The period witnessed a decisive shift toward physiologic neuromonitoring at the patient bedside and during neurosurgical procedures. Researchers established practical methods to quantify cerebral perfusion, including initial-slope measurements of Xenon-133 clearance and cross-validated heat- and inert-gas clearance approaches for regional blood flow. Attendant emphasis on arterial carbon dioxide modulation and cerebral hemodynamics linked ventilatory targets to brain perfusion, while somatosensory evoked potentials introduced objective markers of sensory pathway integrity that underpinned intraoperative monitoring and neurophysiologic monitoring programs. Together, these efforts created a cohesive framework where real-time physiologic data guided clinical decisions and spurred the later development of imaging-based perfusion techniques.