A teen had no idea he had epilepsy linked to a brain tumor. Then, he was helped by the team at CHOP.

A Chester County, Pennsylvania, teenager is getting ready to go back to school after recovering from a special kind of brain surgery. 

Nathan McDonnell and his family had no idea he had epilepsy linked to a brain tumor until they turned to the team at Children's Hospital of Philadelphia. 

"Sometimes I just look at Nathan and cry because I'm just so thankful that he is where he is," Noelle, Nathan's mom, said.

The 13-year-old has his life back after a scary ordeal with epilepsy that seemed to come out of nowhere three years ago. 

"He kind of just stopped talking to me and was staring and mumbling and drooling, and his lips had turned a little bit blue," Noelle said. 

At CHOP, doctors determined a benign brain tumor was causing the seizures that didn't respond to drugs. 

Dr. Benjamin Kennedy, a pediatric neurosurgeon and the director of epilepsy and functional neurosurgery, said surgery was the only option. 

"The risks of this kind of brain surgery really come down to language function and verbal memory," Kennedy said. "These are the essential things that make us human — the ability to communicate with one another. So this is not something that we ever take lightly."

Before the surgery, Nathan was hooked up to machinery that records brain activity, providing doctors with a roadmap for the surgery. 

During the four-hour surgery, the CHOP team was able to isolate and remove the benign tumor. 

Now, after a few complications, Nathan recovered completely. 

"Seizures can be a very debilitating disease to have, and when you can take that away, it's extraordinarily rewarding," Kennedy said.

Nate is back to basketball, flag football and scouting.

"It was a hard experience," Noelle said.

Nathan's grateful family said the ordeal became an important life lesson. 

"Now I think we appreciate life a lot more, but I hope that we're also teaching our kids how to really appreciate life", Noelle said.

Nate was in CHOP's specialized Epilepsy Monitoring Unit that does advanced brain mapping, which doctors said helped make his surgery a success.