An overview of urinary symptoms in Parkinson disease and multiple system atrophy

This study summarized the occurrence and treatment of urinary symptoms in patients with Parkinson disease (PD) and multiple system atrophy (MSA).

Urinary incontinence is a bothersome symptom that can have a considerably impact on quality of life. It can have various causes, including disorders of the central nervous system such as Parkinson disease (PD) and multiple system atrophy (MSA). While the symptoms of PD and MSA often appear similar, the underlying cause of urinary symptoms and thus its treatment are very different. 

The aim of this study was to summarize the incidence and treatment of urinary symptoms in PD and MSA.

It has been estimated that 27 to 63.9% of PD patients display urinary symptoms. These commonly include nocturia (the need to wake up in the night to urinate), increased urinary frequency, and urinary incontinence. They typically occur 5 to 6 years after the onset of motor (movement-related) disorders associated with PD. 35 to 70% of PD patients also have difficulty emptying their bladder.

Up to 96% of MSA patients have been reported to show urinary symptoms. Difficulty passing urine is the most common symptom occurring in about 79% of MSA patients. Nocturia was observed in 74% of patients, urinary urgency in 63%, and urinary incontinence in 63% of patients. Urinary symptoms typically occur before the development of motor disorders in MSA.

Treatment for PD usually involves drugs that increase dopamine levels (a type of neurotransmitter) in the brain. It has been found to improve the severity of urinary symptoms in newly diagnosed patients and worsen symptoms in PD patients already receiving treatment.

Antimuscarinic drugs are commonly used to treat motor symptoms in PD patients. Early studies are suggesting that they may also be effective in reducing urinary symptoms associated with PD. Solifenacin (Vesicare) significantly reduced the number of incontinence episodes per day when compared to placebo (a control drug with no active effect on the body).

Botulinum toxin (Botox) is a muscle paralyzer that is injected directly into the bladder muscle, causing it to relax. A number of studies have found significant improvements in bladder volume, urinary frequency, and quality of life in PD patients after treatment. Botulinum toxin was approved as the FDA in 2011 as a treatment of urinary incontinence due to neurological conditions.

Desmopressin (Minirin) is a type of anti-diuretic and works by signaling the kidneys to produce less urine. A small dose of desmopressin administered through the nose has been found to reduce urinary symptoms such as nocturia in MSA patients.  

Other possible treatments include minimally invasive prostate surgery, cholinergic drugs, neuromodulation, and self-catheterization. However, more studies are needed. 

Authors concluded that urinary symptoms are common in both PD and MSA. First-line treatment for PD with dopamine-based drugs or antimuscarinic drugs could also improve urinary symptoms. Botulinum toxin is a suitable treatment options for urinary incontinence due to a neurological condition. Use of surgical treatments should only be considered if more conservative approaches fail.