Urinary incontinence is believed to have a greater social impact than any other multiple sclerosis (MS) symptom or complication when it comes to quality of life. It discourages people from engaging in outdoor activities and affects their ability to work. While the symptom can be caused by urinary tract infections, which are common in MS, urinary incontinence can also be the result of neurogenic detrusor overactivity (NDO).
NDO is a consequence of a neurological condition, such as a spinal injury or multiple sclerosis. People with a spinal injury have irreversible nerve damage, while people with MS develop lesions in the spinal cord caused by the progression of the disease. In both cases, communication between the spinal cord and the bladder becomes disrupted or broken, leading to overactivity of the detrusor muscles and resulting in unregulated sporadic bladder muscle contractions. The problem increases pressure in the bladder and decreases the volume of urine the bladder can hold, leading to unexpected and frequent urine leakage.
How is neurogenic detrusor overactivity managed in MS?
Management of NDO should start with some routine lifestyle changes, such as increasing the frequency of urination, limiting fluid intake, limiting caffeine and alcohol, and using absorbent underwear and bed pads.
If lifestyle changes are not enough to relieve incontinence, doctors may recommend a pharmacological approach with anticholinergic medicines for first line management. Anticholinergic medicines decrease the detrusor muscle activation. These medications are available orally (oxybutynin, tolterodine, darifenacin, solifenacin, trospium) or transdermally (oxybutynin), but because they are not specific to the bladder muscle, they can cause global side effects that include eye problems, gastric problems, and decreased sweating. Decreased sweating is one of the worst secondary effects because it prevents natural cooling and increases the chances for overheating in people with MS who already struggle with heat intolerance.  Overall, the clinical benefits of these medications are not as good as expected and tolerability is poor.
Use of Botox to control NDO in MS
When anticholinergic medications fail to prove effective, another option is to neutralize the bladder detrusor muscle with intradetrusor injections of botulinum toxin. Onabotulinumtoxin A is marketed under the brand name Botox. Abobotulinumtoxin A is marketed under the brand Dysport.
The benefits of botulinum toxin include a significant improvement in bladder control, patient satisfaction, and urodynamic parameters at up to nine months of follow-up. Repeat injections are as effective as the first injection.
Some possible complications reported within the first 12 weeks after treatment include urinary tract infection, urinary retention, presence of blood in the urine, fatigue, and insomnia. More severe effects happen if the treatment spreads from the area of injection, causing symptoms that can last several weeks. Problems with swallowing, speaking, and breathing can be life-threatening.
Despite possible complications, intradetrusor injections with botulinum toxin represent a cost-effective treatment that controls NDO symptoms and improves quality of life for people with MS.
Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.