For a rare group of people, a scary disease called fatal familial insomnia (FFI), sleep deprivation can be fatal. When we lie awake chasing feverish thoughts, our thoughts slow down and tick off the passing minutes, which adds to the sleepless fear. Others suffer from persistent insomnia, but levels are usually manageable.
This article describes the fatal familial insomnia such as its symptoms and diagnosis. FFI is characterized by sleep disorders, but can also cause a variety of other symptoms, such as muscle spasms and memory and thinking problems. The condition, known as sporadic fatal insomnia, is similar to those that occur naturally due to genetic differences. A doctor who monitors brain activity during sleep can diagnose fatal familial insomnia. Symptoms The primary symptom of this sleep disorder is difficulty falling asleep and sleeping through. Fatal familial insomnia is a sleep disorder in which someone experiences vivid dreams, muscle spasms and stiffness.
Deadly insomnia is a rare sleep disorder and disease caused by an inherited, familial, spontaneous or sporadic mutation in the prion protein gene. The cause and risk factors for fatal familial insomnia develop due to an abnormality in a prion protein (PRNP) gene. Deadly insomnia can affect the entire brain because it affects parts of the brain that control the sleep-wake cycle apart from the prions.
Deadly insomnia is a rare disorder that leads to insomnia, which is its characteristic symptom. Diagnosis is usually based on symptoms supported by sleep studies, PET scans, genetic testing and if the patient has a family history of fatal insomnia.
Clinical diagnosis of a prion disease in a patient with signs of neurodegenerative disease is supported by paying particular attention to aspects of the patient’s medical history, including travel, past surgeries, disease family history and possible changes in the patient’s sleep patterns. Similar to other prion diseases, the diagnosis is confirmed by an autopsy of the brain. Microscopic and biochemical examinations of brain tissue are the gold standard. Companion tests for suspected prion diseases include EEG and MRI measurements of CSF and 14-3-3 proteins, but these tests are not detected in the case of SFI.
Sporadic fatal insomnia takes its name from the fact that it can lead to death within one to two years of the onset of symptoms. It has been described as a rare form of prion, but its clinical phenotype is similar to that of known familial fatal insomnia. What researchers do know about sporadic fatal insomnia is that it does not appear to be genetic.
Deadly insomnia is a Prion disease with symptoms including insomnia, mental deterioration and loss of coordination. Fatal familial insomnia (FFI) is an inherited human prion disease that is caused by a mutation in codon 178 of the proteogénéric (PRNP) prion gene on chromosome 20. FFI is a rare autosomal dominant disease with the PRNP-D178N, 129M mutation, which is the third most common inherited prion disease.
Diagnosis of fatal familial insomnia (FFI) can be difficult, especially if the disease does not occur in the family. Pronounced motor over activation and rapid REM sleep can lead to a misinterpretation of FFI as REM sleep behavioral disorder (RBD).
The brain is a structure that controls many important things, including emotional expression and sleep. FFI can cause a number of other symptoms, such as speech problems and dementia. The earliest description of FFI dates back to 1765, with an account of an Italian gentleman showing symptoms that indicate the disease.
The disease was identified in 1986 by Lugaresi E. et al. Followed by later studies describing its pathophysiology, etiology and clinical course. A rare sporadic form of human prion disease exhibits clinical and histopathological characteristics identical to FFI and sporadic fatal insomnia (SFI), as mentioned above, and is transmitted, like FFI, by transgenic mice expressing wild-type human PRP.
Although sporadic fatal insomnia has been described as prion disease, only a limited number of case reports have been published in the literature. For example, a unique and proven case of a woman with progressive cerebellum deterioration over an 18-month period. Western blot analysis confirmed the presence of an abnormal protease-resistant prion protein (PRPSP) characteristic of SFI. Clinicians should be aware of this disease and consider the importance of autopsy for this unusual neurological disorder.
Improving awareness and knowledge of sleep disorders, a major symptom of fatal familial insomnia (FFI), will improve the accuracy of FFI diagnosis and understanding of its pathophysiology. Another example would be a patient with severe sleep loss associated with generalized motor hyperactivation (agrypnia excitata) and low atonia index who was diagnosed with FFI by genetic testing.
In four out of eleven (23%) patients, an autopsy of the brain was performed, which is indispensable to rule out thalamus atrophy characteristic of FFI, but the histology of the thalamus was not described. Research laboratories continue to investigate prion diseases, and clinical trials are testing a drug called quinicrin that holds promise in the treatment of some of these diseases. The same research could also have benefits for common diseases such as Alzheimer’s and Parkinson’s.