Review article
Abstract
TheĀ subthalamic nucleusĀ (STN) receives input from various cortical areas via hyperdirect pathway (HDP) which bypasses the basal-ganglia loop. Recently, the HDP has gained increasing interest, because of its relevance for STNĀ deep brain stimulationĀ (DBS). To understand the HDP’s roleĀ cortical responses evokedĀ by STN-DBS have been investigated. These responses have short (<2Ā ms), medium (2ā15Ā ms), and long (20ā70Ā ms) latencies. Medium-latency responses are supposed to representĀ antidromicĀ cortical activations via HDP. Together with long-latency responses the medium responses can potentially be used as biomarker of DBS efficacy as well as side effects. We here propose that the activation sequence of the cortical evoked responses can be conceptualized asĀ high frequency oscillationsĀ (HFO) for signal analysis. HFO might therefore serve as marker for antidromic activation. Using existing knowledge on HFO recordings, this approach allows data analyses and physiological modeling to advance the pathophysiological understanding of cortical DBS-evoked high-frequency activity.