The treatment of early
Parkinson disease (PD) is generally symptomatic, although
therapy that also offers neuroprotection in early-stage PD would be welcomed.
Levodopa remains the most effective agent for relief of PD symptoms, but chronic
levodopa therapy is associated with motor fluctuations and
dyskinesias, and clinicians may therefore opt to postpone its use. Alternatives to
levodopa in early PD include
monoamine oxidase (
MAO)-B inhibitors,
amantadine, and
dopamine agonists.
MAO-B inhibitors have only mild symptomatic effects.
Amantadine is associated with improvement in functional disability and, in a subset of PD patients, a robust symptomatic improvement.
Dopamine agonists improve symptoms and may have a
neuroprotective effect. Partial
dopamine agonists,
adenosine A(2A)-receptor antagonists, and
safinamide are symptomatic
therapies that are under investigation. Neuro protective strategies under study include enhancement of mitochondrial function, antiinflammatory mechanisms,
calcium channel blockade, and
uric acid elevation.
Deep brain stimulation may slow cognitive and motor decline when used in early PD. Stem cell
therapy and gene therapy are still under investigation.