Serial positron emission tomographic findings in an atypical presentation of fatal familial insomnia.

Background: Genetic analyses of fatal familial insomnia, a prion disease, disclose a broader range of symptoms than previously described. Although insomnia and dysautonomia have been described as hallmarks of the disease, there is substantial variability in clinical presentation.

Objective: To evaluate serial fluorodeoxyglucose positron emission tomographic and electroencephalographic findings in atypical fatal familial insomnia without clinical insomnia.