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Implanting Retinal Cells in the Brain Eases Parkinson's Symptoms NEW YORK (Reuters Health) Dec 13 - A pilot study has found that levodopa-producing retinal cells implanted in the brains of Parkinson's patients reduce symptoms of the disease. Based on the findings, Dr. Natividad P. Stover of the University of Alabama at Birmingham and her colleagues have launched a randomized, double-blind placebo controlled trial of the technique. Researchers are looking for Parkinson's treatment approaches that will deliver a steadier supply of levodopa to the brain, Dr. Stover and her team note in the December issue of the Archives of Neurology, which could avoid the dyskinesias and motor fluctuations that occur with shorter-acting drugs. Implantation of human retinal pigment epithelial cells, which secrete levodopa, is one such approach. Studies in mouse and monkey models of Parkinson's, they add, have found implanting the cells in the animals' striata resulted in a reduction of symptoms with no apparent ill effects. In the current open label study, six patients with advanced Parkinson's' received surgical implants of 250 microliters of retinal pigment epithelial cells, or roughly 325,000 cells in total, attached to gelatin microcarriers. The implants were placed in the putamen on the side of the brain contralateral to the side of the body with the most severe Parkinson's symptoms. Patients had MRIs just after surgery, and at three, six, 12 and 24 months post-surgery. All patients showed a clinically significant improvement in Unified Parkinson's Disease Rating Scale scores at 12 months after surgery, averaging 48%. Scores were taken while the patients were in the practically defined off-state, meaning they had not taken any medications for at least 12 hours. Disability scores were reduced an average of 41% at 24 months. Patients' on-time increased from 44% to 65% at two years after the surgery, and off time fell from 41% to 28%. No off-state dyskinesias were seen in the patients during the study. One patient had a small, asymptomatic hemorrhage near one of the implants, while one patient developed severe depression with suicidal ideation 14 months after the surgery. The patient's depression resolved within two months of treatment. Benefits were similar to those seen with patients treated with deep brain stimulation, Dr. Stover and her team note. Placebo effects are known to occur in Parkinson's studies, they add, and may have played a role in the current study. Arch Neurol 2005;62:1833-1837. Related Links Resource Centers Parkinson's Disease Resource Center Reuters Health Information 2005. © 2005 Reuters Ltd. Rayilyn Brown Board Member AZNPF Arizona Chapter National Parkinson's Foundation [log in to unmask] ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn