Overactive bladder in Parkinson's disease: alteration of brainstem raphe detected by transcranial sonography

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.

The safety and effectiveness of mirabegron in Parkinson's disease patients with overactive bladder: a randomized controlled trial

PURPOSE

To assess the safety and effectiveness of mirabegron in patients with PD complaining of overactive bladder (OAB).

PATIENTS AND METHODS

From January 2017 to November 2020, we performed a prospective randomized, double-blind, placebo-controlled trial that enrolled PD patients with symptoms of OAB. The total duration of the study was 13 weeks, comprising a 1-week screening period and a 12-week treatment period. A total of 110 patients were randomized in one of two groups: treatment group (mirabegron 50 mg) or placebo group. The primary outcomes of our study were the change from baseline in OAB symptom score (OABSS) and the overactive bladder questionnaire short form (OAB-q SF) score. The secondary outcomes were the change from baseline in the mean number of micturitions/24 hours, the mean number of urgency episodes/24 hours, the mean number of urgency incontinence episodes/24 hours and the mean number of nocturia episodes/night, volume voided/micturition (ml) as recorded on a 3-day bladder diary. Safety assessments included adverse events, electrocardiogram, QT corrected for heart rate using Fridericia's correction (QTcF) interval and blood pressure and pulse rate measurements.

RESULTS

There was a significant improvement in the primary outcome and secondary outcome measures in the treatment group compared to the placebo group. Adverse events were mild and the same in the two groups. The cardiovascular safety profile was high. This study is limited by its sample size and its short follow-up period.

CONCLUSIONS

Mirabegron is a promising drug to control OAB symptoms in patients with PD with an excellent safety profile.

Neurosonological Findings Related to Non-Motor Features of Parkinson's Disease: A Systematic Review

Non-motor symptoms (NMS) in Parkinson’s disease (PD), including neuropsychiatric or dysautonomic complaints, fatigue, or pain, are frequent and have a high impact on the patient’s quality of life. They are often poorly recognized and inadequately treated. In the recent years, the growing awareness of NMS has favored the development of techniques that complement the clinician’s diagnosis. This review provides an overview of the most important ultrasonographic findings related to the presence of various NMS. Literature research was conducted in PubMed, Scopus, and Web of Science from inception until January 2021, retrieving 23 prospective observational studies evaluating transcranial and cervical ultrasound in depression, dementia, dysautonomic symptoms, psychosis, and restless leg syndrome. Overall, the eligible articles showed good or fair quality according to the QUADAS-2 assessment. Brainstem raphe hypoechogenicity was related to the presence of depression in PD and also in depressed patients without PD, as well as to overactive bladder. Substantia nigra hyperechogenicity was frequent in patients with visual hallucinations, and larger intracranial ventricles correlated with dementia. Evaluation of the vagus nerve showed contradictory findings. The results of this systematic review demonstrated that transcranial ultrasound can be a useful complementary tool in the evaluation of NMS in PD.

Increased risk of overactive bladder in patients with idiopathic Parkinson's disease: Insight from a nationwide population-based cohort study

BACKGROUND

Idiopathic Parkinson's disease (IPD) is a progressive neurodegenerative disorder characterized by typical motor impairment. However, lower urinary tract symptoms, including urinary urgency or frequency, which are non-motor phenomena, occur frequently among patients with IPD. In this study, we assess the risk of overactive bladder (OAB) in patients with IPD.

METHODS

The National Health Insurance Research Database of Taiwan was used to identify patients with IPD (IPD cohort) and four-fold controls (non-IPD cohort) from 2000 to 2010. The non-IPD cohort was matched according to age, sex, and baseline comorbidities, including benign prostate hyperplasia, stress incontinence, diabetes, and cerebrovascular diseases. The occurrence of OAB was monitored until the end of 2011. Hazard ratios of OAB were estimated using Cox proportional hazards regression models.

RESULTS

In total, 4,571 and 18,255 patients were included in IPD and non-IPD cohorts, respectively. Results showed a significantly higher overall incidence rate of OAB in the IPD cohort compared with the non-IPD cohort (14.5 vs. 6.37 per 10,000 person-years), with a 2.3-fold increased risk of OAB (95% confidence interval [CI] = 1.51-3.51) after controlling for benign prostate hyperplasia and stress incontinence. The mean follow-up period for the IPD cohort was 5.0 years. This cohort study showed that the cumulative incidence of OAB was 0.65% at the fifth year and 1.54% at the tenth year after IPD diagnosis; this risk was highest in the age group 65-74 years.

CONCLUSION

This study reveals that IPD is independently associated with an increased risk of OAB in patients with IPD. The probability of OAB was 1.54% over a 10-year period after IPD diagnosis; the risk of OAB is considered to be age-dependent and most substantial in patients aged 65-74 years.

Sensory urgency

Overactive bladder is highly prevalent among the general population. This article describes the definition, theories of causation, diagnostic tools and various treatment options for overactive bladder.

Transcranial sonography findings related to non-motor features of Parkinson's disease

Transcranial sonography (TCS) allows high resolution imaging of deep brain structures, provided sufficient imaging conditions and adequate qualification of the investigator. Since TCS can display changes of midbrain structures and basal ganglia that are not or only heavily detected with other neuroimaging methods, TCS has yielded new insights into the pathogenesis also of non-motor features of PD. Abnormal increased echogenicity ('hyperechogenicity') of substantia nigra is not only a characteristic finding in PD, but is also related to increased risk of depression in PD patients (relative risk [RR], 1.9). Reduced echogenicity ('hypoechogenicity') of midbrain raphe indicated increased risk of depression (RR, 2.0) and urinary incontinence (RR, 4.7) in PD patients. Caudate nucleus hyperechogenicity was associated with drug-induced psychosis (RR, 2.4), and frontal-horn dilatation >20mm with dementia (RR, 3.6). TCS findings support the hypothesis of a pathogenetic link between depression and PD. Further studies are warranted to find out whether TCS is useful for detecting increased risk for non-motor complications, such as depression, psychosis, or urinary incontinence, already before they become clinically obvious.

Transcranial midbrain sonography in narcoleptic subjects with and without concomitant REM sleep behaviour disorder

Substantia nigra (SN) hyperechogenicity--a sonographic vulnerability marker for Parkinson's disease (PD)--has been recently described in patients with idiopathic REM sleep behaviour disorder (RBD). It is not known whether subjects with narcolepsy (who frequently have associated RBD) also show SN hyperechogenicity. The aim of this study was to (1) evaluate SN echogenicity in narcolepsy and (2) determine whether transcranial sonography (TCS) differs in narcoleptic subjects with and without RBD. A total of 16 patients with narcolepsy-cataplexy (7 had a concomitant, video-polysomnographically based diagnosis of RBD) were examined with TCS by two investigators blinded to the clinical data. The size of the SN echogenic area in both subgroups was within the range previously described for healthy subjects. The brainstem raphe, however, was reduced in five of seven narcoleptic subjects with RBD, whereas only two of nine narcoleptic subjects without RBD exhibited this TCS finding. We conclude that evaluation of SN echogenicity does not discriminate between both subgroups. The absence of SN hyperechogenicity in narcoleptic patients with RBD supports the hypothesis that SN hyperechogenicity in patients with presumed idiopathic RBD is an additional risk marker for subsequent evolvement of PD rather than an RBD-immanent finding. Reduced echogenicity of the brainstem raphe might indicate an involvement of the serotonergic system in narcoleptic subjects with RBD.