Application of Intraoperative Electrocorticography in Precise Bypass Surgery of Adult Moyamoya Disease: A Preliminary Study

Abstract

Abstract INTRODUCTION Postoperative complications of surgical revascularization are still difficult to predict because of poor knowledge of the underlying pathophysiological process. Since the aim of the surgery is to improve brain dynamics by increasing regional blood flow, we hypothesize that postoperative complications are determined by aberrant electrophysiological changes. Thus, we tried to evaluate the clinical significance of intraoperative electrocorticography (ECoG) in precise bypass surgery of adult moyamoya disease (MMD). METHODS Ninety-one adult patients operated by the same neurosurgeon in our institute was involved (26 in the precise group, 65 in the traditional group). Two 1 × 6 subdural electrode grids were placed parallelly on the middle frontal gyrus and superior temporal gyrus to record ECoG data continuously during the procedure in the precise group. For patients with several candidate recipient M4 arteries, we selected the one closer to the cortex with lower amplitude in the beta band and lower frequency. Postoperative complications, 1-mo follow-up NIHSS and MMSE scores were noted. The power spectral denstity (PSD) values, and its parameter of (delta + theta)/(alpha + beta) ratio (DTABR) were adopted as ECoG metrics. RESULTS No significant difference was noticed between the 2 groups in either postoperative NIHSS or MMSE, while postoperative complication of the precise group was significantly lower than that of the traditional group (P < .05). In the precise group, the post/preop DTABR ratio in the bypass area was significantly correlated with postoperative NIHSS (P = .014 r2 = 0.289) and MMSE changes (P = .007 r2 = 0.266). While in the remote area, neither postoperative NIHSS nor MMSE changes showed significant correlation with post/pre-op DTABR ratio (P > .05). Additionally, in the precise group, patients with postoperative complications exhibited significantly higher DTABR (1.67 ± 0.33 vs 0.95 ± 0.08, P = .003) and PSD of thata band than those without postoperative complications in only bypass area. CONCLUSION This study was the first to explain and guide surgical revascularization from the perspective of electrophysiology. Intraoperative ECoG was not only sensitive to reflect and predict postoperative neurological and cognitive performance, but also usable as a reference for recipient artery selection.