Parkinson's Disease: Stalled Engines

Parkinson's Disease is a cruel foe;
It empties the motor oil from the brain;
The arms and legs get no impulse to go,
Though exhausting effort there is no gain.
The patient, prisoner in his mind;
Oh, what he wills so much but cannot do.
He searches in vain the prize key to find,
Alas, Leva Dopa to the rescue!
Chains are cut and the prisoner set free;
The motor is oiled and ready to roll.
The change is amazing, Oh Glory Be!
The future is waiting, car on the pole.
This is something so hard to comprehend.
How medicine gives one their life again.