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Brain Surgery Boosts Memory For Parkinson's Patients, University of Florida Research Shows October 3rd, 2008 by health GAINESVILLE, Fla.-An increasingly popular surgical technique to alleviate symptoms of Parkinson's disease also improves memory-a finding that surprised researchers, a new University of Florida study shows. Pallidotomy surgery, which involves precision burning of a small spot in the brain, provides relief for many patients from some of the tremors and muscle rigidity associated with the central nervous system disorder. Parkinson's patients also frequently have problems with memory, but researchers did not expect the procedure to help. "The surgery is done in an area of the brain that is not thought to affect cognition-the process by which we learn about the world around us," said Dawn Bowers, a neuropsychologist at UF's College of Medicine. She presented her findings (4/16/97) at a recent meeting of the American Academy of Neurology in Boston. Parkinson's is an incurable chronic movement disorder affecting 500,000 to 1.5 million Americans. Sufferers produce too little dopamine, a chemical that helps transmit messages between regions in the brain that facilitate muscle movement. This leads to increased activity in an area of the brain known as the globus pallidus and contributes to Parkinson's tremors and rigidity. In pallidotomy, a neurosurgeon probes through a small hole in the skull, guided to the pallidus by the body-scanning technique known as magnetic resonance imaging. The neurosurgeon stimulates the area, testing to see which sites affect disease symptoms. Those spots are then heated to interrupt the overactive brain circuitry. At UF, the surgery is performed by Dr. William Friedman, of UF's Brain Institute and College of Medicine. The procedure is not a cure, and patients continue to need medication. But it does improve the quality of life for many who typically have had trouble with routine tasks because of their tremors, stiffness and difficulties with walking and balance. Pallidotomy generally is considered appropriate only when medication loses effectiveness or its side effects become too disabling. "Often what we see in patients with Parkinson's disease is that they have become much slower at all tasks, including the retrieval of memory. It's not to the same degree as with Alzheimer's disease, but they do show mild to moderate problems with memory and slowness in their thinking," Bowers said. In the research presented in Boston, 21 patients were included in the analysis. The improved-memory trends continued with 25 patients not included in the original group, she said. Three months after undergoing the procedure at Shands Neurological Center at UF, patients generally scored better than before the operation on a word memorization test. Specifically, they improved on a section in which they were given hints. "Their cued recall improved, but their free recall did not," said Bowers, an associate professor of neurology and clinical psychology. Across the board, individuals tended to remember, with assistance, two or three more items out of a list of 16 common words than they had before the surgery. "For example, we would ask, `Which of the words were vegetables?' That sort of clue was more helpful after pallidotomy," Bowers said. Different lists were used before and after surgery. "A final part of the test assessed something called recognition memory. There we would ask a yes -or-no question about individual words. `Was pencil on the list?' They also improved in that area," Bowers said. Many patients had not noticed any improvements in their memory. "For others, it was strong enough that they noted it and were pleased, but usually they're happier about the improvements in their motor symptoms. That is much more important to them," Bowers said. A study published last year in the Annals of Neurology provides one possible explanation for the unexpected improvements, Bowers said. "The study showed increased activity in the front part of the brain after pallidotomy. One area that was more active was the dorsolateral frontal lobe. That may be significant because it plays a role in the retrieval of memory." Bowers plans follow-up assessments of the patients in the coming years to determine if the memory improvements are fleeting or long-lasting. The research is supported in part by grants from the National Parkinson Foundation, which has established a Center of Excellence at UF. ---------------- Recent UF Health Science Center news releases also are available on the UF Health Science Center Communications home page. Point your browser to http://www.vpha.health.ufl.edu/hscc/index.html Rayilyn Brown Director AZNPF Arizona Chapter National Parkinson 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