A tumor can grow anywhere in the brain. And because each brain region has a specific function, where a tumor grows determines its symptoms: Do you lose sensation, speech, memory, movement?
And as you might imagine, removing a brain tumor is rather unpleasant. Tumors aren’t simply hanging fruit that can be snipped at their stem and plucked out whole; they’re intermingled with other tissue, with a gradient rather than a clear line between tumor edge and healthy tissue. So when neurosurgeons remove tumors, it’s difficult to know exactly when to stop cutting. They’d like to remove as much as possible, but without cutting away useful bits of your brain. They decide when to stop by the simple method of poking and checking—as long as a conscious patient retains function, a surgeon can keep cutting.
Wünderdrug
What’s this wünderdrug that masks the pain of invasive brain surgery while allowing a patient to stay conscious and coherent? Actually, the drug’s been about 4.5 billion years in R&D and is called nothing. The human brain feels no pain.