Stroke can have life-long consequences, even for those who aren’t among the hardest hit, so any developments that may help stroke patients’ recovery can be a huge step forward. A new study from Oxford University has found that using tiny electric currents across particular areas of the brain improved hand movements in people recovering from stroke.
The study, published in the journal Brain, involved 13 patients who’d had a stroke at least six months before. The participants were men and women, aged from 30 to 80, who’d had different types of stroke. Oxford University researchers, led by Professor Heidi Johansen-Berg, with colleagues at the Oxford Centre for Enablement at the Nuffield Orthopaedic Centre set out to find out whether a brain stimulation technique designed to increase the activity in the motor cortex would improve hand movements in people who’d had a stroke.
When a stroke affects a patient’s movement, recovery seems to be linked to the amount of activity that can be restored in the original brain region governing movement – the primary motor cortex. The brain stimulation technique, called transcranial direct current stimulation (TDCS) works by assigning a small electrical current across part of the brain. This technique is surprisingly simple to carry out using pads applied to the head.
This is a relatively new technique that increases the ‘exciteability’ of neurons in the targeted region of the brain. It doesn’t cause pain, but recipients might feel a slight tingling or itchy sensation on their scalp. For the study patients carried out a simple task involving hand movement, in response to images on a screen. They did this three times, before, during and after brain stimulation using the electric current for 20 minutes.
The results showed that reaction times improved by five to 10%, while the current was switched on and afterwards. “The improvement was almost immediate. It really did work,” says researcher Dr Charlotte Stagg of the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB) at Oxford University. “The approach seems to have an effect in a wide range of stroke patients. Those who had seen least recovery from their stroke seemed to show most improvement in this simple test.
“The improvements in movement and reaction times were significant. Patients certainly noticed them, but they were short-lived; the effects of a single treatment lasted for about an hour. However, we are very hopeful that daily brain stimulation would lead to longer-lasting improvements.”
This was a study in a small group. Much larger clinical studies are needed to show that brain stimulation has a lasting effect in producing clinical benefits for stroke patients. These include greater recovery of movement and the ability to carry out normal daily activities.
While there is still some way to go, this approach already has a number of points in its favour, as Dr Stagg points out. “The brain stimulation technique is relatively cheap, easy to use and it’s portable. You could imagine physiotherapists using it in their practice in the future.”
The Oxford team are now recruiting about 30 stroke patients for a new trial. This will study whether brain stimulation, as well as physiotherapy exercises, can lead to clear benefits after three months.
Stroke can cause severe and lasting damage, such as weakness or total loss of movement on one side of the body. Many stroke patients need a great deal of rehabilitation and physiotherapy to recover or simply regain some movement. So a new therapy, that could clearly aid recovery, would be welcomed with open arms.
*Around 150,000 people have a stroke in the UK each year.
*At least 450,000 people are severely disabled as a result of stroke in England.
*Stroke is the third most common cause of death in England and Wales, after heart disease and cancer.