A new kind of rehabilitation therapy for people who have had a stroke that electrically stimulates muscles while they exercise has helped improve their arm function in a small trial. The treatment involves triggering muscles to contract at the same time that people try to move their limbs voluntarily, which seems to encourage nerve pathways to regrow in the brain.
鈥淧hysiotherapy is the only option we have for helping people recover limb weakness,鈥� says at the UK charity the Stroke Association, who wasn鈥檛 involved in the work. 鈥淎nything that helps people recover more thoroughly would be brilliant.鈥�
A stroke happens when blood flow to part of the brain is disrupted, usually because of a blood clot or burst blood vessel, which causes nerve cells to die. Depending on the area affected, people may lose the ability to speak or to move a limb.
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The usual treatment, physiotherapy exercises, is thought to help forge new neural connections to bypass the damaged areas, but many people still don鈥檛 fully recover, says at Otto von Guericke University in Magdeburg, Germany, who led the work.
The new approach draws on an experimental technique called functional electrical stimulation, which involves placing electrodes on the skin to stimulate nerves that normally make a muscle contract. However, its effectiveness in stroke rehab wasn鈥檛 entirely clear.
This method has mainly been tested in people whose stroke happened several months ago or more. The brain is thought to have more ability to forge new connections between nerve cells when the stroke was more recent, says Sweeney-Reed. 鈥淭here鈥檚 heightened plasticity, a greater readiness to reestablish connections.鈥�
Her team focused on people who a more recent stroke and investigated a refinement of the technique, where the stimulation is delivered at exactly the same time as the person intends to move.
This is done by the user wearing an electroencephalogram (EEG) headset that can detect brainwaves that signal the intention to move. The system was tried out on 20 people who had recently had a stroke that left them with minimal ability to move one of their arms. Half had their stroke within the past month, while the rest had it between one and six months ago.
The participants were asked to lay their affected arm flat on a table and to try to lift their hand by bending the wrist. Unaided, they could barely move it.
Some then had the stimulation timed for when they were trying to move their hand, while the rest received it at random times, to act as a control group. They all had up to five therapy sessions a week, for three to five weeks.
Among those whose stroke was most recent, getting the timed treatment improved their arm function by an average of about 20 points on a 66-point scale often used in stroke research. That compared with a 3-point improvement for those in the control group.
For people who had the therapy between one and six months after their stroke, there was no significant difference between the treatment and control groups.
Jonas says the results tally with other small studies of electrical stimulation in stroke rehab. 鈥淲e are now optimising how it鈥檚 used,鈥� she says. But most people who have had a stroke may be less fit than those who were selected for this trial and so may not respond as well, says Jonas.
medRxiv
