Treatment of Nonmotor Symptoms in 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.

Efficacy of acupuncture for the treatment of Parkinson's disease-related constipation (PDC): A randomized controlled trial

Objective

To evaluate the efficacy of acupuncture in treating Parkinson's disease-related constipation (PDC).

Materials and methods

This was a randomized, controlled trial in which patients, outcome assessors, and statisticians were all blinded. Seventy-eight eligible patients were randomly assigned to either the manual acupuncture (MA) or sham acupuncture (SA) groups and received 12 sessions of treatment over a 4-week period. Following treatment, patients were monitored until the eighth week. The primary outcome was the change in weekly complete spontaneous bowel movements (CSBMs) from baseline after treatment and follow-up. The Constipation Symptom and Efficacy Assessment Scale (CSEAS), the Patient-Assessment of Constipation Quality of Life questionnaire (PAC-QOL), and the Unified Parkinson's Disease Rating Scale (UPDRS) were used as secondary outcomes.

Results

In the intention-to-treat analysis, 78 patients with PDC were included, with 71 completing the 4-week intervention and 4-week follow-up. When compared to the SA group, weekly CSBMs were significantly increased after treatment with the MA group (P < 0.001). Weekly CSBMs in the MA group were 3.36 [standard deviation (SD) 1.44] at baseline and increased to 4.62 (SD, 1.84) after treatment (week 4). The SA group's weekly CSBMs were 3.10 (SD, 1.45) at baseline and 3.03 (SD, 1.25) after treatment, with no significant change from baseline. The effect on weekly CSBMs improvement in the MA group lasted through the follow-up period (P < 0.001).

Conclusion

Acupuncture was found to be effective and safe in treating PDC in this study, and the treatment effect lasted up to 4 weeks.

Clinical trial registration

http://www.chictr.org.cn/index.aspx, identifier ChiCTR2200059979.

Evaluation of the Neuroprotective Effect of Microglial Depletion by CSF-1R Inhibition in a Parkinson's Animal Model

PURPOSE

Neuroinflammation in Parkinson's disease (PD) is known to play a pivotal role in progression to neuronal degeneration. It has been reported that colony-stimulation factor 1 receptor (CSF-1R) inhibition can effectively deplete microglia. However, its therapeutic efficacy in PD is unclear still now.

PROCEDURES

To elucidate this issue, we examined the contribution of microglial depletion to PD by behavioral testing, positron emission tomography (PET) imaging, and immunoassays in sham, PD, and microglial depletion PD model (PLX3397 was administered to PD groups, with n = 6 in each group).

RESULTS

The microglial depletion in PD model showed improved sensory motor function and depressive-like behavior. NeuroPET revealed that PLX3397 treatment resulted in partial recovery of striatal neuro-inflammatory functions (binding values of [¹⁸F]DPA-174 for PD, 1.47 ± 0.12, p < 0.01 vs. for PLX3397 in PD: 1.33 ± 0.26) and the dopaminergic (binding values of ¹⁸F-FP-CIT for PD, 1.32 ± 0.07 vs. for PLX3397 in PD: 1.54 ± 0.10, p < 0.01) and glutamatergic systems (binding values of [¹⁸F]FPEB for PD: 9.22 ± 0.54 vs. for PLX3397 Tx in PD: 9.83 ± 0.96, p > 0.05). Western blotting for microglia showed similar changes.

CONCLUSION

Microglial depletion has inflammation-related therapeutic effects, which have beneficial effects on motor and nonmotor symptoms of PD.

Neuropsychiatric and Cognitive Deficits in Parkinson's Disease and Their Modeling in Rodents

Parkinson’s disease (PD) is associated with a large burden of non-motor symptoms including olfactory and autonomic dysfunction, as well as neuropsychiatric (depression, anxiety, apathy) and cognitive disorders (executive dysfunctions, memory and learning impairments). Some of these non-motor symptoms may precede the onset of motor symptoms by several years, and they significantly worsen during the course of the disease. The lack of systematic improvement of these non-motor features by dopamine replacement therapy underlines their multifactorial origin, with an involvement of monoaminergic and cholinergic systems, as well as alpha-synuclein pathology in frontal and limbic cortical circuits. Here we describe mood and neuropsychiatric disorders in PD and review their occurrence in rodent models of PD. Altogether, toxin-based rodent models of PD indicate a significant but non-exclusive contribution of mesencephalic dopaminergic loss in anxiety, apathy, and depressive-like behaviors, as well as in learning and memory deficits. Gene-based models display significant deficits in learning and memory, as well as executive functions, highlighting the contribution of alpha-synuclein pathology to these non-motor deficits. Collectively, neuropsychiatric and cognitive deficits are recapitulated to some extent in rodent models, providing partial but nevertheless useful options to understand the pathophysiology of non-motor symptoms and develop therapeutic options for these debilitating symptoms of PD.

Impact of Subthalamic Deep Brain Stimulation on Hyposmia in Patients With Parkinson's Disease Is Influenced by Constipation and Dysbiosis of Microbiota

Background: Non-motor symptoms in PD usually arise at very early stage and vary during the whole disease progression. Deep brain stimulation (DBS) is considered as a highly efficient treatment option for PD's motor function. However, the effect of DBS on NMS, especially hyposmia, has not been fully understood and the deep connection between different NMS such as hyposmia and constipation is still unknown. Objective: The objective of this study was to evaluate the therapeutic effect of DBS on hyposmia in PD patients with or without constipation and find potential factors which might influence the efficacy. Methods: A retrospective analysis of 65 PD patients accepted STN-DBS operation in Qilu Hospital during 2019-2020 were conducted to evaluate the exact therapeutic effect of DBS on hyposmia in PD. Sub-group analyses about the relationship between hyposmia and constipation were carried out. Analysis of flora in nasal mucosa was also conducted to evaluate the abundance and variety in different PD groups. Results: Our study showed that DBS had clearly improved olfactory function in Parkinson patients (P = 0.012) and subgroup analysis found that PD patients with constipation have lower olfactory function scores (25.27 ± 3.44 vs. 33.90 ± 6.633, p = 0.014) and worse improvement after DBS operation (ΔTDI 12.11 ± 3.2 vs. 8.78 ± 2.91, p = 0.0072). Analysis of flora indicated the obvious discrepancy on olfactory function scores and degree of improvement might be related to the abundance and dysbiosis of microbiota. Conclusion: In summary, this article presents a study on PD with hyposmia and constipation after DBS operation, explored the relationship between different NMS and offer a potential explanation on why PD patients with constipation usually have worse olfactory function for the less abundance and variety of microbiota.

Prevalence of Non-Motor Symptoms and Non-Motor Fluctuations in Parkinson's Disease Using the MDS-NMS

Background

Non-motor symptoms (NMS) are frequent in Parkinson's disease (PD).

Objectives

To estimate the prevalence of NMS and of non-motor fluctuations (NMF) using the Movement Disorders Society-Non-Motor Rating Scale (MDS-NMS) and other scales assessing NMS, and their relationship with sex and PD severity.

Methods

Cross-sectional study with a sample of 402 PD patients. The Hoehn and Yahr staging system (HY), Clinical Impression of Severity Index for PD (CISI-PD), MDS-NMS (including NMF- subscale), Non-Motor Symptoms scale (NMSS), and MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) were applied. A NMS was considered present when scored ≥1. Differences in scores by sex and HY, CISI-PD, and MDS-UPDRS severity levels were calculated using Fisher's exact and chi-squared tests.

Results

Using the MDS-NMS, NMS were present in 99.7% of patients and the mean number of NMS was 16.13 (SD: 9.36). The most prevalent NMS was muscle, joint or back pain (67.4% of the sample) and the least prevalent was dopamine dysregulation syndrome (2.2%). Feeling sad or depressed was significantly more prevalent in women. Using the MDS-NMS revealed more NMS than the other scales assessing NMS. NMF were present in 41% of the sample, with fatigue being the most prevalent symptom (68.5% patients with NMF), and no differences by sex. Patients with greater PD severity had higher prevalence of NMS than patients with lower severity.

Conclusions

Almost all patients with PD experience NMS, and many experience NMF. Prevalence rates for NMS using the MDS-NMS are higher than on other scales used and increase with higher disease severity.

Suicide in Parkinson's Disease: A Systematic Review

Psychiatric disorders and suicide have been reported in patients suffering from Parkinson's disease. The aims of the present paper were to determine whether patients with Parkinson's disease have an increased rate of suicide and to identify the clinical features possibly associated with suicide risk in Parkinson's disease. We also reviewed the studies on suicide risk in Parkinson's disease in patients after deep brain stimulation. We performed a Medline, Excerpta Medica, PsycLit, PsycInfo and Index Medicus search to identify all articles published on this topic from 1970 to 2019. The following search terms were used: suicide OR suicide attempt OR suicidal ideation OR suicide risk AND Parkinson's disease AND Parkinson's disease and deep brain stimulation. The studies we identified that assessed the suicide rate associated with Parkinson's disease yielded contrasting results, although an increase in suicidal ideation did emerge. The studies on the effect of deep brain stimulation on suicide risk in Parkinson's disease also reported mixed findings. Psychiatric symptoms, including depression, appear to be associated with suicide risk in patients with Parkinson's disease undergoing medical and after surgical treatment. The studies reviewed suggest that suicidal ideation is increased in Parkinson's disease. Further longitudinal studies designed to assess suicidality in this condition are still needed.

Decreased Striatal Vesicular Monoamine Transporter Type 2 Correlates With the Nonmotor Symptoms in Parkinson Disease

OBJECTIVE

Nonmotor symptoms (NMS) are critical players in the patients' quality of life in Parkinson disease (PD). Vesicular monoamine transporter type 2 (VMAT2) has been reported owing to a role in affecting dopamine neurons in the striatum. Therefore, this study set out to characterize the relationship between VMAT2 distribution in the striatum in relation to the NMS in PD.

METHODS

Totally, 21 age-matched normal controls and 37 patients with PD in the moderate stages were included, followed by examination using F-DTBZ (F-AV133) PET/CT. The specific uptake ratio (SUR) of each striatal subregion was then determined with the occipital cortex as the reference background region. The overall NMSs of each individual patient were evaluated. Finally, the role of the striatal SURs in the clinical symptom scores were evaluated through the application of a Spearman correlation analysis as well as a multivariable stepwise regression analysis.

RESULTS

Patients with PD, particularly those at a more advanced stage, exhibited a more pronounced reduction in SURs in the bilateral putamen and caudate nucleus (P < 0.05, vs healthy controls). Meanwhile, patients at more advanced PD stages were found to have significantly worse scores in NMS except cognitive function. The Spearman correlation analysis demonstrated that NMS scores, with the exception of cognition scores, were correlated with striatal SURs (P < 0.05).

CONCLUSION

The key findings of the study identified a correlation between decreased striatal VMAT2 with a broad spectrum of NMS in patients with PD, highlighting the association between diminished dopamine supply and the development of NMS in PD.

Training Neurodegenerative Disease Support Group Leaders: A New Support Group Functioning Scale

Support group leaders play pivotal roles in maintaining healthy community support groups; however, these leaders also have personal support needs and typically lack formal training in managing complex behaviors of neurodegenerative disorders. A support group well-being questionnaire, assessing support group functioning, was developed and piloted among participants of an educational training program designed for support group leaders of various neurodegenerative disorder-specific support groups. An exploratory factor analysis evaluated the questionnaire’s psychometric properties and identified a reliable single factor five-item solution, which was titled the Support Group Functioning Scale (SGFS). Preliminary interpretation guidelines were proposed. Development of this scale is a first step in identifying support group leaders’ needs as they provide frontline assistance to caregivers and individuals with neurodegenerative illnesses. This tool shows promise as an efficient way to identify support groups in need of assistance and to assess the impact of trainings on support group functioning. Further validation of the scale is needed.