In a small-scale study, researchers at at Toronto Western Hospital in Ontario, Canada, found that regular fleeting pulses of electricity helped stop the shrinkage of the brain region associated with the disease.
“In Alzheimer’s disease it is known that the brain shrinks, particularly the hippocampus,” Andres Lozano, who led the study, was quoted as saying by the NewScientist.
In addition, brain scans show that the temporal lobe, the region which contains the hippocampus, and another region called the posterior cingulate, use less sugar than normal, suggesting they have slowed or shut down, Lozano explained.
To try to reverse these degenerative effects, Lozano and his team turned to deep brain stimulation. It involved sending electrical impulses to the brain by inserting electrodes into the brains of six people diagnosed with Alzheimer’s at least a year earlier.
The electrodes were placed next to the fornix — a bundle of neurons that carries signals to and from the hippocampus — and left them there, delivering tiny pulses of electricity 130 times per second.
Follow-up tests a year later showed that the reduced use of glucose by the temporal lobe and posterior cingulate had been reversed in all six people, the researchers reported in the journal Annals of Neurology.
They also saw hippocampal shrinking in four of the volunteers, the region grew in the remaining two participants.
“Not only did the hippocampus not shrink, it got bigger by five per cent in one person and eight per cent in the other,” said Lozano. “It’s an amazing result.”
Tests showed that these two individuals appeared to have better than expected cognitive function, although the other four volunteers did not.
Lozano is not sure exactly how the treatment works, but his team’s recent work in mice suggests that the electrical stimulation might drive the birth of new neurons in the brain.
Deep brain stimulation in mice has also found triggering the production of proteins that encourage neurons to form new connections. The researchers are now embarking on a trial involving around 50 people.
Lozano pointed out that around 90,000 people worldwide with Parkinson’s disease have already received deep brain stimulation.
The incidence of Alzheimer’s is only five times that of Parkinson’s, he said. “If it can be used in Parkinson’s, it can be used in Alzheimer’s.”