Krista and Tatiana Hogan (born October 25, 2006) are Canadians who are conjoined

craniopagus twins Craniopagus twins are conjoined twins that are fused at the cranium. The union may occur on any portion of the cranium, but does not primarily involve either the face or the foramen magnum; their brains are usually separate, but they may share so ...

. They are joined at the head and share a brain. They were born in

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the most populous city in the province, the 2021 Canadian census recorded 662,248 people in the city, up from 631,486 in 2016. T ...

, British Columbia, and are the only unseparated conjoined twins of that type currently alive in Canada. They live with their mother, Felicia Simms, in

Vernon, British Columbia Vernon is a city in the Okanagan region of the Southern Interior of British Columbia, Canada. It is northeast of Vancouver. Named after Forbes George Vernon, a former MLA of British Columbia who helped establish the Coldstream Ranch in nearb ...

, have two sisters and a brother and often travel to Vancouver for care at BC Children's Hospital and Sunny Hill Health Centre for Children.

Birth

The twins were given a 20 percent chance of survival at birth. At birth at B.C. Women's Hospital & Health Centre, they were described as "wriggly, vigorous and very vocal". They weighed 12 and a half pounds when they were born by

Caesarean section Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or mo ...

Early infant life

Tatiana is smaller and less robust than Krista. Tests on them in April 2007 showed that Tatiana's heart was working harder than Krista's and that she had high blood pressure because of it—Tatiana's heart was supplying part of her blood to Krista's brain. A surgery was planned to give Krista's heart a "jump start" so Tatiana's would not have to work so hard. The twins' nervous systems are highly interconnected. Their doctors reported that when one of them is tickled, the other jumps, and that putting a pacifier in the mouth of one could cause the other to stop crying. The twins' birth, potential separation, depth of community support and their family's financial situation have been subject to significant media coverage in Canada. They and their mother were also guests on ''

The Tyra Banks Show ''The Tyra Banks Show'', also known as and shortened to ''Tyra'' or ''The Tyra Show'', was an American talk show hosted by Tyra Banks that aired from 2005 to 2010. While Banks's show covered a variety of topics, there was a sensationalized focus ...

'' in the U.S. In August 2007, it was declared the twins cannot be separated, due to the likelihood of the surgery killing or paralyzing one or both girls. The family reduced the twins' public profile due to a contract giving exclusive access to a documentary crew for

National Geographic ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widely ...

and the

Discovery Channel Discovery Channel (known as The Discovery Channel from 1985 to 1995, and often referred to as simply Discovery) is an American cable channel owned by Warner Bros. Discovery, a publicly traded company run by CEO David Zaslav. , Discovery Channe ...

UK. The show was broadcast first in Britain in spring 2010, and then aired in June in Canada and the U.S.Tatiana and Krista on the move
By Ken MacQueen, Macleans. February 8, 2010. The documentary followed a year in the twins' life and included a "particularly poignant" meeting between the family and Lori and George Schappell, 51, the world’s oldest twins to survive being joined at the head.Today's TV
The Mirror, May 25, 2010 There is evidence that the twins can see through each other's eyes due to brain conjoining. Their

thalami The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...

are joined.

Progression to childhood

In January 2009, a documentary was filmed which reported on the twins, and followed their progress up to their third birthday. This documentary was released and aired in October, 2010. In this documentary, it was confirmed that they share a

thalamus The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...

which connects their

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

s. Through this shared brain tissue structure and the interconnected neurons, one brain receives signals from the other brain and vice versa. This documentary also reported on experiments that were carried out that confirmed that visual cortex signals based on what one girl saw, were received by both girls' brains. So in effect, one twin could see what the other twin was seeing, making them unique even among craniopagus twins. At this time, Tatiana suffered from a

sleep apnea Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times ...

condition that occasionally caused her to stop breathing for up to 20 seconds. A sleep apnea specialist, Dr. Fred Kozak, surgically treated her sleep apnea. Not long after the surgery, her heart shrank to a more normal size and its rate dropped such that it no longer carried all of the burden of circulating blood for both brains. The documentary reports that the twins are progressing well, and have achieved all the normal childhood milestones, such as walking, talking, and counting. A 2014 CBC Radio documentary described how they can feel and taste what the other is experiencing. Later it was also confirmed that they can see through each other's eyes.

References

External links

The Twins
Article about the twins at About.com, www.about.com, retrieved on January 27, 2008

Windsor Star, 2014 *http://dailygleaner.canadaeast.com/canadaworld/article/458621
2017 CBC documentary 'Inseparable: Ten Years Joined At The Head'
{{DEFAULTSORT:Hogan, Krista and Tatiana Conjoined twins Living people People from Vernon, British Columbia Sibling duos Canadian twins 2006 births

Birth

Early infant life

Progression to childhood

See also

References

Further reading

External links