7 Healthcast: Brain stimulation

This is what deep brain stimulation, or DBS, looks like. It's a kind of brain surgery. The patient is awake while doctors insert a probe deep into the brain and stimulating circuits with electrodes.

The technique has contributed to some of the biggest advances this decade in reversing Parkinson's Disease and depression.

But when Toronto researchers tried using DBS to control how an obese patient understands hunger, they stumbled onto something they'll never forget.

"Unexpectedly when we turned on the device for the first time in the operating room the patient reported a very vivid memory and event that happened in his past," said researcher Dr. Andre Lozano.

The region of the brain responsible for appetite is also responsible for memory. So they began setting up memory tests, asking the patient questions about his past. Both with stimulation, and without.

The patient was able to recall more when his brain was being stimulated with the electricity.

"It's very early days yet," said memory clinician Dr. Marypat McAndrews. "We certainly know that it works the way we think it should work, it affects those particular brain circuits in a healthy individual, but it's not clear once we implant it in patients with disease or damage in that area, if we'll see the same positive result."

But the hope is that it can reverse and repair what's happening in an individual with Alzheimer's disease.

So far, it's worked in just one man, so a pilot study of people with early Alzheimer's is going to start in hopes that DBS will have the same success it did with Parkinson's and depression.

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