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Electrical stimulation to improve bladder control after spinal cord injury

Project details

Dr Lynsey Duffell
University College London
Research area
Brain and spinal cord injury
Funding type
Project grant
Awarded in
October 2022


It is estimated that there are around 50,000 people in the UK living with the effects of a spinal cord injury, and around 1,000 new spinal cord injuries each year.

The day-to-day impact of a spinal cord injury varies from person to person, depending on the nature, severity and location of the injury. People will have limited or no ability to feel or move limbs below the level of the injury, and the functions of organs such as the bladder and bowel are also affected, which can be very distressing.

Existing techniques for managing bladder problems are inadequate, and improving bladder management is a priority for those living with spinal cord injury.

In this project, a collaborative, multidisciplinary team lead by Dr Lynsey Duffell at University College London will recruit spinal cord injured volunteers to a trial that will use electrical stimulation of the spinal cord to improve bladder control.

Following rigorous assessment as part of our competitive grant round, this project was recommended for its strong potential to benefit patients affected by a distressing problem. 


An injury to the spinal cord causes an interruption or complete block of the normal messages that pass between the brain and parts of the body. As a result, people living with spinal cord injury (SCI) have limited or no ability to feel or move their affected limbs. The functions of organs such as the bladder and bowel are also affected, which severely impacts quality of life.

The bladder is a simple organ that expands to store urine, and contracts to empty it under voluntary control at a socially convenient time. People with SCI have reduced awareness of their bladder being full, and reflexes can cause it to empty involuntarily. Bladders also tend to become overactive after SCI, meaning that the bladder may contract frequently, before it is full, with little or no warning, and individuals often do not have enough time to find a toilet.

People with SCI usually manage their bladders with a catheter, which may need changing several times a day. Medication is also usually prescribed, but can cause uncomfortable side effects.

These existing management techniques are far from ideal as around half of people living with SCI continue to experience incontinence, constipation and infections, which can lead to much more serious complications and potentially death. Improving bladder and bowel management is a priority among people living with SCI.

Electrical stimulation to improve bladder control after spinal cord injury

“While the bladder is a simple organ, its control system is highly complex, involving interactions between several different nerves, the brain and the spinal cord. We already know that if we apply electrical stimulation to one of these nerves, we can switch off an unwanted bladder contraction, giving the individual more time to find a toilet,” explains Dr Duffell.

However the devices used did not work well when people tried to use them at home – the electrodes did not stay in place well, and the device and wires were found to be inconvenient for daily use.

In this project, the team will test whether they can achieve a similar effect using an implantable device called an epidural stimulator. This involves the implantation of electrodes close to the spinal cord, with the stimulator device and wires implanted around the abdomen. The electrodes apply small electrical pulses to activate nerves, and can be positioned to target all of the nerves that control the bladder and bowel.

This kind of epidural stimulation is currently used in the NHS to treat long-term back and leg pain. It is not routinely used after SCI, but several trials are currently underway in this population, with impressive results. Stimulation targeting the nerves that control leg muscles has enabled people to move their otherwise-paralysed limbs. Patients also reported benefits to their bladder and bowel function, even though the electrodes were not optimally positioned to target these organs.

The team will recruit volunteers who suffered an SCI more than 12 months previously. Those who respond well to a one-day trial with epidural stimulation, where electrodes will be implanted close to the spinal cord, but the device and wires remain external to the body, will be offered a fully implantable epidural stimulator, controllable via a smartphone app. They will be asked to use this at home for six weeks, and will also be given some bladder training exercises to do.

Participants' bladder function will be measured before, and for six months after, the intervention, and they will be asked to complete a diary about their bladder and bowel routines, as well as questionnaires about their quality of life.  

At the end of the trial, the volunteers will be able to choose to have their devices removed or to keep them. Those who keep them will continue to be monitored via the team’s NHS services.


While we know that epidural stimulation has the potential to improve control of the bladder and bowel after SCI, Dr Duffell and team will be the first to use this technique to target these organs specifically.

As epidural stimulators are already available on the market, the route to patient benefit is short.

About the research team

Dr Lynsey Duffell, who has more than 15 years’ experience in SCI research, has developed this project in collaboration with a multidisciplinary team of clinicians, surgeons, scientists and engineers based at University College London (UCL) and the Royal National Orthopaedic Hospital (RNOH) in Stanmore. She has worked closely with all team members on several similar high impact projects to improve life after SCI.

Volunteers will be recruited from the London Spinal Cord Injuries Centre (LSCIC) at the RNOH, one of only 11 centres in the UK designated to receive and treat SCI patients. The team there has extensive experience in the treatment of patients with bladder and bowel problems after SCI, and related research.

The Neuromodulation Centre at RNOH is one of only a few services in the UK commissioned to provide epidural stimulation (for the management of chronic pain), and the team there has recently implanted two people with SCI with epidural stimulators.

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