The Severity of Blood Brain Barrier Dysfunction in Penetrating Compared to Concussive Traumatic Brain Injury

Overview

Penetrating and concussive traumatic brain injuries (TBI) remain major health concerns and are associated with a variety of clinical implications such as memory loss and cognitive deterioration. In particular, recent studies have highlighted the correlation concerning both forms of TBI and cerebral edema due to blood-brain barrier (BBB) dysfunction. More specifically, TBI can cause alterations in expression of proteins critical for maintaining BBB function and disruption in BBB permeability. This study aims to analyze the cascade of events affecting the BBB post-TBI and how type of injury, namely penetrating versus concussive, can affect these events. Analysis of current studies suggests that alterations in BBB permeability and decreased tight junction protein expression are more drastic in penetrating TBI than in concussive injuries. The primary focus is on components of BBB damage such as astrocyte damage, decreased pericyte concentrations, and decreased expression of tight and gap junction proteins. Tight junctions are of particular significance since they regulate selective solute transport across the BBB19. T o assess damage to tight junctions (T J), changes in occludin expression will be assessed— a component of tight junctions that has been shown to be altered by TBI. S100B and immunoglobulin Gare used as measures of BBB permeability as they normally cannot pass through intact BBB. This study incorporates data from both mouse models (CCI versus closed head injury) that closely recapitulate human TBI as well as human studies. Papers have been selected to ensure consistency across timepoints, injury mechanism, experimental measures, and demographics.