Fatal familial insomnia is a rare genetic disorder. It causes sleep problems and brain damage that eventually leads to death.
Although it is characterized by sleep problems, the disorder can cause a wide variety of other symptoms, such as muscle spasms and problems with memory and thinking.
A genetic abnormality causes deadly familial insomnia. Another condition called sporadic fatal insomnia is similar but occurs without the genetic difference.
This article describes fatal familial insomnia, including its symptoms, diagnosis, and treatment options.
Fatal familial insomnia is a rare condition that causes sleep problems and brain damage. These problems worsen over time.
It remains unclear how many people have fatal familial insomnia. It belongs to a group of health problems called prion disorders that affect about 1 in 1 million people each year.
Fatal familial insomnia stems from a genetic abnormality that leads to the death of neurons in the brain. It can also cause problems with functions such as body temperature regulation.
The primary symptom of fatal familial insomnia is difficulty falling asleep or staying asleep. When someone with the disorder sleeps, they may experience vivid dreams and muscle spasms or stiffness.
The hallmark lack of sleep and brain damage can cause a wide variety of other symptoms, including:
- to sweat
- a fever
- high bloodpressure
- a fast heartbeat
- weight loss
- sexual dysfunction
- a loss of temperature control
- memory problems
- difficulty thinking and concentrating
- speech problems
- seeing double or jerky vision
- mood or anxiety disorders
- difficulty swallowing
- muscle spasms or trembling
- a loss of coordination
The symptoms are usually mild at first. Ultimately, the condition can prevent sleep completely.
People with severe symptoms can go into a coma, which can lead to death.
Fatal familial insomnia results from an abnormality in the prion-related protein (PRNP) gene, which produces prion proteins. Researchers understand that these proteins are active in the brain, but their exact function is still unclear.
Mutation of the PRNP gene occurs in people with fatal familial insomnia. The mutation causes PRNP to produce defective or “misfolded” prion proteins.
These misfolded proteins damage the nervous system, including the brain. There is particular damage to the thalamus, a brain region that plays a role in regulating sleep, appetite and body temperature.
Over time, the misfolded proteins accumulate in the thalamus, causing the symptoms of deadly familial insomnia to develop and become increasingly severe.
Because fatal familial insomnia is so rare, there is little information about the risk factors.
Most people with the PRNP gene mutation begins to show symptoms around age 45-50.
A doctor first asks about the person’s symptoms, especially their sleeping habits.
They may ask the person to record their sleep patterns and any disturbances in a diary, as this information can help the doctor make a more informed diagnosis.
The doctor may also suggest a polysomnography test. This usually involves an overnight stay in a sleep center or hospital. During the night, doctors monitor brain activity, breathing, and eye or leg movements.
If they suspect fatal familial insomnia, a doctor may also use a PET scan, which records activity in the body’s tissues and organs. This type of scan can detect abnormalities in the thalamus.
In some cases, a doctor may use genetic testing to check for the trait PRNP gene mutation.
Fatal familial insomnia is so rare that doctors can’t detect every case. Some people with the disorder may be diagnosed with a more common condition, such as dementia.
There is currently no cure or effective treatment for fatal familial insomnia. However, it is possible to treat some symptoms. For example, a doctor may prescribe clonazepam (Klonopin) to treat muscle spasms.
Sleep medication may provide some temporary benefits. For example, eszopiclone (Lunesta) and zolpidem (Ambien) can help treat insomnia.
However, these drugs do not work in the long term.
People who develop fatal familial insomnia typically live 7 months to 3 years after symptoms appear, although some people live longer.
Symptoms are initially mild and may not affect daily activities.
As sleep problems worsen and other symptoms develop, these activities become more challenging. The doctor will recommend treatments for specific symptoms and other ways to improve the person’s quality of life.
During the later stages of the disease, a person may need regular care.
Fatal familial insomnia is a very rare genetic disorder. It causes sleeping problems and brain damage that becomes progressively more severe and leads to death.
The condition can cause a range of other symptoms, such as memory problems and difficulty swallowing.
There is currently no cure for fatal familial insomnia. However, there are treatments for specific symptoms, such as muscle spasms.
People with fatal familial insomnia usually live between 7 months and 3 years after symptoms become apparent.