Overview of Neurovascular Physiology.

PURPOSE OF REVIEW: Neurophysiology is a complex network of cellular, electrical, and vascular systems which function to maximize neuronal functioning and brain performance. The brain exists in a closed system made up of parenchyma, cerebrospinal fluid, and blood with any increase in volume leading to a corresponding decrease in one of the components. Once these compensatory mechanisms are exhausted, there is a precipitous increase in the intracranial pressure leading to decreases in cerebral perfusion and resulting ischemia. The cerebral vasculature has significant control over the total volume of blood and regional flow throughout the brain via autoregulation. Through this process, blood flow is tightly regulated to prevent fluctuations and is coupled precisely with metabolic demand. Moreover, oxygen delivery and aerobic respiration are essential for proper brain functioning and can become deranged in various disease states leading to cellular injury and death.

RECENT FINDINGS: Ongoing trials have provided evidence that in addition to targeted therapy for intracranial pressure monitoring, optimizing brain tissue oxygenation and cerebral autoregulation may lead to improved clinical outcomes. An understanding of neurophysiology is not only essential for treating patients suffering from intracranial injury but also for the development of novel monitoring and therapeutic techniques.