Deep brain electrodes – from the inside

Wired magazine has a fascinating feature article about an operation to implant deep brain stimulation electrodes in a patient with Parkinson’s disease. Crucially, the article is written the patient himself.

Deep brain stimulation involves inserting permanent electrodes into the brain to pump tiny pulses of electricity into key areas.

It’s most commonly used as a treatment for Parkinson’s disease which causes problems with the ‘motor loop’ – a network of brain areas that control movement (actually there are two main ones, the direct and indirect).

This is why patients with Parkinson’s disease have trouble moving and have a visible tremor.

The loops consist of a series of areas that might boost activity or reduce activity in subsequent parts of the loop.

Damage to any of these areas might mean that the following area might not get enough activation (like with a faulty accelerator), or might be too active because it is not being damped down correctly (like with a faulty brake).

Neurosurgeons can try and restore balance in this loop by either damping down an area by surgery (e.g. a pallidotomy) or by increasing activation at an area by deep brain stimulation.

This is exactly the treatment that Steven Guile, the author of the Wired article, describes.

I’ll be kept awake for the entire procedure. During the surgery I will talk and move my limbs on command, which helps Team Hubris know which part of my brain is being poked.

Unfortunately, this also means I’m conscious when [neurosurgeon] Henderson produces what looks like a hand drill and uses it to burr two dime-sized holes into the top of my skull. It doesn’t hurt, but it’s loud.

Team Hubris is installing a deep brain stimulator, essentially a neurological pacemaker, in my head. This involves threading two sets of stiff wires in through my scalp, through my cerebrum ‚Äî most of my brain ‚Äî and into my subthalamic nucleus, a target the size of a lima bean, located near the brain stem. Each wire is a little thinner than a small, unfolded paper clip, with four electrodes at one end. The electrodes will eventually deliver small shocks to my STN. How did I get into this mess? Well, I have Parkinson’s disease. If the surgery works, these wires will continually stimulate my brain in an attempt to relieve my symptoms.

The article is a wonderful tale of neurosurgery from the inside and a great guide to some of the science and medicine of the condition.

There’s also a fantastic a video segment where Gulie narrates and explains the operation.

Link to Wired article ‘A Shock to the System’ (via Neurophilosopher).

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