

Fatal Insomnia

By Pierluigi Gambetti, MD

Fatal insomnia is a rare prion disease that interferes with sleep and leads to deterioration of mental function and loss of coordination. Death occurs within a few months to a few years.

Fatal insomnia has two forms:




The familial and sporadic forms typically begin between the ages of 30 and 50 years.


At first, people may have minor difficulties falling asleep and occasional muscle twitching, spasms, and stiffness. During sleep, they may move a lot and kick. Eventually, they cannot sleep at all. Often, the sleep problems are difficult to detect.

Later, mental function deteriorates and coordination is lost (called ataxia). The heart rate may become rapid, blood pressure may increase, and people may sweat profusely. Death usually occurs 7 to 73 months after symptoms begin.


  • A doctor's evaluation

  • For the familial form, genetic testing

  • For the sporadic form, polysomnography and positron emission tomography


To diagnose the sporadic form, doctors use polysomnography if the person has a history of sleep problems. Positron emission tomography (PET) is also done to check for abnormalities in the thalamus.


No treatment is available. Measures to help people sleep have been tried, but the benefits were only temporary.