Walking again... thanks to a tiny switch in the sock
AN ELECTRONIC implant that helps stroke victims suffering from foot paralysis is now available on the NHS for the first time. Foot drop is caused by weakness or paralysis of the muscles that lift the front part of the foot. This causes sufferers to drag the front of the affected foot while walking, and they compensate by trying to swing the whole leg from the hip.
It is a disorder of the nerves and can be the result of injuries, stroke or conditions such as cerebral palsy and multiple sclerosis.
Journalist and broadcaster Andrew Marr revealed his battle with foot drop following a stroke in 2013.
In the past, those with untreatable foot drop would have had to wear an ankle brace to hold the foot in a normal position.
But now surgeons in Sheffield are implanting a matchboxsize device that uses electrical impulses to stimulate the affected muscles and improve walking.
ActiGait, which was previously only available privately, is controlled by a wireless foot switch, worn under the heel and connected to a component on the ankle.
The device triggers stimulation when the foot is lifted, and stops stimulation when the foot is placed on the ground.
The switch can be concealed in a sock so that the patient can wear normal footwear and, unlike previous models, there are no wires running down the leg.
Richard Fletcher from Sheffield, has struggled to walk since suffering a stroke eight years ago, aged 31. The stroke left him unable to move or speak for more than two months, and even after he regained both functions, he would fall over several times a day.
He was fitted with an ActiGait last October at Sheffield’s Northern General Hospital – the first hospital to offer the device on the NHS. ‘I always thought I would struggle to walk after the stroke,’ says Richard.
‘But since having the device implanted I haven’t fallen once, my confidence has rocketed and my walking speed has doubled.’
Current NHS treatments for foot drop include physiotherapy to strengthen the foot, or wearing an ankle brace.
Another treatment, called functional electrical stimulation (FES), involves electrodes placed on the skin to stimulate the nerves that connect to the paralysed muscles.
While it can improve movement, some patients experience uncomfortable shock sensations and irritations to the skin.
The ActiGait device works on the same premise as FES, but it is an implant rather than an external device. Fitting it involves a two-hour operation, during which an electrode is implanted in the muscle slightly above the knee and wrapped around the nerve that feeds the muscle. The stimulator, an electronic chip measuring about 2.3in by 1in, is implanted in the outside of the upper thigh.
THE electrode is stimulated by signals from a small box worn around the waist to trigger the foot to be lifted. Dr Kidangalil Mathew, a consultant in spinal injuries and specialised rehabilitation at Sheffield Teaching Hospitals NHS Foundation Trust, says that patients will still be offered the external device because it works for many patients and no surgery is involved.
For now, the external ActiGait is only being used by Sheffield, but it is hoped it will be offered by other specialist neurological centres in the near future.
Dr Mathew adds: ‘The device has brought some great improvements to Richard’s quality oflife, and it has the potential to do so for many others in a similar situation.
‘We have been fortunate to persuade the NHS that we can offer the implanted version where patients are unable to use or gain benefit from the external device.’