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Some patients with medically refractory focal epilepsy are chronically implanted with a brain-responsive neurostimulation device (the RNS ® System), permitting neurophysiological measurements at millisecond resolution. This clinical device can be adapted to measure hippocampal dynamics time-locked to cognitive tasks. We illustrate the technique wit...
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... a comparison, we performed the same memory task and signal analysis in five (5) surgical patients implanted acutely for localization of the seizure focus with hippocampal depth leads. We describe the clinical characteristics of the eight (8) patients (3 RNS System, 5 surgical) in Table 1 and in the Supplementary Material section. ...Context 2
... correct). (Table 1), as did performance by the surgical patients (range 40.4-79.2% correct, mean 52.2 +/-15.9 ...Context 3
... correct). During outpatient behavioral testing with our RNS System patients, we found our three RNS System patients were generally able to engage in memory testing for longer periods of time (as demonstrated by the larger block sizes, Table 1) compared to our surgical patients. Although responsive neurostimulation was temporarily disabled, there were no seizures or other complications during testing. ...Context 4
... during signal analysis, we found that we discarded less iEEG data due to environmental noise or epileptiform activity in our RNS System patients compared to our surgical patients. Overall, approximately 25% (124/481) of trials were rejected from the surgical iEEG data, whereas only 5% (30/558) of the trials were rejected from the RNS System iEEG data ( Table 1). ...Context 5
... a proof of principle, we have demonstrated that the hippocampal signature of successful encoding during a paired association task--a robust gamma peak at approximately 1.5 seconds after stimulus presentation--is similar in RNS System patients compared to surgical patients with hippocampal depth electrodes. While this study was performed in only a small number of patients, we have found that RNS System patients are able to engage in the memory task for longer sessions compared to our surgical patients ( Table 1). Testing sessions in our RNS System patients were performed over the span of several months, which is not possible for the surgical patients. ...Context 6
... sessions in our RNS System patients were performed over the span of several months, which is not possible for the surgical patients. Furthermore, during signal analysis, fewer segments were excluded due to environmental noise or interictal epileptiform activity in the RNS System data compared to the surgical data ( Table 1). ...Context 7
... were enrolled between January 2017 and January 2018. Table 1 lists subject characteristics. ...Context 8
... visual inspection of individual trials was used to exclude trials with excessive non-physiological noise. A summary of the trial rejection for each subject is in Table 1. . CC-BY-NC-ND 4.0 International license a certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. ...Similar publications
Epilepsy associated with Rasmussen’s encephalitis (RE) is highly resistant to standard therapy and continues to present a therapeutic challenge. While epilepsy surgery remains the most effective management for patients with drug-resistant focal epilepsy and RE, hemispherotomy may debilitating consequences on adult patients. Here we present the outc...
