxylase (TH) expression. Expression of mRNA and protein of 5-HT2B receptor in animals that became anhedonic decreased to 77.3 and 79.3% of control groups, respectively; in animals that received MPTP but did not develop anhedonia the expression of 5-HT2B receptor did not change. Experiments with FACS-sorted isolated cells demonstrated that decrease in 5-HT2B receptor expression was confined to astrocytes, and did not occur in neurons. Fluoxetine corrected MPTP-induced decrease of 5-HT2B receptor expression and depressive behavior. Our findings indicate that regulation of gene expression of 5-HT2B receptors in astroglia may be associated with pathophysiological evolution of PD-induced depression.

Mechanisms and therapeutic applications of electromagnetic therapy in Parkinson's disease

Electromagnetic therapy is a non-invasive and safe approach for the management of several pathological conditions including neurodegenerative diseases. Parkinson's disease is a neurodegenerative pathology caused by abnormal degeneration of dopaminergic neurons in the ventral tegmental area and substantia nigra pars compacta in the midbrain resulting in damage to the basal ganglia. Electromagnetic therapy has been extensively used in the clinical setting in the form of transcranial magnetic stimulation, repetitive transcranial magnetic stimulation, high-frequency transcranial magnetic stimulation and pulsed electromagnetic field therapy which can also be used in the domestic setting. In this review, we discuss the mechanisms and therapeutic applications of electromagnetic therapy to alleviate motor and non-motor deficits that characterize Parkinson's disease.

Abnormal amygdala function in Parkinson's disease patients and its relationship to depression

Depression is a common occurrence in patients with Parkinson's disease (PD). Thus, there may be a common neural mechanism underlying the two diseases. Lewy body accumulation in specific brain areas of PD patients may damage emotion-related functions, leading to depression. Among these areas, the amygdala may present with the earliest to be damaged in PD. However, it is still unclear whether amygdala structural and functional changes are related to depression in PD. We enrolled 19 depressed PD patients, 19 non-depressed PD patients, and 28 normal control subjects. Clinical assessment, including the Unified Parkinson's Disease Rating Scale, the Hamilton Rating Scale for Depression, and the Mini-Mental State Examination, was carried out on all the patients. Structural and resting-state functional brain images were also acquired to assess volumetric and functional changes of the amygdala in the patients. Results showed that although there is no significant volume change, left amygdala activity increased in the PD group compared with the normal control group, and it correlated with Hamilton Rating Scale for Depression scores. Furthermore, functional connectivity between the right amygdala and fronto-parietal areas was found to be decreased in the depressed PD patients compared with non-depressed PD patients. These results suggest that abnormal amygdala function may underlie the occurrence of depression in PD.