Daily doses of a drug used to treat Parkinson's disease significantly improved function in severely brain-injured people thought to be beyond the reach of treatment, scientists reported Wednesday, providing the first rigorous evidence that any therapy reliably helps such patients.
The improvements were modest, experts said, and aren't a cure, or a quick means of "waking up" someone who has long been unresponsive. But they were meaningful, they said, and if replicated would give rehabilitation doctors something they've never had: a standard treatment for injuries that are not at all standard or predictable in the ways they affect the brain.
Some 50,000 to 100,000 Americans live in states of partial consciousness, and perhaps 15,000 in an unresponsive "vegetative" condition. According to the Department of Defense, more than 6,000 veterans with severe brain injuries would potentially benefit from this therapy. The new report, in today's New England Journal of Medicine, gives doctors a solid basis to address such injuries, if not yet a predictable outcome.
"This study puts the traumatic brain injury field on the first step of the ladder to developing scientific treatments. We've been trying to get there for a long time," said Dr. Ramon Diaz-Arrastia, a researcher who was not involved in the study.
Doctors have long experimented with the Parkinson's drug — amantadine hydrochloride — and others to treat severe brain injuries, with mixed and uncertain results.
For the experiment, researchers from 11 clinics enrolled 184 patients with recent traumatic brain injuries. Some were in a vegetative state, their eyes open during waking, but unresponsive to commands or prompts. Others were in a minimally conscious state, able to track objects and follow commands once in a while.
The research team, led by Joseph Giacino of the JFK Johnson Rehabilitation Institute, and Dr. John Whyte of the Moss Rehabilitation Research Institute, gave one group of patients two doses of amantadine a day and a control group placebos.
"The main finding is that on every single behavioral domain measured, we had a higher incidence of recovery in the amantadine group," said Giacino,.