Description

Sleep serves as a fundamental physiological state whose disruption has profound implications for neurological health. The daily alternation between sleep and wakefulness reflects an intrinsic circadian rhythm that orchestrates critical fluctuations in cortical excitability and functional connectivity throughout the brain. The cerebral cortex, comprising approximately 80% of total brain volume, forms the neural substrate for higher-order cognitive functions including sensory perception, executive control, and memory processes. Importantly, sleep acts as a global brain modulator that dynamically reorganizes patterns of neural communication across distributed cortical and subcortical networks.

Stereoelectroencephalography (SEEG) provides direct access to intracranial electrophysiological activity with exceptional spatiotemporal resolution. When combined with single-pulse electrical stimulation (SPES), this powerful methodology enables quantitative assessment of inter-regional connectivity through analysis of evoked potentials, allowing precise characterization of both connection strength and directionality. This integrated approach offers unique opportunities to examine how different vigilance states modulate cortical excitability and reorganize functional brain networks, particularly in clinical populations with neurological disorders. The ability to track state-dependent changes in network dynamics provides crucial insights into both normal brain function and pathological conditions.