Follow-up multimodal changes on PET/MRI in fatal familial insomnia patient: a case report.

BACKGROUND

Fatal familial insomnia (FFI) has an insidious onset and the typical clinical presentation includes sleep disorders and autonomic dysfunction, making early diagnosis challenging. We present the radiological changes observed in 18F-FDG PET/MRI from onset to advanced stages of FFI.

CASE PRESENTATION: A 42-year-old woman underwent 18F-FDG PET/MRI due to sleep disorders and autonomic dysfunction. 18F-FDG PET/MRI showed decreased glucose metabolism in the bilateral frontal cortex, head of the caudate nucleus, and thalamus, whereas no abnormalities were detected on T1WI, FLAIR, and DWI. Three and a half months later, the patient's symptoms worsened, and 18F-FDG PET/MRI showed a further decline in glucose metabolism and involvement of the bilateral parietal cortex and putamen. Finally, genetic testing confirmed the diagnosis of FFI.

CONCLUSIONS

18F-FDG PET/MRI may provide valuable supportive information in cases of suspected FFI, particularly by revealing characteristic glucose metabolic patterns that complement clinical findings.