What Is a Neuropsychologist Doing in the Operating Room?

From Lesion Localization to Functional Preservation

Clinical neuropsychology was founded on the study of brain–behavior relationships. Early observations of patients with focal neurological injury allowed clinicians to identify how specific brain regions and networks contribute to cognition, behavior, and emotional functioning. From Broca’s work on language localization in the nineteenth century to landmark cases such as Phineas Gage and H.M., neuropsychologists helped establish fundamental links between neural structures and functional outcomes (Broca, 1861; Scoville & Milner, 1957). For much of the twentieth century, neuropsychological assessment served as a primary method for localizing cerebral dysfunction and understanding the cognitive and behavioral consequences of neurological disease. Today, advances in neuroscience have shifted the focus from identifying the location of dysfunction to preserving function itself.

Advances in neuroimaging have transformed the ability to visualize the brain, but they have not eliminated the need for direct assessment of cognition and behavior. Contemporary neuroscience increasingly recognizes that higher-order functions emerge from distributed cortical and subcortical networks rather than isolated cortical “centers.” Modern models of language organization emphasize dynamic interactions among large-scale cortical and subcortical networks and white matter pathways rather than discrete anatomical regions alone (Chang et al., 2015). This perspective extends principles articulated decades earlier in Geschwind’s seminal description of disconnection syndromes, which highlighted how disruption of connections between brain regions can produce substantial functional impairment even when cortical structures remain intact (Geschwind, 1965). As neurosurgery increasingly adopts connectome-based approaches to brain tumor treatment, preservation of functional networks, which can vary among individuals, has become as important as preservation of cortical anatomy.

These developments have reshaped the concept of eloquence in neurosurgery. Traditionally, eloquent cortex referred to brain regions whose injury would produce significant neurological deficits, most notably involving motor, sensory, or language function (Kahn et al., 2017). More recent perspectives suggest that eloquence should be defined not only by anatomy but also by the real-world consequences of functional loss. A recent systematic review emphasized the importance of incorporating patient-specific functional goals and quality-of-life considerations into preoperative determinations of eloquence (Rammeloo et al., 2024). A neurosurgeon may identify regions of anatomical risk, but neuropsychologists are uniquely positioned to identify what functions are truly “eloquent” for a particular patient. Through preoperative evaluation, neuropsychologists can determine which cognitive abilities support a patient’s occupation, relationships, independence, and personal goals. For one patient, language fluency may be critical; for another, executive functioning, memory, or visuospatial abilities may be essential for returning to work and maintaining independence.

The growing importance of this perspective reflects broader advances in neuro-oncology. Improvements in surgical techniques, imaging, and systemic treatments have increased survival and functional outcomes for many patients with brain tumors (Vadhavekar et al., 2024). As patients live longer and increasingly return to work, family responsibilities, and community roles, preservation of cognitive functioning has become a central treatment objective. Return to work is now recognized as a meaningful and patient-centered indicator of recovery and quality of life following brain tumor treatment (Ng et al., 2020). In this evolving landscape, neuropsychologists are increasingly positioned at the intersection of neuroscience, patient-centered care, and functional outcome assessment.