Brain Shock—Toward Pathophysiologic Phenotyping in Traumatic Brain Injury

Abstract

Severe traumatic brain injury (TBI) is a heterogeneous pathophysiologic entity where multiple interacting mechanisms are operating. This viewpoint offers an emerging, clinically actionable understanding of the pathophysiologic heterogeneity and phenotypic diversity that comprise secondary brain injury based on multimodality neuromonitoring data. This pathophysiologic specification has direct implications for diagnostic, monitoring, and therapeutic planning. Cerebral shock can be helpfully subanalyzed into categories via an examination of the different types of brain tissue hypoxia and substrate failure: a) ischemic or flow dependent; b) flow-independent, which includes oxygen diffusion limitation, mitochondrial failure, and arteriovenous shunt; c) low extraction; and d) hypermetabolic. This approach could lead to an alternative treatment paradigm toward optimizing cerebral oxidative metabolism and energy crisis avoidance. Our bedside approach to TBI should respect the pathophysiologic diversity involved; operationalizing it in types of “brain shock” can be one such approach.

Managing Severe Traumatic Brain Injury Across Resource Settings: Latin American Perspectives

“…The main argument for MMM is the fact that sTBI is highly heterogeneous, manifesting in multiple dynamic phenotypes with differing pathophysiology and clinical trajectories. To monitor and prevent secondary brain injury (SBI), one has to decipher mechanisms of cerebral oxidative metabolic failure [ 24 ]. Further, the impetus for considering individualization, beyond the issue of heterogeneity, is related to the idea that the relationship of ICP with clinical outcome becomes qualified when it is investigated in conjunction with other SBI parameters, such as the state of cerebrovascular pressure reactivity, quality of tissue oxygenation, and non-ICP-related metabolic and energy crisis.…”

Predicting short-term outcomes in brain-Injured patients: A comprehensive approach with transcranial Doppler and intracranial compliance assessment

“…Neurocritical patients who require invasive mechanical ventilation are at high risk of death and poor functional outcomes 1,2 . Besides primary injuries following kinetic forces in head incidents or spontaneous intracranial bleedings, further damage may occur because of the in ammatory and immune responses in the subsequent early period after an acute brain injury (ABI) 3,4 . All this combination of phenomena contribute to impairment in cerebrovascular properties, raising risks for the development of intracranial hypertension (IH), a life-threatening condition for the neurocritical patient [5][6][7] .…”