Al writes: "Researchers from Beth Israel Deaconess Medical Center, have discovered that delivering an electric current through parts of the brain damaged by a stroke can help patients recover more motor ability. The team delivered "transcranial direct current stimulation (tDCS)"--in conjunction with physical therapy--to 20 patients who had suffered a stroke on average 2.5 years previously. While it's not yet clear exactly how tDCS improves motor function after stroke, one theory is that it helps repair an imbalance in the interactions between the two hemispheres of the brain. If one side is damaged by stroke, it can no longer effectively inhibit the healthy side, which in turn leads to increased inhibition of the stroke-damaged hemisphere. This is supported by the fact that they delivered stimulation to both hemispheres of the brain, using one direction of current to increase brain activity on the damaged side, and the reverse current to inhibit activity on the healthy side."