Update on the neurology of Parkinson's disease

Transcutaneous tibial nerve home stimulation for overactive bladder in women with Parkinson's disease: A randomized clinical trial

AIMS

This study aims to investigate the efficacy of transcutaneous tibial nerve home stimulation for overactive bladder (OAB) in women with Parkinson's disease (PD).

METHODS

The current study is a prospective, randomized, double-blind, sham-controlled trial. Home intervention was carried out and assessments were conducted at a tertiary hospital in South Brazil. Women with PD and OAB symptoms were included in the study. Patients were randomly divided into two groups: (1) stimulation and (2) sham. Both groups underwent intervention at home for 12 weeks. Patients were evaluated at baseline and at 12 weeks (end of intervention), 30- and 90-day follow-up. The primary outcome was the mean reduction in the number of urgency incontinence episodes, and secondary outcomes included daytime and nighttime urinary frequency, urinary urgency episodes, use of pad (reported in a 24-h bladder diary), OAB-V8 and King's Health Questionnaire scores, and maintenance of symptom relief after discontinuation of the intervention.

RESULTS

In total, 30 consecutive patients completed the study (15/group). The stimulation group showed a reduction in nighttime urinary frequency (0.9 ± 0.6), urinary urgency (1.0 ± 1.2), urgency incontinence episodes (0.5 ± 0.6), use of pads (1.3 ± 1.2), and OAB-V8 (1.3 ± 1.2) and King's Health Questionnaire scores. In a 30-day and 90-day follow-up, 8 (53.3%) and 5 (33.3%) stimulation patients, respectively, reported full maintenance of symptom relief after discontinuation of the intervention. Stimulation patients presented a statistically significant improvement of symptoms as compared with sham patients (p = .001).

CONCLUSIONS

Transcutaneous tibial nerve home stimulation can be used in clinical practice as an effective nonpharmacological resource for the reduction of OAB symptoms in women with PD, and the resulting relief seems to persist in the follow-up (30 and 90 days).

Clinical Rating Scales for Urinary Symptoms in Parkinson Disease: Critique and Recommendations

Background

The prevalence of lower urinary tract symptoms (LUTS) is high in Parkinson's disease (PD). These problems negatively affect quality of life and include both storage and voiding problems. The International Parkinson and Movement Disorder Society established a task force to review clinical rating scales/questionnaires for the assessment of urinary symptoms in PD.

Methods

According to prespecified criteria, these scales/questionnaires were classified as "Recommended" or "Recommended with caveats" when clinimetric properties were satisfactory for Recommended status but had not been assessed specifically in PD, "Suggested" or "Listed." These assessments were applied to rate scales as screening tools for the diagnosis of LUTS and for the rating of symptom severity.

Results

Among scales that included LUTS but focused on overall autonomic or non-motor symptoms in PD, no scale reached the clinimetric rigor to be designated as Recommended or Recommended with caveats, but some were Suggested for either diagnostic screening tools or severity measures. Among primary urological scales, most are well validated in urological setting, but none was validated specifically in PD. DAN-PSS (Danish PSS), ICIQ (International Consultation for Incontinence Questionnaire)-MLUTS (Male Lower Urinary Tract Symptoms), OABq, OABq-SF (ICIQ-OABqol), OAB-V8 (as screening tool), and OABSS (OAB Symptom Score) met criteria for Recommended with caveats.

Conclusion

The Task Force does not recommend the development of a new scale. However, all above-mentioned questionnaires need to be studied further and specifically validated in PD.

Treatment of Older Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. The prevalence of PD increases with age. The spectrum of clinical features, the rate of progression of the disease, the burden of nonmotor symptoms, and the response to medications are different in older patients with PD from the relatively younger patients. Management of symptoms of PD in older patients is challenging because of possible existence of several age-related systemic illness. While dealing with older patients, it is crucial not to attribute all the physical symptoms to PD. Thorough evaluation for existence of diseases such as normal pressure hydrocephalus and vascular parkinsonism which partially mimic the symptoms of PD carries immense importance. Medical management of parkinsonian symptoms should be preferred with levodopa monotherapy. However, in patients with significant motor fluctuations, dopaminergic agents may be added with caution, as they are notorious for several adverse reactions. Nonmotor symptoms must be provided high importance as they substantially worsen the quality of life. In addition to parkinsonian symptoms, older patients with PD may need to undergo surgery for several conditions. Meticulous perioperative management is crucial as older patients with PD may face several surgery-related complications compared to the younger patients. Compliance to treatment is an important issue in old age. Hence multidisciplinary approach to management of PD in older patients should be emphasized.

Lower urinary tract symptoms in Parkinson's disease: Prevalence, aetiology and management

Lower urinary tract symptoms (LUTS) are common in Parkinson's disease (PD), effecting 27-85% of patients with PD. Irritative symptoms predominate and urodynamic studies confirm high prevalence of detrusor overactivity in PD. LUTS are present early in PD and are more common in PD than in age matched controls. The assessment of LUTS in PD is complicated by coexisting bradykinesia and cognitive impairment. Although LUTS become more troublesome as PD progresses it remains unclear if LUTS severity correlates with motor symptoms and/or duration of PD. The underlying cause of LUTS in PD remains to be fully elucidated. Animal and human studies suggest the net effect of the basal ganglia is to supress micturition. Although LUTS are a common in PD, few studies have examined the assessment and management of LUTS specifically in patients with PD. Pilot studies have suggested that bladder training, antimuscarinic drugs and intravesical botulinum toxin maybe helpful but these trials have been small and frequently lacked a suitable control group making them vulnerable to the placebo effect. Furthermore the adverse effects of antimuscarinic drugs on cognitive and gastrointestinal function may limit the use of these drugs in PD. In this review we summarise the literature describing the prevalence of LUTS in PD, discuss the emerging data delineating the underlying pathophysiology of LUTS and examine interventions helpful in the management of LUTS in people with PD.

Transcriptome Profile Changes in Mice with MPTP-Induced Early Stages of Parkinson's Disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Despite progress in the study of the molecular, genetic, and pathogenic mechanisms of PD, it is unclear which processes trigger the development of the pathology associated with PD. Models of the presymptomatic and early symptomatic stages of PD induced by MPTP have been used to analyze changes in transcriptome profile in brain tissues, to identify specific patterns and mechanisms underlying neurodegeneration in PD. The whole-transcriptome analysis in the brain tissues of the mice with MPTP-induced PD showed that striatum is involved in the pathogenesis in the earliest stages and the processes associated with vesicular transport may be altered. The expression profiles of the genes studied in the substantia nigra and peripheral blood confirm that lymphocytes from peripheral blood may reflect processes occurring in the brain. These data suggest that messenger RNA (mRNA) levels in peripheral blood may provide potential biomarkers of the neurodegeneration occurring in PD. The changes in expression at the mRNA and protein levels suggest that Snca may be involved in neurodegeneration and Drd2 may participate in the development of the compensatory mechanisms in the early stages of PD pathogenesis. Our data suggest that the brain cortex may be involved in the pathological processes in the early stages of PD, including the presymptomatic stage.

Preserved micturition after intradetrusor onabotulinumtoxinA injection for treatment of neurogenic bladder dysfunction in Parkinson's disease

BACKGROUND

To assess the efficacy and safety of intradetrusor onabotulinumtoxinA (OnabotA) injection treatment in patients with neurogenic lower urinary tract dysfunction (NLUTD), especially for patients with Parkinson disease (PD).

METHODS

PD patients refractory to oral antimuscarinic participated in an off-label use study and were evaluated prior and after 200 IU OnabotA injection into detrusor muscle, including trigone. Changes due to treatment were evaluated using bladder diaries, urodynamics, and questionnaires. Statistical analysis comprised Wilcoxon rank-sum test. Values are presented as mean ± standard deviation.

RESULTS

Ten PD patients (4 female and 6 male, mean age: 67.9 ± 5.36 years) with LUTD were enrolled. All patients tolerated the treatment. Bladder diary variables decreased significantly (p ≤ 0.011) after OnabotA injection compared to variables prior injection. Desire to void and maximum bladder capacity increased significantly in urodynamics (p ≤ 0.05). Maximum detrusor pressure during voiding phase normalised from 56.2 to 18.75 cm/H20. Detrusor overactivity was less often detectable. All patients voided spontaneously. Mean post void residual (PVR) volume was 77.0 ± 119.78 mL postoperatively. No urinary retention or side effects have been observed during/after treatment. Mean follow-up time was 4 months (range of 1-12). 4 patients requested repeated injection after a mean period of 10 months between first and second injection.

CONCLUSIONS

Our data confirm the efficacy and safety of 200 IU OnabotA injection in patients with neurogenic LUTD due to PD. The risk of urinary retention or high post-urinary residual volumes seems to be minor after OnabotA-injection. More research is needed with larger sample size to confirm the significance of these findings.

TRIAL REGISTRATION

TRIAL NUMBER

ISRCTN 11857462 , Registration Date 2016/10/08.

A guideline for the management of bladder dysfunction in Parkinson's disease and other gait disorders

Parkinson's disease (PD) is a common neurodegenerative disorder, and lower urinary tract (LUT) dysfunction is one of the most common autonomic disorders with an estimated incidence rate of 27-80%. Studies have shown that bladder dysfunction significantly influences quality-of-life (QOL) measures, early institutionalisation, and health economics. We review the pathophysiology of bladder dysfunction in PD, lower urinary tract symptoms (LUTS), objective assessment, and treatment options. In patients with PD, disruption of the dopamine D1-GABAergic direct pathway may lead to LUTS. Overactive bladder (OAB) is the most common LUT symptom in PD patients, and an objective assessment using urodynamics commonly shows detrusor overactivity (DO) in these patients. The post-void residual (PVR) volume is minimal in PD, which differs significantly from multiple system atrophy (MSA) patients who have a more progressive disease that leads to urinary retention. However, subclinical detrusor weakness during voiding may also occur in PD. Regarding bladder management, there are no large, double-blind, prospective studies in this area. It is well recognised that dopaminergic drugs can improve or worsen LUTS in PD patients. Therefore, an add-on therapy with anticholinergics is required. Beta-3 adrenergic agonists are a potential treatment option because there are little to no central cognitive events. Newer interventions, such as deep brain stimulation (DBS), are expected to improve bladder dysfunction in PD. Botulinum toxin injections can be used to treat intractable urinary incontinence in PD. Transurethral resection of the prostate gland (TURP) for comorbid BPH in PD is now recognised to be not contraindicated if MSA is excluded. Collaboration of urologists with neurologists is highly recommended to maximise a patients' bladder-associated QOL. Neurourol. Urodynam. 35:551-563, 2016. © 2015 Wiley Periodicals, Inc.

Parkinson's disease

Parkinson's disease (PD) is the most common age-related motoric neurodegenerative disease initially described in the 1800's by James Parkinson as the 'Shaking Palsy'. Loss of the neurotransmitter dopamine was recognized as underlying the pathophysiology of the motor dysfunction; subsequently discovery of dopamine replacement therapies brought substantial symptomatic benefit to PD patients. However, these therapies do not fully treat the clinical syndrome nor do they alter the natural history of this disorder motivating clinicians and researchers to further investigate the clinical phenotype, pathophysiology/pathobiology and etiology of this devastating disease. Although the exact cause of sporadic PD remains enigmatic studies of familial and rare toxicant forms of this disorder have laid the foundation for genome wide explorations and environmental studies. The combination of methodical clinical evaluation, systematic pathological studies and detailed genetic analyses have revealed that PD is a multifaceted disorder with a wide-range of clinical symptoms and pathology that include regions outside the dopamine system. One common thread in PD is the presence of intracytoplasmic inclusions that contain the protein, α-synuclein. The presence of toxic aggregated forms of α-synuclein (e.g., amyloid structures) are purported to be a harbinger of subsequent pathology. In fact, PD is both a cerebral amyloid disease and the most common synucleinopathy, that is, diseases that display accumulations of α-synuclein. Here we present our current understanding of PD etiology, pathology, clinical symptoms and therapeutic approaches with an emphasis on misfolded α-synuclein.

Rodent models for urodynamic investigation

Rodents, most commonly rats, mice, and guinea pigs are widely used to investigate urinary storage and voiding functions, both in normal animals and in models of disease. An often used methodology is cystometry. Micturitions in rodents and humans differ significantly and this must be considered when cystometry is used to interpret voiding in rodent models. Cystometry in humans requires active participation of the investigated patient (subject), and this can for obvious reasons not be achieved in the animals. Cystometric parameters in rodents are often poorly defined and do not correspond to those used in humans. This means that it is important that the terminology used for description of what is measured should be defined, and that the specific terminology used in human cystometry should be avoided. Available disease models in rodents have limited translational value, but despite many limitations, rodent cystometry may give important information on bladder physiology and pharmacology. The present review discusses the principles of urodynamics in rodents, techniques, and terminology, as well as some commonly used disease models, and their translational value.

Development of bladder dysfunction in a rat model of dopaminergic brain lesion

AIMS

Parkinson's disease (PD) is one of the most common neurological disorders causing lower urinary tract dysfunction. We evaluated the temporal development of bladder dysfunction in rat PD model where urodynamic changes were induced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle (MFB).

METHODS

Female Sprague-Dawley rats underwent a unilateral stereotaxic injection of 6-OHDA or vehicle (sham group) into the MFB. Cystometry was performed in conscious animals at 3, 14, and 28 days after the injury. Aged-matched unlesioned rats were used as healthy controls.

RESULTS

Three days after lesion 6-OHDA rats showed higher threshold (TP), maximum pressures (MP), and spontaneous activity (SA) compared to healthy controls. Sham animals exhibited higher TP. After 14 days 6-OHDA rats had also higher micturition frequency, decreased bladder capacity, micturition volume and bladder compliance (Bcom) compared to sham and healthy controls. Sham animals showed lower Bcom and higher MP and SA. After 28 days, 6-OHDA rats exhibited the same changes as those in 14 days, while sham-operated animals showed parameters similar to those in healthy controls.

CONCLUSIONS

These findings suggest that 6-OHDA lesion of the MFB causes bladder dysfunction already after 3 days. A pattern of detrusor overactivity was more clearly defined 14 days after the injection and persisted for 28 days. Cystometry may be a useful tool to study the pathophysiology of bladder dysfunction in PD, and urodynamic parameters may possibly be used to evaluate the effects of therapeutic interventions.

Questionnaire-based assessment of pelvic organ dysfunction in multiple system atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease characterized clinically by any combination of autonomic, cerebellar, and extrapyramidal symptoms. Autonomic symptoms are usually severe, and urinary symptoms are one of the cardinal features of MSA. Bowel dysfunction and sexual dysfunction are also common in MSA. Quality of life (QOL) in patients with MSA is severely impaired by the presence of pelvic organ dysfunction. Therefore, we aimed to examine the prevalence of pelvic organ dysfunction in patients with MSA. We recruited 256 patients with MSA seen at our neurology clinic. The mean age was 62 years. The control group comprised 158 individuals, and the mean age was 52 years. We administered a questionnaire on pelvic organ dysfunction to the MSA and control groups. The questionnaire had sections focusing on the bladder, bowel, and sexual function. Dysfunction, as described in the responses, was evaluated as normal, mild (>once a month), moderate (>once a week), or severe (>once a day). The Mann-Whitney's U-test was used for statistical analysis. When compared with the control group, the prevalence of pelvic organ dysfunction in the MSA group was significantly higher for urinary storage and voiding dysfunction, bowel dysfunction, and sexual dysfunction. QOL in the MSA group was therefore significantly impaired because of urinary dysfunction (70%, 76%), bowel dysfunction (40% of the men), and sexual dysfunction (26%, 45%). Pelvic organ dysfunction is common in MSA, and QOL is severely impaired in patients with MSA.