Low-Frequency Dual Target Deep Brain Stimulation May Relieve Parkinsonian Symptoms.

BackgroundDeep brain stimulation (DBS) reduces the motor symptoms of Parkinsons disease. The two most common targets are the subthalamic nucleus and the globus pallidus. Dual target deep brain stimulation may better reduce symptoms and minimize side effects, but the optimal parameters of dual target deep brain stimulation and their potential interactions are unknown. ObjectiveOur purpose was to quantify the frequency response of dual target DBS on bradykinesia and beta oscillations in participants with Parkinsons disease, and to explore intrahemispheric pulse delays as a means to reduce total energy delivered. MethodsWe applied dual target DBS using the Summit RC+S in six participants, varying deep brain stimulation frequency. ResultsDual target DBS at 50 Hz was effective at reducing bradykinesia, whereas increasing deep brain stimulation frequency up to 125 Hz also significantly reduced beta power. This frequency effect on beta power was replicated in a biophysical model. The model suggested that 22 Hz dual target deep brain stimulation, with an intrahemispheric delay of 40 ms, can reduce beta power by 87%. ConclusionWe conclude that dual target DBS at 125 Hz best reduced bradykinesia. However, low frequency DBS with an appropriate intrahemispheric delay could improve symptom relief.