A type of pacemaker has been implanted into the brain of an Alzheimer's patient in an attempt to reverse the effects of the condition.
Surgeons at the Johns Hopkins Centre in the US conducted the procedure after a successful trial involving six patients in Canada.
It is believed that the electrical stimulation of the region of the brain that deals with memory and learning could help to slow the cognitive decline brought on by Alzheimer's.
Stimulation of the brain has previously been used to treat Parkinson's and epilepsy, but those procedures place electrodes into the brain, whereas the device itself in this procedure is surgically implanted inside the brain.
Dr Paul B Rosenberg, director of the trial, said: "This is a very different approach, whereby we are trying to enhance the function of the brain mechanically."
Alzheimer's patients typically display decreases in glucose metabolism - an indicator of activity in the brain - but the five patients who have undergone the procedure in Canada have shown an a "sustained increase" since their implant was installed.
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