Neuro‐ophthalmological findings in early Fatal Familial Insomnia

Fatal familial insomnia (FFI) is a rare inherited prion disease characterized by sleep, autonomic and motor disturbances. Neuro-ophthalmological abnormalities have been reported at the onset of disease, though not further characterized. We analyzed video recordings of eye movements of six FFI patients from three unrelated kindreds, seen within six months from the onset of illness. Excessive saccadic intrusions was the most prominent finding. In patients with severe insomnia, striking saccadic intrusions are an early diagnostic clue for FFI. The fact that the thalamus is the first structure affected in FFI also suggests its role in the control of steady fixation. This article is protected by copyright. All rights reserved.