How can parkinson be cured to some extent. If not completely in an aged person? What all is required other than medicines of levodopa nd cardiopa

Not cured. Sadly these meds do help but only for a while. Slows the process; stem cells show real promise of a true cure. Marvelous stuff.
Stem cell research? I am not aware of cure but some progress has been made with stem cell research. Also there are some implantable devices in the hypothalamus than can help to control the severe cases of distonias caused by the medicines. Medicine wise we are a little too far from cure .
No cure yet. Relief, not cure, is available with medications. Deep brain stimulation offers excellent control of many pd symptoms in selected patients. Even successful dbs may still require supplemental meds. Cure is still on the horizon. Stem cell or engineered cells brain implantation may restore Dopamine production. Genetic engineering is an evolving prospect for repair of brain Dopamine producing cells.