Everybody suffers from a little insomnia once in a while, but what if you were unable to sleep for months?

Early studies conducted on dogs showed that the absence of sleep was fatal in a few days. In one brutal experiment conducted by a couple of Italian physiologists in the late 19th century, dogs were kept awake for two weeks by forcing them to walk, after which they died. Microscopic study of the dogs’ brain cells showed degenerative changes in the brain’s neurons.

In 1964, an American high school student, Randy Gardner, went a record eleven days without sleeping. Although Gardner, because of his remarkable fitness, was still able to play basketball his cognitive and sensory abilities suffered. As the days wore on, Gardner became increasingly moody, had difficulty concentrating, suffered from short term memory loss, hallucinated things that were not present and became consumed by paranoia. Gardner cut short his dangerous experiment before it ate into his health, but for a handful of families scattered across the world sleep is a luxury. They carry within their DNAs a very cruel gene that causes a very rare sleeping disorder called fatal familial insomnia.