Executive Function Is Related to the Urinary Urgency in Non-demented Patients With Parkinson's Disease

Alpha Synuclein Toxicity and Non-Motor Parkinson's

Parkinson's disease (PD) is a common multisystem neurodegenerative disorder affecting 1% of the population over the age of 60 years. The main neuropathological features of PD are the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the presence of alpha synuclein (αSyn)-rich Lewy bodies both manifesting with classical motor signs. αSyn has emerged as a key protein in PD pathology as it can spread through synaptic networks to reach several anatomical regions of the body contributing to the appearance of non-motor symptoms (NMS) considered prevalent among individuals prior to PD diagnosis and persisting throughout the patient's life. NMS mainly includes loss of taste and smell, constipation, psychiatric disorders, dementia, impaired rapid eye movement (REM) sleep, urogenital dysfunction, and cardiovascular impairment. This review summarizes the more recent findings on the impact of αSyn deposits on several prodromal NMS and emphasizes the importance of early detection of αSyn toxic species in biofluids and peripheral biopsies as prospective biomarkers in PD.

The brain, gut, and bladder health nexus: A conceptual model linking stress and mental health disorders to overactive bladder in women

OBJECTIVE

A small, but growing literature links stressors and mental health disorders (MHDs) across the life course to overactive bladder (OAB) and urinary incontinence symptoms. Mechanisms by which stressors and MHDs may impact bladder health are not fully understood, limiting novel prevention and treatment efforts. Moreover, potential biopsychosocial mechanisms involving the brain and gut have not been considered in an integrated, comprehensive fashion.

METHODS

Members of the prevention of lower urinary tract symptoms Research Consortium developed conceptual models to inform research on biopsychosocial mechanisms through which stress and MDHs may impact bladder health among girls and women, focusing on brain and gut physiology.

RESULTS

Two conceptual models were developed-one to explain central (brain-based) and peripheral (gut-based) mechanisms linking stressors and MHDs to OAB and bladder health, and one to highlight bidirectional communication between the brain, gut, and bladder. Traumatic events, chronic stressors, and MHDs may lead to a maladaptive stress response, including dysregulated communication and signaling between the brain, gut, and bladder. Gut bacteria produce molecules and metabolites that alter production of neurotransmitters, amino acids, short-chain fatty acids, and inflammatory immune response molecules that mediate communication between the gut and brain. Microbiota signal neurogenesis, microglia maturation, and synaptic pruning; they also calibrate brain-gut-bladder axis communication through neurotransmission and synaptogenesis, potentially influencing bladder symptom development. Life course trajectories of risk may be prevented or interrupted by central and peripheral resources for neuropsychological resilience.

CONCLUSIONS

Depicted pathways, including brain-gut-bladder communication, have implications for research and development of novel prevention and treatment approaches.

Pattern of prefrontal cortical activation and network revealed by task-based and resting-state fNIRS in Parkinson’s disease’s patients with overactive bladder symptoms

Background

Overactive bladder (OAB) symptoms are common in Parkinson’s disease (PD), and negatively contribute to the quality of life (QoL) of patients. To explore the underlying pathophysiological mechanism, we investigated the correlation between the prefrontal cortex (PFC) function and OAB symptoms in PD patients.

Methods

One hundred fifty-five idiopathic PD patients were recruited and classified either as PD-OAB or PD-NOAB candidates based on their corresponding OAB symptom scores (OABSS). A linear regression analysis identified a correlative connection of cognitive domains. Then cortical activation during the performance of the verbal fluency test (VFT) and brain connectivity during resting state were conducted by functional near-infrared spectroscopy (fNIRS) for 10 patients in each group to investigate their frontal cortical activation and network pattern.

Results

In cognitive function analysis, a higher OABS score was significantly correlated with a lower FAB score, MoCA total score, and sub-scores of visuospatial/executive, attention, and orientation as well. In the fNIRS study, the PD-OAB group exhibited significant activations in 5 channels over the left hemisphere, 4 over the right hemisphere, and 1 in the median during the VFT process. In contrast, only 1 channel over the right hemisphere showed significant activation in the PD-NOAB group. The PD-OAB group revealed hyperactivation, particularly in certain channel in the left dorsolateral prefrontal cortex (DLPFC), compared with PD-NOAB (FDR P < 0.05). In the resting state, there was a significant increase of the resting state functional connectivity (RSFC) strength between the bilateral Broca area, left frontopolar area (FPA-L) and right Broca’s area (Broca-R), between the FPA and Broca’s area if merging the bilateral regions of interest (ROI), and also between the two hemispheres in the PD-OAB group. The Spearman’s correlation confirmed that the OABS scores were positively correlated with RSFC strength between the bilateral Broca area, FPA-L and Broca-R, between the FPA and Broca area if merging the bilateral ROI.

Conclusion

In this PD cohort, OAB was related to decreased PFC functions, with particularly hyperactivated left DLPFC during VTF and an enhanced neural connectivity between the two hemispheres in the resting state as observed by fNIRS imaging.

Cross-Cultural Differences in Stigma Associated with Parkinson's Disease: A Systematic Review

BACKGROUND

Stigma is an important social attitude affecting the quality of life (QoL) of people with Parkinson's disease (PwP, PD) as individuals within society.

OBJECTIVE

This systematic review aimed to 1) identify the factors associated with stigma in PD and 2) demonstrate culture-based diversity in the stigmatization of PwP. We also reported data from the Turkish PwP, which is an underrepresented population.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a literature search of the PubMed/Medline electronic database was performed covering the last 26 years. Articles on self-perceived stigma in PD with a sample size >  20 and quantitative results were included. Data were extracted by independent reviewers.

RESULTS

After screening 163 articles, 57 were eligible for review, most of which were from Europe or Asia. Only two studies have been conducted in South America. No study from Africa was found. Among the 61 factors associated with stigma, disease duration, sex, and age were most frequently studied. A comparison of the investigated factors across the world showed that, while the effect of motor impairment or treatment on stigma seems to be culture-free, the impact of sex, education, marriage, employment, cognitive impairment, and anxiety on stigma may depend on culture.

CONCLUSION

The majority of the world's PD population is underrepresented or unrepresented, and culture may influence the perception of stigma in PwP. More diverse data are urgently needed to understand and relieve the challenges of PwP within their society.

Prevalence of lower urinary tract symptoms, urinary incontinence and retention in Parkinson's disease: A systematic review and meta-analysis

Background

Lower urinary tract symptoms (LUTS) are common non-motor symptoms but are often overlooked in Parkinson's disease (PD). The prevalence of LUTS in PD is inconsistent among different studies.

Objective

To estimate the prevalence of LUTS, urinary incontinence, and urinary retention in PD patients, then, investigate potential sources of inconsistency in prevalence estimation.

Methods

We searched PubMed, EMBASE, and Web of Science databases from inception to May 2022. Studies reporting the prevalence of LUTS or LUTS subtypes in PD were included. Pooled prevalence of LUTS, LUTS subtypes, urinary incontinence, and urinary retention was calculated via random-effects models. Meta-regression and subgroup analyses were performed.

Results

Of 7,358 studies after duplicate removal, a total of 73 studies comprising 14,937 PD patients were included. The pooled prevalence of LUTS was 61% (95% CI 53–69; 27 studies; n = 5,179), while the pooled prevalence of storage symptoms and voiding symptoms was 59% (44–73; 9 studies; n = 798) and 24% (14–33; 11 studies; n = 886), respectively. The pooled prevalence of urinary incontinence, retention and post-void residual (PVR) volume ≥ 100 ml were 30% (95% CI 22–39; 21 studies; n = 6,054), 27% (17–37; 14 studies; n = 1,991), and 4% (1–7; 5 studies; n = 439), respectively. The prevalence of LUTS, urinary incontinence, or urinary retention was significantly associated with diagnostic methods.

Conclusion

LUTS and its subtypes present in a significant proportion of PD patients. It is necessary to use standardized and validated methods to detect and screen LUTS and its subtypes.

Systematic review registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022311233, Identifier: CRD42022311233.

Characteristics and risk factors of lower urinary tract dysfunction in patients with Parkinson's disease: A systematic evaluation and meta-analysis

To systematically evaluate the risk factors of lower urinary tract dysfunction in patients with Parkinson's disease(PD), and to provide theoretical basis for clinical medical staff to identify the risk factors of lower urinary tract dysfunction in patients with PD. From the establishment of the database to January 2021, PubMed, the Cochrane Library, EMBASE, Web of Science, other English database, were searched for literatures about the risk factors of lower urinary tract dysfunction in patients with Parkinson's disease. According to the inclusion and exclusion criteria, after browsing the title, abstract and full text, the high-quality literature in line with the inclusion criteria was selected, and the Newcastle-Ottawa Scale（NOS）document quality evaluation tool was used to evaluate the literature quality and extract the data. The included research results were analyzed by RevMan 5.3 software. A total of 8 studies were included for Meta analysis. The results showed that 7 of the 20 related risk factors were statistically significant, and the statistically significant risk factors were duration of disease [Mean Difference (MD)= 0.59, 95% Confidence Interval (CI) (0.04, 1.14), P < 0.005], age [MD = 2.01, 95%CI (-0.36, 3.34), P < 0.005], Hoehn-Yahr (H-Y) score >2 [Odds Ratio (OR) = 1.56, 95%CI (1.09, 2.23), P < 0.001], sleep disorder [OR = 1.79, 95%CI (1.36,2.35), P < 0.001], constipation [OR = 1.88, 95%CI (1.42,2.48), P < 0.001], unified Parkinson's disease rating scale (UPDRS III) [MD= 4.43, 95%CI (2.20, 6.66), P < 0.001], Mini-mental state examination (MMSE) [MD = -1.16, 95%CI (1.23, -1.09), P < 0.001]. Age, duration of disease, H-Y score >2, sleep disorder, constipation, higher UPDRS Ⅲ score and lower MMSE score were the risk factors of lower urinary tract dysfunction in patients with Parkinson's disease.

Interplay Between Cognitive and Bowel/Bladder Function in Multiple Sclerosis

Purpose

The aim of this study was to evaluate the prevalence of bowel/bladder dysfunction in multiple sclerosis (MS) and its associations with cognitive impairment.

Methods

We prospectively enrolled 150 MS patients. Patients were administered the Symbol Digit Modality Test (SDMT), the Neurogenic Bowel Dysfunction Score (NBDS), and the Actionable Bladder Symptom Screening Tool (ABSST). The associations between bowel/bladder dysfunction and cognitive function were assessed through hierarchical regression models using the SDMT and clinicodemographic features as independent variables and NBDS and ABSST scores as dependent variables.

Results

The prevalence of bowel/bladder deficits was 44.7%, with 26 patients (17.3%) suffering from bowel deficits and 60 patients (40%) from bladder deficits. The total NBDS and ABSST scores were correlated with the SDMT (β=-0.10, P<0.001 and β=-0.03, P=0.04, respectively) after correction for demographic features and physical disability.

Conclusions

Bowel/bladder disorders are common in MS and are associated with both physical and cognitive disability burdens. As SDMT is embedded into routine clinical assessments, a lower score may warrant investigating bowel/bladder dysfunction due to the strong interplay of these factors.

Classifying Parkinson's Disease Patients With Syntactic and Socio-emotional Verbal Measures

Frontostriatal disorders, such as Parkinson's disease (PD), are characterized by progressive disruption of cortico-subcortical dopaminergic loops involved in diverse higher-order domains, including language. Indeed, syntactic and emotional language tasks have emerged as potential biomarkers of frontostriatal disturbances. However, relevant studies and models have typically considered these linguistic dimensions in isolation, overlooking the potential advantages of targeting multidimensional markers. Here, we examined whether patient classification can be improved through the joint assessment of both dimensions using sentential stimuli. We evaluated 31 early PD patients and 24 healthy controls via two syntactic measures (functional-role assignment, parsing of long-distance dependencies) and a verbal task tapping social emotions (envy, Schadenfreude) and compared their classification accuracy when analyzed in isolation and in combination. Complementarily, we replicated our approach to discriminate between patients on and off medication. Results showed that specific measures of each dimension were selectively impaired in PD. In particular, joint analysis of outcomes in functional-role assignment and Schadenfreude improved the classification accuracy of patients and controls, irrespective of their overall cognitive and affective state. These results suggest that multidimensional linguistic assessments may better capture the complexity and multi-functional impact of frontostriatal disruptions, highlighting their potential contributions in the ongoing quest for sensitive markers of PD.