Urinary symptoms are common in Parkinson disease. About 25% and 40% of people with Parkinson disease will experience troubling bladder symptoms, and about 15% to 25% of people with Parkinson disease will have frank urinary incontinence. Fortunately there is something you can do to help manage these problems.
What urinary problems can be associated with Parkinson disease have?
The two most common bladder symptoms are nocturia, the need to urinate frequently overnight; and urinary urgency, the sudden, intense feeling of needing to urinate. If this urgency is strong enough, it can lead to urge incontinence, urination before one is able to get to the bathroom. A few people with Parkinson disease, but not many, will experience difficulty urinating even though they feel an urge, producing only a weak stream that takes a long time to initiate; this is referred to as dyssynergia.
Can my bladder problem also be just getting older? What are some of the other bladder problems that can occur with aging?
Of course, people with PD can also have other causes of urinary symptoms, just as anyone else can. When more than one type of incontinence is present, the syndrome is called mixed urinary incontinence. For instance, stress incontinence – the involuntary loss of urine during coughing, laughing, sneezing, or exercising – is quite common in women who have gone through childbirth, among other causes. This may be combined with the urgency of Parkinson disease to produce mixed urinary incontinence. Stress incontinence can be seen in men after urologic surgery, such as surgery for prostate cancer.
Mixed urinary incontinence may also result when urgency due to PD is combined with overflow incontinence, which is a constant or frequent dribbling of urine without sensation. This is often due to prostate problems in men, or bladder damage or complications of diabetes in either gender.
What causes urinary symptoms in Parkinson disease?
Although the exact cause of urinary symptoms in Parkinson disease is not fully understood, we do know a lot about bladder function and we have some important clues about its dysfunction in PD. Urinary urgency is caused by a condition known as detrusor hyperreflexia. The detrusor is one of two principal muscles involved in urination. This muscle wraps around the bladder and squeezes down to help eliminate urine. The other muscle, the external urethral sphincter keeps a tight seal around the opening in the bladder to keep urine contained. Urination is triggered when the cells lining the bladder get stretched and send a signal to the spinal cord that the bladder is full. This initiates a reflex that causes the detrusor muscle to contract and the sphincter to relax, allowing the bladder to empty. In normal bladder function, this reflex is controlled by signals from centers in the brain (specifically, in the prefrontal cortex, insula, and basal ganglia) and brainstem. That control prevents contraction of the detrusor until urination is acceptable. However, when anything interferes with the signals from these higher control centers, the reflex is unchecked, and becomes overactive. Hyperreflexia means over activity of a reflex; hence the term detrusor hyperreflexia.
We believe that this is generally what happens in Parkinson disease to cause the urinary symptoms. In PD, the problem probably lies in the basal ganglia, one of the higher centers in the brain that helps to control the urination reflex. We know that as urine is stored in healthy individuals, dopamine increases in the basal ganglia. The primary problem in Parkinson disease is that not enough dopamine is produced, so it may be that there is not enough dopamine in the basal ganglia to allow urine to be stored. This results in urinary urgency and frequency, and incontinence as it becomes advanced.
Author: Daniel J. Burdick, MD, Movement Disorders Fellow, University of Washington, VA Puget Sound Health Care System
Benarroch E. Neural control of the bladder: recent advances and neurologic implications. Neurol 2010; 75: 1839-1846.
Winge K and Fowler C. Bladder dysfunction in parkinsonism: mechanisms, prevalence, symptoms, and management. Mov Dis 2006; 21(6): 737-745.