ABSTRACT
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.