Permeability of the Blood-Brain Barrier after Traumatic Brain Injury: Radiological Considerations

Traumatic brain injury (TBI) is a leading cause of death and disability, especially in young persons, and constitutes a major socioeconomic burden worldwide. It is regarded as the leading cause of mortality and morbidity in previously healthy young persons. Most of the mechanisms underpinning the development of secondary brain injury are consequences of disruption of the complex relationship between the cells and proteins constituting the neurovascular unit or a direct result of loss of integrity of the tight junctions (TJ) in the blood-brain barrier (BBB). A number of changes have been described in the BBB after TBI, including loss of TJ proteins, pericyte loss and migration, and altered expressions of water channel proteins at astrocyte end-feet processes. There is a growing research interest in identifying optimal biological and radiological biomarkers of severity of BBB dysfunction and its effects on outcomes after TBI. This review explores the microscopic changes occurring at the neurovascular unit, after TBI, and current radiological adjuncts for its evaluation in pre-clinical and clinical practice.

Automated summary

Traumatic brain injury (TBI) is a major cause of death and disability, particularly among young people. The development of secondary brain injury after TBI is mainly due to disruptions in the complex relationship between cells and proteins in the neurovascular unit, or a loss of integrity in the blood-brain barrier (BBB). Changes in the BBB after TBI include loss of tight junction proteins, pericyte loss and migration, and altered expressions of water channel proteins in astrocyte end-feet processes. Research is increasingly focused on identifying biological and radiological biomarkers of BBB dysfunction severity and its impact on outcomes after TBI. This review explores microscopic changes in the neurovascular unit and current radiological methods for evaluating it in pre-clinical and clinical practice.