Basal ganglia Classification of Movement and Cerebellar Disorders Movement disorders are commonly classified as those with Decreased or slow movement (hypokinetic disorders) Increased movement (hyperkinetic disorders) The classic and most common hypokinetic disorder is Parkinson disease Hyperkinetic disorders refer to Tremor Myoclonus Dystonia Chorea (including hemiballismus [rapid chorea] and athetosis [slow chorea]) Tics Stereotypies Akathisia Restless leg syndrome However, this classification does not account for overlap between categories (eg, tremors that occur in Parkinson disease).