Implanting electrodes in the brain and zapping it helps patients with Parkinson's and other disorders, but doctors have never been sure why, exactly. Now, researchers from UC San Francisco think that the therapy (called deep-brain stimulation, or DBS) works by altering neural timings, in much the same way a defibrillator resets heart rhythms. In a healthy brain, neuron firing is controlled by low frequency rhythms that sync up movement, memory and other functions. But the UC team found that the synchronization is too strong in Parkinson's patients, making it harder for them to move voluntarily.
The brain needs a balance between autonomy and rhythm, which is where DBS comes in. The implants appear to lower the overly lock-step synchronization, improving patient coordination and other symptoms. But the invasive, six-hour-long surgery requires implanting probes into deep brain structures and the patient must be awakened mid-surgery to test it out -- so anything that can make it more effective is helpful. According to the researchers, "we can (now) begin to think of new ways for stimulators to be automatically controlled by brain activity, which is the next innovation in treatment for movement disorders."
[Image credit: Coralie de Hemptinne]