Spatial Neurophysiological Gradients at High Resolution Differentiate Tumor Types in the Human Cortex at the...

Brain tumors interact bidirectionally with neural circuits, but direct electrophysiological evidence in the human brain across tumor types remains limited. We analyzed intraoperative clinical, mesoscale, and high-density surface electroencephalography recordings from 100 participants undergoing tumor resection, epilepsy surgery, or deep brain stimulation. Population-averaged measures poorly separated diagnoses, whereas spatially resolved aperiodic exponent and high-gamma activity varied with both tumor distance and nearby tumor volume fraction across scales. Gradients differed among IDH-mutant glioma, IDH-wildtype glioblastoma, and metastases. Connectivity further distinguished infiltrative gliomas: beta coherence across tumor-brain connections was reduced in IDH-mutant tumors (p=0.0006; Kruskal-Wallis; mean coherence: tumor-brain 0.26, tumor-tumor 0.44, brain-brain 0.34), unlike IDH-wildtype tumors or metastases. Physiological abnormalities extended into radiographically normal-appearing brain, indicating tumor-type-dependent physiological signatures that may dynamically map the tumor-brain interface complementing structural imaging, with future possibilities as a spatial biomarker of tumor infiltration and network organization in humans.