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 At Johns Hopkins,
we have built a large clinical practice in our efforts to care for and treat patients
with medically refractory movement disorders. Dr. Frederick Lenz, the neurosurgeon performing these surgeries at Johns Hopkins, has extensive experience with functional stereotactic procedures for the treatment of movement disorders and chronic pain. He has performed more than 550 functional stereotactic procedures during his fourteen years at Johns Hopkins. Dr. Lenz is a highly respected world leader in the exquisitely delicate intracranial procedures known as pallidotomy, thalamotomy and deep brain stimulation (DBS). He uses a highly sophisticated brain-mapping technique to chart structures in the brain. Then, by placing a microelectrode wire into the brain, he is able to "read" electrical currents emitted by individual cells and describe the exact location of errent cells. "Brain-mapping is offered by only a hand-full of centers," Lenz says, "but it's the gold standard." click on image to enlarge  The experience of stereotactic functional neurosurgery at The Johns Hopkins Hospital is illustrated in the chart to the left. This series includes 145 thalamotomies, 132 pallidotomies, and 233 DBS procedures (186 for movement disorders and 47 for chronic pain in the sensory thalamus, Vc). Dr. Lenz has been using DBS for the treatment of chronic pain since his arrival at Johns Hopkins in 1989. Although the FDA only approved the use of DBS for tremor in 1997 and Parkinson's disease in 2002, Dr. Lenz has pioneered the use of this technique to treat these conditions. Until 1997, the majority of procedures performed for tremor were thalamotomies. Following the FDA approval for Vim-DBS for tremor, lesioning Vim was replaced with Vim-DBS. As illustrated in the chart above, one can see the resurgence of pallidotomies in the mid-1990's, which were later replaced by stimulation (GPi-DBS) in 2000. Stimulation of the STN is now our most common procedure to surgically treat Parkinson's disease, as evidenced by the rise in cases from 1999 to present. |
