[Parkinson therapy yesterday, today, tomorrow. Neuroprotection gains in importance].

Owing to a lack of knowledge of the pathophysiology and pathochemistry of Parkinson's disease, conservative treatment was long restricted to the treatment of symptoms. In recent decades, as the role of dopamine became better known, progressive improvements in therapy were achieved, which initially meant the administration of the precursor, L-Dopa, of the primarily non-replaceable neurotransmitter, and later augmentation of the activity of dopamine in addition. Amantadine, a highly effective drug with a wide spectrum of action and a high level of tolerability, was successfully introduced in 1969. The recently discovered NMDA antagonism, also in conjunction with a description of the mechanism of action of amantadine, which makes it possible to inhibit the effect of excitatory amino acids--in particular glutamate--in the CNS, led to the principle of neuro-protection, which is now considered the key to the treatment of Parkinson's disease.