Abstract
We have read with great interest the article by Johnson and colleagues1 describing novel observations of pallidal evoked resonant neural activity (ERNA) during deep brain stimulation (DBS) of the globus pallidus internus (GPi).
ERNA has garnered much research interest following its description by Sinclair et al. in 2018 as an electrophysiological signature which occurs during DBS of the subthalamic nucleus (STN).2 This phenomenon was subsequently reproduced by colleagues across various DBS centres,3–5 and it has moreover been reported that recordings of ERNA are of greatest amplitude at contacts that produce the best clinical effects when used for stimulation.2,6 Such findings suggest that ERNA could be considered as a physiomarker to guide DBS implantation location and titration of stimulation settings, as now corroborated by Johnson et al.1 in the context of GPi-DBS. Importantly, the neural basis of ERNA has been validated experimentally, to rule out the possibility that this signature is a stimulation-induced artefact.
