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4th June 2015

Parkinson’s, Alzheimer’s, depression and the switch that might turn them off

When we use a radio, we switch it on, tune into the station we want to listen to and then adjust the volume by turning it up and down. Could we switch conditions like Parkinson’s and Alzheimer’s off in the same way?

In very basic terms, deep brain stimulation actually kind of works like a radio. By placing electrodes in different circuits of the brain and then adjusting the dials by turning them up and down, we can correct dysfunctions in diseases such as Parkinson’s, dystonia, depression, Alzheimer’s and anorexia.

Let’s take the case of a young Israeli boy, who we’ll call David. David has condition called dystonia, which causes the body to twist involuntarily. The disease had progressed throughout over his first three years of life, relegating him to the floor, and leaving him unable to walk or stand. Moving only by crawling on his stomach, David had effectively been robbed of his childhood.

However, the effects of his surgery were truly remarkable. Within three months, he wasn’t just able to walk again, but he could run. In his post-surgery video, we can barely recognise this cheeky and happy 9-year-old as he practices running up and down a hallway. He is now a college student and leads a completely normal life.

In his Ted Talk on the subject, Dr Andres Lozano, Chair of neurosurgery at the University of Toronto and a pioneer in deep brain stimulation, offers fascinating insights into how this emerging technique can be used to treat a number of disorders of movement, mood and cognitive function. In a flick of a switch the tremors associated with Parkinson’s disease can be alleviated, helping patients to regain control of their body. Scientists also believe that by sending electricity to areas of the brain that have been eroded by Alzheimer’s, they can reverse the impact of disease, effectively bringing the brain back to life.

The mechanics of the technology is really quite straightforward. By pinpointing exactly where malfunctions exist, electrodes are placed in the brain by making small holes in the skull, thus localising brain functions within a circuit. The amount of stimulation is then controlled by a pacemaker device placed under the skin in a person’s upper chest. Using a remote control, similar to that of a TV control, individuals can adjust how much electricity is delivered to these areas of the brain. These electrodes then produce electrical impulses that affect certain cells and chemicals within the brain, regulating the activity of abnormal neurones.

So, the next time you tune in to the radio, turn up the volume on the TV using a remote or adjust the temperature in your house, remember that the simple action of flicking a switch and adjusting it up or down can have a profound and transformative effect on a person’s life.