While deep brain stimulation has been successful in treating movement-related symptoms of neurological disorders like Parkinson’s disease and essential tremor, the technology hasn’t yet been widely applied to other conditions that begin in the brain.
That’s beginning to change, however, as researchers have recently ramped up studies of how neurostimulators can be adapted to the much more difficult work of regulating especially complicated disorders like Alzheimer’s disease and treatment-resistant depression. So far, these studies have been launched by a range of academic institutions and devicemakers, including UCSF Health, Verily, Magnus Medical and Abbott.
The last of those is the subject of a new breakthrough device designation from the FDA. Abbott said Tuesday that it has earned the agency’s acknowledgement for an ongoing project to apply its deep brain stimulation system to treatment-resistant depression. The label gives the technology a more expedited pathway toward potential FDA clearance.
Abbott’s deep brain stimulation system centers on a pulse generator that’s implanted under the skin on a patient’s chest. The device sends out electrical impulses that travel through thin wires, the ends of which have been placed on specific areas of the brain—in this case, the regions that are responsible for regulating mood. The pulses aim to block and modulate signals to the brain that cause abnormal activity.
The adjustable system can be monitored and controlled remotely through Abbott’s NeuroSphere Virtual Clinic technology, which requires a cellular or WiFi connection and a separate patient controller.
Until now, the tech has been used primarily to treat the symptoms of movement disorders like Parkinson’s. Its use in addressing treatment-resistant depression is still limited only to investigational use, and Abbott said it is working with the FDA to develop a plan to evaluate the system’s safety and functionality there.
Treatment-resistant depression encompasses cases of major depressive disorder that fail to respond to at least four different antidepressant regimens. According to Abbott, as many as 2.8 million Americans are diagnosed with the condition each year, representing about one in every three people diagnosed with clinical depression.
A study published last fall described UCSF Health researchers’ efforts to apply neurostimulation—which typically takes a one-size-fits-all approach in its traditional applications—to the highly differentiated symptoms of mood disorders like treatment-resistant depression.
The research team began by plotting out a map of how a single patient’s brain activity matched up with changes in her mood, then used the resulting “depression circuit” to program an implanted stimulation device.
That ultra-personalized approach began easing the patient’s symptoms almost immediately, and that relief lasted throughout the 15 months between when the device was implanted and the study’s publication—far beyond the four to eight weeks of relief promised by current neurostimulation approaches to depression.