Motor fluctuations and dyskinesias in advanced/end stage Parkinson's disease: a study from a population of brain donors

Motor fluctuations and dyskinesias are considered one of the most important problems in the long-term management of Parkinson’s disease. However, only a few studies have examined the characteristics of motor fluctuations and dyskinesias in advanced and end stages of the disease. Here, the authors assess both motor fluctuations and dyskinesias in 61 patients with advanced or end stage Parkinson’s disease. A total of 62.3% of patients experienced wearing-off phenomena, 68.9% on-off motor fluctuations and 60.7% dyskinesias, but a substantial number of patients experienced a spontaneous resolution of their motor complications during the last two years of their disease without treatment modifications. Both age at onset and disease duration were associated with dyskinesias. The authors conclude that the heterogeneity of motor fluctuations reveal a complex series of pathological mechanisms, and that although disease duration and levodopa administration are closely tied to their development, synaptic aging, altered neuronal plasticity and post-synaptic degeneration may also be involved.