The stages of dyskinesia that develop from treatment with levodopa include peak dose and diphasic dyskinesia, and on-state and off-state dystonias, according to PubMed Central. Tardive or chronic dyskinesias develop with long-term treatment with antipsychotic drugs, such as haloperidol, adds MedlinePlus.
Dystonias are the second most common form of levodopa-induced dyskinesias, informs PubMed Central. Individuals begin levodopa treatment with low doses and gradually increase the dose to a therapeutic level. These movements are characterized as sustained muscle contractions that occur as plasma levodopa levels change throughout the day. On-state dystonias occur when plasma levels are high, such as evening times, whereas off-state dystonias occur when plasma levels are low, such as during the mornings.
Diphasic dyskinesia similarly occurs during changes in plasma levels of levodopa, adds PubMed Central. Diphasic dyskinesias produce involuntary movements in the upper arms when plasma levels of levodopa are rising or falling but not when levels reach the peak dose. Additionally, diphasic dyskinesias do not improve with reduced levodopa doses.
Conversely, peak-dose dyskinesias produce movements in the upper half of the body, including the head, trunk and limbs, advises PubMed Central. These movements occur when levodopa levels plateau, but do not occur when plasma levels are rising or falling. Additionally, peak-dose dyskinesias can improve with a reduced drug dose.