What does the future hold for the Twins Who Share a Brain?
from VANCOUVER MAGAZINE, Sept. 1, 2011
The moment they were born, on October 25, 2006, in Vancouver, this much was known about Krista and Tatiana Hogan. The girls were conjoined—what used to be called “Siamese”—twins. Their skulls were fused such that their tiny bodies together made the shape of an open hinge, the girls facing the same direction but essentially away from each other. Each had her own organs and limbs, but they shared plenty of blood vessels in the netlike sheath beneath their scalp. And they shared something else, too, something believed to be unprecedented among living twins: a “bridge” of tissue connected their otherwise-separate brains amidships, at a crucial relay station called the thalamus.
Eight hours after the twins’ birth, a remarkable thing happened, and it immediately transformed the story of two little girls from Vernon, B.C., into something almost mythic. Tatiana got a shot and Krista flinched. Clearly, the girls were not just attached but connected. Sensory information passed between them.
“This is not telepathy. This is not ‘sixth sense,” says Douglas Cochrane, a veteran pediatric neurosurgeon at BC Children’s Hospital who has been the twins’ wingman—their doctor, advocate, and, in a sense, protector—since they were in utero. “The girls send chemical messengers in the bloodstream between each other. They send electrical impulses and information between each other along this bridge”—on the CT-scan image he’s pointing to, it looks like a long kidney bean—“and I’m sure along the coverings that they share.”
The bridge has been likened to a FireWire connection between their brains, and its bandwidth appears broad. Months after their birth, tests confirmed that images falling on the retina of Tatiana were processed in the visual cortex of Krista. What one girl looks at, the other girl sees.
This development, bordering on miraculous, had a flipside: separating them would be a bear. The risks were extraordinary. At best it would likely mean, at the end of many complicated operations teasing apart bone, skin, and vessels, some vision and speech impairment for both girls. Plus: “Given the way the brains are packed together—they’re physically separate but they sort of interdigitate like the teeth of a zipper—it was clear to me that we’d end up with weakness on one side for one twin and on the opposite side for the other,” Cochrane explains. “What else would happen no one knows.”
A semi-crazy-sounding philosophical question presented itself: Is it better to be healthy and fused to someone at the head, or to be impaired and partially paralyzed but on your own? To answer means having to assign a value to independence. Do we perhaps overvalue it? And undervalue—because no singleton can appreciate it—the presence of someone who gets you because they are in you, of you?
Cochrane viewed his job, in those early days, as articulating what splitting the girls up would mean (in terms of gains and losses), and then stepping back and letting mother Felicia Simms—then just 21—and the rest of the family make the call. The family chose not to separate. The twins would move into the future as one.
Brain surgeons have a reputation for an appalling bedside manner—almost as if they’re unwilling to devote even a bit of RAM to niceties that could go instead to saving lives. But David Douglas Cochrane has somehow found space inside himself for both. He is a big man with softly recessed eyes and a cultivated patience. On the consumer website RateMDs.com, where patients can describe their experiences with physicians, a father weighed in. Cochrane had successfully excised a bone cyst from his son’s skull. “Dr. Cochrane is the most professional, talented, kind, humble man I have ever met,” he wrote. Other comments strike a similarly devotional tone. (Alerted to the praise, Cochrane laughingly dismissed it because the sample size isn’t statistically significant.)
Cochrane became a doctor for some of the usual reasons: he wanted to help people, a family friend whom he idolized practised family medicine in hometown Cambridge, Ontario, and he (Douglas) had the brains and the stamina to get through med school. His ambitions drew him into the wider world. At the University of Toronto, he won the Faculty of Medicine’s Cody gold medal, then struck out for Angola and worked under the medical missionary Robert Foster at the tail end of a brutal civil war. Foster’s resourcefulness under fire (literally) provided a new benchmark. Cochrane decided there to specialize in neurosurgery. Neurosurgeons are medicine’s bomb squad—brain disorders are among the most threatening to patients, and treatments carry the most risk. Family medicine it isn’t, but for Cochrane that combination of complexity and high stakes was exactly the appeal. “I found I enjoyed trying to solve tough problems,” he says. Pediatric neurosurgery is the no-limit table: the highest stakes of all. If your itch is to help, life offers few more useful places to scratch. He has been at Childrens’, where he specializes in fetuses with congenital neurological malformations, for 25 years.
But nothing in his background, he says, prepared him for a case like the Hogan twins. Cochrane is watching and listening like everyone else to see what the girls reveal about who they are.
The twins, chestnut-haired and blue-eyed, are nearly five years old. Developmentally they’re closer to four, Cochrane says, but that may just be the Ginger Rogers syndrome: they do what other kids do, but backwards and in heels, so to speak. “They have had to learn motor movements differently,” Cochrane says. “They had to work on how to sit and stand and cruise and walk.” (Even bum-scooting required heroic teamwork.)
Their language has come slowly. Cochrane admits he doesn’t quite know why but reckons the answer might be social rather than physiological. The twins are the not-so-still centre of an extended family of 14 people, all mustered under the roof of a 10-room rented house, all more or less devoted to the insatiable needs of the world’s rarest craniopagus twins. “You could say that there’s a household there that’s so full of adults and kids communicating that they’re kind of communicating for them,” Cochrane says. “It’s like the third child: he’s not going to talk until he’s three because the other two are doing all the talking for him.”
Exactly what the girls’ internal landscape is like we can’t yet know. The best tool for getting a real-time snapshot of what’s happening in the brain is an fMRI scan, which measures changes in blood flow (which correlate to changes in neural activity). For those pictures the girls will need to go into the scanner without anesthetic, which means getting their cooperation. It’ll likely be at least a year before Cochrane lets that happen. For now everybody is guessing.
Some things are established. It seems clear that Tatiana will “see” the sickle moon that Krista is looking at (and vice-versa). Very likely, in some fashion, she will hear the Bruno Mars song piping into Krista’s ear bud, and taste the Tin Roof ice cream Krista just licked, and feel the give of the soft-shelled crab Krista just picked up. (One exception: she may not smell the chrysanthemum Krista has leaned down to sniff; olfaction appears to be the one sense that routes around the thalamus.) The fear Krista experiences in her nightmare will agitate sleeping Tatiana, too. And when Krista jars awake, so will Tatiana. (The thalamus governs wakefulness.) So they will save money on alarm clocks.
It’s not clear how their brains will sort out the interference from the two-way traffic on the bridge. If they are both reading a book, will each see both sets of words? (Some neurologists wonder if the twins will have an increased chance of synesthesia—a blending of senses disproportionately common in visual artists.) The communication between them will likely prove to be a uniquely intimate call-and-response. But can we say what they are sharing are actual thoughts?
The thalamus relays not only sensory information but also some memory information to a part of the midbrain called the cingulate cortex, which is involved in, among other things, processing emotion. So the exchange is bound to have at least a dimension of what we think of as “thoughts.”
Felicia Simms is convinced her girls are playing a sort of private game of tennis, mentally. Kelowna filmmaker Alison Love, who spent a year with the twins while helping create the documentary Twins Who Share a Brain, believes it, too. “In the beginning we weren’t sure ourselves,” she says. “Is it just Mom hoping that the kids are really more special than they are?” But then both she and filmmaking partner David McIlvride began to see the same thing: a tight, coded link between the girls’ behaviour without a sound passing between them.
Cochrane, for his part, is somewhat a kindred spirit to Atul Gawande, a Boston-based endocrine surgeon and popular writer. Both men crusade for patient safety, ensured by systems of checklists and protocols for doctors to work more efficiently and limit catastrophic errors. Gawande wrote a book called Better, which promotes these issues; Cochrane co-directs the Canadian Patient Safety Institute and was recently appointed to chair the inquiry into thousands of medical scans performed and interpreted by a couple of B.C. doctors unlicensed to do so.
But Cochrane is like Gawande in another way, too. Gawande has an oft-quoted line that could easily be Cochrane’s mantra: “The social dimension turns out to be as essential as the scientific.” Cochrane is a listener above all else. Patients know better than doctors do whether their treatment has been “successful,” but that’s not the way the equation works now. Correcting that thinking, Cochrane says, “becomes more important to me the older I get.”
A powerful social lens may prove one of Cochrane’s best assets as far as the girls are concerned. (For theirs is going to be as much a social story as a medical one, a story of standing out and fitting in.) Cochrane is a curator of the twins’ uniqueness who emphasizes their ordinariness. “My sort of mental model of these kids is that they’re two kids who come to visit me,” he says. “I’m involved in the care of many kids with deformities and malformations, kids who don’t look normal and their arms and legs don’t work normally.” In this sense, the twins are like any other of his patients. “I see them as children.” If this case were special, the other ones wouldn’t be.
Cochrane doesn’t burn much daylight thinking about the philosophical and poetic implications of the girls who share a brain. Even the twists and turns of the neuroscience don’t preoccupy him. “I am interested,” he says, “and when the time is right we’ll try and put some sense to this. But I’m not prepared to put the girls out as medical curiosities. I mean, where historically did these people end up? In circuses.”
This is Cochrane as protector—trying to create normalcy around a family circumstance that would quicken the pulse of a reality-show producer. That 14-member extended family—including mom Felicia and father Brendan, five kids (the twins have an older brother and a sister, plus a baby sister called Shaggy), grandmother Louise, and various aunts and uncles and cousins—are stretched impossibly thin. The monthly budget doesn’t cover the frequent car trips to Vancouver for medical tests, which are only partly subsidized by the provincial health ministry. Some of the adults, at least three of whom have health issues of their own, report that they sometimes go hungry so that the twins can eat. To manage the twins’ exposure and drum up income (through things like speaking gigs for Felicia), the family has retained Los Angeles agent Chuck Harris. The self-described “Wizard of Odd,” Harris counts among his other clients “Lizard Boy,” “Wolf Boy,” and a guy who balances a car on his head. (Not to mention 49-year-old Lori and George Schappell of Reading, Pennsylvania, the world’s oldest set of craniopagus twins.)
The frenzy of academic interest in the twins is its own kind of P.T. Barnum scrum, in Cochrane’s view. “It’s ‘Who’s published about it? Show me the article!’” he says. And here the face of this perfectly controlled man clouds with frustration. (Cochrane has published no papers on the girls himself.) “The kids need to develop in order for us to understand some of the things that they’re asking. And the case study of these two twins will in fact be important when we can do it.”
The Hogan twins—the fact of them—is a little like the fact of life on Earth: a series of odds-defying events compounded to a level of staggering improbability. They weren’t supposed to make it this far. Early fears were that Tatiana’s heart, which was doing almost the work of two hearts, might fail. But now that the twins have grown, and grown stronger, that fear has faded and they are thriving beyond all expectation. Cochrane heaps credit on the family. “The support I remain in awe of,” he says. “That family has remained absolutely committed and absolutely strong. Without them the girls probably would have ended up in foster care.”
Out in public the girls still generate strong reactions. That’s not likely to change. “People’s immediate response is, ‘The twins should be separated—let’s make them like us,’ ” Cochrane says. Whatever the motives for that reflex—to spare the girls an impossibly complicated life or just to spare ourselves the uncomfortable feelings they might arouse in us—it’s not likely to happen now. “The only two other twins I know of who had this form of joining, though not the bridge, were two Iranian sisters,” Cochrane says. “They chose to do it in adulthood. And they did not survive.”
So, barring some game-changing microsurgical advance 30 years down the road, these two British Columbian sisters, bred in the bone, will move through life together, communicating in ways they’ll probably never be able fully to articulate. No one else will understand. But one man will understand better than most.