Typically, mild TBI causes no gross pathology, such as haemorrhage or abnormalities that can be seen on a conventional CT scan of the brain,8 but instead causes rapidonset neurophysiological and neurological dysfunction that, in most patients, resolves in a spontaneous manner over a fairly short period of time. However, approximately 15% of individuals with mild TBI develop persistent cognitive dysfunction.9, 10 Mild TBI is usually caused by an impact to the head (contact loading) that induces rotational acceleration of the brain (inertial loading). In some patients, mild TBI occurs without an impact to the head, such as after rapid rotational acceleration of the head in restrained occupants during a motor vehicle crash.11 At a neurophysiological level, these mechanical and inertial forces result in the stretching of white matter axons, leading to diffuse axonal injury.12Although axonal disconnection rarely occurs at the time of injury, the rapid stretching of axons causes an unreg