This is a horrible procedure with an interesting history. Frontal lobotomies were performed for almost half a century in the late 1800s and early 1900s. Doctors basically disconnected the front of the brain (the part that sits above and close to your eyes) from the rest of it. The basic theory was that the "frontal lobes" are responsible for "executive function." This part of the brain is responsible for making us act like normal functioning adults. Doctors at the time thought that patients with severe mental illness (patient not acting like normal functioning adults) had a problem with the frontal lobes of their brain, and by disconnecting this part of the brain from the rest, patients might function more normally.
It didn't really work, but thousands of frontal lobotomies were performed anyway. This was in an era of medicine when you didn't need the FDA to "approve" a therapy for use on humans. Interestingly, the FDA probably wouldn't approve aspirin today, if given the option, because of the side effects (it is a leading cause of stomach ulcers in the US).
Most notably, Walter Freeman, a neurologist, traveled around the country severing off the frontal lobes of patients for almost any indication. He even performed this procedure on Howard Dully, a boy of 12 years of age, after his stepmother was simply tired of his "youthful defiance". You can imagine that disconnecting the part of the brain that makes you act like a normally functional adult in a 12 year old boy, with the indication that he was acting like a 12 year old boy, might not have been the best treatment.
Interestingly, in 1950 the USSR was the first country to outlaw frontal lobotomies... because it didn't seem to work and was inhumane. That's right - the USSR took the lead in outlawing bizarre, inhumane practice!
Today, frontal lobotomies are almost only performed in patients with severely refractory OCD. These patients need fail multiple other therapies over the course of years before the procedure is even considered. Thus, "youthful defiance" is no longer considered an indication for having the front of your brain removed!