Treating Dystonia from Inside the MRI Core
Deep brain stimulation (DBS) can provide significant control for tremors associated with dystonia. In adults, the neurosurgeon uses stereotactic guidance to implant the device, then awakens the patient during surgery to see whether symptoms have subsided. Cincinnati Children’s offers an alternative approach that uses real-time magnetic resonance imaging guidance, allowing the patient to be asleep throughout the procedure.
DBS is used in only a small number of patients, and is just one aspect of the hospital’s comprehensive, multidisciplinary approach to caring for children with dystonia and other movement disorders. “We see these patients in our Movement Disorder Clinic and Dystonia and Surgical Movement Disorder Clinic, where we collaborate with subspecialists from areas such as physical therapy and neuropsychology,” says Steven Wu, MD, pediatric neurology, director of the Dystonia and Surgical Movement Disorder Clinic. “Our team offers the experience, technology and staff support necessary to provide long-term care for these patients.”
Sub-millimeter precision
When a patient is identified as a potential candidate for DBS electrode placement, Wu collaborates with Sudhakar Vadivelu, DO, the only fellowship-trained pediatric neurosurgeon in the United States specializing in both open and endovascular cerebrovascular surgery. The surgery takes place in the bore of a fixed, high-resolution MRI scanner, and involves guiding a fiber-sized wire into the deep structures of the brain. Vadivelu implants the electrode into the globus pallidus or, less commonly, the subthalamic nucleus. “MRI guidance means we can navigate toward the target and be absolutely sure that we’ve hit it,” says Vadivelu. “We are able to achieve sub-millimeter accuracy, even if the brain shifts during surgery.”
Within a few weeks of the DBS electrode placement, the patient returns to the hospital for an outpatient procedure to implant a pulse generator in the chest. Wu programs the technology and can make adjustments to voltage, stimulation frequency and other settings as needed.
Dramatic improvements
“We have used DBS to treat patients with different forms of primary genetic dystonia and secondary dystonia related to cerebral palsy, stroke or other rare conditions, such as Lesch-Nyhan Syndrome,” says Wu. “Outcomes depend largely on the patient’s underlying etiology, but everyone we have treated with DBS has experienced some degree of improvement. For some, this has meant functional improvement in fine motor skills and gait; for others, the improvement is more about impacting quality of life through better sleep or decreased daytime tremors.”
Sometimes the improvement is dramatic, as in the case of a child with Lesch-Nyhan Syndrome who had been in restraints 24/7 because of self-injurious behavior. Vadivelu targeted two locations within the globus pallidus internus – one anterior and the other posterior. Since the surgery, the patient is no longer in restraints and has been able to feed himself for the first time.
“Another one of our patients had experienced unilateral tremors following a thalamic stroke,” Vadivelu says. “His tremors were so severe that he could not walk, talk or even use assistive communication devices. Now, he can actually use an iPad to write and to operate his wheelchair.”
To learn more, contact Steve Wu at Steve.Wu@cchmc.org or Sudhakar Vadivelu at Sudhakar.Vadivelu@cchmc.org.
