Fatal familial insomnia, or FFI, is a
degenerative brain disease that is
genetically inherited. The actual disease is caused by a
prion protein that is manufactured by the body and
degrades the
thalamus(which controls sleep). It was first described in 1986 and is fairly rare.
The average age of onset is 49. The disease begins with
insomnia that gets progressively worse as the disease advances. As the
thalamus degrades further the
insomnia gets more severe, leading to things such as shortness of temper,
hallucinations and other things associated with prolonged
sleep deprivation. It progresses into nearly total
insomnia and brings severe loss of weight and memory. At this point, clinical diagnosis is very tricky, which is one of the reasons the disease wasn't described until 1986. The symptoms that any given person who suffers from FFI vary wildly. It is often
misdiagnosed as
Parkinson's or
Alzheimer's, since the symptoms may be similar. The final stage of the disease are total insomnia,
dementia and eventually
death. The disease can take as long as a year to run its course and as much as half of that is spent totally unable to sleep.
Diagnosis before death is often difficult, since it is impossible to verify the
symptoms were the result of FFI without taking a sample of protein from the
thalamus.