Immediate Improvement of the Involuntary Movements with Methylphenidate. The patient executed the following tasks prior to and 30 minutes after methylphenidate hydrochloride administration: running, performing rapid alternating movements, pouring water into a cup, and writing a series of loops with her dominant hand. There was a significant reduction in her choreic movements and dystonic postures, especially in the limbs. All tasks were carried out faster and with more precision after receiving her medication.