Fatal familial insomnia is one of the rare but horrifying neurodegenerative illnesses. It is inherited familial disease caused by mutation in the gene responsible for formation of normal protein in brain into prion protein or the abnormal protein. This protein causes damage in the thalamus, a part of brain which mainly controls sleep and wake cycle.
The symptom of fatal familial insomnia begins in twenties and thirties and gradually progresses. Persistent and progressive sleep disruption leading to insomnia is the salient hallmark of this condition. Patient also suffers from other symptoms such as weight loss, loss of appetite, memory loss, etc. There is no cure for fatal familial insomnia. Hence the main aim is to slowdown the progression of disease with possible supportive measures.
What Causes Fatal Familial Insomnia?
Fatal familial insomnia (FFI) is a rare form of neurodegenerative disease. It is a genetically inherited prion disease. Almost all cases are caused due to mutation in PNRP gene, inherited from a parent.
The normal protein in the brain in certain parts changes into abnormal protein. This abnormal protein gets accumulated in the thalamus part of brain because it is resistant to enzymetic breakdown. Too much accumulation of this protein results into brain damage. Prion diseases have long progression which results in neurological damage with fatal outcome.
In fatal familial insomnia the thalamus part of brain gets damaged. Thalamus is important part of brain which has several functions to play. One such important function is managing sleep wake cycle. Progressive death of thalamic cells will hamper its function. In very rare cases FFI can be sporadic in origin. In sporadic version there is no change observed in PNRP gene and hence the disease does not pass down to the children.
Symptoms Of Fatal Familial Insomnia
Fatal familial insomnia begins between the age of 32 to 70 years. It has a long incubation period. The early symptom of FFI can be lethargy and tiredness. Sometimes dementia can be early symptom. But the hallmark of this disease is long standing insomnia. Patient experiences difficulty in falling asleep or staying asleep for several hours. This is often accompanied with twitching of muscles, muscle spasm and stiffness.
Because person is not able to sleep, he moves here and there in his bed. Later on patient also suffers from other symptoms such as weight loss, lack of appetite, low or high body temperature, panic attacks etc. Excessive sweating, erectile dysfunction, hallucination, confusion, muscle twitching, frequent jerks, memory loss, often accompany the main symptom of insomnia.
Diagnosis And Treatment Of Fatal Familial Insomnia
Diagnosis of fatal familial insomnia is made by the doctor after taking proper medical history, evaluation of symptoms and certain tests. History of insomnia for a long time, frequent memory loss and attention, mood changes and repeated jerks gives the hint to the doctor of this dreaded condition. The doctor also inquires for any family history of fatal familial insomnia. To confirm the diagnosis further the doctor recommends patient to undergo certain tests which include PET scan of the thalamus area. Changes are noted in thalamus. Further confirmation of diagnosis is made by genetic testing.
There is no particular treatment that can cure fatal familial insomnia. The main aim is to manage the symptoms and make the patient as comfortable as possible. Gene therapy is not successful. Research is going on to find the effective treatment. The prognosis of fatal familial insomnia is not encouraging. After the symptoms have developed, patient usually dies within 12 to 18 months period.