Fatal Familial Insomnia: What to Know About FFI

Fatal familial insomnia (FFI) robs people of their sleep. And because there is no cure, the disease eventually takes their life.

fatal familial insomnia

Fatal familial insomnia (FFI) is an inherited prion disease that, as the National Institutes of Health notes, affects the brain and other parts of the nervous system.

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Insomnia takes on many forms and has many causes. For some people, stress or depression keeps them from getting a good night’s sleep. For others, the problem is prescription medication or too much caffeine. And for many people, advancing age, an underlying medical condition like Parkinson’s disease, or just poor sleep habits are to blame.

But in extremely rare cases, a brain condition known as fatal familial insomnia (FFI) robs people of their sleep. And because there is no cure, the disease eventually takes their life. Fatal familial insomnia is an inherited condition, while a related disease called sporadic fatal insomnia has no genetic component. Fewer than 100 people worldwide are known to have the disease.

What Causes Fatal Familial Insomnia?

Both fatal familial insomnia and sporadic fatal insomnia are among a group of conditions known as prion diseases. This is because they are diseases that affect prion proteins, which are found throughout the brain. People with the disease have a mutation in the gene responsible for manufacturing prion proteins. This mutation leads to the formation of abnormal prion proteins, which clump together in the brain and damage healthy neurons.

In the case of fatal familial insomnia, the gene is passed from one or more parents to their child. With sporadic fatal insomnia, the prion proteins spontaneously change into the unhealthy versions. It’s unknown how or why this happens.

Fatal Familial Insomnia: Symptoms and Diagnosis

Unlike other prion diseases that can affect various regions of the brain, fatal familial insomnia and sporadic fatal insomnia primarily affect one part of the brain—the thalamus. This is the part of the brain that helps control your sleep/wake cycles. These conditions damage the thalamus to the point at which the brain remains in a state of wakefulness.

Symptoms often develop gradually. You may have increasing difficulty falling or staying asleep. You may twitch or kick involuntarily while you sleep. Eventually, sleep becomes impossible.

As you know, sufficient sleep is vital for the health of your brain and the rest of your body. It’s necessary for the memory and cognitive functions of the brain to operate normally. Sleep also plays an important role in energy conservation and the regulation of hormones and our metabolism.

The physical and psychological symptoms of fatal familial insomnia and sporadic fatal insomnia include panic attacks and hallucinations, an accelerated heart rate, excessive sweating, and wild mood swings. As the diseases advance, weight loss and dementia occur. A patient with fatal insomnia may become mute toward the end of his life.

Death may come within a year of symptoms developing or it may take up to five or six years, depending on how quickly the disease progresses. Usually, fatal familial insomnia and sporadic fatal insomnia develop in adulthood, between the ages of 30 and 50.

Diagnosing the problem starts with a doctor’s review of symptoms. Fatal familial insomnia can be identified through genetic testing. Sporadic fatal insomnia involves a sleep test that measures electrical and muscular activity in the body while sleeping (or trying to sleep), and positron emission tomography (PET). PET scans can provide detailed images of how an organ, such as the brain, is working.

Fatal Familial Insomnia Treatment

Sadly, there is little doctors can do to treat fatal familial insomnia or sporadic fatal insomnia. Medications to help patients sleep have only mild, temporary effects. They usually cannot slow down the progress of the disease. In some cases, sedatives have worsened symptoms.

In one case, doctors tried to induce a coma in an Illinois man with fatal familial insomnia, but they found that the brain activity associated with wakefulness was still going on.

The greatest hope for a cure lies in gene therapy. This can involve replacing a mutated gene with a healthy copy of that gene or targeting a mutated gene and preventing it from causing more damage. Gene therapy research also looks at how a new gene can be given to a patient to fight a disease.

It may be some time before such treatments are possible, but research is ongoing. And anyone who is part of the few dozen affected families is encouraged to undergo genetic testing before having children.


Originally published in 2016, this post is regularly updated.

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Jay Roland

Jay Roland has been executive editor of Massachusetts General Hospital’s Mind, Mood & Memory since 2017. Previously, he held the same position with Cleveland Clinic’s Heart Advisor, since 2007. In … Read More

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