The degeneration of nigrostriatal dopamine neurons in the human brain is known to be the

primary pathology of Parkinson’s disease (PD) and underlies the profound motor

syndrome associated with the disease, involving bradykinesia, rigidity and tremor. The

discovery in the 1950s that administration of the dopamine precursor L-3, 4-dihydrox-

yphenylanaline (L-DOPA) could reverse a similar dopamine-denervation syndrome in

experimental animals (1) rapidly led to the clinical application of L-DOPA. When

administered orally, together with the peripheral decarboxylase inhibitor carbidopa,

L-DOPA proved an effective therapy for this previously untreatable condition. Subsequent

innovations have increased the potency and efficacy of L-DOPA therapy, such as the

development of slow releasing forms of the drug, as well as the use of other dopamine

agonists such as bromocriptine. Since the mid 1970s, countless thousands of Parkinson’s

sufferers have benefited from the treatment and to this day, L-DOPA remains the mainstay

of treatment for PD.