The standard SRS thalamotomy uses a radiation-delivering device called a Gamma Knife, which delivers aimed beams of radiation to a precise point in the brain, targeting the spot which triggers the tremor while minimizing damage to surrounding tissue. The down side to a Gamma Knife procedure is that a patient has a frame attached to their skull ;to aid in the aiming of the radiation beams.
This frame is drill into the skull and can cause discomfort. The beams are deliver through small openings in a large; helmet-like device placed over the patient’s head. It is cumbersome, complicate and uncomfortable. Each beam of radiation takes a different vector through the collimator helmet until they come together at the site where the tremor originates.
They ‘ve improved on that process by creating a “virtual cone” technique using a new, non-invasive linear accelerator called the Varian Edge. It replaces the frames and physical cones with non-invasive image-guided techniques that deliver radiation with extreme accuracy and improve the overall patient experience.”
Complicated and uncomfortable
Markus Bredel, M.D., Ph.D., professor of radiation oncology and the Sharon A. Spencer Distinguished Endowed Chair in Translational Radiation Oncology at UAB Bredel says the UAB Advanced Stereotactic Radiosurgery Program for Movement Disorders is the first program in the United States to use the Varian Edge radiosurgery system and the virtual cone technology for functional SRS on movement disorder patients; such as essential tremor or tremor-dominant Parkinson’s patients.
“Advanced structural and functional brain magnetic resonance imaging allows us to better pinpoint the area in the brain that is potentially responsible for the tremor;” Bredel said. “The virtual cone SRS procedure delivers the right amount of radiation to create a tiny lesion at that spot; which eliminates or reduces the tremor. Tremor is reduced significantly in 80 to 85 percent of patients.”
Control abnormal movements
The medications left me in a mental haze totally unsuitable for an optometrist;” he said. The next option considered was DBS, or deep brain stimulation. This surgical procedure is extensively used to control abnormal movements by placing electrodes in the brain to modulate brain activity. While it is extremely effective in controlling tremor, it is invasive.
Then a relative who worked in UAB’s Department of Radiation Oncology in the School of Medicine, told him about another; newer option. One that is only available at UAB.Patients such as Agee. His tremor was worse in his left hand, so Bredel, in collaboration with Barton Guthrie, M.D., professor of neurosurgery at UAB and surgical director of the Functional and Stereotactic Neurosurgical Program, treated the right side of his brain in the summer of 2018.