Second Edition - Ontario Neurotrauma Foundation - Published September 2013
"Mild traumatic brain injury (mTBI) is a significant cause of morbidity and mortality, with many survivors of mTBI dealing with persisting difficulties for years post injury. Over the years, various terms have been used synonymously with mild traumatic brain injury, such as mild head injury and concussion. In this document, the terms mTBI and concussion are used interchangeably and denote the acute neurophysiological effects of blunt impact or other mechanical energy applied to the head, such as from sudden acceleration, deceleration or rotational forces.4,5 Mild TBI is among the most common neurological conditions with an estimated annual incidence of 500/100,000 in the United States.
A recent Canadian study examining both hospital-treated cases as well as those presenting to a family physician calculated the incidence of mTBI in Ontario to lie between 493/100,000 and 653/100,000, depending on whether diagnosis was made by primary care physicians or a secondary reviewer.
The acute symptoms that may follow mTBI are often categorized according to the following domains:
1.- physical,
2.- behavioural/emotional, and
3.- cognitive.
Computed Axial Tomography (CAT) and conventional Magnetic Resonance Imaging (MRI) usually fail to detect evidence of structural brain abnormalities in mTBI. However, reviews of recent advances in the biomechanical modeling of mTBI in humans and animals conclude that mTBI leads to functional neuronal disruption, and at times structural damage."