Brain Restoration in Alzheimer's Disease: Deep Brain Stimulates Reversal of Brain Shrinkage

BRAIN shrinkage in people with Alzheimer's disease can be reversed in some cases - by jolting the degenerating tissue with electrical impulses. Moreover, doing so reduces the cognitive decline associated with the disease. _NS

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Alzheimer's disease is an increasingly common cause of total disability in the ageing population. One of the manifestations of Alzheimer's is a shrinking and shutting down of activity in multiple centres of the brain which are critical to memory function. Cells die and crucial brain tissue is lost, as part of the disease process. Now scientists at Toronto Western Hospital in Ontario, believe they may have found an effective approach -- for some.

The group inserted electrodes into the brains of six people who had been diagnosed with Alzheimer's at least a year earlier. They placed the electrodes 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 (Annals of Neurology, DOI: 10.1002/ana.22089).

The researchers have now begun to investigate the effects on the hippocampus. At the Society for Neuroscience annual meeting in Washington DC last week they announced that while they 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 5 per cent in one person and 8 per cent in the other," says Lozano. It's an "amazing" result, he adds.

Tests showed that these two individuals appeared to have better than expected cognitive function, although the other four volunteers did not.

Though Lozano is not sure exactly how the treatment works, 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 also triggers the production of proteins that encourage neurons to form new connections _NS

This approach is worth pursuing further. It is too invasive to be used on a wide scale, but it is likely that there will be no shortage of volunteers for the procedure. What is learned from this research can be used to devise less invasive approaches which will be more appropriate for use in larger populations.

In the meantime, research into the use of pharmaceuticals, growth factors, and stem cell therapies for Alzheimer's will continue.