Some patients with Parkinson’s disease, especially in the middle and late stages, may develop tardive dyskinesia, or dance-like involuntary movements, and a few patients may develop myoclonus, myotonia, and dystonia. The former is the most common, and can involve the head, face, extremities, and trunk. There are three types of heterokinesia: 1. Dose peak heterokinesia: appears during the expiration date of the drugs taken to treat Parkinson’s disease. 2, biphasic isokinetic disorder: appears at the beginning of taking the drug and at the end of the drug effect. 3. Dystonia: often manifests as painful spasms of the lower legs and feet, most of which occur in the morning before taking the medication.