Fatal Familial Insomnia
When we talk about fatal familial insomnia we mean a very rare disease. Its frequency of appearance is extremely low and those who suffer from it have a history of the disorder in their parents or grandparents.
Although it is a hereditary pathology, it is also caused by prions. These are abnormal proteins that can cause disease. Both factors combine so that this prion capable of causing the disorder is transferred from parents to children.
As the name implies, fatal familial insomnia consists of the inability to sleep. The causative prions alter the patient’s circadian rhythm to the point of preventing him from ever falling asleep. In the long run, the mental and physical demands cause a kind of coma that ends in death.
Fatal familial insomnia is within the group of prion diseases called spongiform encephalopathies. Perhaps the most well-known disorder in the world has been mad cow disease, which has similarities with this disease in terms of its causes.
Patients are usually between 30 and 60 years old, which are the decades between which the prion is activated to generate symptoms. There are younger case records, but this is not normal. In some families it is suspected from the antecedents of other individuals.
Causes of fatal familial insomnia
As we have already anticipated, fatal familial insomnia is a prion disease. Prions originate from a DNA mutation that is ultimately expressed in a defective protein. If the prion attacks the neurons, then we have a spongiform encephalopathy, as is this case.
The mechanism is very similar to mad cow disease and Creutzfeldt-Jakob disease. In fatal familial insomnia, transmission is hereditary, from parents to children.
The gene altered for prion disease is identified and is called PRNP. The protein that is altered affects the thalamus area, which is the region that regulates a large part of the circadian rhythms, especially the sleep-wake cycle. The thalamus progressively degenerates and the result ends up being a coma.
Symptoms of the disease
The quintessential sign of fatal family insomnia is the inability to sleep. Even sleepy and tired, the patient cannot fall asleep. If he enters a period of drowsiness, he usually leaves it agitated, with hallucinations and with changes in the respiratory rhythm.
The persistence of this state leads to coma. The body needs the functions of sleep for the physiology of neurons and other cells to restart and remain healthy. The appearance of hallucinations, memory loss and behavioral changes are a consequence of this lack of rest.
The stress, of course, is extremely high. A person who does not rest one night already feels upset. Therefore, spending months without sleep cannot lead to a state of calm. In addition, the change in the circadian rhythm is coupled with an increase in the secretion of the hormone cortisol, which generates symptoms of stress.
How is fatal familial insomnia diagnosed?
Diagnosing fatal familial insomnia can be easy or difficult, depending on the patient’s family history. If a parent or grandparent has suffered from it, the suspicion will be well founded.
The patient consults at first due to insomnia, that is, due to the lack of ability to conciliate sleep. To this can be added the other symptoms of stress and memory loss. Your doctor will most likely order a sleep study first.
The next complementary method is positron emission tomography, which will be able to identify metabolic changes in the thalamus. The most frequent finding is a decrease in the metabolic activity of this region due to the degeneration that it entails.
In the field of genetics, gene identification is possible. Today, if a family has a history of fatal familial insomnia, children and grandchildren are screened for the mutation before signs appear.
The most serious insomnia of all
Fatal familial insomnia is a serious illness with no cure. It progressively evolves destroying the thalamus and causes a coma that leads to death. The quality of life of these patients is terrible in their last months of life.
As it is a rare and very rare disease, research on it does not enjoy many followers or large funding. However, there are research groups dedicated exclusively to finding treatments for these people.
