Urinary Tract Infections (UTIs) and Multiple Sclerosis: Connection Between UTIs and Neurological Progression?
Harris E. Foster, Jr., MD, Associate Professor of Surgery (Urology), Yale University School of Medicine, New Haven, CT
Progress to Date
Bladder problems are common in people with multiple sclerosis (MS), affecting up to 90% to 100% of patients during the course of their disease (Foster, 2002). Patients may have trouble with holding their urine (incontinence) or with emptying the bladder completely (retention). When urine is retained in the bladder, there is an increased risk of bladder infection. Urinary tract infections (UTIs) also occur in patients who are managed with intermittent self-catheterization or an indwelling catheter. Inappropriate care of the catheters and drainage systems can increase the risk for UTI. UTIs can be serious and have the potential to affect functioning in people with MS. Some people are prone to repeated infections and should be followed by a urologist. Under some circumstances, infection can spread to the kidneys, causing serious illness.
Normal bladder emptying requires the bladder to contract at the same time the sphincter muscle in the urethra opens. In some patients with MS, the coordination between these two muscles is lost. If the sphincter muscle doesnâ€™t relax and open during bladder contraction, problems can arise. One potential problem is that the bladder may not be completely emptied, even if some urine is pushed past an incompletely relaxed sphincter; this retained urine is much more likely to be colonized by bacteria, leading to UTIs. Another problem is that the increased pressure on the urine-filled bladder from the contracting bladder muscle can force the urine back up toward the kidneys, which can lead to kidney infection and kidney stones. Another problem that can lead to high bladder pressures and backflow of urine occurs when the bladder wall becomes rigid and loses its ability to stretch properly to accommodate changes in urine volume. In this case, normal filling or contractions can cause high pressures.
Bladder infections with kidney involvement can occur in both sexes, but are more common in men. Fortunately, however, these serious â€œupper urinary tractâ€ infections are relatively rare in MS, affecting only .09% to 3.0% of patients (Metz, McGuinness, & Harris, 1998). When the upper urinary tract is involved, however, the result can be severe illness with resultant permanent damage to the kidneys.
Current Research and Issues
Despite the fact that UTIs are frequent in MS, there are very few published articles that specifically deal with the management or consequences of UTIs in patients with MS. There are, however, some interesting accounts that link UTIs with or without kidney involvement with increased neurological difficulties.
Hillman, Burns, and Kraft (2000) wrote a report on a single patient with MS who had a serious infection from kidney stones, impaired kidney function, and a large abscess. As the infection worsened, the patientâ€™s disabilities, already serious, also worsened. He lost strength and independence, becoming unable to care for himself or drive his power wheelchair with his right hand. After the infection was treated, the patient recovered much of his previous strength, dexterity, and independence. It is not clear from this article, however, how the increased neurological problems might have been related to the infection.
An intriguing article written by a different clinical group (Metz et al., 1998) suggests a link between UTIs and relapses. This article reviews three patients, two men and a woman, who had repeated UTIs over several years that were difficult to control. In all three cases, the patients suffered progressive neurological impairment during the time that they had the repeated UTIs. In the case of the female patient, all 18 relapses during a 5-year period were accompanied by a UTI. After the UTIs were brought under control, this patientâ€™s relapse rate dropped to 1/year, and her disabilities improved. Both of the men saw their disease become stable without further increase in disability, and one had some improvement, once the UTIs were controlled.
The authors of this article claim that they frequently see UTIs at the time a patient has an acute relapse and that repeated UTIs are often associated with increased disability. They believe the infections may trigger a response in the body that activates MS. This idea is supported by research that shows viruses can cause the body to make chemicals called cytokines and interferons, which influence the immune system (Metz et al., 1998). Many patients with MS are familiar with interferon-beta, a drug that helps suppress MS. Other interferons, like interferon gamma, appear to precipitate relapses. The authors point out that viral infections, which trigger interferon production, have been associated with increased risk for relapses. They believe that bacterial infection, which can also lead to interferon production, may be involved in precipitating relapses and in increasing patients’ disabilities.
The little that has been published concerning UTIs and MS suggests an interesting link between bacterial infection and the progression of MS. There is, however, far too little information at this point to conclude that this link is real. More studies are needed that investigate this possibility further.
Future work also needs to focus on how to manage repeated bladder infections, which can be very difficult to control, and on how to improve the management of bladder disorders in patients with MS so that UTIs are avoided.
Implications for Patient Care
UTIs are frequent in patients with MS and can lead to serious consequences if they are not resolved (Pusztai & Choudhry, 1996). Patients with MS should be evaluated for urological disorders by a urologist and should have frequent reevaluations because MS symptoms, including urological ones, often change over time.
There is some controversy over how closely the upper urinary tract should be monitored, given that kidney infection is relatively rare in MS; some clinicians recommend annual upper urinary tract imaging and laboratory tests. In any case, clinicians need to be aware that bladder dysfunction can result in recurrent UTIs and irreversible changes in the urinary tract; therefore, patients should be closely monitored if they have any symptoms consistent with upper urinary tract involvement or if they do not respond rapidly to standard treatment for UTIs. Finally, patients should be managed from the outset in ways that avoid increased risk of UTIs and upper urinary tract involvement (Klotkin & Milam, 1997). For example, bladder disorders leading to high bladder pressure or retention of urine should be managed carefully, and the use of indwelling catheters should be avoided if possible. If this is not possible, dietary modifications, adequate amount of fluids, and good hygiene are important strategies to prevent complications.
References (* – denotes suggested reading)
Foster, H. E., Jr. (2002). Bladder symptoms and multiple sclerosis. Multiple Sclerosis Quarterly Report, 21(1): 5-8.
Hillman, L. J., Burns, S. P., & Kraft, G. H. (2000). Neurological worsening due to infection from renal stones in a multiple sclerosis patient. Multiple Sclerosis, 6, 403-406.
Klotkin, L., & Milam, D. F. (1997). Evaluation and management of the urologic consequences of neurologic disease. Techniques in Urology, 2, 210-219.
*Metz, L. M., McGuinness, S. D., & Harris, C. (1998). Urinary tract infections may trigger relapse in multiple sclerosis. AXON, June 1998, 67-70.
Pusztai, L., & Choudhry, W. (1996). Recalcitrant UTI in a patient with multiple sclerosis. Hospital Practice, March 15, 1996, 63-66.