How can traumatic brain injury disrupt neural networks?

Traumatic brain injury (TBI) disrupts neural networks through both immediate mechanical forces and a subsequent cascade of biological damage.

Primary Mechanical Disruption

When a force is applied to the head—whether through direct impact, penetrating trauma, or rapid acceleration—it causes the brain to shift, stretch, and deform within the skull. This physical stress leads to:
* Tissue Shearing: The movement of brain tissue against the rough interior of the skull causes bruising (contusions) and tearing of blood vessels and nerve cells.1
* Diffuse Axonal Injury (DAI): Rotational and acceleration forces can stretch and tear axons deep within the brain, resulting in widespread, diffuse damage that disrupts communication between neurons.1

Secondary Biological Cascade

The initial trauma triggers a self-perpetuating cycle of cellular damage that can persist for days or weeks. This includes:
* Cell Death: Neurons may die through necrosis due to metabolic failure or through apoptosis, a programmed breakdown of the cell triggered by the injury.1
* Inflammation and Edema: The disruption of the blood-brain barrier leads to brain swelling (edema), which increases intracranial pressure and causes further compression and damage to otherwise intact neural tissue.12

Current research into neuroplasticity aims to develop techniques that encourage surviving neurons to form new connections to compensate for these lost networks.1