Treatment of refractory urge urinary incontinence with sacral spinal nerve stimulation in multiple sclerosis patients

Background Urge urinary incontinence in multiple sclerosis patients is usually due to detrusor hyperreflexia. Patients who do not respond to conservative measures such as anticholinergics, with or without clean intermittent catheterisation, are difficult to manage. Methods We applied electrical stimulation to the S3 sacral spinal nerves with the aim of activating afferent somatic nerve fibres. Stimulation of these fibres can inhibit the micturition reflex. An S3 electrode coupled to a subcutaneously placed pulse generator was implanted in four women who had shown a good response during temporary stimulation via a percutaneously placed wire electrode. All patients were followed for at least 2 years. Findings The number of leakage episodes decreased from a mean of 4 to 0·3 per 24 h. Two patients were completely dry. The hyperreflexia disappeared in one, improved in two, and got worse in one patient. The urodynamic result in the last patient may be explained by clinical progression of the multiple sclerosis. Interpretation Chronic stimulation of the S3 sacral spinal nerve by an implantable neuroprosthesis is a promising treatment option for selected multiple sclerosis patients with refractory urge incontinence.