![Fatal insomnia is an extremely rare disorder that results in trouble sleeping as its hallmark symptom.[2] The problems with sleeping typically](https://upload.wikimedia.org/wikipedia/commons/d/da/Cranial_imaging_of_a_FFI_patient.jpg "Fatal insomnia - Wikipedia")
Fatal insomnia - Wikipedia
Fatal insomnia is an extremely rare disorder that results in trouble sleeping as its hallmark symptom.[2] The problems with sleeping typically start out gradually and worsen over time.[3] Other symptoms may include speech problems, coordination problems, and dementia.[4][5] It results in death within a few months to a few years.[2]
It is a prion disease of the brain.[2] It is usually caused by a mutation to the gene encoding protein PrPC.[2] It has two forms: fatal familial insomnia (FFI), which is autosomal dominant and sporadic fatal insomnia (sFI) which is due to a noninherited mutation. Diagnosis is suspected based on symptoms and can be supported by a sleep study, a PET scan, and genetic testing if the patient's family has a history of the disease. Similar to other prion diseases, the diagnosis can only be confirmed by a brain autopsy at post-mortem.[1]
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.[6] The average survival time from onset of symptoms is 18 months.[6] The first recorded case was an Italian man, who died in Venice in 1765.[7]
