Fatal Familial Insomnia (FFI) is a devastating disease that is, fortunately, quite rare. It is a genetic sleep disorder that has been found in only a few dozen families so far. It attacks the part of the brain that regulates sleep.
The thalamus is the part of the brain that is responsible for sleep regulation. When this disease strikes it causes a mutation in the protein in the brain tissue that results in a mis-folding that destroys the normal structure in the thalamus. These mutated proteins are called "prion proteins".
The cause of this fatal insomnia is this damage to the thalamus and is similar to other "prion diseases" such as the much better known Creutzfeldt-Jakob Disease (CJD), Kuru (which occured famously among the Fore tribe in Papua New Guinea due to their coming in contact with infected tissue, particularly brain tissue during their funeral practices) and Bovine Spongiform Encephalopathy (BSE) in cattle. BSE has made headlines around the world and you may have heard of it referred to as "Mad Cow Disease".
There are basically four stages in the course of this sleep disorder before the patient eventually dies.
It is unknown where fatal familial insomnia began but researchers believe that the first case occured about 250 years ago in a wealthy Venetian doctor, referred to as "Patient Zero". After his death in 1765 the disease has been found throughout the generations in families that descended from him.
As the disease progresses it transforms a vital, healthy and dynamic individual into an unresponsive, delerious shell of their former selves.
Sleep begins to slip away. Eight hours of sleep a night become seven, then five, then down to only one. Eventually, even that precious hour is lost to complete and utter sleeplessness.
Without sleep it is impossible to remain physically or mentally healthy. As the REM cycles of sleep that result in dreaming invade the sleepless mind hallucinations come and then go. Moments of lucidity drift in and out becoming ever less frequent.
They are trapped in an excruciating state of exhaustion and can even appear to be about to fall into a blissful sleep — but sleep never comes.
The struggle goes on for the patient and their families who can only look on in horror and do what they can to aid and comfort their loved one as fatal familial insomnia mercilessly advances toward inevitable death.
This disease is particularly insideous as it usually only becomes active after a person has reached child bearing years and has already passed the genetic disorder to the next generation. Children of parents with fatal insomnia have a 50 percent chance of inheriting it.