An MSA-P patient presenting with preserved glucose metabolism in the putamen, cerebellar hypometabolism and pronounced loss of presynaptic dopamine transporter in the striatum

Positron emission tomography (PET) of the brain using [18F]fluorodeoxyglucose (FDG) is becoming increasingly important for the diagnosis and differential diagnosis of atypical parkinsonian syndrome such as multiple system atrophy (MSA), which is characterized by hypometabolism of the putamen, pons, and cerebellum. We report on a patient with clinically established MSA based on a rapidly progressive, poorly levodopa-responsive parkinsonian syndrome, multidomain autonomic failure, and imaging findings where hereditary spastic paraplegia was discussed as a differential diagnosis. PET images revealed a well-preserved glucose metabolism in the striatum, specifically in the putamen, while metabolism in the cerebellum was significantly reduced. This pattern of glucose metabolism might indicate a distinct subtype of synucleinopathy as proven by seed-amplification assay and should be taken into account when diagnosing patients with MSA.