me, so i m hoping this will allow me to do that, to allow guitar. i m a finger picker. i want to record. i want to perform live again. reporter: carter, the 500th person to undergo the surgery at ucl aand first in the world to have brain surgery covered live for the world to see on twitter and short video share app, vine. he hopes sharing the videos will help other patients that are battling this disorder. joining us now is the neurosurgeon who led the team on brad carter s surgery. it didn t hurt him? he wasn t in any pain, and by strumming the guitar it was guiding you what to do? explain that to us. absolutely. we do the surgery to help patients with tremor. we want to personalize the surgery and treating symptoms most important for the patient. we had his bring his guitar,