When something goes wrong with your body, doctors usually have to put things back together, like by stitching a wound or setting a broken bone.

But sometimes, healing your body requires taking it apart— like when you have to get an infected appendix removed—. And that's true for the brain, too.

For some people with certain psychiatric or neurological diseases, the best way to fix the brain is to damage it. Just really, really carefully. [INTRO ♪]. Surgery for brain conditions has a messy history.

Unregulated lobotomies where doctors would essentially cut off the brain's frontal lobe to “cure” things like schizophrenia were widespread in psychiatric hospitals across the US in the 1940s and ‘50s. At the time, the procedure was crude and often left people lethargic, with a dulled personality, and unable to function on their own. Thankfully—like, really thankfully—we know a lot more about the brain now than we did back then, and our technology has gotten better as well.

Today, surgery for neurological and psychiatric conditions is a lot more specific and targeted. It's also much safer, and really only used when other treatments, like medication, don't work. One of these surgeries is the corpus callosotomy, also known as a split-brain surgery.

This procedure involves severing the corpus callosum, the band of nerves that connects the two hemispheres of the brain. It's designed to help those with severe epilepsy when typical medications and treatments aren't working. Specifically, the surgery helps ease seizures, which are caused by abnormal electrical firing in the brain, from spreading from one hemisphere to the other.

It won't stop the seizures completely, but it will at least keep them confined. And the good news is, it's effective. In a 2013 study in the journal Neurosurgery, 50 people who went through the procedure had a statistically significant drop off in the frequency and severity of seizures.

And the outcomes were even better if they had the procedure done when they were younger. Also importantly, this surgery helps reduce atonic or drop seizures: seizures where the person loses control of their muscles and falls to the ground, putting them at risk for injury. We don't really know why they happen, but corpus callosotomies reduce their frequency.

That 2013 study found that 40% of the patients had no more drop seizures after the surgery, and 64% had the frequency reduced. And in a 2014 study of 26 patients in the journal Epilepsy & Behavior, drop attacks went down by half or more in 65% of patients. Now, there are side effects and risks to the procedure, like headaches, stuttering or other trouble with speech, and coordination problems.

But reducing seizures typically improves quality of life dramatically, so for some patients, it makes the most sense. Surgery is also used to treat severe cases of obsessive compulsive disorder, or OCD, which causes recurrent, intrusive thoughts and repetitive behaviors. Scientists are increasingly confident that the neurological root of the disorder is a small hook of tissue towards the front of the brain called the anterior cingulate cortex.

This region, also called the ACC, is involved with the regulation of emotion. It serves as a connector between the brain's limbic system, which deals with emotions, and the prefrontal cortex, which handles cognitive control. In OCD, the ACC is hyperactive.

So people whose OCD isn't treatable with medications or therapy sometimes undergo surgery to try and modify its activity. One way to do this is by using deep brain stimulation, or

DBS: a procedure that places a small electrode inside the brain by the target brain region. The electrode sends out pulses to disrupt abnormal activity in that region and restore normal patterns, and multiple studies have shown that it helps manage symptoms. From what we can tell, it's also safe in the long term, according to a follow up study on six patients published in 2016 in PLOS One, and it improves the quality of life for patients. Like all brain surgeries, it does come with its side effects, like headaches or lightheadedness, but many of them can be managed by adjusting the frequency and strength of pulses.

Finally, deep brain stimulation is also used to treat Parkinson's, to help ease the tremors and movement problems characteristic of the disease. Many Parkinson's symptoms are caused by the death of neurons in the brain that produce the neurotransmitter dopamine. Dopamine regulates several pathways in the brain, including ones involved in movement.

So without enough of it, multiple brain regions become overactive. To treat symptoms, surgeons will sometimes cut or burn out those regions, but deep brain stimulation is safer and more easily adjusted, so it's become the preferred procedure. DBS can't replace that lost dopamine or anything, but like with OCD, it can help normalize brain activity by stopping those extra signals.

And it seems to work. A 2014 meta-analysis of six trials, which included over 1000 patients, found that it significantly improved motor signs of Parkinson's, functionality, and quality of life. And similar results have been replicated in more recent studies, too.

All this goes to show that, even if the brain is a unique and special part of the body, it's also just another organ. Sometimes, diseases and disorders make it work against you, and surgically changing it can be the best way to heal. Thanks for watching this episode of SciShow Psych!

If you'd like to learn more about surprising neurological treatments, you can watch our episode about — of all things — LSD. [OUTRO ♪].