Introduction: The preservation of the human self—a fundamental yet underexplored aspect of neurosurgical practice—has gained increasing attention in recent years. Research question: How can neural correlates of self-consciousness be identified, monitored, and protected during brain tumor surgery, and how might this reshape the concept of “onco-functional balance”? Material and methods: This review synthesizes emerging evidence from neuroimaging, neuropsychology, and intraoperative neurophysiology to build a framework for integrating the concept of self into modern neurosurgical practice. Results: We describe the anatomical and functional basis of bodily and cognitive self-awareness, highlighting the roles of interoception, multisensory integration, and higher-order cortical networks such as the medial prefrontal cortex, insula and temporoparietal junction. We outline perioperative tools for clinical assessment, including validated scales for anosognosia and disownership, as well as the Self-Other Voice Discrimination (SOVD) paradigm and Heartbeat-Evoked Potentials (HEPs), which offer quantifiable markers of self-processing. Discussion and conclusion: We argue for a reconceptualization of “eloquent” cortex to include regions critical for the preservation of self. As neurosurgery advances toward precision-guided, patient-centered care, protecting the self must become an explicit goal alongside motor, sensory, and language preservation. Future directions include real-time intraoperative monitoring of HEPs, development of functional risk maps for self-related structures, and broader implementation of personalized, neurocognitive surgical planning. Ultimately, this work proposes a shift from an “onco-functional” to an “onco-functional-identity” paradigm—where the integrity of the patient's personality, agency, and awareness becomes a measurable, preservable endpoint of neurosurgical care.