Alzheimer’s: Deep brain stimulation ‘reverses’ disease

Scientists in Canada have raised a tantalising prospect – reversing Alzheimer’s disease.

Brain shrinkage, declining function and memory loss had been thought to be irreversible.

They used a technique known as deep brain stimulation – applying electricity directly to regions of the brain. In two patients, the brain’s memory hub reversed its expected decline and actually grew.

Deep brain stimulation has been used in tens of thousands of patients with Parkinson’s as well as having an emerging role in Tourette’s Syndrome and depression.

Yet precisely how it works is still unknown.

The procedure is all done under a local anaesthetic. An MRI scan identifies the target within the brain. The head is held in a fixed position, a small region of the brain is exposed and thin electrodes are positioned next to the region of the brain to be stimulated.

The electrodes are hooked up to a battery which is implanted under the skin next to the collar bone.

Prof John Stein, from the University of Oxford, said: “Most people would say we do not know why this works.”

His theory is that in Parkinson’s, brain cells become trapped in a pattern of electrical bursts, followed by silences, then bursts and silences and so on. Continuous high frequency stimulation then disrupts the rhythm. However, he accepts that “not everyone will accept this account”.

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