Deep brain stimulation, in which electrodes implanted in a person's brain carry electrical pulses from a pacemaker-like unit implanted in the chest, has been used for more than two decades. These systems quell Parkinson's disease and essential tremor and lessen the side effects of medications that patients take for those movement disorders.
The software and hardware allow doctors and patients to adjust the energy being sent to the brain to improve patients' movement and reduce tremor, said Dr. Andrew Ko, a UW Medicine neurosurgeon. While this treatment is safe and effective, the interaction between the device and the brain has been one-way. Major adjustments made to the stimulator must be done by a doctor in clinic, based on trial and error.
The manufacturer Medtronic recently received the U.S. Food and Drug Administration's approval to distribute new a neuro-stimulator that can simultaneously stimulate and record signals from the brain. Please watch animation from Medtronic.
"It gives us more information about the effects of stimulation on the patient's brain, which can help us refine the treatment," Ko said.
Medtronic's updated device saw its first deployment in Seattle July 8, when Ko implanted one in a man who had to be hospitalized because of his inability to move or talk; the battery for his previous DBS system had run down, leaving him without therapy for his Parkinson's disease. After the replacement, he is back at his previous level of function. Medtronic confirmed it was the first such implant on the West Coast.
New software allows the transceiver to record a snapshot of brain activity in a programmed way, for example, every 10 minutes, and patients also can activate a recording of brain activity anytime they aren't feeling well.
"In the past, we'd adjust the energy stimulus during a clinic visit and then ask the patient to perform a task to confirm that the adjustment helps," Ko explained. "This new system lets us see what's happening to the patient when they're not sitting in clinic-more data over a longer period of time. The important thing is that we use this to see what needs to be changed, based directly on what the brain is doing."
The new device's storage will allow physicians to download collected data when a patient comes for a checkup. In this way it precludes the need for patients to try to remember or keep a written diary of symptom flare-ups or times when medication seems to have an adverse effect.
Ultimately, Ko said, the ideal would be to have the device run an algorithm that could make adjustments in real time based on what the patient's brain is doing: a closed feedback loop.
Patients who have Parkinson's and essential tremor compose most users of DBS. The therapy was more recently approved for dystonia, another movement disorder, obsessive-compulsive disorder, and epilepsy.
Later this month, Ko is scheduled to implant the updated Medtronic system and brain probes in a patient with epilepsy. She will be first person in Seattle to receive DBS for that condition, which is an option if definitive treatment by a brain resection is not viable.
