| Over the past decade, the scientific information on | | | | Overall, recent research has shown the many |
| traumatic brain injury has increased considerably. A | | | | shortcomings of current MTBI assessments rating |
| number of models, theories and hypotheses of | | | | scales, neuropsychological assessments and brain |
| traumatic brain injury have been elaborated. | | | | imaging techniques. |
| Despite dramatic advances in this field of medicine, | | | | Humans are able to compensate for mild neuronal |
| traumatic brain injury, including the mild 2 Slobounov | | | | loss because of redundancies in the brain structures |
| and Sebastianelli traumatic brain injury (MTBI), | | | | that allow reallocation of resources such that |
| commonly known as a concussion, is still one of the | | | | undamaged pathways and neurons are used to |
| most puzzling neurological disorders and least | | | | perform cognitive and motor tasks. |
| understood injuries facing the sport medicine world | | | | Three to four weeks after conception, one of the |
| today. | | | | two cell layers of the gelatin-like human embryo, now |
| Definitions of concussion are almost always qualified | | | | about one-tenth of an inch long, starts to thicken and |
| by the statement that loss of consciousness can | | | | build up along the middle. As this flat neural plate |
| occur in the absence of any gross damage or injury | | | | grows, parallel ridges, similar to the creases in a paper |
| visible by light microscopy to the brain. | | | | airplane, rise across its surface. |
| According to a recent NIH Consensus Statement, | | | | Within a few days, the ridges fold in toward each |
| mild traumatic brain injury is an evolving dynamic | | | | other and fuse to form the hollow neural tube. The |
| process that involves multiple interrelated | | | | top of the tube thickens into three bulges that form |
| components exerting primary and secondary effects | | | | the hindbrain, midbrain and forebrain. The first signs |
| at the level of individual nerve cells (neuron), the level | | | | of the eyes and then the hemispheres of the brain |
| of connected networks of such neurons (neural | | | | appear later. |
| networks), and the level of human thoughts or | | | | How does all this happen? Although many of the |
| cognition. | | | | mechanisms of human brain development remain |
| The need for multidisciplinary research on mild brain | | | | secrets, neuroscientists are beginning to uncover |
| injury arises from recent evidence identifying | | | | some of these complex steps through studies of the |
| long-lasting residual disabilities that are often | | | | roundworm, fruit fly, frog, zebrafish, mouse, rat, |
| overlooked using current research methods. The | | | | chicken, cat and monkey. |
| notion of transient and rapid symptoms resolution is | | | | Knowing how the brain is put together is essential for |
| misleading since symptoms resolution is not indicative | | | | understanding its ability to reorganize in response to |
| of injury resolution. | | | | external influences or to injury. These studies also |
| There are no two traumatic brain injuries alike in | | | | shed light on brain functions, such as learning and |
| mechanism, symptomology, or symptoms resolution. | | | | memory. |
| Most grading scales are based on loss of | | | | Brain diseases, such as schizophrenia and mental |
| consciousness (LOC), and post-traumatic amnesia, | | | | retardation, are thought to result from a failure to |
| both of which occur infrequently in MTBI. There is still | | | | construct proper connections during development. |
| no agreement upon diagnosis and there is no known | | | | Neuroscientists are beginning to discover some |
| treatment for this injury besides the passage of time. | | | | general principles to understand the processes of |
| LOC for instance, occurs in only 8% of concussion | | | | development, many of which overlap in time. |
| cases. | | | | |