Daily doses of a drug used to treat Parkinsons disease significantly improved function in severely brain-injured people thought to be beyond treatment,scientists reported in the New England Journal of Medicine on Wednesday,providing the first rigorous evidence to date that any therapy reliably helps such patients.
The improvements were modest,experts said,and hardly amounted to a cure,but the progress was meaningful,experts said,and,if replicated,would give rehabilitation doctors something they have never had: a standard treatment for injuries that are not at all standard or predictable in the ways they affect the brain.
Doctors have long experimented with the Parkinsons drug amantadine hydrochloride as well as many others to treat severe brain injuries,with mixed and uncertain results.
Previous studies of amantadine suggested some benefit,but the numbers were small and experts were unsure of the findings.
The new experiment put those doubts to rest,by testing the drug against a placebo in two large groups of patients.
A consortium of researchers from 11 clinics enrolled 184 patients who recently had a traumatic brain injury from a car accident or from blows to the head.
Some were in a vegetative state,breathing,their eyes open when awake,but unresponsive to commands or prompts.
Others were in what is known as a minimally conscious state,able to track objects and follow commands once in a while,but not predictably.
The research team divided the patients into two groups,carefully matched for the severity of their injuries.
Members of one group got two doses of amantadine a day,given through their feeding tubes. Members of the other group received placebo pills.
After four weeks,the researchers analysed the patients progress,using a standard scale that rates abilities in such areas as coordination and communication.
The group receiving amantadine showed more improvement,by two points on the disability scale.
Two points is not a dramatic difference,but it occurred in just a month,a short period of time in terms of recovery.
When doctors took patients off the drug,the rate of recovery slowed down.
The patients on the drug showed no adverse effects,Dr John Whyte said.
Among other effects,amantadine increases the activity of dopamine,a chemical messenger that is highly active in the frontal areas of the brain behind the forehead.
Those areas control attention and help plan and execute deliberate actions and responses,and are at least partly damaged or offline in people with severe brain injuries.