An implanted nerve stimulator helps drop foot sufferers walk faster and better

The partners in EUREKA project E! 2526 IMPULSE have developed an implanted nerve stimulator which helps patients with drop foot to walk much better. Over 500,000 people suffer from a stroke each year in Europe and 10% of stroke victims are left with drop foot, which causes severe walking problems.

Drop foot is a chronic condition, often caused by a stroke which is characterised by the inability to raise the foot during the swing phase of walking. People affected tend to have a laboured and unsafe gait, and suffer from fatigue which further reduces their speed and the distance they can walk.

The current approaches for dropped foot correction have significant drawbacks. “Either the ankle joint is fixed by a brace, or electrical stimulation is applied to a nerve in the leg through electrodes attached to the skin surface. The electrodes must be placed accurately, which is difficult, painful and time consuming,” says Professor Dr Hermie Hermens, cluster manager at the Dutch lead partner, Roessingh Research and Development BV.

“The new system, in contrast to the surface stimulators, has an implanted component that is directly attached to the appropriate nerves, eliminating the problems of electrode placement. Also, the electrical stimulation is not painful as the stimulation current does not pass across the skin,” explains Hermens.

The project used technology developed by the UK project partner, FineTech Medical, through its work on bladder stimulation. The device is implanted during surgery and produces the dual, balanced signals required to produce the correct walking action.

A clinical trial is currently testing the device and patients’ reactions to it. Feedback is excellent – patients are able to walk better, faster and further, with a more normal gait.

Although the device is a world first and is expected to generate a market of 30,000 units a year, the partners first have to explain the benefits to patients and demonstrate the surgical procedure to clinicians.

“We are working with surgical teams to promote the benefits of the system, but the market is limited while we train surgeons to implant the new devices,” says John Spensley, Finetech’s General Manager.

Only EUREKA could have made this research possible. “EUREKA is essential for this type of work. The necessary expertise does not exist in one single country, so European partnership was needed,” says Hermens.