Dr. Casey Halpern

with the goal of trying to provide somebody with a meaningful therapy.

But when we deliver electrical stimulation, these electrodes, while they might be sitting in a very small region of the brain, there are regions within a few millimeters of where these electrodes are that, if stimulated, could cause a temporary, very brief

a moment of laughter, like you said, or a moment of panic.

And of course we can just shut that electrode off, but often these side effects could be therapeutic.

And actually that's how we have discovered ways to use deep brain stimulation, not just for movement disorders like Parkinson's disease, but for example, patients with Parkinson's disease,

that have a psychiatric comorbidity like depression or obsessive compulsive disorder.

A lot of these patients are highly compulsive and impulsive.

sometimes these problems actually melt away.

And we're trying to help their tremor, but the patients also tell us that their gambling issue has gotten better or their mood has improved.

And why is that?

Well, you know, there's probably more than one reason.

You know, you can help somebody's mood by making their tremor go away, of course.

But we see laughter in the clinic sometimes.

And why is that?

And that's because we're stimulating parts of the brain that are not just involved in these motor circuits, but they're also involved in

what we call a limbic circuit or part of the brain involved in emotion.

And if we learn how to modulate those areas therapeutically, step-by-step, we can actually develop these therapies for other indications like depression.

I would say the most impressive and consistent effect we have when we have a patient with tremor who has been tremoring for the past 20 years, if we can deliver stimulation through that electrode in the clinic, we have immediate relief of tremor.

That is the effect that inspired me to be a neurosurgeon when I was in college.

I've never really wanted to do anything else except help develop that type of therapeutic for another kind of symptom.