Motor and non-motor predictors of illness-related distress in Parkinson's disease

Towards a biological diagnosis of PD

Since the original description by James Parkinson, Parkinson's disease (PD) has intrigued us for over 200 years. PD is a progressive condition that is incurable so far, and affects millions of people worldwide. Over the years, our knowledge has expanded tremendously, and a range of criteria have been put forward and used to try to define PD. However, owing to the complexity of the problem, it is still not consensual how to diagnose and classify a disease that manifests with diverse features, and that responds differently to existing therapies and to those under development. We are now living a time when 'biological' information is becoming abundant, precise, and accessible enabling us to attempt to incorporate different sources of information to classify different forms of PD. These refinements are essential for basic science, as they will enable us to develop improved models for studying PD, and to implement new findings into clinical practice, as this will be the path towards effective personalized medicine.

The Effects of Mindfulness-Based Interventions in People with Parkinson's Disease: A Systematic Review and Meta-Analysis

OBJECTIVES

To examine the effectiveness of mindfulness-based interventions (MBIs) on psychological symptoms, motor symptoms, and quality of life in patients with Parkinson's disease (PD).

METHODS

Published studies in Chinese and English languages, conducted from inception to March 2023, were identified by searching PubMed, Web of Science, Cochrane Library, CINAHL, PsycINFO, and two Chinese electronic databases. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines.

RESULTS

Twelve studies were selected for quantitative syntheses. The impact of MBIs on reducing depression and anxiety, and improving mindfulness and quality of life in PD patients was statistically significant compared to the control group. However, no statistically significant effect on motor symptoms was observed. Subgroup analysis indicated that participants from Asia, those who received face-to-face sessions, and those whose sessions lasted 1.5 hours showed a more positive effect than other subgroups.

CONCLUSIONS

Patients with PD may benefit from MBIs to improve psychological symptoms and quality of life. MBIs represent a pivotal non-pharmacological therapeutic approach in clinical practice.

CLINICAL IMPLICATIONS

MBIs confer positive improvements in psychological well-being and quality of life in PD patients. However, it remains challenging to conclusively determine their efficacy in addressing motor symptoms.

Subthalamic nucleus-deep brain stimulation improves autonomic dysfunctions in Parkinson's disease

Background

To study the effects of subthalamic nucleus-deep brain stimulation (STN-DBS) on autonomic dysfunctions in Parkinson’s disease (PD) patients.

Methods

A total of 57 PD patients who underwent bilateral STN-DBS from March to December 2018, were retrospectively analyzed. Preplanned assessments at baseline and postoperatively at 1, 3, and 6 months also included the Scales for Outcomes in Parkinson’s Disease-Autonomic questionnaire (SCOPA-Aut), the Unified Parkinson’s Disease Rating Scale (UPDRS) III score, levodopa equivalent day dose (LEDD), Parkinson’s Disease Quality of Life Scale (PDQ-39), the Hamilton Anxiety Rating Scale (HAMA), and the Hamilton Depression Rating Scale (HAMD).

Results

The SCOPA-Aut scores improved significantly [14.59% (18.32%), 24.00% (27.05%), 22.16% (27.07%), all P < 0.001] at 1 month, 3 months, and 6 months of STN-DBS, respectively. Analysis of the SCOPA-Aut sub-items showed significant improvements only in urine and thermoregulation sub-items at 6 months after surgery (P < 0.001). There was no significant correlation between improvements of SCOPA-Aut scores and improvements of PDQ-39 scores (P > 0.05) at 6 months after surgery. SCOPA-Aut scores were positively correlated with age (r = 0.428, P = 0.001); the improvements of SCCOPA-Aut scores were positively correlated with improvements of HAMA and HAMD scores (HAMA: r = 0.325, P = 0.015; HAMD: r = 0.265, P = 0.049) at 6 months after surgery.

Conclusion

STN-DBS improved autonomic dysfunction symptoms of PD patients, and urinary and thermoregulatory sub-items of autonomic dysfunction were improved in the short-term after surgery. There was a close relationship between improved autonomic symptoms and improved anxiety and depression 6 months after surgery. We should therefore direct more attention to autonomic dysfunctions in PD involving detailed preoperative evaluations and postoperative follow-ups, to improve the quality of life of patients.

The Challenge and Opportunity to Diagnose Parkinson's Disease in Midlife

Parkinson's disease (PD) is the most common neurodegenerative movement disorder that affects extensive regions of the nervous system. Its current clinical diagnosis is based on motor symptoms that appear late during disease progression when substantial proportions of the nigrostriatal dopaminergic neuron population are lost already. Although disturbances in sleep and other biofunctions often surface years prior to motor impairments and point to a long prodromal phase, these phenotypic signs in a person's midlife lack predictive power. They do, however, signal the unfolding of the disease and suggest molecular correlates that begin deviating early on. Revealing such trajectories, hence, promises not only a better understanding of prodromal PD but may also enable a much-needed earlier diagnosis. A nexus that may harbor such molecular trajectories is the epigenome as key etiological factors of PD-genetics, age, and environment-influence this substrate. An earlier diagnosis would also allow earlier interventions and lifestyle adjustments to improve brain function and reduce symptoms. In this review, we describe the challenges of diagnosing PD early on and highlight the opportunities that may arise from steering research efforts towards comprehensive interrogations of molecular layers during the long-time neglected midlife phase. In particular, we emphasize how existing cohorts of at-risk individuals, available animal models, and suitable markers may come together and aid in revealing molecular trajectories that offer diagnostic utility for PD in its prodromal stage.

Gender and onset age related-differences of non-motor symptoms and quality of life in drug-naïve Parkinson's disease

OBJECTIVE

This study aims to explore the gender and onset age-related differences of non-motor symptoms (NMS) and the determinants of quality of life (QoL) in a large cohort of Chinese drug-naïve Parkinson's disease (PD) patients.

PATIENTS AND METHODS

A cross-sectional analysis of 569 drug-naïve PD patients was conducted. The frequency and severity of each NMS was evaluated by Non-Motor Symptom Scale (NMSS), which consists of 9 subdomains. PD Questionnaire-39 (PDQ-39) was used to assess the QoL of PD patients. A stepwise multiple regression model was used to explore the determinants of QoL.

RESULTS

A total of 552 patients (97.0%) exhibited at least one NMS. The three most common NMS were sleep/fatigue (74%), attention/memory (62.7%) and miscellaneous (62%). The frequencies of sleep/fatigue and mood/apathy were more prevalent in women and the frequencies of urinary and sexual dysfunction were more prevalent in men (P < 0.05). Patients with late-onset PD showed higher frequencies of perceptual problems/hallucinations, attention/memory, gastrointestinal, urinary, sexual dysfunction, and miscellaneous compared to patients with early-onset PD (P < 0.05). The multiple regression analysis model indicated that female, disease duration, UPDRS III score, depression, and NMSS subcores including sleep/fatigue, mood/apathy, attention/memory, and gastrointestinal were the determinants of QoL in patients with drug-naïve PD.

CONCLUSIONS

NMS was common in untreated PD patients. They are heterogeneous in patients with drug-naïve PD, which are dramatic determinants on decreased QoL in PD. Our results are beneficial for clinical management of NMS in drug-naïve PD.

Low-Grade Inflammation Aggravates Rotenone Neurotoxicity and Disrupts Circadian Clock Gene Expression in Rats

A single injection of LPS produced low-grade neuroinflammation leading to Parkinson's disease (PD) in mice several months later. Whether such a phenomenon occurs in rats and whether such low-grade neuroinflammation would aggravate rotenone (ROT) neurotoxicity and disrupts circadian clock gene/protein expressions were examined in this study. Male rats were given two injections of LPS (2.5-7.5 mg/kg), and neuroinflammation and dopamine neuron loss were evident 3 months later. Seven months after a single LPS (5 mg/kg) injection, rats received low doses of ROT (0.5 mg/kg, sc, 5 times/week for 4 weeks) to examine low-grade neuroinflammation on ROT toxicity. LPS plus ROT produced more pronounced non-motor and motor dysfunctions than LPS or ROT alone in behavioral tests, and decreased mitochondrial complex 1 activity, together with aggravated neuroinflammation and neuron loss. The expressions of clock core genes brain and muscle Arnt-like protein-1 (Bmal1), locomotor output cycles kaput (Clock), and neuronal PAS domain protein-2 (Npas2) were decreased in LPS, ROT, and LPS plus ROT groups. The expressions of circadian feedback genes Periods (Per1 and Per2) were also decreased, but Cryptochromes (Cry1 and Cry2) were unaltered. The circadian clock target genes nuclear receptor Rev-Erbα (Nr1d1), and D-box-binding protein (Dbp) expressions were also decreased. Consistent with the transcript levels, circadian clock protein BMAL1, CLOCK, NR1D1, and DBP were also decreased. Thus, LPS-induced chronic low-grade neuroinflammation potentiated ROT neurotoxicity and disrupted circadian clock gene/protein expression, suggesting a role of disrupted circadian in PD development and progression. Graphical Abstract ᅟ.

Change in Cognition and Other Non-Motor Symptoms With Obstructive Sleep Apnea Treatment in Parkinson Disease

STUDY OBJECTIVES

Parkinson disease (PD) non-motor symptoms are associated with sleep disorders and impair quality of life. Our objective was to assess the effect of obstructive sleep apnea (OSA) treatment using continuous positive airway pressure (CPAP) on PD non-motor symptoms.

METHODS

In this prospective observational study, 67 patients with idiopathic PD underwent polysomnography. Those with moderate-severe OSA were offered CPAP therapy. Subjects were divided into those without OSA (OSA-), and those with OSA (OSA+). Analyses were conducted for 6 and 12 months' follow-up data. At 6 months, those who had used CPAP at home for at least 1 month were considered CPAP users (OSA+CPAP+), whereas those who did not try it, or declined further treatment following a short trial were considered non-users (OSA+CPAP-). For the 12-month analysis, only those still actively using CPAP at 12 months were included in the OSA+CPAP+ group. Non-motor symptom measurements were: Epworth Sleepiness Scale, Montreal Cognitive Assessment (MoCA), Unified Parkinson's Disease Rating Scale part 1 (UPDRS1), Parkinson's Disease Sleep Scale (PDSS), Fatigue Severity Scale, Apathy Scale, Beck Depression Inventory, and Hospital Anxiety and Depression Scale (HADS).

RESULTS

Sixty-five participants were re-assessed at least once. At 6 months, 30 participants were categorized as OSA+CPAP+, 11 OSA+CPAP-, and 18 OSA-. At 12 months, 21 were categorized as OSA+CPAP+, 21 OSA+CPAP-, and 17 OSA-. The UPDRS1 and PDSS improved from baseline in OSA+CPAP+ at 6 months (-2.7, standard deviation [SD] 4.0, P = .001, and 7.9, SD 19.0, P = .03, respectively) and 12 months (-4.1, SD 5.4, P = .002, and 11.4, SD 24.4, P = .04, respectively), but not in other groups. The MoCA and HADS-A improved in OSA+CPAP+ at 12 months (1.7, SD 3.5, P = .04, and -2.1, SD 3.8, P = .02, respectively). The MoCA improved in those with low baseline MoCA and those with REM sleep behavior disorder. Mean CPAP use in users at 12 months was 3 hours 36 minutes per night.

CONCLUSIONS

CPAP treatment of OSA in PD is associated with improved overall non-motor symptoms, sleep quality, anxiety, and global cognitive function over a 12-month period.

Nonmotor Effects of Conventional and Transdermal Dopaminergic Therapies in Parkinson's Disease

Nonmotor symptoms (NMS) are an integral component of Parkinson's disease (PD). Because the burden and range of NMS are key determinants of quality of life for patients and caregivers, their management is a crucial issue in clinical practice. Although a range of NMS have a dopaminergic pathophysiological basis, this fact is underrecognized, and thus, they are often regarded as dopamine unresponsive symptoms. However, substantial evidence indicates that many NMS respond to oral and transdermal dopaminergic therapies. In contrast, certain NMS are exacerbated or even precipitated by dopaminergic drugs and these unwanted effects may be seriously dangerous. Therefore, a dopaminergic strategy for NMS should be based on a consideration of the benefits vs the risks in individual patients with PD.

Risk Factors for Malnutrition in Older Adults: A Systematic Review of the Literature Based on Longitudinal Data

The present systematic review critically examines the available scientific literature on risk factors for malnutrition in the older population (aged ≥65 y). A systematic search was conducted in MEDLINE, reviewing reference lists from 2000 until March 2015. The 2499 papers identified were subjected to inclusion criteria that evaluated the study quality according to items from validated guidelines. Only papers that provided information on a variable's effect on the development of malnutrition, which requires longitudinal data, were included. A total of 6 longitudinal studies met the inclusion criteria and were included in the systematic review. These studies reported the following significant risk factors for malnutrition: age (OR: 1.038; P = 0.045), frailty in institutionalized persons (β: 0.22; P = 0.036), excessive polypharmacy (β: -0.62; P = 0.001), general health decline including physical function (OR: 1.793; P = 0.008), Parkinson disease (OR: 2.450; P = 0.047), constipation (OR: 2.490; P = 0.015), poor (OR: 3.30; P value not given) or moderate (β: -0.27; P = 0.016) self-reported health status, cognitive decline (OR: 1.844; P = 0.001), dementia (OR: 2.139; P = 0.001), eating dependencies (OR: 2.257; P = 0.001), loss of interest in life (β: -0.58; P = 0.017), poor appetite (β: -1.52; P = 0.000), basal oral dysphagia (OR: 2.72; P = 0.010), signs of impaired efficacy of swallowing (OR: 2.73; P = 0.015), and institutionalization (β: -1.89; P < 0.001). These risk factors for malnutrition in older adults may be considered by health care professionals when developing new integrated assessment instruments to identify older adults' risk of malnutrition and to support the development of preventive and treatment strategies.

Sustained attention training reduces spatial bias in Parkinson's disease: a pilot case series

Individuals with Parkinson's disease (PD) commonly demonstrate lateralized spatial biases, which affect daily functioning. Those with PD with initial motor symptoms on the left body side (LPD) have reduced leftward attention, whereas PD with initial motor symptoms on the right side (RPD) may display reduced rightward attention. We investigated whether a sustained attention training program could help reduce these spatial biases. Four non-demented individuals with PD (2 LPD, 2 RPD) performed a visual search task before and after 1 month of computer training. Before training, all participants showed a significant spatial bias and after training, all participants' spatial bias was eliminated.

Improved nutritional status is related to improved quality of life in Parkinson's disease

Background

Quality of life is poorer in Parkinson’s disease than in other conditions and in the general population without Parkinson’s disease. Malnutrition also results in poorer quality of life. This study aimed at determining the relationship between quality of life and nutritional status.

Methods

Community-dwelling people with Parkinson’s disease >18 years old were recruited. The Patient-Generated Subjective Global Assessment (PG-SGA) assessed nutritional status. The Parkinson’s Disease Questionnaire 39 (PDQ-39) measured quality of life. Phase I was cross-sectional. The malnourished in Phase I were eligible for a nutrition intervention phase, randomised into 2 groups: standard care (SC) with provision of nutrition education materials only and intervention (INT) with individualised dietetic advice and regular weekly follow-up. Data were collected at baseline, 6 weeks, and 12 weeks.

Results

Phase I consisted of 120 people who completed the PDQ-39. Phase II consisted of 9 in the SC group and 10 in the INT group. In Phase I, quality of life was poorer in the malnourished, particularly for mobility and activities of daily living domains. There was a significant correlation between PG-SGA and PDQ-39 scores (Phase I, r_s = 0.445, p = .000; Phase II, r_s = .426, p = .002). In Phase II, no significant difference in the PDQ-39 total or sub-scores was observed between the INT and SC groups; however, there was significant improvement in the emotional well-being domain for the entire group, X²(2) = 8.84, p = .012.

Conclusions

Malnourished people with Parkinson’s disease had poorer quality of life than the well-nourished, and improvements in nutritional status resulted in quality of life improvements. Attention to nutritional status is an important component of quality of life and therefore the total care of people with Parkinson’s disease.

Trial registration

ACTRN12610000819022

Conceptualizing and prioritizing clinical trial outcomes from the perspectives of people with Parkinson's disease versus health care professionals: a concept mapping study

BACKGROUND

Focusing clinical investigations on outcomes that are meaningful from an end-user perspective is central in clinical research, particularly in chronic disorders such as Parkinson's disease (PD). However, little is known about how end-users such as people with PD (PwPD) and health care professionals (HCPs) view and prioritize therapeutic outcomes.

PURPOSE

To compare the perspectives of PwPD and HCPs regarding prioritized areas for outcome measurement in clinical PD trials.

METHODS

Concept mapping was used to identify prioritized outcomes (statements) through focus groups (n = 27; 12 PwPD, 12 HCPs, three researchers), statement sorting and importance rating (n = 38; 19 PwPD, 19 HCPs), followed by quantitative (multidimensional scaling, cluster analysis, procrustes analysis) and qualitative analysis.

RESULTS

Sorting of 99 statements by PwPD and HCPs yielded 2D maps (PwPD/HCPs stress values, 0.31/0.21) with eight clusters per group. The correlation between raw sorting data of PwPD and HCPs was 0.80, and there was a significant concordance (m 12 = 0.53; P < 0.001; i.e., r = 0.68) between the spatial arrangements in their respective maps. Qualitatively, the maps from the two groups represented partially different perspectives. There were no significant differences between PwPD and HCP item importance ratings.

CONCLUSION

Although similarities dominated, there were differences in how the relationships between items were perceived by the two groups, emanating from different perspectives, i.e., the clinical biomedical ("disease") versus the lived experience ("illness"). This study illustrates the clinical importance of attention to the perspective of PwPD; taking this into account is likely to provide evidence from clinical investigations that are meaningful and interpretable for end-users.

Emergence of nonmotor symptoms as the focus of research and treatment of Parkinson's disease: introduction to the special section on nonmotor dysfunctions in Parkinson's disease

Parkinson's disease (PD) is traditionally characterized by the cardinal motor symptoms of tremor, rigidity, slowness of movement, and impairments of posture, gait, and balance. A relatively new focus of research and treatment is the nonmotor symptoms of the disease, following from recent understanding of the neuropathological stages. Disruptions of arousal, mood, sleep, and autonomic function before the first motor signs of PD implicate the lower brainstem, which is affected before the substantia nigra and dopaminergic system. In later stages of the disease, the pathology extends to the cortex, accompanied by impairments in cognition and perception. The articles in this special section advance our knowledge of the brain bases of the nonmotor symptoms of PD, including disrupted visual perception, impaired cognition across a range of domains, and psychiatric and artistic manifestations. Subtypes under investigation include those described by side of disease onset (left or right body side), predominant cognitive profile, and gender. Taken together, the articles in this special section reflect the field's growing focus on the nonmotor symptoms of PD, their brain bases, and the corresponding potential for their treatment.

The spectrum of nonmotor symptoms in early Parkinson disease

OBJECTIVE

Nonmotor symptoms (NMS) are common in patients with established Parkinson disease (PD) but their frequency in early PD has not been extensively studied. Our aim was to determine the frequency of NMS in a cohort of patients with newly diagnosed PD.

METHODS

A total of 159 patients with early PD and 99 healthy controls participated in this study. NMS were screened for using the nonmotor symptom questionnaire. Other assessments included measures of motor disability (Movement Disorders Society-revised unified Parkinson's disease rating scale [MDS-UPDRS]), disease severity (Hoehn & Yahr staging), depression (geriatric depression scale), and global cognitive function (Mini-mental state examination and Montreal cognitive assessment).

RESULTS

The PD group reported a significantly greater number of NMS compared with controls (8.4 [4.3] vs. 2.8 [2.6]). In the PD group, the most commonly experienced NMS were excessive saliva, forgetfulness, urinary urgency, hyposmia, and constipation. Patients with higher MDS-UPDRS III scores and those with the postural instability gait subtype experienced a greater number of NMS.

CONCLUSION

NMS are common in early PD and reflect the multisystem nature of the disorder. Even in the earliest stages of PD, NMS may be detrimental to patients' functional status and sense of well-being.