Australian scientists have made a key discovery in the search for a way to stunt the spread of motor neurone disease through the body.
They believe they have found how the disease moves from one brain cell to the next, which could be the vital clue they need to block its path.
At present there is limited understanding of the disease, which progressively disables its victims, most of whom die within three years.
"We know the symptoms start at a specific point and progress quite rapidly to different parts of the brain and therefore different parts of the body," said Dr Justin Yerbury, from the Illawarra Health and Medical Research Institute at the University of Wollongong.
"Now we think we understand how it spreads.
"It is similar to the way an infectious disease spreads. One neuron catches the disease off the previous one. It's a domino type of thing."
Dr Yerbury, Dr Brad Turner from the University of Melbourne and Canadian Professor Neil Cashman have published their findings in the journal Proceedings of the National Academy of Sciences of the United States of America.
"If we can block it from spreading to the next cells, then maybe we can stop the progression of the disease," said Dr Yerbury.
"It could have a similar outcome to HIV drugs, where they can't kill the virus, but they can block its progression.