Juvenile-onset Huntington's disease - Spectrum and evolution of presenting movement disorders.

Juvenile-onset Huntington's disease (HD) is a rare subset of HD with symptom-onset before the age of 18. In contrast to the adult population, children present early-on with behavioral, psychiatric, and cognitive symptoms, in addition to a diverse spectrum of movement disorders. This poses a distinct challenge in diagnosis and management. We here describe the spectrum of movement disorders, accompanied with detailed video recordings, in seven cases of juvenile-onset HD. Our findings highlight early cognitive and behavioral symptoms, preceding motor symptoms. The diverse movement disorder phenotypes included dystonia, Parkinsonism, myoclonus, and chorea, findings which underscore the heterogeneity of presenting symptoms.