The Japanese Society of Child Neurology

Movement disorders, such as dystonia, chorea, myoclonus or mixed, are a frequent manifestation of inherited neurometabolic diseases. Proper characterization and classification of the movement disorders is crucial. The main diseases causing movement disorders include metal-storage diseases, neurotransmitter synthesis defects, energy metabolism disorders, and lysosomal storage diseases. The diagnostic work-up should be focused first on treatable condition, such as Glut1 deficiency or sepiapterin reductase deficiency. In this presentation, we briefly review inherited neurometabolic diseases causing movement disorders in children, and propose a simple diagnostic approach to guide metabolic investigations based on the clinical course of symptoms, the type of abnormal movements, and brain MRI abnormalities.