Cortical stimulation parameters for functional mapping

Abstract

Wide ranges of thresholds exist for the different responses between patients and within different regions of the same patient. With multivariate analysis in these series, no clinical or demographic factors predicted physiological response or afterdischarge threshold levels.

Electrocorticographic high‐gamma modulation with passive listening paradigm for pediatric extraoperative language mapping

“…The geometry of current spread into the brain tissue during ESM, and its effects on electrical activity of different types of cells in the cerebral cortex, are not well defined. Recently, it has been shown that ESM current thresholds for cortical excitability and functional responses are correlated, but their patient‐related or technique‐related determinants remain unknown . Given the high prevalence of ADs during ESM, including ADs occurring at remote sites, it is possible that some of the functional responses during ESM localize not to the cortex directly beneath the stimulated electrode pair, but rather to another node of the functional network with preferential connectivity to the stimulated site .…”

“…Recently, it has been shown that ESM current thresholds for cortical excitability and functional responses are correlated, but their patient-related or technique-related determinants remain unknown. 2,29 Given the high prevalence of ADs during ESM, including ADs occurring at remote sites, it is possible that some of the functional responses during ESM localize not to the cortex directly beneath the stimulated electrode pair, but rather to another node of the functional | 799 network with preferential connectivity to the stimulated site. 1,30 This is a probable explanation for the distributed topography of HGM compared to ESM language sites ( Figures 2 and 3).…”

Response: Therapeutic brain‐responsive neurostimulation in eloquent cortex can be delivered without symptoms

“…1,2 We would like to clarify that the patients participating in the RNS System trials received test stimulations during in-office programming visits. If involuntary movements or other responses were elicited during testing, the stimulation parameters including the current amplitude were adjusted until the responses were no longer produced.…”

Passive functional mapping of receptive language areas using electrocorticographic signals

“…While its utility is undisputed, the use of ECS does have noteworthy limitations that include substantial time requirements (typically several hours (Hamberger, 2007; Ritaccio et al, 2018)), an increased risk for induced pathological brain activity such as after-discharges or seizures (Corley et al, 2017), and common difficulties with pediatric and other populations (Chitoku et al, 2001; Korostenskaja et al, 2014a; Paus et al, 1999). These issues are exacerbated in the intraoperative scenario and lead to increased morbidity (Nossek et al, 2013).…”