Go inside the operating room with Cyla Daniels in the multimedia version of this story.

Cyla Daniels remembers her first seizure well.

It was March, 2011 and she was 19. She and a friend were lying on a bed watching a movie, when a sudden stabbing pain pierced her below the right armpit. The pain faded to a tingle; her face felt numb and droopy.

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"It felt like I was getting shocked, like I'd stuck my finger in a socket," Daniels, now 23, recalls.

More than three years later, Daniels would have a brain tumour removed by an international medical team that had joined forces at Toronto's St. Michael's Hospital.

The team helped refine an anesthesia protocol that allows doctors to safely perform the longest craniotomies on awake patients ever recorded in the medical literature, including in high-risk cases such as the old, the obese and those afflicted with tough-to-extract brain tumours.

They are also test-driving a tablet for neurological testing that is safe to use inside an MRI machine and on the operating table while patients are awake.

Taken together, these are small but significant advances, the kind that often happen quietly in hospitals and labs across Canada. But such advances are momentous to individual patients like Cyla Daniels. She let The Globe and Mail photograph and film her as she underwent an awake brain surgery, providing a snapshot of a remarkable procedure whose outcome was far from certain.

At first, the petite brunette (whose name is pronounced Ky-la) was not terribly fussed about her debut seizure. She seemed in superb health, ably juggling her part-time job at a fish and chips restaurant with her final year of high school in Oshawa, Ont. She was preparing to begin an advanced law-clerk program that fall, with an eye to applying for law school.

But the seizures kept coming. Sometimes Daniels suffered two or three episodes a day, each usually lasting about five minutes and leaving her feeling temporarily numb and weak on the right side.

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In July, 2011, an MRI scan revealed something disturbing: A small white-matter lesion deep inside the left half of her brain.

Daniels went to St. Michael's Hospital to see if Dr. Sunit Das could make sense of the discovery. It was small and lodged in the part of her brain critical for speaking, reading and writing; he advised her to keep a close eye on the tumour with an MRI scan every three months.

Her parents, Clinton Daniels and his ex-wife, Nelly Daniels, could only wait and watch.

Daniels, meanwhile, breezed through her law-clerk program, moved into her own tidy basement apartment on a cul-de-sac, became a supervisor at Tim Hortons, met her boyfriend, Patrick Ellis, and welcomed her first niece. The seizures dogged her, but she managed.

Then one morning in May of this year, Daniels couldn't manage any longer. She was two hours into her shift at Tim Hortons and she had already suffered six or seven seizures.

Ellis drove her to the emergency room at St. Michael's where, after waiting a day and a half, an MRI scan revealed a frightening development: The lesion had doubled in size. The surge meant the lesion, now roughly the size of a date, was undoubtedly a tumour.

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"At that point," Daniels recalled, "I was scared because I just didn't want it to keep growing and they didn't know how fast it was growing."

How long would it be before it damaged her ability to think, to speak, to write? How long before it jeopardized her dream of becoming a lawyer?

There was only one way to find out safely. Das suggested an awake craniotomy, a procedure that would involve Daniels performing a series of speaking, reading and writing tests while he stimulated her exposed brain in hopes of discovering a safe way to extract the tumour.

While all brains have a similar landscape, the elements differ from person to person, a bit like a park with same-sized gardens and different paths. The goal of this procedure would be to find the safe path to cut through the vegetation and pluck out the weed – the tumour – all while preserving the components that make it possible for a patient to speak, read, write and move.

Finding this safe path to her tumour was the best-case scenario, Das predicted. In a less ideal case, the surgical team would open her skull and discover the tumour was fenced in by crucial brain matter, beyond safe reach. Or, through a biopsy, they would find that – against the odds – the tumour was malignant, meaning Daniels would need chemotherapy or radiation.

EVOLUTION OF AWAKE BRAIN SURGERY

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Canadians with even a fleeting knowledge of medical history will recognize the name Dr. Wilder Penfield, the groundbreaking neurologist and neurosurgeon who in the 1930s helped perfect the "Montreal Procedure," a method that allowed him to electronically stimulate the brains of hundreds of epileptic patients as they lay awake and, eventually, to create the first functional maps of the surface of the human brain. (His work was cemented in the popular imagination with a Canadian Heritage Minute on TV that featured a woman on an operating table exclaiming: "Dr. Penfield, I can smell burnt toast!") After Penfield's breakthroughs, however, operating on awake patients fell out of fashion.

"I think a lot of people thought that awake brain surgery was barbaric," said Dr. Mark Bernstein, a neurosurgeon at Toronto Western Hospital who has performed more than 1,000 awake craniotomies since 1991.

The St. Michael's medical team that would operate on Daniels has added its own small footnote to that legacy.

Das, a Bangladeshi-born, American-raised neurosurgeon whose fascination with the human mind led him to study philosophy at Harvard before he earned his MD, was lured to St. Michael's from Chicago in 2010. One of his goals was to have St. Michael's join the ranks of Canadian hospitals offering awake craniotomies.

Das hoped to start the program with an "ideal" patient. His first case was a challenge: A 29-year-old man with a softball-size tumour lodged deep in his brain, nestled against fibres that control motor function. Das felt an awake craniotomy would be best, but he feared the surgery could take as long as six hours – much longer than the standard three- or four-hour safe limit for the procedure.

He approached Dr. Marco Garavaglia, an international medical resident from Italy, for help. Could Garavaglia find a way to keep a patient comfortable and wake him multiple times during such a long operation?

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After poring over the research, Garavaglia suggested they try dexmedetomidine, an intravenous sedative that Health Canada had approved under the brand name Precedex in December, 2009. St. Michael's was already using the drug in other types of surgery and it seemed to offer everything they needed: sedation, anxiety relief and pain relief, all without compromising the ability to breathe. Airway control is critical in awake craniotomies, so that the patient can still speak.

The dexmedetomidine, coupled with an epidural-like scalp nerve block that Dr. Andrea Rigamonti, another Italian-born anesthesiologist on staff at St. Michael's, had helped refine, allowed this especially challenging and time-consuming awake surgery to proceed.

It lasted an astonishing nine hours. Because he was able to communicate with the patient to learn which areas of the brain had to be preserved, Das was able to remove much more of the tumour than would have been possible if the 29-year-old had been asleep.

The St. Michael's team has used the protocol in more than 30 cases, the first 10 of which they recounted in a clinical report published in the Journal of Neurosurgical Anesthesiology in July. They now use it on all their awake-craniotomy patients, even those like Daniels whose surgery was only expected to last a few hours.

Long awake craniotomies are somewhat controversial, however. Patients with their heads locked in pins can become uncomfortable and claustrophobic as the operation drags on.

"I'm very sensitive about time. Anything that I think will go longer than four hours I don't book for an awake craniotomy," said Bernstein, the veteran Toronto Western neurosurgeon.

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Still, Bernstein said he is pleased that St. Michael's is offering what he calls a "terrific operation," and noted that Toronto Western has also started using dexmedetomidine, but in shorter procedures.

St. Michael's, meanwhile, has just launched a different sort of study of the dexmedetomidine protocol, one that aims to measure the short- and long-term psychological effects of being awake during brain surgery.

GETTING INTO CYLA'S HEAD

Early on the afternoon of Aug. 18, Daniels was propped up in a hospital bed and rolled into the operating room at St. Michael's.

A blue hospital gown engulfed her tiny frame. White earbuds connected to her iPhone filled her mind with music from the playlist she had created for her surgery, a distraction that – along with the administration of an anti-anxiety drug at the last minute – was supposed to smooth her frayed nerves.

"The bottom line was she was scared," said Clinton Daniels, who came with Cyla's mother and about a dozen friends and family members to await the results of the surgery.

As Garavaglia prepared to put her into a deep sleep for the first part of the surgery, he leaned over and trilled in his heavy Italian accent, "Do you have any questions, darling?"

"Just don't let me feel any pain," she said.

Daniels hit shuffle on her iPhone and settled in to the first strains of Get Your Shine On, by the country duo Florida Georgia Line.

After the doctors turned Daniels on her side, secured her head in a brace and draped her body in sterile sheets, they sliced a reverse-question mark incision above her left ear and exposed her brain. Then, Garavaglia turned off the dexmedetomidine and the team waited for her to wake up.

TESTS DESIGNED TO BE FAILED

It took more than 20 minutes to rouse Daniels.

"We're going to start doing the testing in just a moment," said Das, standing over the incision with a wand he would use to apply small electric charges to her brain as he asked her to perform a series of tasks.

A microphone amplified her voice and a video feed let Das watch her face as he worked.

"Cyla, can you count from 1 to 10 for me?," Das asked. "Nice and slow. Nice and clearly."

"1, 2, 3…." Daniels paused. A moment later she resumed, the words running together. "… 4, 5, 6, 7, 8 … 9, 10."

Das asked her to count more than a dozen times, shifting his wand as she spoke.

Sometimes she plowed through the kindergarten chant with ease; other times her voice dropped off halfway through and picked up again after Das removed the electric charge. In this way, a clearer understanding of Daniels's brain began to emerge.

After the counting test, Das challenged Daniels's brain in other ways, including asking her to read words flashed on a screen and to write on the tablet, which was designed by Dr. Simon Graham, a senior scientist and engineer at Toronto's Sunnybrook Research Institute.

Though Daniels had used the tablet to perform similar tasks inside an MRI machine, allowing the doctors to make a rudimentary map of the area around her tumour, on the operating table the tests proved frustrating. The words scrolled by too quickly.

"I don't get it. It's not making sense," she said, on the verge of tears. "It's going too fast! 'Kay, stop it! If they change, it's going too fast, I can't …," she trailed off.

The doctors and Melanie Morrison, a graduate student from Graham's lab, tried to slow the pace of the flashing words.

They then asked Daniels to write on the tablet.

"Can you write the word cat?" Morrison asked.

Daniels wrote an illegible scrawl on the tablet. "I just did thaaaaat. It doesn't woooooork," she cried. "C-A-T, that's what it looks like. It's riiiiight. This is not working and you guys are really confused but I know how to spell cat! C-A-T. I know how to write it. C-A-T. This thing isn't working. C-A-T."

The team fiddled with the awkward angle of the tablet and the pen. "See?" Daniels exclaimed. "You can't spell cat either!" The doctors laughed out loud.

Under the influence of the anesthetic, Daniels had lost her filter. Asked next to write a word that begins with F on the tablet, she slashed the pen across the screen. "That's my word: Fuck."

When the neurological tests ended, Daniels's emotions were raw. She feared she had failed an exam on which her life depended. She cried and apologized repeatedly. Of course, she needed to fail the tests to light the safe way to the tumour, a reality she could not grasp in the twilight state induced by the drugs.

"I did bad though?" she asked.

"You did great," Garavaglia reassured her.

"No, I feel bad because I didn't the way I was supposed to …," she mumbled.

"Cyla, you did spectacular," Das interjected. "You showed us what we needed to see. You did great …"

"Can you get it out?" she asked.

"We're going to start right now," Das said.

Daniels turned on her iPhone and fell back to sleep. She had been awake for a little more than 25 minutes. Now, Das could try to remove the tumour.

SUCCESS

Back in the St. Michael's family room, Daniels's parents stood up expectantly when Das walked in.

"We were able to find a safe corridor to the tumour," he began in a hushed tone. They visibly relaxed, nodding as Das shared the good news.

The initial pathology results – a sample of Daniels's tumour had been sent to the lab during surgery – showed the tumour was a less-aggressive ganglioglioma, a benign, slow-growing tumour that often affects children and young adults. Das had removed most of it, all but a minuscule shelf attached to a critical blood vessel.

Further pathology testing reinforced the initial findings. An MRI reading after the surgery yielded even better news. If any tumour matter was left, it was invisible. Her scan was clear.

Three weeks after the surgery, Daniels was back in her apartment, looking well on her way to a full recovery. Her chestnut hair had already begun to grow back, covering over the C-shaped scar on the side of her head.

In the days immediately following the surgery, the pain was intense, like she had been "run over by a truck," she said.

She slept almost constantly. She could not challenge her brain with complicated mental tasks such as reading. On her doctor's advice, she agreed to take three months away from school and work to allow her brain to recuperate.

The awake portion of the surgery felt like a hallucination – Daniels could only recall a few dream-like snatches, including writing the F-word on the tablet. But she had no memory of the performance anxiety she expressed at the end of the neurological testing. Surviving her seizures and the surgery has boosted her confidence.

"Now I actually want more of [my hair] shaved on the side to kind of show off my scar because I'm kind of really proud of it," she said. "I'm just proud of what I went through and how strong I was."