In a new editorial for The New Yorker, Clarke recalls the moment she suffered the near-fatal medical emergency, saying that it happened while she was working out.
"On the morning of February 11, 2011, I was getting dressed in the locker room of a gym in Crouch End, North London, when I started to feel a bad headache coming on," she shared. "I was so fatigued that I could barely put on my sneakers. When I started my workout, I had to force myself through the first few exercises."
"Then my trainer had me get into the plank position, and I immediately felt as though an elastic band were squeezing my brain. I tried to ignore the pain and push through it, but I just couldn't. I told my trainer I had to take a break," Clarke continued.
"Somehow, almost crawling, I made it to the locker room. I reached the toilet, sank to my knees, and proceeded to be violently, voluminously ill. Meanwhile, the pain—shooting, stabbing, constricting pain—was getting worse. At some level, I knew what was happening: my brain was damaged," she confessed.
After getting help, Clarke was quickly rushed to a nearby hospital for medical attention, where she was advised that she would have to have brain surgery.
"I remember being told that I should sign a release form for surgery. Brain surgery? I was in the middle of my very busy life—I had no time for brain surgery," she said. "But, finally, I settled down and signed. And then I was unconscious. For the next three hours, surgeons went about repairing my brain. This would not be my last surgery, and it would not be the worst. I was twenty-four years old."
"That first surgery was what is known as 'minimally invasive,' meaning that they did not open up my skull. Rather, using a technique called endovascular coiling, the surgeon introduced a wire into one of the femoral arteries, in the groin; the wire made its way north, around the heart, and to the brain, where they sealed off the aneurysm," Clarke went on to reveal.
"The operation lasted three hours. When I woke, the pain was unbearable. I had no idea where I was. My field of vision was constricted. There was a tube down my throat and I was parched and nauseated. They moved me out of the I.C.U. after four days and told me that the great hurdle was to make it to the two-week mark. If I made it that long with minimal complications, my chances of a good recovery were high," she added.
She spent much more time in the hospital and required more surgery, as doctors discovered another aneurysm on the other side of her brain.
Clarke then confessed that "after keeping quiet all these years, I'm telling you the truth in full. Please believe me: I know that I am hardly unique, hardly alone. Countless people have suffered far worse, and with nothing like the care I was so lucky to receive."
Game of Thrones Season 8 premieres on HBO on Sunday, April 14 at 9 p.m. ET.