What Is Fatal Familial Insomnia (FFI): Symptoms, Causes and Treatment

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There is a rare genetic condition that literally robs some people of the ability to get sleep. The rare disease is known as fatal familial insomnia (FFI), and it usually leads to a quick demise for anyone who develops it.

Imagine suddenly not being able to sleep. And no, we’re not talking about an occasional bout of insomnia or even the level of chronic sleep deprivation that most of us consider normal in modern society. Rather, consider being awake 24/7 for months and completely unable to fall asleep even for a few minutes.

Though it may sound scary or even impossible, there is a rare genetic condition that literally robs some people of the ability to get sleep. The rare disease is known as fatal familial insomnia (FFI), and it usually leads to a quick demise for anyone who develops it.

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What is Fatal Familial Insomnia?

FFI is an extremely rare disorder that’s passed down through families. The disease affects the area of the brain where many important functions, such as sleep and emotional expression, are controlled, known as the thalamus. Though the main symptom of FFI is insomnia, it can also lead to other symptoms like dementia and speech problems.

And what’s even scarier is that there’s an even more rare variant known as sporadic fatal insomnia. The good news is that as of 2016, there have only been 24 documented cases of this condition. Still, researchers know very little about this disorder, except that it’s probably not genetic.

Fatal familial insomnia gets its name in part due to the fact that most people die within two years of developing symptoms. However, this timeline varies between people. FFI is part of a family of conditions referred to as prion diseases. Prion diseases are rare conditions that lead to the loss of nerve cells within the brain. Creutzfeldt-Jakob disease and kuru are other prion diseases, but FFI is considered the rarest of all. According to Johns Hopkins, the United States has only about 300 cases of prion diseases each year.

What are the Causes of Fatal Familial Insomnia?

It’s vital to note that even though FFI contains the word insomnia, it’s not a sleep disorder – it’s a prion disease. Hence, the condition is caused by a malfunction of proteins found within the brain. Some of these diseases are genetic, such as FFI, but others can be caused by infections.

In people with FFI, it’s been found that a mutation to the PRNP gene is what causes prion malfunction. The mutation takes place in the sperm or egg that forms the baby. In most cases, the mutation is passed down to the child from a parent. However, the gene can spontaneously mutate in rare cases.

The PRNP gene is important because it controls PrP protein creation. Experts don’t quite know exactly what this protein does, but when this gene mutation is present, the proteins are formed in incorrect shapes, which are toxic to your body. This malformed protein then builds up in the thalamus region of your brain over time and damages it.

The thalamus controls how you eat and sleep and regulates body temperature, so this damage that occurs begins to impact these processes for people suffering from FFI. The mutation that causes fatal familial insomnia is considered an autosomal dominant mutation, so you only need one copy of the gene to get the disease. If you have the PRNP mutation, you have a 50 percent chance of passing FFI onto your child with each pregnancy.

Affected Populations

Fatal familial insomnia is extremely rare, and the exact prevalence and incidence of the condition are unknown. SFI, or sporadic fatal insomnia, is even rarer and has only been found in around 24 patients. However, collectively, prion disorders only affect about one person per one million people each year.

It’s estimated that genetic prion disorders are thought to be present in about 15 percent of those with prion diseases. Yet, since rare diseases often go misdiagnosed or undiagnosed, it’s challenging to determine how often it actually happens in the general population.

Fatal familial insomnia has been noted in populations worldwide. What is known is that FFI affects women and men in equal numbers. Though some patients have been diagnosed in their teens or elderly years, the average age of onset is between 45 and 50 years old.

What Are the Symptoms of FFI?

As we mentioned, fatal familial insomnia symptoms usually appear between the ages of 40 to 60. Symptoms begin mild but worsen quickly. Among the first symptoms that people notice is difficulty sleeping or insomnia, which can also be accompanied by trouble focusing and confusion. This insomnia will worsen over time, and other symptoms will probably begin to appear. FFI symptoms can include:

  • Rapid heartbeat
  • Difficulty managing body temperature
  • High blood pressure
  • Unintentional weight loss
  • Double vision
  • Vivid dreams when sleep occurs
  • Hyperhidrosis (excessive sweating)

As fatal familial insomnia progresses, more severe symptoms can begin, such as:

  • Delirium
  • Ataxia (difficulty controlling movement)
  • Dysphagia (difficulty swallowing)
  • Hallucinations

Unfortunately, most symptoms that appear after insomnia are caused by sleep deprivation. Since it’s such a severe illness, most people with FFI die within six to 36 months once symptoms begin. Most of these deaths are caused by infection or heart problems that were brought on by the underlying disease.

How is FFI Diagnosed?

If you think you have FFI, your healthcare provider will begin by asking you to keep detailed notes about your sleep schedules for a set period of time. They may even have you join a sleep study, which involves sleeping at a sleep center or hospital while doctors record data about your heart rate, brain activity, and more. This is an excellent option for ruling out other causes of sleep issues like narcolepsy or sleep apnea.

After the initial phases, the next step will be to undergo a PET scan. This imaging test will give your doctor a good idea if your thalamus is functioning correctly. The other thing that helps diagnose FFI is genetic testing. However, it’s important to note that in the U.S., you must have a family history of FFI or present evidence that strongly suggests you have FFI to get this testing done. Furthermore, if your family has a confirmed case of FFI, then you are also eligible to undergo prenatal genetic testing.

Fatal Familial Insomnia Treatment Methods

Currently, there is no cure for FFI, but there are a few treatments that effectively manage symptoms. For example, sleeping pills offer temporary relief for some but don’t work as a long-term treatment.

At this time, researchers are actively working toward finding preventative and treatment measures for FFI. Some past studies have suggested immunotherapy, but more research and human clinical studies are required to learn more. Another recent study was conducted that involved the use of the antibiotic doxycycline. Some researchers believe this medication may effectively prevent fatal familial insomnia in those who carry the PRNP mutation.

That said since there is no cure, FFI treatment focuses on relieving the person’s symptoms. Because this disease is so rare, there’s currently not even a standard protocol for managing symptoms. Most patients work with a team of doctors that includes psychiatrists, neurologists, social workers, and other professionals who can address symptoms.

Treatment options can include:

  • Eating a healthy, balanced diet
  • Taking vitamins and supplements
  • Speaking with a therapist
  • Changing or stopping medications that make it worse
  • Using melatonin, sedatives, or antipsychotics to sleep


To prevent other members of your family from coming down with FFI, doctors may recommend everyone undergo genetic testing. Because FFI doesn’t appear until middle age, if genetic testing isn’t done, family members may pass it on before they know they carry the gene mutation.

Why is Sleep Important?

With all this talk about insomnia, is sleep that important? Yes! As you sleep, your brain shrinks by nearly 20 percent. During this process, it rids the toxins and trash left over from your day. So, all of that work you did, those decisions you made, and the anxiety you experienced exercised your brain, as all those things require energy.

What most people don’t realize is that the brain is the body’s most metabolically active organ. Your brain consumes nearly one-third of your energy and creates waste byproducts in doing so. It’s thought that sleep is the process that cleans it all up. For this reason, sleep is a much more complex process than most of us believe, and it’s very much a cleaning time for your brain. When someone is suffering from FFI or can’t sleep for other reasons, these toxins build up. Over time, this build-up can cause severe cognitive consequences.

In fact, as researchers have spent considerable time looking into sleep, they’ve realized that a lack of sleep is associated with many health conditions, especially those within the brain. One such condition is Alzheimer’s, which is eerily similar to FFI in that they are both degenerative and progressive neurological disorders that cause symptoms similar to dementia.

The other thing these two conditions share is that they both cause a build-up of waste byproducts and proteins in the brain. Hence, when these conditions are present, the waste is not cleaned up in the brain as it should be, which leads to neuron damage. The main difference between Alzheimer’s and FFI is that fatal familial insomnia progresses much faster. Additionally, Alzheimer’s is not a prion disease and is far more common.

When to See a Doctor for Fatal Familial Insomnia

Though it’s not likely that your insomnia is FFI unless there’s a family history, it’s always a good idea to speak with your doctor if you have prolonged trouble sleeping. This is especially true if you are also having problems with motor control or confusion. Either way, stay calm and call your doctor because these symptoms can also be signs of other illnesses.

Living With FFI

At the end of the day, it can be years before FFI symptoms appear. However, once they begin, they do progress quickly, often over the course of one or two years. As we mentioned, there’s lots of ongoing research about potential cures and treatments for FFI, but as of now, most patients get temporary relief with the help of sleeping aids.


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