People who have died of fatal familial insomnia show evidence of degeneration in the

People who have died of fatal familial insomnia show evidence of degeneration in the thalamus.
Thalamus is the part of the brain which has to do with relaying sensory and motor signals to your body, as well as regulating consciousness, sleep, and alertness. Given that these people died of insomnia, it means that something was wrong with their regulation of sleep, which is the job of thalamus.