BESCES is a study that aims to explore the feasibility of intraoperative brief epidural electrical stimulation (ES) for patients undergoing routine decompression for cauda equina syndrome. In consenting patients, brief ES will be applied using a CE-marked SCS trial kit once sufficient decompression is achieved. In participants who do not recover function following decompression, brief post-op ES will be applied to see if can facilitate micturition and/or removal of the catheter.

The study will assess:

The feasibility of intervention. If brief ES can facilitate conduction in residual neurons. If brief ES can facilitate neuronal recovery

Cauda equina syndrome (CES), defined as a compression of nerves controlling bowel, bladder and sexual function due to lumbar disc prolapse has a prevalence of 2 per 100,000 UK population per year. It mostly affects individuals 30-49 years of age. Emergency surgery to decompress the nerves is the mainstay of treatment. Despite adequate decompression, 17% of patients are left incontinent and 50% experience persistent bowel, bladder or sexual dysfunction needing long-term supportive symptomatic management and compromising their social cohesion and economic productivity.

Theoretically, there are two possible ways of improving these functions - improving regeneration of damaged cells and improving conduction in partially damaged/residual cells. The use of perioperative electrical stimulation (ES) has shown significant promise in facilitating recovery in peripheral nerve compression syndromes. Epidural stimulation is routinely used for treating neuropathic pain and there is anecdotal evidence of improved bladder and bowel function in patients with CES who have received epidural spinal cord stimulation for chronic pain.

The overall aim of this feasibility study is to determine if a full definitive RCT is possible. The investigators want to see if it is possible to timely and safely deliver epidural stimulation in patients presenting with bowel, bladder or sexual dysfunction due to cauda equina compression, undergoing emergency lumbar decompression, assess the potential effect size of brief post-decompression ES proximal to the level of compression in facilitating axonal regeneration to support further RCT. The investigators also want to see if brief ES can improve conduction in residual neurons.

40 patients presenting with CES shall be enrolled. At the time of decompression surgery, consenting patients shall receive ES. With standard care, patients who still have symptoms after decompression, remain symptomatic at 1 year. Comparison of functional outcomes post-surgery and at 3, 6 and 12 months will enable assessment of recovery due to axonal regeneration.

Results shall assess the safety and feasibility of doing the study in emergency settings - enrolment and consent issues and assess effect size, this will provide sufficient information and, if successful, will lead to a definitive Randomised Control Trial (RCT).

Inclusion Criteria:

• Age >18.
• Cauda equina syndrome with bladder, bowel or sexual dysfunction (CES-I or CES-R) secondary to acute lumbar disc prolapse.
• Selected for emergency surgery.

Exclusion Criteria:

• No bladder, bowel or sexual dysfunction (Only bilateral radicular symptoms).
• Previous spinal surgery with risk of adhesions.
• Multilevel degeneration with inadequate safe space to pass epidural electrode.
• Pre-existent bladder, bowel or sexual dysfunction.
• History of peripheral neuropathy.
• Contraindications to neurostimulation (e.g. pacemaker, immune deficiency, uncontrolled diabetes, sepsis, active pressure sore, spinal cord stimulator in situ).
• Intraoperative CSF leak.