Can insomnia be fatal?
Fatal insomnia is an extremely rare sleep disorder disease that’s caused by either an inherited (familial) or spontaneous (sporadic) mutation in the prion protein gene. The disorder affects the part of the brain that controls the sleep-wake cycle. Eventually, the disorder will affect the whole brain; it just involves the part that controls sleep-wake earlier than other prions.
Prion diseases are rare progressive, fatal and currently untreatable degenerative disorders of the brain (and rarely of other organs) that occur when a protein changes into an abnormal form called prion.
Fatal Familial Insomnia (FFI) is more common than sporadic cases. FFI is considered autosomal dominant, which means that if you inherit the gene you’re very likely to develop the disease at some point in time. The age at onset is unpredictable but on average around 50 years of age.
Fatal insomnia causes the rapid progressive loss of nerve cells with the earliest symptom being insomnia. It’s closely related to Creutzfeldt-Jakob disease (CJD) but with the loss of nerve cells is distributed differently with different initial symptoms.
Signs and symptoms of fatal insomnia
Initially, a person might have mixed symptoms of daytime fatigue and sleepiness and the inability to fall asleep and stay asleep. As the disease progresses, a person will experience behavioral and personality changes, abnormal body movements, vision changes, difficulty walking and maintaining consciousness.
Fatal insomnia is difficult to diagnose initially. Some patients can be diagnosed with spinal fluid studies, others can be diagnosed with clinical signs and imaging findings. Some, ultimately, are diagnosed after having a brain biopsy or through an autopsy after they die.
Fatal insomnia is typically a genetic condition and very rarely due to a sporadic mutation. It's considered transmissible in vitro, but there haven’t been any human cases.
Jesse Mindel, MD, is an assistant clinical professor at The Ohio State University Wexner Medical Center who specializes in Neurology and Sleep Medicine.