The Role of Intraoperative Neurophysiologic Monitoring in Asleep AVM Resection: Indication or Redundancy?

PURPOSE: The surgical resection of cerebral arteriovenous malformations (AVMs) presents a significant neurosurgical challenge, particularly because of the need to achieve complete obliteration of the nidus while preserving neurologic function. AVMs located within or adjacent to eloquent regions such as the motor or language cortex carry a high risk of postoperative deficits. To mitigate these risks, a variety of intraoperative tools have been developed to enhance surgical safety and decision making. METHODS: Cortical and subcortical mapping is a dynamic technique that helps identify and preserve critical functional areas by applying targeted electrical stimulation to the cortex or subcortical white matter and observing motor or sensory responses. Additional neuromonitoring modalities include electrocorticography (ECoG), somatosensory evoked potentials, and motor evoked potentials, each contributing distinct insights into neural pathway integrity during resection. RESULTS: A systematic review was performed using 2 databases (PubMed/MEDLINE and Scopus), yielding 892 initial results. After applying inclusion and exclusion criteria, six studies were selected for final analysis. These studies collectively included 63 patients who underwent AVM resection with the aid of intraoperative neurophysiologic monitoring or mapping. CONCLUSIONS: Intraoperative neurophysiologic monitoring plays a critical role in the safe resection of high-grade or eloquently located AVMs. Although its routine use in low-grade lesions remains debatable, intraoperative neurophysiologic monitoring offers significant intraoperative value by helping surgeons recognize functional limits in real time. In select cases, it enables a strategic shift toward subtotal resection with planned adjuvant radiosurgery, reducing the risk of permanent neurologic deficits.