Beyond the iron mask: towards better recognition and treatment of depression associated with Parkinson's disease

Effects of astrocytes in the dorsal hippocampus on anxiety-like and depressive-like behaviors in hemiparkinsonian rats

Anxiety and depression are the most common neuropsychiatric manifestations of Parkinson's disease (PD) patients. Growing evidence have shown that the dorsal hippocampus (dHIPP) and astrocytes (AS) may be involved in regulating depression and anxiety, but the role and mechanism are still unclear, especially in PD-related depression and anxiety. Unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta (SNc) were used to establish the rat model of PD. Behavioral tests and measurement of monoamine levels in the depression and anxiety related brain regions were performed to investigate the effects of chemogenetic activation or inhibition of dHIPP AS on PD-related anxiety and depression. The present results showed that unilateral lesions of the SNc induced anxiety-like and depressive-like behaviors, decreased dopamine (DA) levels in some related brain regions, but did not change the density of glial fibrillary acidic protein-positive AS in the CA1, CA3 and dentate gyrus in rats. Chemogenetic inhibition of dHIPP AS significantly improved anxiety-like and depressive-like behaviors only in the lesioned rats, while chemogenetic activation of dHIPP AS had no effects on anxiety-like and depressive-like behaviors in sham-operated and the lesioned rats. Chemogenetic activation of dHIPP AS only decreased DA level in the ventral hippocampus (vHIPP) in sham-operated rats, while inhibition of dHIPP AS increased 5-hydroxytryptamine (5-HT) levels in the medial prefrontal cortex (mPFC) and vHIPP in sham-operated rats and also in the amygdala, mPFC, lateral habenula, dHIPP and vHIPP in the lesioned rats. These results indicate that chemogenetic inhibition of dHIPP AS improves the anxiety-like and depressive-like behaviors in the lesioned rats through the changes in monoamine in some brain regions.

Depressive symptoms and quality of life in patients with benign essential blepharospasm under long-term therapy with botulinum toxin

Regular and long-term injections of botulinum toxin (BoNT) are considered the first line therapy for essential blepharospasm (BEB), but no data exists on the long-term effect of this therapy on depressive symptoms and quality of life. This study aims to prospectively evaluate the long-term effects of BoNT therapy on depressive symptoms as well as on daily activities, emotional well-being and quality of life using validated questionnaires (BEB-scale, Beck`s Depression Inventory (BDI)). 86 patients diagnosed with BEB were followed up for a median of 4 years. Clinical symptoms improved significantly after BoNT-injections. Everyday activities and subjective assessment of the overall situation improved gradually under long-term BoNT therapy. Significant correlations (p < 0.0001; r-values between 0.498 and 0.706) were found between the BDI and items of the BEB-scale. No significant antidepressive effect of long-term BoNT therapy was found with a low median BDI total score (5/max. 63), but up to 31.3% of BEB patients had a BDI score ≥ 11, indicating clinically relevant depressive symptoms. Of these, 65.4% had no known history of depression. Although, several studies reported an antidepressant effect of botulinum toxin injections in patients with major depression, this effect does not seem to be present in patients with BEB despite clinical improvement of symptoms. A high prevalence of previously undetected depressive symptoms was found in BEB patients. As this may influence BoNT therapy success, identifying potential depressive symptoms at the time of BEB diagnosis and initiating appropriate treatment seems important.

German Society of Neurology guidelines for the diagnosis and treatment of cognitive impairment and affective disorders in people with Parkinson's disease: new spotlights on diagnostic procedures and non-pharmacological interventions

BACKGROUND AND OBJECTIVE

Cognitive impairment and dementia as well as affective disorders are common and debilitating syndromes that develop in people with Parkinson's disease (PwPD). The authors summarized recommendations for the 2023 updated German guidelines on "Parkinson's disease" from the German Neurological Society (DGN), focusing on the diagnosis and treatment of these disorders.

METHODS

The recommendations were based on literature reviews, other relevant guidelines, and expert opinions.

RESULTS

Measurements to assess cognitive and affective states were reviewed for psychometric properties, use in routine clinical practice, and availability in German. To improve mild cognitive impairment, cognitive training and physical aerobic training are recommended. To treat Parkinson's disease (PD)-related dementia, cognitive stimulation (as a non-pharmacological intervention) and acetylcholinesterase inhibitors (AChEIs, i.e., rivastigmine) are recommended. Cognitive behavioral therapy is recommended to treat depression, anxiety, and fear of progression. Physical interventions are recommended to treat depression, fatigue, and apathy. Optimized dopaminergic treatment is the first-line pharmacological strategy recommended to manage depression, apathy, anhedonia, fatigue, and mood swings. Major depression can be additionally treated using venlafaxine or desipramine, while moderate depression can be treated pharmacologically according to its clinical phenotype (psychomotor retardation or agitation) and comorbidities (e.g., sleep disturbances, pain). Venlafaxine and nortriptyline can be used to treat anhedonia, while citalopram can be used for anxiety.

CONCLUSIONS

In addition to the updated pharmacological treatment options, new insights into recommendations for standardized diagnostics and non-pharmacological interventions were provided for the German health care system. However, more studies are needed to explore the full potential of non-pharmacological interventions to treat and prevent cognitive impairment and affective disorders.

Analysis of diffusion changes in cerebral tissues of Parki̇nson's patients who underwent subthalamic nucleus deep brain stimulation: Correlation of improvements in motor and neuropsychiatric symptoms

OBJECTIVE

Parkinson's disease (PD) as a neurodegenerative disorder characterized by a reduction in both the quantity and functionality of dopaminergic neurons. This succinctly highlights the central pathological feature of PD and its association with dopaminergic neuron degeneration, which underlies the motor and non-motor symptoms of the disease. This study aims to elucidate the nuances of apparent diffusion coefficient (ADC) changes in different cerebral regions by after the bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery of PD, as well as to investigate their potential interactions with the motor and neuropsychiatric spectrum.

METHODS

Patients who underwent STN-DBS surgery for PD between 2017 and 2019 were included in this study. The results of diffusion magnetic resonance imaging (MRI), Unified Parkinson Disease Rating Scale (UPDRS) III scores, Beck and Hamilton depression tests were recorded before and at the 3rd month of postoperative stimulation. The data obtained were evaluated with the Wilcoxon signed rank test. Result of the statistical tests were within the 95 % confidence interval and p values were significant below 0.05.

RESULTS

Our study was conducted with a total of 13 patients, 8 men and 5 women. As a result of measurements made in a total of 32 different regions, especially in the motor and neuropsychiatric areas of the brain, an increase in ADC values was found in all areas. ADC changes of eight localizations such as left corpus callosum, right corona radiata, left corona radiata, hippocampus, right insula, left superior cerebellar peduncle, left caudate nucleus and left putamen were statistically significant. UPDRS III scores improved by 57 % (p <0.05), and Beck and Hamilton depression scores by 25 % and 33 %, respectively (p> 0.05).

CONCLUSIONS

This article implicate that bilateral STN-DBS surgery potentially exerts beneficial effects on both motor and neuropsychiatric symptomatology in individuals with PD. We believe that this therapeutic mechanism is hypothesized to involve modulation of diffusion alterations within distinct cerebral tissues.

Different risks of early-onset and late-onset Parkinson disease in individuals with mental illness

We aimed to investigate the association of various mental illnesses, including depression, bipolar disorder, schizophrenia, insomnia, and anxiety, with the risk of early-onset Parkinson's disease (EOPD) (age <50 years) and compare it with that of late-onset PD (LOPD) (age ≥50 years). This nationwide cohort study enrolled 9,920,522 people who underwent a national health screening examination in 2009, and followed up until 31 December 2018. There was a significantly increased risk of EOPD and LOPD in individuals with mental illness, and EOPD showed a stronger association than LOPD (EOPD, hazard ratio (HR) = 3.11, 95% CI: 2.61‒3.72; LOPD, HR = 1.70, 95% CI: 1.66‒1.74; p for interaction <0.0001). Our results suggest that people with mental illnesses aged < 50 years are at a higher risk of PD than those aged ≥50 years. Future studies are warranted to elucidate the pathomechanism of EOPD in relation to mental illness.

miR-218-5p and miR-320a-5p as Biomarkers for Brain Disorders: Focus on the Major Depressive Disorder and Parkinson's Disease

Depression is one of the early and most persistent non-motor symptoms of Parkinson's disease (PD), which remains ignored, resulting in the underdiagnosis of PD. Unfortunately, scarce studies and the non-availability of diagnostic strategies cause countless complications, highlighting the need for appropriate diagnostic biomarkers. Recently, brain-enriched miRNAs regulating vital neurological functions have been proposed as potent biomarkers for therapeutic strategies. Therefore, the present study is aimed to identify the brain-enriched miR-218-5p and miR-320-5p in the serum of the Chinese depressed PD patients (n = 51) than healthy controls (n = 51) to identify their potency as biomarkers. For this purpose, depressive PD patients were recruited based on HAMA and HAMD scores and miR-218-5p and miR-320-5p and IL-6, and S100B levels were analyzed using real-time PCR (qRT-PCR) and ELISA assay, respectively. In silico analysis was performed to identify key biological pathways and hub genes involved in the psychopathology of depression in PD. Here, we found significantly downregulated miR-218-5p and miR-320-5p following higher levels of IL-6 and S100B in depressed PD patients than in control (p < 0.05). The correlation analysis revealed that both miRNAs were negatively correlated with HAMA and HAMD, and IL-6 scores, along with a positive correlation with PD duration and LEDD medication. ROC analysis showed AUC above 75% in both miRNAs in depressed PD patients, and in silico analysis revealed that both miRNA's targets regulate key neurological pathways such as axon guidance, dopaminergic synapse, and circadian rhythm. Additional analysis revealed PIK3R1, ATRX, BM1, PCDHA10, XRCC5, PPP1CB, MLLT3, CBL, PCDHA4, PLCG1, YWHAZ, CDH2, AGO3, PCDHA3, and PCDHA11 as hub-genes in PPI network. In summary, our findings show that miR-218-5p and miR-320-5p can be utilized as future biomarkers for depression in PD patients, which may aid in the early diagnosis and treatment of Parkinson's disease.

Rehabilitation for non-motor symptoms for patients with Parkinson's disease from an α-synuclein perspective: a narrative review

Parkinson's disease (PD) is a common neurodegenerative disorder affecting aged population around the world. PD is characterized by neuronal Lewy bodies present in the substantia nigra of the midbrain and the loss of dopaminergic neurons with various motor and non-motor symptoms associated with the disease. The protein α-synuclein has been extensively studied for its contribution to PD pathology, as α-synuclein aggregates form the major component of Lewy bodies, a hallmark of PD. In this narrative review, the authors first focus on a brief explanation of α-synuclein aggregation and circumstances under which aggregation can occur, then present a hypothesis for PD pathogenesis in the peripheral nervous system (PNS) and how PD can spread to the central nervous system from the PNS via the transport of α-synuclein aggregates. This article presents arguments both for and against this hypothesis. It also presents various non-pharmacological rehabilitation approaches and management techniques for both motor and non-motor symptoms of PD and the related pathology. This review seeks to examine a possible hypothesis of PD pathogenesis and points to a new research direction focus on rehabilitation therapy for patients with PD. As various non-motor symptoms of PD appear to occur earlier than motor symptoms, more focus on the treatment of non-motor symptoms as well as a better understanding of the biochemical mechanisms behind those non-motor symptoms may lead to better long-term outcomes for patients with PD.

Increased depressive symptoms in Parkinson’s disease during the COVID‐19 pandemic: preliminary findings from longitudinal analysis of the PHASE study

Introduction

The cumulative number of patients has increased through the four waves of the pandemic in Japan. Many people experienced mental stress due to the fear of infection, and restrictions of leaving the house and leisure activities. No longitudinal study has assessed the fluctuation of neuropsychiatric symptoms during the COVID-19 pandemic using the same scale. We examined changes in non-motor symptoms, and the scores of a Parkinson’s Disease (PD)-specific questionnaire between the early and later periods during the COVID-19 pandemic.

Methods

We conducted a questionnaire survey during the first wave (from February to April 2020) and the fourth wave of the COVID-19 pandemic (from March to April 2021). We compared the number of symptoms from the two periods.

Results

Compared with the first wave, the Geriatric Depression Scale score was significantly higher in the fourth wave of the pandemic (median score of GDS: 4.00 vs. 5.50, p = 0.022). Consistently, the scores of symptoms on MDS-UPDRS part 1 in the fourth wave were significantly higher in hygiene (p = 0.033), handwriting (p = 0.033), performing hobbies and other activities (p = 0.035), and turning in bed (p = 0.046) than in the first wave.

Conclusions

Our observation over a year between the early and later phases of the COVID-19 pandemic showed an increase in the severity of depression in patients with PD.

Longitudinal analysis of the Non-Motor Symptoms Scale in Parkinson's Disease (NMSS): An exploratory network analysis approach

Introduction

Parkinson's disease (PD) is a multisystem neurodegenerative disorder characterized by motor and non-motor symptoms. In particular, non-motor symptoms have become increasingly relevant to disease progression. This study aimed to reveal which non-motor symptoms have the highest impact on the complex interacting system of various non-motor symptoms and to determine the progression of these interactions over time.

Methods

We performed exploratory network analyses of 499 patients with PD from the Cohort of Patients with Parkinson's Disease in Spain study, who had Non-Motor Symptoms Scale in Parkinson's Disease ratings obtained at baseline and a 2-year follow-up. Patients were aged between 30 and 75 years and had no dementia. The strength centrality measures were determined using the extended Bayesian information criterion and the least absolute shrinkage and selection operator. A network comparison test was conducted for the longitudinal analyses.

Results

Our study revealed that the depressive symptoms anhedonia and feeling sad had the strongest impact on the overall pattern of non-motor symptoms in PD. Although several non-motor symptoms increase in intensity over time, their complex interacting networks remain stable.

Conclusion

Our results suggest that anhedonia and feeling sad are influential non-motor symptoms in the network and, thus, are promising targets for interventions as they are closely linked to other non-motor symptoms.

Advances in the Pharmacological and Non-pharmacological Management of Non-motor Symptoms in Parkinson's Disease: An Update Since 2017

BACKGROUND

Non-motor symptoms (NMS) are an important and ubiquitous determinant of quality of life in Parkinson's disease (PD). However, robust evidence for their treatment is still a major unmet need.

OBJECTIVE

This study aimed to provide an updated review on advances in pharmacological, nonpharmacological, and exercise-based interventions for NMS in PD, covering the period since the publication of the MDS Task Force Recommendations.

METHODS

We performed a literature search to identify pharmacological, non-pharmacological, and exercise-based interventions for NMS in PD. As there are recent reviews on the subject, we have only included studies from the 1st of January 2017 to the 1st of December 2021 and limited our search to randomised and non-randomised (including open-label) clinical trials.

RESULTS

We discuss new strategies to manage NMS based on data that have become available since 2017, for instance, on the treatment of orthostatic hypotension with droxidopa, several dopaminergic treatment options for insomnia, and a range of non-pharmacological and exercise-based interventions for cognitive and neuropsychiatric symptoms, pain, and insomnia and excessive sleepiness.

CONCLUSION

Recent evidence suggests that targeted non-pharmacological treatments, as well as some other NMS management options, may have a significant beneficial effect on the quality of life and need to be considered in the pathways of treatment of PD.

Sexual Dysfunction Among Egyptian Idiopathic Parkinson's Disease Patients

BACKGROUND

One of the non-motor features of idiopathic Parkinson's disease (IPD) is sexual dysfunction (SD) which is under-recognized and, consequently, undertreated. This study aimed to evaluate SD in patients with IPD.

PATIENTS AND METHODS

The study was conducted on 67 IPD patients; 30 healthy subjects with age and gender matching with the patients served as the control group. All participants were subjected to sexual function assessment using the Arabic version of Arizona Sexual Experience Scale (ASEX), Mini-Mental State Examination (MMSE), and Beck Depression Inventory (BDI), while the severity of IPD was assessed using the modified Hoehn and Yahr scoring scale and MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS).

RESULTS

There were no statistically significant differences between patients with IPD and the control group regarding MMSE, hypertension, diabetes mellitus, or dyslipidemia. However, BDI scores were significantly higher in patients with IPD. The rate of SD among our patients was 64% compared to 30% in the control group. The total score and subscales of ASEX were significantly higher in IPD patients than in controls. SD showed a significant correlation with the severity of the IPD irrespective of other variables, including patient age, sex, disease duration, hypertension, diabetes, dyslipidemia, smoking, and dose of L-dopa.

CONCLUSION

SD is a commonly underrated feature in patients with IPD; it should be investigated carefully as it is an important non-motor symptom that correlates with disease severity.

Multifunctional role of natural products for the treatment of Parkinson's disease: At a glance

Natural substances originating from plants have long been used to treat neurodegenerative disorders (NDs). Parkinson's disease (PD) is a ND. The deterioration and subsequent cognitive impairments of the midbrain nigral dopaminergic neurons distinguish by this characteristic. Various pathogenic mechanisms and critical components have been reported, despite the fact that the origin is unknown, such as protein aggregation, iron buildup, mitochondrial dysfunction, neuroinflammation and oxidative stress. Anti-Parkinson drugs like dopamine (DA) agonists, levodopa, carbidopa, monoamine oxidase type B inhibitors and anticholinergics are used to replace DA in the current treatment model. Surgery is advised in cases where drug therapy is ineffective. Unfortunately, the current conventional treatments for PD have a number of harmful side effects and are expensive. As a result, new therapeutic strategies that control the mechanisms that contribute to neuronal death and dysfunction must be addressed. Natural resources have long been a useful source of possible treatments. PD can be treated with a variety of natural therapies made from medicinal herbs, fruits, and vegetables. In addition to their well-known anti-oxidative and anti-inflammatory capabilities, these natural products also play inhibitory roles in iron buildup, protein misfolding, the maintenance of proteasomal breakdown, mitochondrial homeostasis, and other neuroprotective processes. The goal of this research is to systematically characterize the currently available medications for Parkinson's and their therapeutic effects, which target diverse pathways. Overall, this analysis looks at the kinds of natural things that could be used in the future to treat PD in new ways or as supplements to existing treatments. We looked at the medicinal plants that can be used to treat PD. The use of natural remedies, especially those derived from plants, to treat PD has been on the rise. This article examines the fundamental characteristics of medicinal plants and the bioactive substances found in them that may be utilized to treat PD.

COVID-19 and Parkinson's Disease: Possible Links in Pathology and Therapeutics

The outbreak of SARs-CoV-2 with emerging new variants is leading to global health crisis and has brought a major concern for patients with comorbidities. Parkinson's disease (PD) is a motor neurodegenerative disease involving various metabolic and psychological ailments along with the common occurrence of hyposmia as observed in COVID-19 patients. In addition, the observed surplus inflammatory responses in both diseases are also alarming. Alongside, angiotensin-converting enzyme 2 (ACE2) receptor, essentially required by SARS-CoV-2 to enter the cell and dopamine decarboxylase (DDC), required for dopamine synthesis is known to co-regulate in the non-neuronal cells. Taken together, these conditions suggested the probable reciprocal pathological relation between COVID-19 and PD and also suggested that during comorbidities, the disease diagnosis and therapeutics are critical and may engender severe health complications. In this review, we discuss various events and mechanisms which may have implications for the exacerbation of PD conditions and must be taken into account during the treatment of patients.

Effects of Bilateral Subthalamic Nucleus Stimulation on Depressive Symptoms and Cerebral Glucose Metabolism in Parkinson's Disease: A 18F-Fluorodeoxyglucose Positron Emission Tomography/Computerized Tomography Study

Subthalamic nucleus (STN) deep brain stimulation (DBS) can improve motor symptoms in Parkinson's disease (PD), as well as potentially improving otherwise intractable comorbid depressive symptoms. To address the latter issue, we evaluated the severity of depressive symptoms along with the severity of motor symptoms in 18 PD patients (mean age, 58.4 ± 5.4 years; 9 males, 9 females; mean PD duration, 9.4 ± 4.4 years) with treatment-resistant depression (TRD) before and after approximately 1 year of STN-DBS treatment. Moreover, to gain more insight into the brain mechanism mediating the therapeutic action of STN-DBS, we utilized ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to assess cerebral regional glucose metabolism in the patients at baseline and 1-year follow-up. Additionally, the baseline PET data from patients were compared with PET data from an age- and sex-matched control group of 16 healthy volunteers. Among them, 12 PD patients underwent post-operative follow-up PET scans. Results showed that the severity of both motor and depressive symptoms in patients with PD-TRD was reduced significantly at 1-year follow-up. Also, patients used significantly less antiparkinsonian medications and antidepressants at 1-year follow-up, as well as experiencing improved daily functioning and a better quality of life. Moreover, relative to the PET data from healthy controls, PD-TRD patients displayed widespread abnormalities in cerebral regional glucose metabolism before STN-DBS treatment, which were partially recovered at 1-year follow-up. Additionally, significant correlations were observed between the patients' improvements in depressive symptoms following STN-DBS and post-operative changes in glucose metabolism in brain regions implicated in emotion regulation. These results support the view that STN-DBS provides a promising treatment option for managing both motor and depressive symptoms in patients who suffer from PD with TRD. However, the results should be interpreted with caution due to the observational nature of the study, small sample size, and relatively short follow-up.

Brain Networks Involved in Depression in Patients with Frontotemporal Dementia and Parkinson’s Disease: An Exploratory Resting-State Functional Connectivity MRI Study

Depression is characterized by feelings of sadness, loss, or anger that may interfere with everyday activities. Such a neuropsychiatric condition is commonly reported in multiple neurodegenerative disorders, which are quite different from each other. This study aimed at investigating the brain networks involved in depression in patients with frontotemporal dementia (FTD) and Parkinson’s disease (PD) as compared to healthy controls (HC). Fifty participants were included in the study: 17 depressed FTD/PD patients; 17 non-depressed FTD/PD patients; and 16 non-depressed HCs matched for age and gender. We used the Beck depression inventory (BDI-II) to measure depression in all groups. On the same day, 3T brain magnetic resonance with structural and resting-state functional sequences were acquired. Differences in resting-state functional connectivity (FC) between depressed and non-depressed patients in all the experimental groups were assessed by using seed-to-seed and network-to-network approaches. We found a significant seed-to-seed hyperconnectivity patterns between the left thalamus and the left posterior temporal fusiform cortex, which differentiated FTD/PD depressed patients from the HCs. Network-to-network analysis revealed a significant hyperconnectivity among the default-mode network (left lateral-parietal region), the medial prefrontal cortex and the left lateral prefrontal cortex (i.e., part of the central executive network). We investigated whether such FC patterns could be related to the underlying neurodegenerative disorder by replicating the analyses with two independent samples (i.e., non-depressed PD and non-depressed FTD patients) and adding clinical parameters as covariates. We found no FC differences in these groups, thus suggesting how the FC pattern we found may signal a common depression-related neural pathway implicated in both the neurocognitive disorders.

Pharmacological Rescue with SR8278, a Circadian Nuclear Receptor REV-ERBα Antagonist as a Therapy for Mood Disorders in Parkinson's Disease

Parkinson's disease is a neurodegenerative disease characterized by progressive dopaminergic neuronal loss. Motor deficits experienced by patients with Parkinson's disease are well documented, but non-motor symptoms, including mood disorders associated with circadian disturbances, are also frequent features. One common phenomenon is "sundowning syndrome," which is characterized by the occurrence of neuropsychiatric symptoms at a specific time (dusk), causing severe quality of life challenges. This study aimed to elucidate the underlying mechanisms of sundowning syndrome in Parkinson's disease and their molecular links with the circadian clock. We demonstrated that 6-hydroxydopamine (6-OHDA)-lesioned mice, as Parkinson's disease mouse model, exhibit increased depression- and anxiety-like behaviors only at dawn (the equivalent of dusk in human). Administration of REV-ERBα antagonist, SR8278, exerted antidepressant and anxiolytic effects in a circadian time-dependent manner in 6-OHDA-lesioned mice and restored the circadian rhythm of mood-related behaviors. 6-OHDA-lesion altered DAergic-specific Rev-erbα and Nurr1 transcription, and atypical binding activities of REV-ERBα and NURR1, which are upstream nuclear receptors for the discrete tyrosine hydroxylase promoter region. SR8278 treatment restored the binding activities of REV-ERBα and NURR1 to the tyrosine hydroxylase promoter and the induction of enrichment of the R/N motif, recognized by REV-ERBα and NURR1, as revealed by ATAC-sequencing; therefore, tyrosine hydroxylase expression was elevated in the ventral tegmental area of 6-OHDA-injected mice, especially at dawn. These results indicate that REV-ERBα is a potential therapeutic target, and its antagonist, SR8278, is a potential drug for mood disorders related to circadian disturbances, namely sundowning syndrome, in Parkinson's disease.

Acceptability and Feasibility of a Mindfulness Intervention Delivered via Videoconferencing for People With Parkinson's

Mindfulness-based group therapy is a rapidly growing psychological approach that can potentially help people adjust to chronic illness and manage unpleasant symptoms. Emerging evidence suggests that mindfulness-based interventions may benefit people with Parkinson's. The objective of the paper is to examine the appropriateness, feasibility, and potential cost-effectiveness of an online mindfulness intervention, designed to reduce anxiety and depression for people with Parkinson's. We conducted a feasibility randomized control trial and qualitative interviews. Anxiety, depression, pain, insomnia, fatigue, impact on daily activities and health-related quality of life were measured at baseline, 4, 8, and 20 weeks. Semi-structured interviews were conducted at the end of the intervention. Participants were randomized to the Skype delivered mindfulness group (n = 30) or wait-list (n = 30). Participants in the mindfulness group were also given a mindfulness manual and a CD with mindfulness meditations. The intervention did not show any significant effects in the primary or secondary outcome measures. However, there was a significant increase in the quality of life measure. The incremental cost-effectiveness ratio was estimated to be £27,107 per Quality-Adjusted Life Year gained. Also, the qualitative study showed that mindfulness is a suitable and acceptable intervention. It appears feasible to run a trial delivering mindfulness through Skype, and people with Parkinson's found the sessions acceptable and helpful.

When Sick Brain and Hopelessness Meet: Some Aspects of Suicidality in the Neurological Patient

Neurological diseases expose individuals to a higher risk of suicidal ideation and suicidal behavior, including completed suicides and suicide attempts. They also represent a paradigmatic arena to study the etiopathogenic mechanisms underlying suicidality because they are emblematic of the heterogeneity and complexity of mutual interrelationships characterizing this issue. On the one hand, neurological diseases imply strictly biological impairments that are postulated to be the basis of vulnerability to suicide or result in the need for treatments for which a suicidal risk has been hypothesized. On the other hand, they question some subjective experiences of neurological patients, up to near existential positions. Often, in fact, they are accompanied by severe hopelessness. The latter may originate in, particularly for the most severe neurological diseases, the absence of curative treatments, unpredictable disease progression that leads to acute relapses or chronicity, a decrease in autonomy or selfidentity, progressive social isolation, a sense of becoming useless, and perception of feeling stigmatized. This may ultimately cause a slip into experiencing an absurd condition. At the confluence of neurobiology and hopelessness, frequent psychiatric comorbidities may play a primary role. To conclude, neurological patients require special attention from clinicians in form of openly verbalizing and exploring the suicidal thematic, inquiring about protective and risk factors, and promptly initiating both a psychopharmacological treatment and, where possible, psychological support.

Management of Parkinson's Disease in the COVID-19 Pandemic and Future Perspectives in the Era of Vaccination

The current coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a serious global health crisis. Increasing evidence suggests that elderly individuals with underlying chronic diseases, including Parkinson's disease (PD), are particularly vulnerable to this infection. Changes in the routine care of PD patients should be implemented carefully without affecting the quality provided. The utilization of telemedicine for clinical consultation, assessment and rehabilitation has also been widely recommended. Therefore, the aim of this review is to provide recommendations in the management of PD during the pandemic as well as in the early phase of vaccination programs to highlight the potential sequelae and future perspectives of vaccination and further research in PD. Even though a year has passed since COVID- 19 emerged, most of us are still facing great challenges in providing a continuum of care to patients with chronic neurological disorders. However, we should regard this health crisis as an opportunity to change our routine approach in managing PD patients and learn more about the impact of SARS-CoV-2. Hopefully, PD patients can be vaccinated promptly, and more detailed research related to PD in COVID-19 can still be carried out.

5-HTTLPR polymorphism and depression risk in Parkinson's disease: an updated meta-analysis

The relationship between the 5-hydroxytryptamine transporter gene-linked polymorphic region (5-HTTLPR) and depression in Parkinson's disease (PD) has remained controversial. Therefore, we conducted this meta-analysis to evaluate the relationship between 5-HTTLPR polymorphisms and depression in PD. Relevant online databases were searched for cross-sectional, case-control or cohort studies examining relations between 5-HTTLPR polymorphisms (S/L) and the risk of developing depression of PD using a meta-analysis. Odd ratios (ORs) of 5-HTTLPR polymorphisms (S/L allele genotype) were calculated between depression in PD and PD for each study. Five observational studies were identified. Overall ORs for 5-HTTLPR S-Allele genotype was 1.98 (95% CI 0.92-4.26) in the dominant model, 1.43 (95% CI 1.08-1.90) in the recessive model, 2.64 (95% CI 1.01-6.88) in the additive model, independently. The overall ORs of S-Allele genotype was 1.51 (95% CI 0.63-3.64) for the Caucasian subgroup, and 1.44 (95% CI 1.05-1.98) for the non-Caucasian subgroup in the recessive model. This meta-analysis indicates that the 5-HTTLPR genotype (S/S-Allele) is correlated with an increased depression risk in PD, and this highlights the needs for these people to take some effective approaches (if any) in prevention of depression of PD before its onset.

Antidepressant-Like Properties of Intrastriatal Botulinum Neurotoxin-A Injection in a Unilateral 6-OHDA Rat Model of Parkinson's Disease

Parkinson’s patients often suffer from depression and anxiety, for which there are no optimal treatments. Hemiparkinsonian (hemi-PD) rats were used to test whether intrastriatal Botulinum neurotoxin-A (BoNT-A) application could also have antidepressant-like properties in addition to the known improvement of motor performance. To quantify depression- and anxiety-like behavior, the forced swim test, tail suspension test, open field test, and elevated plus maze test were applied to hemi-PD rats injected with BoNT-A or vehicle. Furthermore, we correlated the results in the forced swim test, open field test, and elevated plus maze test with the rotational behavior induced by apomorphine and amphetamine. Hemi-PD rats did not show significant anxiety-like behavior as compared with Sham 6-OHDA- + Sham BoNT-A-injected as well as with non-injected rats. However, hemi-PD rats demonstrated increased depression-like behaviors compared with Sham- or non-injected rats; this was seen by increased struggling frequency and increased immobility frequency. Hemi-PD rats intrastriatally injected with BoNT-A exhibited reduced depression-like behavior compared with the respective vehicle-receiving hemi-PD animals. The significant effects of intrastriatally applied BoNT-A seen in the forced swim test are reminiscent of those found after various antidepressant drug therapies. Our data correspond with the efficacy of BoNT-A treatment of glabellar frown lines in treating patients with major depression and suggest that also intrastriatal injected BoNT-A may have some antidepressant-like effect on hemi-PD.

COVID-19 Pandemic and Psychiatric Symptoms: The Impact on Parkinson's Disease in the Elderly

Background: The coronavirus disease 2019 (COVID-19) pandemic represents a condition of increased vulnerability and frailty for elderly patients with Parkinson's disease (PD). Social isolation may worsen the burden of the disease and specifically exacerbate psychiatric symptoms, often comorbid with PD. This study aimed at identifying risk/protective factors associated with subjective worsening of psychiatric symptomatology during the COVID-19 outbreak in a sample of individuals with PD aged 65 years or older. Methods: Patients with PD routinely followed at the outpatient clinic of Gemelli University Hospital, Rome, were assessed for subjective worsening of psychiatric symptoms through a dedicated telephone survey, after Italy COVID-19 lockdown. Patients' medical records were reviewed to collect sociodemographic and clinical data, including lifetime psychiatric symptoms and pharmacological treatment. Results: Overall, 134 individuals were assessed and 101 (75.4%) reported lifetime psychiatric symptoms. Among those, 23 (22.8%) presented with subjective worsening of psychiatric symptomatology during the COVID-19 outbreak. In this group, the most frequent symptom was depression (82.6%), followed by insomnia (52.2%). Subjective worsening of neurological symptoms (Wald = 24.03, df = 1, p = 0.001) and lifetime irritability (Wald = 6.35, df = 1, p = 0.020), together with younger age (Wald = 5.06, df = 1, p = 0.038) and female sex (Wald = 9.07 df = 1, p = 0.007), resulted as specific risk factors for ingravescence of psychiatric presentation. Lifetime pre-existing delusions, having received antipsychotics, and not having received mood stabilizer were also associated with subjective worsening of psychiatric symptomatology due to the COVID-19 pandemic. Conclusions: Individuals with PD and lifetime history of psychiatric symptoms may be exposed to increased vulnerability to the stressful effect of COVID-19 outbreak. Interventions aimed at reducing irritability and mood instability might have an indirect effect on the health of patients with PD during the COVID-19 pandemic.

Clinically relevant connectivity features define three subtypes of Parkinson's disease patients

Parkinson's disease (PD) is characterized by complex clinical symptoms, including classic motor and nonmotor disturbances. Patients with PD vary in clinical manifestations and prognosis, which point to the existence of subtypes. This study aimed to find the fiber connectivity correlations with several crucial clinical symptoms and identify PD subtypes using unsupervised clustering analysis. One hundred and thirty-four PD patients and 77 normal controls were enrolled. Canonical correlation analysis (CCA) was performed to define the clinically relevant connectivity features, which were then used in the hierarchical clustering analysis to identify the distinct subtypes of PD patients. Multimodal neuroimaging analyses were further used to explore the neurophysiological basis of these subtypes. The methodology was validated in an independent data set. CCA revealed two significant clinically relevant patterns (motor-related pattern and depression-related pattern; r = .94, p < .001 and r = .926, p = .001, respectively) among PD patients, and hierarchical clustering analysis identified three neurophysiological subtypes ("mild" subtype, "severe depression-dominant" subtype and "severe motor-dominant" subtype). Multimodal neuroimaging analyses suggested that the patients in the "severe depression-dominant" subtype exhibited widespread disruptions both in function and structure, while the other two subtypes exhibited relatively mild abnormalities in brain function. In the independent validation, three similar subtypes were identified. In conclusion, we revealed heterogeneous subtypes of PD patients according to their distinct clinically relevant connectivity features. Importantly, depression symptoms have a considerable impact on brain damage in patients with PD.

Motor Dysfunction as a Prodrome of Parkinson's Disease

BACKGROUND

Recognition of motor signs in the prodromal stage could help identify those at risk of developing Parkinson's disease (PD).

OBJECTIVE

This study identified motor symptoms and signs in individuals suspected of having PD but who did not have a progressive reduction in the speed and amplitude of finger tapping or other physical signs indicative of bradykinesia.

METHODS

146 patients, who had symptoms or signs suggestive of PD, were serially evaluated by a movement disorder specialist, using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III and video recordings. If the patients 'converted' to PD during follow-up, they were categorized as cases and compared with those who did not meet PD criteria during follow-up (non-cases).

RESULTS

The 82 cases were more likely to have action dystonia or postural/action/rest tremor of a limb (OR 2.8; 95% CI 1.1-7.1; p = 0.02), a reduced blink rate at rest (OR 2.3; 95% CI 1.2-4.6; p = 0.01), anxiety (OR 8.9; 95% CI 2.6-31.1; p < 0.001), depression (OR 7.0; 95% CI 2.9-17.2; p < 0.001), or a frozen shoulder (OR 3.1; 95% CI 1.6-6.2) than the 64 'non-cases'.A reduction of the fast blink rate was common in patients who met the criteria for PD (p < 0.001).

CONCLUSIONS

This study emphasizes that motor dysfunction is a component of the clinical prodrome seen in some patients with PD.

Molecular Connections Between Circadian Clocks and Mood-related Behaviors

The circadian system consists of individual cellular clocks. It organizes and synchronizes biochemical and physiological processes in order to optimally adapt an organism to its environment. This requires that the circadian system is responsive to environmental cues, which contain information about geophysical time (e.g., light), and allows an organism to predict daily recurring events. However, the system needs to be responsive to unpredictable cues (e.g., predators, stress) as well, which makes it vulnerable in its task to synchronize body functions on a 24-h time scale. If unpredictable signals occur only occasionally, this will have a minor effect on the clock system. Conversely, stress signals that occur more frequently will desynchronize the various cellular and tissue clocks in the body. This will result in biochemical and physiological disorder and as a consequence will lead to various diseases including neurological and mood disorders. In this review, I will describe molecular mechanisms that have been associated with the circadian clock and mood-related behaviors.

Clinical implications of early caudate dysfunction in Parkinson's disease

OBJECTIVE

Although not typical of Parkinson's disease (PD), caudate dopaminergic dysfunction can occur in early stages of the disease. However, its frequency and longitudinal implications in large cohorts of recently diagnosed patients remain to be established. We investigated the occurrence of caudate dopaminergic dysfunction in the very early phases of PD (<2 years from diagnosis) using ¹²³I-FP-CIT single photon emission CT and determined whether it was associated with the presence or subsequent development of cognitive impairment, depression, sleep and gait problems.

METHODS

Patients with PD and healthy controls were identified from the Parkinson's Progression Markers Initiative (PPMI) database. We defined a clinically significant caudate dysfunction as ¹²³I-FP-CIT binding <-2 SDs compared with the controls' mean and categorised three groups accordingly (no reduction, unilateral reduction, bilateral reduction). All statistical analyses were adjusted for mean putamen binding.

RESULTS

At baseline, 51.6% of 397 patients had normal caudate dopamine transporter binding, 26.0% had unilateral caudate involvement, 22.4% had bilaterally impaired caudate.Compared with those with a baseline normal caudate function, at the4-year follow-up patients with a baseline bilateral caudate involvement showed a higher frequency of cognitive impairment (p<0.001) and depression (p<0.001), and worse cognitive (p<0.001), depression (<0.05) and gait (<0.001) ratings. Significant caudate involvement was observed in 83.9% of the population after 4 years (unilateral 22.5%, bilateral 61.4%).

CONCLUSIONS

Early significant caudate dopaminergic denervation was found in half of the cases in the PPMI series. Baseline bilateral caudate involvement was associated with increased risk of developing cognitive impairment, depression and gait problems over the next 4 years.

[Neuropsychopathology of people suffering from Parkinson's disease (2/2)]

A cognitive and psychological approach is essential to take into account all the phenomena which can be observed in the everyday life of patients with Parkinson's disease. In order to provide patients and their carer(s) with clear and specific answers to help them gain a better insight into their future everyday life, the non-motor symptoms associated with the disease must be identified: cognitive, psychological and behavioural disorders.

Parkinson's Disease Is Associated with Risk of Sexual Dysfunction in Men but Not in Women: A Systematic Review and Meta-Analysis

BACKGROUND

Mounting evidence has emerged suggesting that patients with Parkinson's disease (PD) are susceptible to sexual dysfunction (SD).

AIM

To better clarify the relationship between PD and SD.

METHODS

PubMed, Embase, Cochrane Library database, and PsychINFO database were systematically searched for pertinent studies evaluating sexual function in the patients with PD. This systematic review and meta-analysis have been registered on PROSPERO (ID: CRD42018108714; http://www.crd.york.ac.uk/PROSPERO).

OUTCOMES

The association between PD and SD was assessed using relative risk (RR) with 95% CI. The quality of evidence was ranked by the GRADE profiler.

RESULTS

11 observational studies met the predefined criteria for inclusion, enrolling 30,150 subjects from both the PD group and healthy control group (mean age 54.6-75.1 years). Synthesis results revealed that PD was associated with an elevated risk of SD in males (7 studies; 1.79; 95% CI = 1.26-2.54, P = .001; heterogeneity: I2 = 73.2%, P < .001). However, when restricted to female subjects, the combined RR from 3 eligible studies suggested a lack of significant association between PD and SD (RR = 1.3, 95% CI = 0.64-2.61, P = .469; heterogeneity: I2 = 80.0%, P = .007). The GRADE profiler indicated the overall quality of the evidence was low in studies including males and very low in studies including females.

CLINICAL IMPLICATIONS

The current meta-analysis indicated that men with PD were more likely to experience SD than those without PD. In female subjects, however, PD seemed to not be associated with a high prevalence of SD compared with healthy controls. Based on these findings, patients with PD should be routinely assessed for sexual functioning, especially males.

STRENGTHS & LIMITATIONS

This is the first systematic review and meta-analysis of the association between PD and the risks of SD in both males and females. However, substantial heterogeneities were detected across the included studies.

CONCLUSION

A hazardous effect of PD for developing SD was detected in men but not in women. As a result, sexual function assessment and appropriate therapy are recommended for men with PD in clinical practice. Zhao S, Wang J, Xie Q, et al. Parkinson's Disease Is Associated with Risk of Sexual Dysfunction in Men but Not in Women: A Systematic Review and Meta-Analysis J Sex Med 2019;16:434-446.

Botulinum toxin relieves anxiety and depression in patients with hemifacial spasm and blepharospasm

OBJECTIVE

To explore the efficacy of botulinum toxin type A (BTX-A) therapy in relieving anxiety and depression in patients with hemifacial spasm (HFS) and benign essential blepharospasm (BEB).

PATIENTS AND METHOD

Ninety idiopathic HFS patients and 90 BEB patients were enrolled. The anxiety and depression status were evaluated by self-rating anxiety scale (SAS) and self-rating depression scale (SDS), respectively, before and after the injection of BTX-A.

RESULTS

Before treatment, the SAS and SDS scores of HFS patients were 41.25±6.35 and 42.25±7.57, respectively. The SAS scores were 40.17±8.36 for males and 43.56±6.10 for females (P=0.031). The SDS scores were 40.25±6.46 for males and 45.48±7.31 for females (P=0.008). After treatment, the SAS and SDS scores were 30.12±4.35 and 30.58±4.89, respectively. There was a significant difference in the SAS and SDS scores before and after treatment. Before treatment, the SAS scores of male and female BEB patients were 56.45±8.75 and 60.89±9.11, respectively, and the SDS scores of male and female BEB patients were 57.90±7.93 and 60.12±8.35, respectively. After treatment, the SAS score was 38.17±3.67 and the SDS score was 38.12±4.15, with a significant difference in before and after treatment scores.

CONCLUSION

In HFS and BEB, especially in female patients, there is an association with anxiety and depression. BTX-A can improve the symptoms of anxiety and depression.

Psychiatric Manifestation in Patients with Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Although its major manifestation is motor symptoms, resulting from the loss of dopaminergic neurons in the substantia nigra, psychiatric symptoms, such as depression, anxiety, hallucination, delusion, apathy and anhedonia, impulsive and compulsive behaviors, and cognitive dysfunction, may also manifest in most patients with PD. Given that the quality of life - and the need for institutionalization - is so highly dependent on the psychiatric well-being of patients with PD, psychiatric symptoms are of high clinical significance. We reviewed the prevalence, risk factors, pathophysiology, and treatment of psychiatric symptoms to get a better understanding of PD for improved management.

NMDA antagonists for treating the non-motor symptoms in Parkinson's disease

Among patients with Parkinson's disease (PD), depression is prevalent and disabling, impacting both health outcomes and quality of life. There is a critical need for alternative pharmacological methods to treat PD depression, as mainstream antidepressant drugs are largely ineffective in this population. Currently, there are no recommendations for the optimal treatment of PD neuropsychiatric symptoms. Given the dual antidepressant and anti-dyskinetic effects of ketamine and other N-methyl-D-aspartate (NMDA) antagonists for PD, this review aims to examine the current evidence of NMDA antagonists for treating neuropsychiatric symptoms, including memantine, amantadine, ketamine, dizoclopine, and d-cycloserine. A comprehensive literature search was conducted using the PubMed database. We also searched the following databases up to March 1, 2018: Ovid MEDLINE, PsycINFO, CINAHL, Google Scholar, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. The following keywords were used: NMDA antagonist and Parkinson's disease. Two authors independently reviewed the articles identified from the search using specific selection criteria, focusing on studies of mood, psychiatric condition, depression, cognition, and quality of life, and the consensus was reached on the 20 studies included. There is a preliminary evidence that NMDA antagonists may modulate psychiatric symptoms in PD. However, current evidence of psychiatric symptom-modifying effects is inconclusive and requires that further trials be conducted in PD. The repurposing of old NMDA antagonists, such as ketamine for depression and newer therapies, such as rapastinel, suggests that there is an emerging place for modulating the glutamatergic system for treating non-motor symptoms in PD.

Salience Network and Depressive Severities in Parkinson's Disease with Mild Cognitive Impairment: A Structural Covariance Network Analysis

Purpose: In Parkinson’s disease with mild cognitive impairment (PD-MCI), we investigated the clinical significance of salience network (SN) in depression and cognitive performance.

Methods: Seventy seven PD-MCI patients that fulfilled multi-domain and non-amnestic subtype were included. Gray matter structural covariance networks were constructed by 3D T1-magnetic resonance imaging and seed based analysis. The patients were divided into two groups by psychiatric interviews and screening of Geriatric Depression Scale (GDS): PD-MCI with depression (PD-MCI-D) or without depression (PD-MCI-ND). The seed or peak cluster volume, or the significant differences in the regression slopes in each seed-peak cluster correlation, were used to evaluate the significance with the neurobehavioral scores.

Results: This study is the first to demonstrate that the PD-MCI-ND group presented a larger number of voxels of structural covariance in SN than the PD-MCI-D group. The right fronto-insular seed volumes and the peak cluster of left lingual gyrus showed significant inverse correlation with the Geriatric Depression Scale (GDS; r = -0.231, P = 0.046).

Conclusions: This study is the first to validate the clinical significance of the SN in PD-MCI-D. The right insular seed value and the SN correlated with the severity of depression in PD-MCI.

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.

Influence of Mild Cognitive Impairment, Depression, and Anxiety on the Quality of Life of Patients with Parkinson Disease

Background

Neuropsychiatric symptoms (NPS) and mild cognitive impairment (MCI) are common in Parkinson disease (PD) and have a negative impact on the patient's quality of life (QoL). We aim to describe the effect of NPS and MCI on each other and on QoL.

Methods

Sixteen MCI and 37 non-MCI PD patients completed different self-assessment questionnaires including the Parkinson's Disease Questionnaire (PDQ-39), the Beck Depression Inventory (BD), the Beck Anxiety Inventory (BAI), and the Self-Report Manic Inventory (SRMI). Linear regression with stepwise elimination was used to select the significant predictors of QoL and to control for confounding factors.

Results

The significant linear regression model (R² = 0.68, p ≤ 0.01) revealed significant effects of MCI (p = 0.03), BDI (p ≤ 0.01), BAI (p ≤ 0.01), age (p = 0.03), a trend of SRMI (p = 0.06), and disease duration (p = 0.08) on QoL.

Conclusions

MCI, anxiety, depression, and age decrease QoL in patients with PD. NPS has the main influence in the prediction of QoL in patients with PD, whereas MCI is only of minor importance.

Implications of Circadian Rhythm in Dopamine and Mood Regulation

Mammalian physiology and behavior are regulated by an internal time-keeping system, referred to as circadian rhythm. The circadian timing system has a hierarchical organization composed of the master clock in the suprachiasmatic nucleus (SCN) and local clocks in extra-SCN brain regions and peripheral organs. The circadian clock molecular mechanism involves a network of transcription-translation feedback loops. In addition to the clinical association between circadian rhythm disruption and mood disorders, recent studies have suggested a molecular link between mood regulation and circadian rhythm. Specifically, genetic deletion of the circadian nuclear receptor Rev-erbα induces mania-like behavior caused by increased midbrain dopaminergic (DAergic) tone at dusk. The association between circadian rhythm and emotion-related behaviors can be applied to pathological conditions, including neurodegenerative diseases. In Parkinson's disease (PD), DAergic neurons in the substantia nigra pars compacta progressively degenerate leading to motor dysfunction. Patients with PD also exhibit non-motor symptoms, including sleep disorder and neuropsychiatric disorders. Thus, it is important to understand the mechanisms that link the molecular circadian clock and brain machinery in the regulation of emotional behaviors and related midbrain DAergic neuronal circuits in healthy and pathological states. This review summarizes the current literature regarding the association between circadian rhythm and mood regulation from a chronobiological perspective, and may provide insight into therapeutic approaches to target psychiatric symptoms in neurodegenerative diseases involving circadian rhythm dysfunction.

Limbic grey matter changes in early Parkinson's disease

The purpose of this study was to investigate local and network‐related changes of limbic grey matter in early Parkinson's disease (PD) and their inter‐relation with non‐motor symptom severity. We applied voxel‐based morphometric methods in 538 T1 MRI images retrieved from the Parkinson's Progression Markers Initiative website. Grey matter densities and cross‐sectional estimates of age‐related grey matter change were compared between subjects with early PD (n = 366) and age‐matched healthy controls (n = 172) within a regression model, and associations of grey matter density with symptoms were investigated. Structural brain networks were obtained using covariance analysis seeded in regions showing grey matter abnormalities in PD subject group. Patients displayed focally reduced grey matter density in the right amygdala, which was present from the earliest stages of the disease without further advance in mild‐moderate disease stages. Right amygdala grey matter density showed negative correlation with autonomic dysfunction and positive with cognitive performance in patients, but no significant interrelations were found with anxiety scores. Patients with PD also demonstrated right amygdala structural disconnection with less structural connectivity of the right amygdala with the cerebellum and thalamus but increased covariance with bilateral temporal cortices compared with controls. Age‐related grey matter change was also increased in PD preferentially in the limbic system. In conclusion, detailed brain morphometry in a large group of early PD highlights predominant limbic grey matter deficits with stronger age associations compared with controls and associated altered structural connectivity pattern. This provides in vivo evidence for early limbic grey matter pathology and structural network changes that may reflect extranigral disease spread in PD. Hum Brain Mapp 38:3566–3578, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Impact of STN-DBS on mood, drive, anhedonia and risk of psychiatric side-effects in the population of PD patients

BACKGROUND

DBS is a surgical method of choice for various movement disorders, especially for Parkinson's disease (PD). Many publications showing improvement in motor symptoms and quality of life have been presented while there is little comprehensive research evaluation of the impact of DBS on mental state and psychiatric side-effects.

OBJECT

The purpose of this study was to assess the impact of DBS on mood, drive, anhedonia and psychotic symptoms in the group of PD patients.

METHODS

60 patients with PD were treated with STN-DBS. Mental state and psychiatric side effects were assessed with the use of MADRS, HADRS, BDI, BPRS, YMS, SHAPS, CGI and PGI rating scales. Evaluation was performed five times in the period from the day before surgery to six months after implantation of the DBS.

RESULTS

This study showed an improvement of mood, which has followed within a month after the start of stimulation and manifested in MADRS, HADRS, BDI scores reduction. The trend towards improvement was maintained over the following 6months. No manic episodes appeared, 2 cases of mild hypomania were observed. Psychotic symptoms occurred in 1 patient. Anhedonia reduction observed during the first 30days after initiating the stimulation persisted in the assessment six months after implantation of the DBS.

CONCLUSIONS

The survey results confirm the effect of stimulation on mood, drive, ability to feel pleasure. Psychiatric side effects such as phase change were rare and mild, while psychotic symptoms that occurred in one patient ware manageable through medication. Further intensive research in this topic are required.

Presynaptic dopaminergic terminal imaging and non-motor symptoms assessment of Parkinson's disease: evidence for dopaminergic basis?

Parkinson's disease (PD) is now considered to be a multisystemic disorder consequent on multineuropeptide dysfunction including dopaminergic, serotonergic, cholinergic, and noradrenergic systems. This multipeptide dysfunction leads to expression of a range of non-motor symptoms now known to be integral to the concept of PD and preceding the diagnosis of motor PD. Some non-motor symptoms in PD may have a dopaminergic basis and in this review, we investigate the evidence for this based on imaging techniques using dopamine-based radioligands. To discuss non-motor symptoms we follow the classification as outlined by the validated PD non-motor symptoms scale.

Distant delivery of a mindfulness-based intervention for people with Parkinson's disease: the study protocol of a randomised pilot trial

Background

Psychological difficulties, especially depression and anxiety, are the most prevalent non-motor symptoms in Parkinson’s disease. Pharmacological treatments for these conditions appear relatively ineffective in Parkinson’s disease. Mindfulness courses are increasingly popular and recognised as effective for managing emotional states, and there is growing evidence for the effectiveness of mindfulness courses for people with long-term medical conditions. With this exploratory pilot trial, we want to assess the feasibility of the procedures and processes, including recruitment, most appropriate outcome measure(s), acceptability of type and number of measures, potential nocebo effects, and potential effectiveness and cost-effectiveness of a specially adapted distance-delivered mindfulness-based intervention in people affected by Parkinson’s disease.

Methods/Design

This is a pilot two-arm randomised parallel group controlled trial. Sixty participants who meet eligibility criteria will be randomly assigned either to an 8-week mindfulness-based intervention group or a wait-list control group. The mindfulness intervention will include 1-h weekly sessions delivered by a health psychologist trained to facilitate mindfulness courses. Participants in both groups will complete standardised questionnaires assessing anxiety, depression, pain, insomnia, fatigue, and daily activities at four time points (baseline, 4, 8, and 20 weeks). The analysis will also consider potential mechanisms of change, such as acceptance, self-compassion, and tolerance of uncertainty, as well as health economic outcomes. Participants’ experiences of the mindfulness interventions will be explored via in-depth interviews.

Discussion

A mindfulness-based intervention for people with Parkinson’s delivered remotely, through Skype group videoconferences, may represent a viable, more accessible, intervention for people with mobility limitations and people who live in rural areas. The trial will provide important information about the feasibility, potential efficacy and cost-effectiveness, and acceptability of the intervention as well as mechanisms of psychosocial adjustment. The results of this pilot trial will help us design a phase III trial to assess efficacy of an online mindfulness-based intervention in Parkinson’s disease and evaluate significance.

Trial registration

ClinicalTrials.gov, NCT02683330

Cognitive Behaviour Therapy for Depression and Anxiety in Parkinson's Disease

Evidence is reviewed demonstrating that cognitive behavior therapy (CBT) is effective in the treatment of depression and anxiety in Parkinson’s disease. The aims were to review the extant literature, specify a model of cognitive and behavioral maintenance factors in depression and anxiety in Parkinson’s disease and provide a guide to treatment. It is argued that treatment should take into account specific cognitive and behavioral maintaining factors. Symptoms of depression and anxiety are highly prevalent in Parkinson’s disease and therapists should consider how to augment the efficacy of CBT for patients with Parkinson’s disease. Cognitive and behavioral interventions can help people overcome some of the challenges in living with PD by maximizing wellbeing and overall quality of life.

Imbalance of Glial-Neuronal Interaction in Synapses: A Possible Mechanism of the Pathophysiology of Bipolar Disorder

There is a wave of new information suggesting that glia, especially astrocytes, are intimately involved in the active control of neuronal activity and synaptic transmission. Synaptically associated astrocytes should be viewed as integral modulatory elements of tripartite synapses consisting of the presynapse, the postsynapse, and the glial element (astrocytes). Smit and coworkers proposed a model of a cholinergic tripartite synapse based on the identification of a glial-derived binding protein (BP) that is secreted into the synapse and binds free acetylcholine (ACh), thus reducing the levels of ACh available for stimulating the postsynapse. Here the author proposes an explanatory model of the pathophysiology of bipolar disorder focusing on the possible dynamics in cholinergic tripartite synapses. The hypothesis is that an imbalance between neurotransmitters and glial BPs in the synaptic cleft is determined by glia. If glial BPs are overexpressed, synaptic transmission is suppressed because of reduced levels of bioavailable neurotransmitters. This state could cause a depression on the behavioral level. In contrast, if glial BPs are underexpressed, the excess of neurotransmitters in the cleft leads to an overbalanced state of synaptic information transmission. This state could cause manic behavior. Under certain conditions, underbalanced and overbalanced synapses at different locations in the same brain could disturb brain function in parallel causing a mixed episode of bipolar disorder. If glial BPs and mutations in genes expressing glial BPs in the various synapses of the brain are identified, this hypothesis can be experimentally tested.

The Network Model of Depression as a Basis for New Therapeutic Strategies for Treating Major Depressive Disorder in Parkinson's Disease

The high prevalence of major depressive disorder in people with Parkinson’s disease (PD), its negative impact on health-related quality of life and the low response rate to conventional pharmacological therapies call to seek innovative treatments. Here, we review the new approaches for treating major depressive disorder in patients with PD within the framework of the network model of depression. According to this model, major depressive disorder reflects maladaptive neuronal plasticity. Non-invasive brain stimulation (NIBS) using high frequency repetitive transcranial magnetic stimulation (rTMS) over the prefrontal cortex has been proposed as a feasible and effective strategy with minimal risk. The neurobiological basis of its therapeutic effect may involve neuroplastic modifications in limbic and cognitive networks. However, the way this networks reorganize might be strongly influenced by the environment. To address this issue, we propose a combined strategy that includes NIBS together with cognitive and behavioral interventions.

Rumination and behavioural factors in Parkinson's disease depression

OBJECTIVE

Parkinson's disease is associated with high rates of depression. There is growing interest in non-pharmacological management including psychological approaches such as Cognitive Behaviour Therapy. To date, little research has investigated whether processes that underpin cognitive models of depression, on which such treatment is based, apply in patients with Parkinson's disease. The study aimed to investigate the contribution of core psychological factors to the presence and degree of depressive symptoms.

METHODS

104 participants completed questionnaires measuring mood, motor disability and core psychological variables, including maladaptive assumptions, rumination, cognitive-behavioural avoidance, illness representations and cognitive-behavioural responses to symptoms.

RESULTS

Regression analyses revealed that a small number of psychological factors accounted for the majority of depression variance, over and above that explained by overall disability. Participants reporting high levels of rumination, avoidance and symptom focusing experienced more severe depressive symptoms. In contrast, pervasive negative dysfunctional beliefs did not independently contribute to depression variance.

CONCLUSION

Specific cognitive (rumination and symptom focusing) and behavioural (avoidance) processes may be key psychological markers of depression in Parkinson's disease and therefore offer important targets for tailored psychological interventions.

An update on the rotenone models of Parkinson's disease: their ability to reproduce the features of clinical disease and model gene-environment interactions

Parkinson's disease (PD) is the second most common neurodegenerative disorder that is characterized by two major neuropathological hallmarks: the degeneration of dopaminergic neurons in the substantia nigra (SN) and the presence of Lewy bodies in the surviving SN neurons, as well as other regions of the central and peripheral nervous system. Animal models have been invaluable tools for investigating the underlying mechanisms of the pathogenesis of PD and testing new potential symptomatic, neuroprotective and neurorestorative therapies. However, the usefulness of these models is dependent on how precisely they replicate the features of clinical PD with some studies now employing combined gene-environment models to replicate more of the affected pathways. The rotenone model of PD has become of great interest following the seminal paper by the Greenamyre group in 2000 (Betarbet et al., 2000). This paper reported for the first time that systemic rotenone was able to reproduce the two pathological hallmarks of PD as well as certain parkinsonian motor deficits. Since 2000, many research groups have actively used the rotenone model worldwide. This paper will review rotenone models, focusing upon their ability to reproduce the two pathological hallmarks of PD, motor deficits, extranigral pathology and non-motor symptoms. We will also summarize the recent advances in neuroprotective therapies, focusing on those that investigated non-motor symptoms and review rotenone models used in combination with PD genetic models to investigate gene-environment interactions.

Norepinephrine transporter inhibition with desipramine exacerbates L-DOPA-induced dyskinesia: role for synaptic dopamine regulation in denervated nigrostriatal terminals

Pharmacological dopamine (DA) replacement with Levodopa [L-dihydroxyphenylalanine (L-DOPA)] is the gold standard treatment of Parkinson's disease (PD). However, long-term L-DOPA treatment is complicated by eventual debilitating abnormal involuntary movements termed L-DOPA-induced dyskinesia (LID), a clinically significant obstacle for the majority of patients who rely on L-DOPA to alleviate PD-related motor symptoms. The manifestation of LID may in part be driven by excessive extracellular DA derived from L-DOPA, but potential involvement of DA reuptake in LID severity or expression is unknown. We recently reported that in 6-hydroxydopamine (6-OHDA)-lesioned striatum, norepinephrine transporter (NET) expression increases and may play a significant role in DA transport. Furthermore, L-DOPA preferentially inhibits DA uptake in lesioned striatum. Therefore, we hypothesized that desipramine (DMI), a NET antagonist, could affect the severity of LID in an established LID model. Whereas DMI alone elicited no dyskinetic effects in lesioned rats, DMI + L-DOPA-treated rats gradually expressed more severe dyskinesia compared with L-DOPA alone over time. At the conclusion of the study, we observed reduced NET expression and norepinephrine-mediated inhibition of DA uptake in the DMI + L-DOPA group compared with L-DOPA-alone group in lesioned striatum. LID severity positively correlated with striatal extracellular signal-regulated protein kinase phosphorylation among the three treatment groups, with increased ppERK1/2 in DMI + L-DOPA group compared with the L-DOPA- and DMI-alone groups. Taken together, these results indicate that the combination of chronic L-DOPA and NET-mediated DA reuptake in lesioned nigrostriatal terminals may have a role in LID severity in experimental Parkinsonism.

Neuroimaging in Parkinson disease: from research setting to clinical practice

Over the past three decades, neuroimaging studies-including structural, functional and molecular modalities-have provided invaluable insights into the mechanisms underlying Parkinson disease (PD). Observations from multimodal neuroimaging techniques have indicated changes in brain structure and metabolic activity, and an array of neurochemical changes that affect receptor sites and neurotransmitter systems. Characterization of the neurobiological alterations that lead to phenotypic heterogeneity in patients with PD has considerably aided the in vivo investigation of aetiology and pathophysiology, and the identification of novel targets for pharmacological or surgical treatments, including cell therapy. Although PD is now considered to be very complex, no neuroimaging modalities are specifically recommended for routine use in clinical practice. However, conventional MRI and dopamine transporter imaging are commonly used as adjuvant tools in the differential diagnosis between PD and nondegenerative causes of parkinsonism. First-line neuroimaging tools that could have an impact on patient prognosis and treatment strategies remain elusive. This Review discusses the lessons learnt from decades of neuroimaging research in PD, and the promising new approaches with potential applicability to clinical practice.