Any time a doctor opens your skull ...

In 1986 a neurosurgeon incised part of my scalp and part of my right temple. He peeled back the skin and with a sort-of doorknob drill drilled through my skull. He took out the circle of bone and then began moving aside parts of my brain in order to reach a vein that had burst almost two weeks before. Reaching the vein, he attached a stainless steel spring-loaded clip, sealing the cavity. After withdrawing instruments from inside my brain, the doctor waterproofed the edges of the plug of bone and slid it back into place. The operation was successful. I did not die; I was not paralyzed; I still had vision and speech. But, as an attending neurologist said, every time you touch the brain, you cause damage.

The linked article is much worth reading.

“I woke early on the morning of the operation and lay in bed thinking about the young mother I had operated on the previous week. I had operated on a tumour deep in the right side of her brain and somehow – I do not know how since the operation had seemed to proceed uneventfully – I had caused a major stroke, so that she awoke from the operation paralysed down the left side of her body. I had probably tried to take too much of the tumour out. I had probably strayed too deeply into her brain. I must have been too self-confident.

…

“Each brain tumour is different – some are as hard as rock, some as soft as jelly. Some are completely dry, some pour with blood – sometimes to such an extent that the patient can bleed to death during the operation. Some shell out like peas from a pod, some are hopelessly stuck to the brain and its blood vessels. You can never know for certain from a brain scan exactly how a tumour will behave until you start to remove it. This man’s tumour was, as surgeons say, co-operative, and with a good surgical plane – in other words, it was not stuck to the brain. I slowly cored it out, collapsing the tumour in on itself away from the surrounding brain. After three hours it looked as though I had got most of it out.”

http://www.granta.com/New-Writing/Henry-Marsh

Linked from maggiesfarm.