Video-urodynamic characteristics of lower urinary tract dysfunctions in patients with chronic brain disorders

Lower urinary tract dysfunction in the central nervous system neurogenic bladder and the real-life treatment outcome of botulinum toxin A

Neurogenic lower urinary tract dysfunction (NLUTD) is common in patients with central nervous system (CNS) lesions. Cases of cerebrovascular accidents (CVA), Parkinson's disease, dementia, and other intracranial lesions develop poor bladder control with or without urinary difficulty due to loss of cortical perception of bladder filling sensation and poor coordination of urethral sphincter relaxation during reflex micturition. Patients with CNS lesions usually have overactive bladder (OAB) symptoms, including urgency, frequency, incontinence, voiding symptoms of dysuria, large postvoid residual volume, and retention. In elderly patients with severe CNS disease the OAB symptoms are usually difficult to adequately relieve by medical treatment, and thus, their quality of life is greatly. Botulinum toxin A (BoNT-A) is currently licensed and has been applied in patients with idiopathic and neurogenic OAB due to spinal cord injury or multiple sclerosis. However, the application of BoNT-A in the treatment of urinary incontinence due to NLUTD in chronic CNS lesions has not been well-documented. Although cohort studies and case series support BoNT-A treatment for neurogenic OAB, chronic urine retention after intravesical BoNT-A injection for OAB and exacerbated urinary incontinence after urethral BoNT-A injection for voiding dysfunction have greatly limited its application among patients with NLUTD due to CNS lesions. This article reviews the pathophysiology and clinical characteristics of NLUTD in patients with CNS lesions and the clinical effects and adverse events of BoNT-A injection for patients with NLUTD. A flowchart was created to outline the patient selection and treatment strategy for neurogenic OAB.

Role of Urological Botulinum Toxin-A Injection for Overactive Bladder and Voiding Dysfunction in Patients with Parkinson's Disease or Post-Stroke

Botulinum toxin A (BoNT-A) paralyzes muscle by blocking acetylcholine release at the synaptic junction. BoNT-A has shown its therapeutic effects in neurological disorders such as Parkinson's disease (PD) and post-stroke spasticity. A high proportion of patients with PD and post-stroke develop neurogenic detrusor overactivity (nDO) and then develop urinary incontinence and overactive bladder (OAB) symptoms. This study aimed to disclose the safety and efficacy of BoNT-A injection in treating bladder and voiding dysfunction in PD and post-stroke patients by reviewing the current evidence. At present, intradetrusor injection of BoNT-A is a Food and Drug Administration (FDA)-approved third-line therapy for nDO and idiopathic OAB. Although intradetrusor injection of onaBoNT-A 200 U is already approved for nDO treatment, most researchers would like to manage PD and post-stroke patients by using onaBoNT-A 100 U intradetrusor injection to achieve long-term efficacy and reduce adverse effects. However, in contrast to its inclusion in the International Continence Society guidelines for PD treatment, the clinical use of BoNT-A for post-stroke patients is limited to experimental use due to the development of urinary retention in about one-fifth of patients. For treating urethral pseudodyssynergia, half of patients may respond to onaBoNT-A 100 U urethral injection. However, refinement is needed to reduce unwanted urinary incontinence.

Molecular Mechanism Operating in Animal Models of Neurogenic Detrusor Overactivity: A Systematic Review Focusing on Bladder Dysfunction of Neurogenic Origin

Neurogenic detrusor overactivity (NDO) is a severe lower urinary tract disorder, characterized by urinary urgency, retention, and incontinence, as a result of a neurologic lesion that results in damage in neuronal pathways controlling micturition. The purpose of this review is to provide a comprehensive framework of the currently used animal models for the investigation of this disorder, focusing on the molecular mechanisms of NDO. An electronic search was performed with PubMed and Scopus for literature describing animal models of NDO used in the last 10 years. The search retrieved 648 articles, of which reviews and non-original articles were excluded. After careful selection, 51 studies were included for analysis. Spinal cord injury (SCI) was the most frequently used model to study NDO, followed by animal models of neurodegenerative disorders, meningomyelocele, and stroke. Rats were the most commonly used animal, particularly females. Most studies evaluated bladder function through urodynamic methods, with awake cystometry being particularly preferred. Several molecular mechanisms have been identified, including changes in inflammatory processes, regulation of cell survival, and neuronal receptors. In the NDO bladder, inflammatory markers, apoptosis-related factors, and ischemia- and fibrosis-related molecules were found to be upregulated. Purinergic, cholinergic, and adrenergic receptors were downregulated, as most neuronal markers. In neuronal tissue, neurotrophic factors, apoptosis-related factors, and ischemia-associated molecules are increased, as well as markers of microglial and astrocytes at lesion sites. Animal models of NDO have been crucial for understanding the pathophysiology of lower urinary tract (LUT) dysfunction. Despite the heterogeneity of animal models for NDO onset, most studies rely on traumatic SCI models rather than other NDO-driven pathologies, which may result in some issues when translating pre-clinical observations to clinical settings other than SCI.

Surgical outcome of male patients with chronic central nervous system disorders and voiding dysfunction due to bladder outlet obstruction

PURPOSE

Voiding dysfunction is common in patients with chronic central nervous system (CNS) diseases and has great impact on quality of life. Patients with chronic CNS disorders might have concomitant detrusor overactivity, detrusor underactivity, and voiding dysfunction. Although bladder outlet surgeries could relieve bladder outlet obstruction (BOO), patients might have persistent or exacerbated storage symptoms. This study investigated surgical outcome of patients with chronic CNS disorders after bladder outlet surgery.

METHODS

A total of 63 male patients with cerebrovascular accident (CVA, n = 44), Parkinson's disease (PD, n = 11), and early-stage dementia (n = 8), had received bladder outlet surgery after videourodynamic proven BOO refractory to medical treatment. The preoperative and postoperative lower urinary tract symptoms (LUTS) and uroflowmetry parameters were assessed. If the storage symptom subscore decreased or increased by 1, the outcome was considered improved or exacerbated after treatment. When patients had improvement in maximum flow rate (Qmax) and voiding efficiency (VE) and decreased voiding symptom subscore, they were considered having improvement of voiding dysfunction.

RESULTS

The mean age was 71.1 ± 9.8 years and mean duration from diagnosis of BOO to surgical intervention was 15.1 ± 25.0 months. Overall, there was significant improvement in voiding LUTS and urinary retention after surgery. The post-void residual volume (PVR), corrected Qmax (cQmax), and VE significantly improved after surgery. In subgroup analysis, although voiding symptoms improved in CVA patients, urgency and exacerbated urgency incontinence persisted after surgery. In PD patients, there was improvement in voiding condition such as PVR, cQmax and VE, but the storage symptoms did not change after surgery. Patients with dementia had no improvement both in storage and voiding symptoms.

CONCLUSIONS

Bladder outlet surgeries are effective to relieve voiding dysfunction in patients with CVA and PD, but have little effect on storage LUTS in patients with chronic brain lesions.