The history of a complex disease: In 1817, the English physician James Parkinson first described the condition that now bears his name in "An Essay on the Shaking Palsy." Tremor and movement disorders (akinesia) had been known for a long time, but Parkinson recognized that the symptoms were part of a single disease. About 50 years later, Jean-Martin Charcot in Paris completed the clinical picture and also conducted initial therapeutic trials. Numerous researchers and doctors have since worked on understanding and treating the disease. A significant advancement was made in Vienna by Oleh Hornykiewicz, who demonstrated a severely reduced level of the neurotransmitter dopamine in certain brain areas of affected individuals. This was followed by the application of the precursor substance L-Dopa by Oleh Hornykiewicz and Walther Birkmayer in Vienna.