[Gerstmann-Sträussler-Scheinker disease].

Prion diseases are a group of rare neurodegenerative diseases with a challenging diagnosis due to their phenotypic heterogeneity. One of the genetic forms of prion proteopathies is Gerstmann-Sträussler-Scheinker disease (GSSD). The article presents a clinical case of a patient with progressive cerebellar ataxia and mild cognitive and behavioral disorders who has been verified as having GSSD. The specific feature of the case was the use of positron emission tomography with 18F-fluorodeoxyglucose to identify regional metabolic disorders in the basal ganglia and cerebellum before the appearance of MRI changes and apparent clinical manifestations. The challenges of differential diagnosis with other neurodegenerative diseases associated with cognitive and cerebellar disorders, as well as the relevance of considering prion diseases in this differential diagnosis, are discussed.