UK Edition
Mind-control device helps stroke patients retrain brains to move paralysed hands
Tens of thousands of stroke patients left with disabilities have been offered new hope after scientists proved it is possible to retrain the undamaged side of the brain to move paralysed limbs.
Around 100,000 people suffer a stroke each year in Britain and two thirds of the 60,000 survivors will leave hospital with a disability.
Although many are offered rehabilitation, often the damage to the brain is too extensive.
But now scientists in the US have invented a device which retrains the undamaged side of the brain to take over the tasks of the damaged part.
"We have shown that a brain-computer interface using the uninjured hemisphere can achieve meaningful recovery in chronic stroke patients," said Prof Eric Leuthardt
In general, the left hemisphere controls the right side of the body and vice versa but about a decade ago, Prof Leuthardt and Dr David Bundy discovered that a small area of the brain on the same side of the limb sends the first ‘movement’ signal.
They theorised that if they could harness and amplify that initial signal, they could use it to control movement in a paralysed limb.
The new device comprises of a cap containing electrodes to pick up the brain signal and send it to a moveable brace on the arm. The device detects the wearer's intention to open or close the paralyzed hand, and moves it accordingly.
Over time, the brain starts to link the signal to movements in the hand and forms new connections so that the process can happen without the brace.
The team selected 10 patients who were still suffering significant paralysis six months on from their stroke. They were invited to use the device for up to two hours a day for 12 weeks.
At the end of the study their ability to grasp objects was far better and , the patients' movement scores increased an average of 6.2 points on a 57-point scale.
"An increase of six points represents a meaningful improvement in quality of life," added Prof Leuthardt.
"For some people, this represents the difference between being unable to put on their pants by themselves and being able to do so."
The study was published in the journal Stroke.