What are the side effects of deep brain stimulation for a Parkinson's patient?

Side effects of deep brain stimulation in people to treat Parkinson's may include impulsivity and depression. Biomedical engineer Sri Sarma, PhD, explains why in this video.

Transcript

00:00

A millimeter away, a few millimeters away is the limbic part. The limbic, it's a part of the region

00:06

of the subthalamic nucleus that's connected to a limbic circuit, which controls our emotions. [MUSIC PLAYING]

00:19

So a couple of things-- so medications have lots of side effects. Deep-brain stimulation can also come with side effects

00:26

because, remember, you're changing the electrical patterns in, hopefully, a very small region of the brain. But with Parkinson's disease, one of the typical targets

00:36

is what's called a subthalamic nucleus. OK, it's a very small region in the brain. And I kind of describe it as like

00:43

a little egg-shaped structure, whose diameter is on the order of millimeters. Now-- a few millimeters.

00:49

Now, your DBS electrode, the tip of it, it's on the order of half a millimeter. So here you are trying to put an electrode,

00:57

looking for a very, very small target. Now, in the subthalamic nucleus, there's a subregion that's motor--

01:04

motor related. And that's the region you want to target for a Parkinson's patient. But right adjacent to it, a millimeter away,

01:12

a few millimeters away, is the limbic part. The limbic, it's a part of the region of the subthalamic nucleus that's

01:19

connected to a limbic circuit, which controls our emotions. So if you excite that, if you get the electrode slightly off,

01:27

or you excite too much of the tissue where you're hitting, the limbic part of the circuit, you can change their emotions.

01:33

So some of the side effects for DBS is impulsivity. People can become more impulsive.

01:39

They can become depressed. So you're altering-- you're kind of playing around with some of their emotional states.