Conjoined twins are twins whose bodies are physically connected at birth. Conjoined twins happen about once every 50,000 to 60,000 births. Approximately 70% of conjoined twins are female, and most are stillborn. But did you know that twins conjoined by the head share a brain and can see through each other’s eyes?
In British Columbia, a pair of twins joined at the head can see through each other’s eyes and “hear” each other’s thoughts because they share a brain.
Two Lives in One Brain
Krista and Tatiana Hogan were born in Vancouver, British Columbia, on October 25, 2006. The Hogan twins of British Columbia, featured in the documentary Inseparable, are quite unique. Their brains are joined at the head by a thalamic bridge, giving them neurological abilities that researchers are only beginning to understand. They are still like any other twelve-year-old in Canada; they go to school, have a favorite pet, and are part of a large, loving family determined to live each day to the fullest. Here are a few examples:
Craniopagus twins who are joined at the head are extremely rare. About one in every 2.5 million. The vast majority of twins like this die within 24 hours. The twins’ CT scan revealed that they could never be separated due to the risk of serious injury or death.
The structure of the twins’ brains distinguishes them from other people. Their brains are linked by a thalamic bridge connecting one thalamus to the other. The thalamus relays sensory and motor signals while also regulating consciousness.
Krista and Tatiana Hogan share touch and taste and can even control each other’s limbs. Tatiana can see through Krista’s eyes, whereas Krista can only see through one. Tatiana has three arms and one leg, while Krista has three legs and one arm. They can also switch to limb self-control.
The twins claim they can read each other’s minds without speaking. They describe it as talking in their heads. The girls have diabetes and epilepsy. They follow a strict regimen of pills, blood tests, and daily insulin injections. (Source: Mama Mia)
Learning and Living Together
The twins attended a regular school and began Grade 6 in September 2017. Despite their academic delay, they learn to read, write, and do basic arithmetic. The twins have three siblings: Rosa and Shaylee, sisters, and Christopher, also known as Toad. The personalities of the girls are very different. Tatiana is outgoing, talkative, and high-spirited, whereas Krista is quieter, more relaxed, and enjoys telling jokes.
The girls ride a specially designed bicycle, toboggan down hills, cross-country ski, and are learning to swim as part of their physical therapy.
Dr. Douglas Cochrane, who has been following the girls’ progress since their birth, says the only twins he knows who had this joining but not the bridge were two Iranian sisters. The girls chose to have surgery as they approached adulthood to try to separate, but they did not survive. Strangers frequently make this remark to the girls and their families.
The girls will remain as they are, as Krista and Tatiana Hogan’s family has explained in various documentaries over the years. (Source: Mama Mia)
Image from Cbc.Ca