Fatal insomnia

Fatal familial insomnia is a neurodegenerative disease that eventually results in a complete inability to sleep. Many patients go six to nine months without sleep, during which time they develop dementia and become unresponsive. Death follows. It is incurable and untreatable. Inducing a coma still keeps the brain awake. Because it is a form of prion disease, similar to mad cow disease, it's irreversible even by genetic therapy because once the protein exists in the body, it will slowly transform healthy proteins into their prion form.