Figure 1: Relationship between LID and DOPA plasma level. “Peak of dose” or “on” period dyskinesia is correlated to high level of levodopa and in parallel with the maximal clinical benefit. Diphasic dyskinesia appears at the onset and offset of the levodopa effect in relationship with increment or decrement of plasma level. “Off” period dystonia is characterized by painful postures in lower extremities and is correlated with the lowest levodopa level. Generally a full spectrum of the three types is present in patients with motor fluctuations.