According to the researchers, the patient’s behavior changed as soon as the device was switched on. “Prior to the trial, he was in a sort of chronic state of under-arousal,” Joseph Giacino, a neuropsychologist at the JFK Johnson Rehabilitation Institute, in Edison, NJ, and lead scientist on the study, said at the press conference. He usually kept his eyes closed even though he was awake, and he rarely mouthed a single word. After the procedure, said Giacino, “most striking to us was that he regained normal eye opening. He turned his head and focused on the person speaking to him.”
The researchers analyzed the patient’s behavior over the next six months, turning the device on and off to assess its impact. They found that improvements in motor and cognitive function were clearly linked to the electrical boost. The patient also showed a slow but steady gain in function even when the device was turned off. The findings are particularly noteworthy because they show a benefit so long after the initial injury, says James Bernat, a neurologist at Dartmouth Medical School who was not involved in the study.
While the official test period is over, the patient continues to receive the electric stimulation in 12-hour cycles–to correspond with the sleep-wake cycle–and he continues to get better. “Now he can consistently respond verbally when he is prompted,” said Giacino. “The most recent change is that he’s able to say the first 16 words of the Pledge of Allegiance.”
Still, the team cautions that it’s too early to predict how well deep brain stimulation will work on other minimally conscious patients. Success is likely to depend on the precise nature of the injury, and on whether some of the critical neural circuits remain intact. At the conference, Schiff said he suspects that there will be many patients in a minimally conscious state who will not benefit.
The researchers are planning to surgically implant devices in 11 additional patients, which should give them a better sense of how well the treatment might work in the larger patient pool. If successful, the technology might eventually be applicable to a broader group of brain-injury patients, says Ali Rezi, a neurosurgeon at the Cleveland Clinic Center for Neurological Restoration who performed the surgery. Head-trauma patients with less severe impairments may one day benefit as well, he says.
For the moment, Schiff and others hope that the findings will bring new focus on a group of patients who have largely been given up on, receiving only custodial care. “Most patients who show [minimally conscious state] behaviors are essentially discounted from further medical treatment,” said Schiff. “But there may be patients that harbor greater reserves. That’s what pushed our interest.”