Parkinson’s disease is a neurodegenerative condition that, among other things, affects movement, balance, gait, and muscle control. Some of the most visible symptoms result from the loss of neurons in an area of the brainstem called the substantia nigra. The axons of these neurons extend up into the putamen, where they release dopamine that helps to regulate movement. Once around 50–80% of these neurons are lost, a person’s movement becomes noticeably affected.
Cell therapy may have the benefit of replacing and repairing damaged dopamine-producing nerve cells within the brain.