Fatal familial insomnia

Fatal familial insomnia is an autosomal dominant inherited, non-infectious brain disease. It is caused by prions, similar to Creutzfeldt-Jakob Disease and Bovine Spongiform Encephalopathy. A certain protein is altered (asparagine-178 is replaced by aspartic acid), causing amyloid plaques in the thalamus, the region of the brain responsible for sleep. The dysfunction of the thalamus results in insomnia.

The age of onset is variable ranging from 18 to 60. The presentation of the disease varies considerably from person to person, even among patients from within the same family. Common symptoms and signs include

• intractable insomnia
• dysfunction of the autonomic system - causing hyperthermia, hypertension, tachycardia, tachypnea and hyperhydrosis
• dementia
• motor paralysis.

As with other prion related diseases, this disease is ultimately fatal and incurable.

There is no known cure; hopes rest on the so far unsuccessful gene therapy.