[ 18 F]FDG-PET/CT in Movement Disorders

Movement disorders are defined as neurologic syndromes in which there is either an excess of movement or a scarcity of voluntary and automatic movements, unrelated to weakness or spasticity [1]. Movement disorders are related to dysfunction of different nervous system structures involved in the modulation and regulation of movement. Among them the basal ganglia, cerebellum, cortex, and different thalamic nuclei represent the dynamic assembly that is differently impaired in movement disorder syndromes. The broad set of functions regulated by those neuronal circuits may explain the variability and richness of clinical signs in different domains expressed by patients with movement disorders. Different neurodegenerative or acquired central nervous system diseases that affect any part of this circuitry may cause movement disorders, which in many of the cases are of neurodegenerative nature. From a classification perspective, movement disorders are classified by the clinical phenomenology of the movement disorders (parkinsonian syndromes, tremor, chorea, myoclonia, dystonia, and ataxias) and are grossly subdivided in hypokinetic and hyperkinetic movement disorders.