麻豆传媒

In what they鈥檙e calling a world first, a group of Canadian scientists have used a technique involving electrical brain stimulation to treat Alzheimer鈥檚 disease -- and their findings were completely unexpected.

Alzheimer鈥檚 disease and dementia affect nearly 36 million people, including more than 747,000 Canadians. These incurable diseases literally shrink the brain as they eat away at memory and other mental faculties.

The cause of these conditions, apart from age, isn鈥檛 well understood. But Andres Lozano, a neurosurgeon at the Toronto Western Research Institute, said his team didn鈥檛 expect the results they found while studying the effects of something called deep brain stimulation on Alzheimer鈥檚 patients.

In the trial, the patients were treated with steady electrical pulses through a brain implant (powered by a pacemaker) over the course of a year. Similar techniques have been used to treat Parkinson鈥檚 disease and other neurological disorders.

Four of Lozano鈥檚 six patients continued to regress over the period of study, with their brains shrinking in size as predicted.

鈥淏ut in two patients, we were completely surprised,鈥� said Lozano. 鈥淏ecause not only did the brain not shrink in these two patients, the brain actually grew. The hippocampus grew.鈥�

The hippocampus is the part of the brain that Alzheimer鈥檚 hits first and hardest, according to Lozano. But in his study, instead of continuing to wither, two of the patients鈥� brains ended up with a moderate amount of growth from the treatment -- a five to eight per cent increase in size -- to almost pre-disease states.

The study is published in the journal Brain Stimulation.

Lozano said the two patients鈥� conditions had both progressed only mildly, compared to others whose brain circuitry was decayed because of more advanced Alzheimer鈥檚. Lozano suspected stimulation had spurred the growth of tissue.

鈥淲e think the reason for that is, as you鈥檙e more advanced, these circuits are completely destroyed as the illness progresses,鈥� he said. 鈥淪o we think we went in too late in some of the patients.鈥�

Though the results are promising, researchers are still cautious. For one, said neurology professor Howard Chertkow, the study would need to be replicated with more than two patients.

Chertkow, who works at the Jewish General Hospital at McGill University, also pointed out that Alzheimer鈥檚 disease affects more than just memory, which this treatment targeted.

鈥淭here are changes in emotion, changes in personality, other changes in thinking,鈥� he said. 鈥淭hese are different networks in the brain which would not be affected by this stimulation.鈥�

And though he also said the treatment had the potential to be restrictively expensive -- $10,000 to $20,000 per patient -- Chertkow said he鈥檚 still excited about the research.

鈥淭his shows for the first time that stimulation with electricity or magnetism can affect the growth of new nerve cells in the hippocampus in the brain,鈥� he said.

And Lozano said the second phase of his team鈥檚 study will involve 42 patients with early symptoms of the disease, giving the researchers a more robust data set.

Lozano said the results of that study will be available in May.

With a report from CTV鈥檚 medical specialist Avis Favaro and producer Elizabeth St. Philip