UK doctors in Sheffield say patients with multiple sclerosis (MS) are showing "remarkable" improvements after receiving a treatment usually used for cancer.
About 20 patients have received bone marrow transplants using their own stem cells. Some patients who were paralysed have been able to walk again.
Prof Basil Sharrack, of Sheffield's Royal Hallamshire Hospital, said: "To have a treatment which can potentially reverse disability is really a major achievement."
Around 100,000 people in the UK have MS, an incurable neurological condition. Most patients are diagnosed in their 20s and 30s.
The disease causes the immune system to attack the lining of nerves in the brain and spinal cord.