BACKGROUND AND METHODS: Fatal familial insomnia (FFI) is a rare genetic disease 
characterized by intractable insomnia, dysautonomia, and dementia. Herein we 
describe a patient with FFI. In order to study brain glucose hypometabolism in 
the patient, we used statistical parametric mapping (SPM) analysis of 
[(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET).
CASE REPORT: The patient was a 34-year-old Korean man. He presented with 
intractable insomnia, rapidly progressive dementia and autonomic disturbances. A 
comprehensive clinical investigation was conducted, including brain MRI, 
electroencephalography, polysomnography, neuropsychological tests, FDG-PET and 
genomic tests. SPM analysis was performed using 7 healthy controls. Direct 
sequencing of the PRNP gene identified a heterozygous p. Asp179Asn mutation 
homozygous for methionine at codon 129 and for glutamate at codon 219. The 
results of the SPM analysis showed marked hypometabolism in the deep cerebral 
nuclei (including the bilateral thalami, caudate nuclei, and hypothalamus), 
association cortices (including the frontal, lateral temporal, inferior parietal 
lobule and posterior cingulate gyri), and midbrain.
CONCLUSIONS: This is the first Korean report of FFI, in which the family showed 
male phenotypic predominance. The patient's SPM analysis demonstrated brain 
hypometabolism in the midbrain and the hypothalamus, as well as the thalami, 
caudate nuclei, and multiple cortical regions. These results contribute further 
to the overall understanding of the pathophysiology of FFI.