Brain stimulator helps slow man's Alzheimer's disease
Published Tuesday, March 6, 2012 10:19PM EST
For a man diagnosed with Alzheimer's disease six years ago, Robert Linton, is doing exceedingly well. Instead of struggling with becoming more forgetful, he is feeling great. And he believes it's all because of an experimental treatment that has slowed his disease.
Linton is one of only six Alzheimer's patients in the world who has had an electrical stimulator implanted into his brain that appears to be keeping his memory healthy.
Robert, 66, is doing great though most with his brain disease might have been in a nursing home so many years after diagnosis. He still drives and has little trouble recalling the words he needs to complete a crossword puzzle.
Linton credits the device in his brain for keeping his memory healthy.
"I think it is the answer to Alzheimer's -- 100 per cent," he says.
- CTVNews.ca will host a live web chat Wednesday at 12 p.m. ET with Dr. Andres Lozano, neurosurgeon and scientist at the Krembil Neuroscience Centre, Toronto Western Hospital, along with fellow researcher Dr. David Tang-Wai, a neurologist in the Memory Clinic at the Krembil Neuroscience Centre, whose research focuses on Alzheimer's disease.
Four years ago, doctors at the Krembil Neuroscience Unit at Toronto Western Hospital drilled holes in Linton's skull and implanted two electrodes deep into his brain. The electrodes send out electrical bursts into the regions of Linton's brain that govern memories-- an area usually damaged by Alzheimer's.
The system is powered by a pacemaker-sized battery pack that sits under the skin of Linton's upper chest.
Neurosurgeon Dr. Andres Lozano implanted similar devices in five other patients as part of a study to determine whether brain stimulation can slow Alzheimer's progression. The research team has tracked the patients to see how their disease has progressed.
After two years, the team had the patients undergo a standard cognitive functioning test, known as the "mini-mental." In three of the patients, their test scores declined, suggesting the treatment hadn't worked. In two patients, their test scores remained the same, suggesting their disease has stabilized rather than worsened as one would expect.
In Linton's case, many of his Alzheimer's symptoms, such as his poor memory and problem solving skills, have actually improved -- much to the delight of doctors
"Rather than seeing a decline in his cognition and memory, we saw that he improved. That is exciting because it suggests maybe we are having an impact," says Dr. Lozano.
Linton himself has noticed it's easier to recall things since he had the stimulator implanted.
"If I want to remember something, I relax for a bit and it pops in," he says.
Linton's wife Barb says her husband's Alzheimer's isn't completely gone, but it isn't getting worse either.
"Whether (the treatment) slowed it or stopped it... we can only ask what would have happened had we not gone ahead with it," she says.
Robert is convinced the brain stimulator can take all the credit.
"I would have gradually declined and ended up in a nursing home. Yes, I think I see brighter worlds out there because of the operation," he says.
Doctors also performed MRI exams on the brains of the six patients. In most Alzheimer's patients, the areas of the brain controlling memory tend to shrink over time. But in Robert and another patient with early stage disease, the electrical stimulation appeared to have made the memory area of their brains grow.
It was a finding that surprised even Dr. Lozano.
"We are thrilled he is doing so well and we are trying to understand why is it he is doing so well," says Dr. Lozano.
Lozano speculates that the best candidates for the treatment may be those, like Linton, who are in the earliest stages of Alzheimer's disease. That way, the treatment can intervene before too much brain tissue has been lost to the disease.
It took Lozano's team 18 months to get ethics approval to conduct the small, Phase 1 trial of deep brain stimulation in Alzheimer's patients. The findings from that phase were published in the journal Annals of Neurology.
Lozano's team would now like to move to larger Phase 2 and Phase 3 trials, to test the technique in 40 to 50 patients, but they are still waiting for approval. Each phase of those trials would likely take about three years each, meaning wider availability of the treatment is likely still many years away -- assuming all goes well in those studies.
There are also questions about the costs of the procedure, and whether it's a feasible treatment for the broader population.
While there's much more work to be done, this research is an important first step for learning how to slow a disease with so few treatment options.
With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip