Clinical observations in early and late onset Parkinson's disease.

The present study compares 30 patients who developed idiopathic Parkinson's disease (PD) at the age of 48 years or younger and 47 patients who developed the disease at the age of 68 years or older. PD patients with early onset had rigidity and bradykinesia as the predominant features at onset and during the course of the illness. In contrast older onset patients exhibited more often tremor at the beginning while later in the course most of them developed the full triad of symptoms i.e. tremor-rigidity-bradykinesia. In spite of such differences the overall disability status did not differ between the two groups of patients. An additional observation was that the early onset patients were apter to show earlier and more often abnormal movements and response fluctuations related to the L-Dopa therapy.