Conjoined Twins Krista and Tatiana

Tatiana and Krista Hogan were born on October 25, 2006 in Canada. They are craniophagus fused on the back and sides. The operation to separate them was a priority but, unfortunately it is impossible. The majority of the blood supply of Krista's brain comes from Tatiana's heart, who started to suffer from hypertrophic cardiomyopathy. The challenges posed by these twins do not end here!

At the age of 4 months they underwent a CT-scan which shown a "medical marvel". They have independent brainstems (separate vital functions) but they share some brain matter and furthermore, they share the same thalamus!

This means that the sensory inputs of Tatiana can be felt by Krista and vice-versa. When we tickle Tatiana, Krista also giggles.

National Geographic Channel made a documentary about them called "The Twins Who Share a Brain" and I gathered this information from there. Watch it!



These might be the only twins on the world that are sharing neurological connections. The limits of these synapses are far away from what we can imagine. Because of this sharing, the twins are able to "see" through each other eyes. The visual information is received by the common thalamus and then it is sent to both visual cortices. Further tests were able to conclude that the "brain of one twin records signals from the other's visual field". When Tatiana is "looking" throught Krista's eyes, her own eyes show nystagmoid movements, according to their mother Filicia.

Are they also sharing thoughts? Can they see each other thoughts?
Those are scary questions and I am sure that more discoveries will be made from them. Unfortunately, despite they are having a normal but much slower development, Tatiana's heart will eventually get too tired in the following years.

You can see some pictures of these prodigious babies at http://www.shareordie.in/the-conjoined-twins-krista-and-tatiana/ and a small video at http://abcnews.go.com/Nightline/video/conjoined-twins-medical-10915371.

The sky is the limit!