'Concussion' is not a true diagnosis

Abstract

In current usage ‘concussion’ describes a clinical presentation, but does not identify the underlying pathological process and therefore cannot be considered a true diagnosis. However, mounting evidence indicates diffuse axonal injury as a likely pathological substrate for concussion, thereby providing a framework to develop true diagnostic criteria.

Figure 1:. Diffuse axonal injury in concussion

a | The principal mechanical trigger of traumatic brain injury is head rotational acceleration, which induces dynamic deformation of brain tissue. b | Axonal microtubules (blue and red) are ruptured at the moment of head impact, leading to interruption of protein transport, accumulation of cargos proteins (green) and the development of periodic varicose swelling along white matter axons. Part a adapted from ref, part b adapted from ref.