<unk>  is an extremely rare genetic (and even more rarely, sporadic) disorder that results in trouble sleeping as its hallmark symptom. The problems with sleeping typically start out gradually and worsen over time. Other symptoms may include speech problems, coordination problems, and dementia. It results in death within a few months to a few years.<unk>  is a prion disease of the brain. It is usually caused by a mutation to the gene encoding protein PrPC. It has two forms:<unk>  familial<unk>  (FFI), which is autosomal dominant and sporadic<unk>  (sFI), which lacks the gene 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.<unk>  has no known cure and involves progressively worsening<unk> , which leads to hallucinations, delirium, and confusional states like that of dementia, until the patient slips into a stupor and eventually dies. The average survival time from onset of symptoms is 18 months. The first recorded case was an Italian man, who died in Venice in 1765.
Fatal insomnia
Transmissible spongiform encephalopathy
Excited delirium
Frontotemporal dementia
Masked depression
Alzheimer's disease
Suicide crisis
Transient epileptic amnesia