Patients who have advanced Parkinson"s disease saw significant improvements in their movement and coordination after retinal pigment epithelial (RPE) cells from the eye of a deceased donor were implanted in their brains, according to a study in the December issue of Archives of Neurology.
RPE cells produce levodopa, a drug Parkinson"s patients take to restore levels of dopamine--a neurotransmitter responsible for the body"s smooth movement and other motor and cognitive functions.
Currently, there are 1.5 million Americans who have Parkinson"s disease, and it is estimated that 60,000 new cases are diagnosed each year, according to the National Parkinson Foundation. Parkinson"s disease, which has no cure, occurs when neurons that normally produce dopamine become impaired or die. Patients then experience shaking, rigidity, balance problems, and slow movement.
The condition often affects those past age 65, though 15% of Parkinson"s patients are younger than age 50. Men and women are almost equally affected.
Researchers from the Department of Neurology at the University of Alabama at Birmingham implanted thousands of RPE cells in the brains of six Parkinson"s patients. Results showed an average improvement of 48% on the Unified Parkinson"s Disease Rating Scale (UPRDS) motor subscore 12 months after the implantations, and this improvement continued after two years. (The UPDRS is a rating tool designed to follow the longitudinal course of Parkinson"s disease.)
Researchers also noted gains in activities of daily living, motor fluctuations, and quality of life.
Stover NP, Bakay RA, Subramanian T, Raiser CD, et al. Intrastriatal implantation of human retinal pigment epithelial cells attached to microcarriers in advanced Parkinson disease. Arch Neurol 2005 Dec;62(12):1833-7.