Krista and Tatiana Hogan
Krista Hogan and Tatiana Hogan (born October 25, 2006) are craniopagus conjoined twins
Conjoined twins
Conjoined twins are identical twins whose bodies are joined in utero. A rare phenomenon, the occurrence is estimated to range from 1 in 50,000 births to 1 in 100,000 births, with a somewhat higher incidence in Southwest Asia and Africa. Approximately half are stillborn, and a smaller fraction of...

. They are joined at the top, backs, and sides of their heads. They were born in Vancouver
Vancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...

, British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

, Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, and are the only unseparated craniopagus twins
Craniopagus twins
Craniopagus twins are conjoined twins who are conjoined at the cranium. This condition occurs in conjoined twin in about 1 in every 2,500,000 births...

 currently alive in Canada. They live with their mother, Felicia Simms, in Vernon, British Columbia
Vernon, British Columbia
Vernon is a city in the south-central region of British Columbia, Canada. Named after Forbes George Vernon, a former MLA of British Columbia who helped found the famed Coldstream Ranch, the City of Vernon was incorporated on December 30, 1892. The City of Vernon has a population of 35,944 , while...

 and often travel to Vancouver for care at BC Children's Hospital and Sunny Hill Health Centre for Children. Their father is Brendan Hogan. Tatiana and Krista have one older sister, Rosa, and one older brother, Christopher, and one younger sister, Shaylee. Their grandmother, Louise McKay, is involved with raising them.


Based on statistics, the Hogan twins were given a 20% chance of survival at birth. At birth, they were described as "wriggly, vigorous and very vocal."

Early infant life

Tests on the twin girls in April 2007 showed that Tatiana's heart was working harder than her sister's and that she had high blood pressure because of it—her heart supplies part of the blood to Krista's brain. Tatiana is smaller and less robust than Krista. A surgery was planned to give Krista's heart a "jump start" so Tatiana's heart would not have to work so hard.

The twins' nervous systems are highly interconnected; their doctors reported that when one of the girls is tickled, the other jumps, and that putting a pacifier in the mouth of one child could cause the other to stop crying.

Their birth, potential separation, depth of community support and their family's financial situation have been subject to significant media coverage in Canada. The twins and their mother were also guests on The Tyra Banks Show
The Tyra Banks Show
The Tyra Banks Show, also known as and shortened to Tyra or The Tyra Show, is an American talk show hosted by Tyra Banks. The last new episode aired on Friday, May 28, 2010.-2005-2009: Syndication:...

in the US.

In August 2007, it was declared the girls 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 and the Discovery Channel
Discovery Channel
Discovery Channel is an American satellite and cable specialty channel , founded by John Hendricks and distributed by Discovery Communications. It is a publicly traded company run by CEO David Zaslav...

 UK. The show was broadcast first in Britain in spring 2010, and then aired in June in Canada and the U.S.

The documentary followed a year in the twins' life and included a "particularly poignant" meeting between the family and Lori and George Schappell, 49, the world’s oldest twins to survive being joined at the head.

There is suspicion that they can see through each other's eyes, due to brain conjoining. In their brains their thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

es are joined.

Progression to childhood

In January 2009, a documentary was filmed which reported on Tatiana and Krista Hogan, and followed their progress up to their 3rd birthday. This documentary was released and aired in October, 2010. In this documentary, it was confirmed that Tatiana and Krista shared a thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

 which connected their brainstems. 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 which were carried out which confirmed that visual cortex signals were received at the other brain. 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
Sleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...

condition which occasionally caused her to stop breathing for up to 20 seconds. A sleep apnea specialist, Dr. Fred Kozak, performed surgery on Tatiana and was able to successfully treat her sleep apnea. Not long after the surgery, Tatiana's heart shrank to a more normal size and her heart rate dropped such that it no longer carried all of the burden of circulating blood for both brains.

The documentary reports that Tatiana and Krista are progressing well, and have achieved all the normal childhood milestones, such as walking, talking, and counting.

External links

  • The Twins, Article about the twins at,, retrieved on January 27, 2008
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