One promising approach could also help with other neurodegenerative disorders, including Alzheimer’s and Huntington’s disease.
Walking in the east London neighborhood of Shoreditch in the early 1800s, the physician James Parkinson noticed certain individuals who moved differently from the crowd. In 1817 he articulated their symptoms, such as tremor, rigidity, slow movements and stooped gait. His “Essay on the Shaking Palsy” became the first description of what is now called Parkinson’s disease. Toward the end of this classic document, Parkinson remarked in passing, “there appears to be sufficient reason for hoping that some remedial process may ere long be discovered, by which, at least, the progress of the disease may be stopped.”
Some 200 years later, the disease, which affects one million Americans and seven million people world-wide, still hasn’t been cured. While drugs such as L-dopa and surgeries such as deep brain stimulation can help manage the symptoms, all attempts to slow, stop or reverse the disease’s course have failed. Efforts to protect dopamine cells with drugs, to revive dopamine cells with special growth factors and, most controversially, to graft new dopamine-making cells derived from fetal tissue into the brains of Parkinson’s patients, have not panned out.