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Continuing the article "Pallidotomy the Second Time Around" in the _Harvard Health Letter_ the author, Patricia Thomas, writes that long before there were effective drugs for the treatment of Parkinson's disease, surgeons operated to destroy a small group of hyperactive cells using an electrode. Too often this surgical procedure was unsafe and ineffective. "In the 1940s, the advent of stereotactic frames (headgear that helps surgeons more reliably locate specific brain regions) paved the way for pallidotomy and a related operation called thalamotomy." "The rationale for these procedures is that the progressive loss of dopamine-producing cells ... somehow causes certain cells in other parts of the brain to become hyperactive. The group that pallidotomy aims to destroy is in the globus pallidus; when they are overactive the result is dyskinesia. Thalamotomy targets different cells, located in the thalamus, that produce tremors when they go into overdrive." During the 1950s, thalamotomy was more common and less dangerous than the pallidotomy procedure. But both became somewhat obsolete with the advent of L-Dopa in 1968. "This medication could control tremor, relieve the painfully slow movements that frustrated so many patients, and reduce rigidity -- all without the dangers inherent in brain surgery." "Sinemet does not work indefinitely, and in some people it produces serious and disabling side effects." Beginning with the work of Swedish neurosurgeons in 1992 pallidotomy became less dangerous and more successful. "Pallidotomy has boomed since then. Magnetic resonance imaging (MRI) has played a key role by enabling surgeons to visualize their target directly. ... This was not possible when the procedure was originally used. And once the surgery is underway, doctors now have electro-physiologic probes that enable them to make sure they're in the right place, so that they don't permanently destroy the wrong bit of brain." -------------------- Sid Roberts 66/dx2 [log in to unmask] Youngstown, Ohio