A new study says a non-invasive device can clear toxic TDP-43 protein clumps linked to ALS. Here is what that means. TDP-43 is a protein found in nearly all our cells. In about 97 per cent of ALS cases, it misfolds and piles up inside motor neurons, the nerve cells that control muscles. These clumps are thought to poison the cells and speed up the disease. ALS, also called Lou Gehrig's disease, gradually robs patients of movement, speech and breathing. No approved therapy has yet reduced these clumps. The new peer-reviewed study tested multi-site direct current stimulation, gentle electrical pulses applied through the scalp, on mice engineered to model ALS. After four weeks, treated mice had 76 per cent fewer TDP-43 clumps per motor neuron and better motor function. The catch is that this is a mouse study, not a human trial. PathMaker says its second ALS clinical trial is nearing full enrolment, and that is where the real test begins. Results in mice often fail to translate to people.