PET/CT in Movement Disorders: Update.

This review synthesizes recent literature, primarily from the last 5 years, to highlight the impact of innovative technologies and analytical approaches on the application of positron emission tomography (PET) in movement disorders. PET remains a cornerstone for investigating these conditions, with recent advancements enhancing our understanding of disease pathophysiology and progression. Established findings, such as the ability of [F]-fluorodeoxyglucose PET (18F-FDG PET) to differentiate Parkinson's disease (PD) from atypical parkinsonian syndromes based on characteristic metabolic patterns, have been consistently validated. PD typically presents with relative hypermetabolism in the basal ganglia, thalamus and cerebellum, while atypical parkinsonisms exhibit more widespread subcortical hypometabolism. Technological innovations, particularly in quantification methods and metabolic connectivity analysis, have improved diagnostic precision and provided deeper insights into disease mechanisms. Dopaminergic PET imaging, crucial for assessing presynaptic and postsynaptic dysfunction, has also benefited from these advances. The field is further evolving with the development of novel tracers targeting pathological hallmarks, such as alpha-synuclein in PD and multiple system atrophy (MSA), tau in progressive supranuclear palsy (PSP) and cortico-basal degeneration (CBD), and tracers for neuroinflammation, microglial activation, and neurotransmitter systems like serotonin and acetylcholine. While PET is not yet routinely used for the clinical assessment of Huntington's disease or ataxia, research applications are expanding, driven by the potential of these new tracers and analytical techniques. These advancements not only reinforce existing knowledge but also open new avenues for enhancing the understanding and management of movement disorders.