Fatal insomnia
Channel: 宇宙のすべての知識 プリンシピア
Date: 2019-03-17

Fatal insomnia, by Wikipedia https://en.wikipedia.org/wiki?curid=43871 / CC BY SA 3.0

#Neurodegenerative_disorders
#Transmissible_spongiform_encephalopathies
#Unsolved_problems_in_neuroscience
#Sleep_disorders
#Rare_diseases
#Sleeplessness_and_sleep_deprivation
Fatal insomnia

Fatal insomnia is an extremely rare sleep disorder that is typically inherited and results in death within a few months to a few years after onset. The main symptom is insomnia, but the disease can also cause a range of other symptoms, such as speech and physical coordination problems and dementia.
It is a prion disease of the brain, and is almost always caused by a mutation to the protein PrP. It has two forms. In the autosomal dominant inherited form, it is called fatal familial insomnia (FFI). It can also develop spontaneously as a noninherited mutation variant called sporadic fatal insomnia (sFI). The first recorded case was an Italian man, who died in Venice in 1765.
Fatal insomnia has no known cure and involves progressively worsening insomnia, which leads to hallucinations, delirium, confusional states like that of dementia, and eventually death. The average survival time for patients diagnosed with FFI after the onset of symptoms is 18 months.
The mutated protein, called PrP, has been found in just 40 families worldwide, affecting about 100 people. If only one parent has the gene, the offspring have a 50% risk of inheriting it and developing the disease. With onset usually around middle age, potential parents must be tested if they wish to avoid passing FFI on to their children.
The age of onset is variable, ranging from 18 to 60 years, with an average of 50. The disease can be detected prior to onset by genetic testing. Death usually occurs between 7–36 months from onset. The presentation of the disease varies considerably from person to person, even among patients from within the same family.
The disease has four stages:
Other symptoms include profuse sweating, pinpoint pupils, the ...