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MS Bladder – Intravesical Botulinum Toxin — SCE Neurology MCQ

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ModerateMultiple Sclerosis & CNS InflammationMS Bladder – Intravesical Botulinum ToxinSCE Neurology

A 35-year-old woman with MS has chronic urinary urgency, frequency, and nocturia. Bladder ultrasound shows a low post-void residual (30 mL). Urodynamics confirm detrusor overactivity without detrusor-sphincter dyssynergia. She has tried oxybutynin (intolerable dry mouth), solifenacin (constipation), and mirabegron (headache). What is the next recommended intervention?

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Correct answer: B — Intravesical botulinum toxin A injection into the detrusor muscle

For detrusor overactivity in MS that is refractory to oral antimuscarinics and mirabegron, intravesical botulinum toxin A (onabotulinumtoxinA) injection into the detrusor muscle is the recommended next step. It reduces detrusor overactivity and urinary urgency/frequency for approximately 6–9 months per treatment cycle. The main risk is urinary retention requiring temporary ISC — patients must be counselled about this and willing to perform ISC if needed. A: ISC is for incomplete emptying, not primary OAB management. C: Sacral nerve stimulation is further down the pathway. D: Suprapubic catheter is a last resort. E: Urinary diversion is extreme.

Reference: NICE NG100 MS; NICE NG123 Urinary Incontinence