"Some people like skiing, or mountain climbing, or playing poker. I like operating on people’s brains"

It felt absolutely medieval. This wasn’t a manoeuvre that would work with gradual pressure, like the tightening of a vice. It needed a quick, crushing force. So I used a head holder, with one-inch-long steel pins, to secure the skull to the operating table. That way, if my patient started to move, her head would remain still, and I wouldn’t accidentally kill her.

The three metal pins would need to bite down into her skull after puncturing her scalp: one pin in her forehead, two in the back, all connected to a C-shaped clamp. While my assistant held up the patient’s head from the neck, I explosively captured her cranium in-side the steel device.

The jarring noise from the metal gears made the students, nurses, and doctors standing behind me in the operating room fall silent. The first of several hundred steps that needed to go smoothly, quickly, and perfectly had just been completed.

So began my first time opening the skull of a living human being.

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I was a third-year resident at the University of California, San Diego, Department of Neurosurgery. My patient was in her mid-thirties and had come to the hospital’s emergency room two days before, reporting a peculiar weakness and awkwardness in her left arm and hand. An MRI had revealed a bright white abnormality on her brain — a tumour the size of a peach.

Many times before, I had stood beside senior neurosurgeons, assisting, observing, and learning. But this was my first time going solo. It’s an odd thing — brain surgery. There’s fear, of course, but also awe that you’re literally inside somebody’s head, which elicits intensity as well as excitement.

I don’t want to sound indelicate, but for me it’s a thrill. Some people like skiing, or mountain climbing, or playing poker. I like operating on people’s brains. The risk is that I will nick a vein and a part of the brain will die. Or I will go in at the wrong spot and won’t be able to reach most of the tumour. Or everything will seem to go perfectly during the surgery, but the patient will wake up unable to speak for the rest of their life.

The hope — and why I do it — is that this woman, who just got married three months ago and has much of her life ahead of her, will have her strength and fine control of her left hand restored as good as new.

Despite having abnormal tissue in her brain, this patient was pretty lucky because the mass wasn’t malignant. Her life was not at risk from the tumour, just from me. But as long as the tumour remained and continued to grow, her muscle weakness could worsen and spread.

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It was nestled in the motor strip of the right parietal lobe — a half-inch-wide, seven-inch-long ribbon of brain tissue that sends movement signal to the left side of the body. This particular type of tumour is called a meningioma because it grows from the lining (meninges) of the brain.

Since the skull can’t stretch, the tumour knuckles into the brain, deforming it, without actually penetrating the tissue. The pressure, however, interferes with the electrical signals, leading to weakness.

After drilling off a circular piece of bone near the top of her skull — what brain surgeons call “turning the flap” — I gently sliced with a number-11 scalpel into the dura — the thin, cloth-like membrane that protects the brain. I scored and lifted the dura but went no farther.

And there it was. I could see the tumour on the very surface of the brain. In contrast to the glistening opalescence of healthy brain tissue, it was yellow, dull, and irregularly spherical.

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I began by entering the centre of the tumour, coring it like the yolk of a hard-boiled egg until it was hollow, leaving behind only its tougher rim. Then, I delicately worked its shell away from the surrounding brain, collapsing it into itself. This is the hard part, because the edges have bridging spider-silk-thin fibres, and the surrounding tissue is as soft as pudding.

Slowly, methodically, I divided those wisps with a curved eight-inch scissor. Two hours of doing this under magnification and illumination, and the tumour was out. I bathed the brain’s surface with sterile water to check for any oozing or dripping blood vessels.

Then it was time to close through reverse manoeuvres. I reattached the bone flap to the rest of the skull with a thin titanium mesh and tiny plates and screws, stitched the scalp back in place, and finally removed the clamp holding her head still.

Three days later, when her brain was no longer stunned by my invasion, she had full strength back in her left hand and arm, and I knew what I wanted to be great at.