[Early-onset Parkinsonism. A report on a Spanish series].

Introduction: Early-onset Parkinsonism is a condition that has received little attention from researchers due to its low incidence and prevalence. We conducted a retrospective, cross-sectional, multi-centre study in order to obtain a representative sample of the Spanish population.

Patients And Methods: The study involved 92 Spanish patients who had been diagnosed with idiopathic Parkinson's disease that began before the age of 40 years and these patients were divided into two groups: group 1, which consisted of 86 patients, with an age at onset of between 21 and 40 years (early-onset Parkinsonism), and group 2, with an age at onset of below 21 years, which included a total of 6 patients (juvenile Parkinsonism).