Parkinson's Disease

It often begins inconspicuously. A finger that trembles when the hand is at rest. Handwriting that grows smaller and smaller. A gait that becomes heavier, as if the feet have forgotten the rhythm. And then, at some point, the sentence at the doctor's office that changes everything: Parkinson's disease.

Medically, Parkinson's is a neurodegenerative condition in which cells slowly die in a particular nucleus of the midbrain — the substantia nigra — cells that produce dopamine. Dopamine is the messenger that smooths, controls, and permits movement. When it is absent, the body becomes caught in a paradox: it trembles where it should be resting. And it freezes where it should be flowing.