Intraoperative monitoring with visual evoked potentials for brain surgeries

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The goal of this study was to determine the performance of intraoperative visual evoked potentials (VEPs) in detecting visual field changes.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Assessments of VEPs were performed with simultaneous retinal responses by using white light-emitting diodes protected from scialytic microscope lights. The alarm criterion was a reproducible decrease in amplitude of the VEP P100 wave of 20% or more. Visual fields were assessed preoperatively and 1 month postsurgery (Goldmann perimetry).</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The VEPs were analyzed for 29 patients undergoing resection of a brain lesion. In 89.7% of patients, steady VEP and retinal responses were obtained for monitoring. The absence of alarm was associated in 94.4% of cases with the absence of postoperative visual changes (specificity). The alarms correctly identified 66.7% of cases with any postoperative changes and 100% of cases with changes more severe than just a discrete quadrantanopia or deterioration of an existing quadrantanopia (sensitivity, new diffuse deterioration &lt; 2 dB). In 11.5% of patients, a transitory VEP decrease with subsequent recovery was observed without postoperative defects.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>Intraoperative VEPs were performed with simultaneous recording of electroretinograms, with protection from lights of the operating room and with white light-emitting diodes. Intraoperative VEPs were shown to be reliable in predicting postoperative visual field changes. In this series of intraaxial brain procedures, reliable intraoperative VEP monitoring was achieved, allowing at minimum the detection of new quadrantanopia. The standardization of this technique appears to be a valuable effort in regard to the functional risks of homonymous hemianopia.</jats:p></jats:sec>

Intraoperative Flash Visual Evoked Potential Recording and Relationship to Visual Outcome

“…A recent study showed that if the criterion for significant FVEP change is decreased to ≥20% amplitude reduction (instead of ≥50%) while using multiple recording sites (O1, O2, and Oz) and white light stimulation, then there may be improved detection of iatrogenic injury resulting in quadrantanopia. 25 The high success rate in this study was mostly related to the use of restrictive filtering, optimal reject window settings, mastoid reference, concomitant ERG recordings, and TIVA anesthesia. 4 In a previous paper, we showed that FVEPs are more reproducible in the presence of low-amplitude EEG than high-amplitude EEG.…”

Deep Learning for Automatically Visual Evoked Potential Classification During Surgical Decompression of Sellar Region Tumors

“…We have several limitations to our study. We did not have postoperative visual outcomes, but we argued the correlation of intraoperative monitoring and the outcome had been investigated by other studies,4–6,14–21 and our study did not focus on this topic. We have a relatively small sample size for a deep learning study.…”

“…Several groups used a 20% to 50% increase or decrease in amplitude as the criterion 20–22. Recent studies also argued the effectiveness of intraoperative VEP monitoring during surgeries that might have the risk of optic injury 4–6. On the contrary, several studies concluded that this procedure had no predictive value for postoperative prognosis 18,19.…”

“…Electrophysiological monitoring by the intraoperative real-time recording of visual evoked potential (VEP) can detect any possible VEP deviations during the surgical procedure and act as a surrogate for optic nerve injury. Several studies showed that this procedure had the potential to improve visual outcome 4–6. Nevertheless, detection of the massive amount of data generated in real-time requires labor-intensive work, which limits its wide usage in clinical settings.…”

Latency-shift of intra-operative visual evoked potential predicts reversible homonymous hemianopia after intra-ventricular meningioma surgery

“…Another study (Gutzwiller et al, 2018) reported that a decrease in amplitude of the VEP P100 wave of 20% correctly identified only 66.7% of cases with any postoperative change.…”