Fatal Familial Insomnia
Fatal familial insomnia is an extremely rare disorder that affects the thalamus, a part of the brain responsible for sleep and emotion regulation. As a prion disease, abnormal proteins (called prions) accumulate in this part of the brain, ultimately leading to neuron death.
FFI is caused by a mutation in the PRPN gene. Most people with FFI have a family history of the disorder, but it can also occur sporadically among individuals without any known connection.
By their late 40s or 50s, people often begin experiencing symptoms such as change in sleeping patterns, anxiety, depression, changes in mood, psychiatric symptoms and difficulty controlling the autonomic nervous system (which regulates bodily functions such as blood pressure, heart rate, breathing temperature sweating urination and erectile dysfunction). They may also have difficulty moving or experience changes when walking.
Stage One (Up to 6 Months): Mood changes may take place and involuntary functions such as heart rate, blood pressure, breathlessness and breathing become difficult to regulate. They could become difficult to manage in combination with issues related to weight loss, fatigue or difficulty maintaining body temperature may worsen.
Phase Two (Lasts up to 3 Months): Disruptions to involuntary and semi-voluntary functions, such as sleep-wake cycles, can occur. At this point, someone suffering from fatal familial insomnia might lose all ability to speak or move, leading to a coma which usually ends in death.
In some cases, those suffering from fatal familial insomnia may be diagnosed through positron emission tomography (PET), which measures brain activity. These scans may reveal abnormalities in the thalamus and other parts of the brain associated with this disorder.