System uses small electrical currents to aid stroke patients

Researchers at Oxford University have shown that their technique — which applies milliamp current through simple pads — is safe and temporarily improves hand dexterity.

‘Electric currents have been used for the treatment of neurological diseases for thousands of years, from electric fish in ancient Egypt through to galvanic currents in depression,’ said Dr Charlotte Stagg of the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB).

‘We’re beginning to understand a bit more about how it works, and we think simply that it changes the membrane potential and that has an effect on the firing rate of the neuron, and then that changes the strength of the connection between the neurons.’

Stagg explained that neurons are held at a resting membrane potential of around -70mV and when that increases to -40mV, the cell fires. The researchers believe the technique, called anodal transcranial direct current stimulation (TDCS), increases that resting potential slightly, making it more likely neurons will fire, increasing the overall firing rate.