User:E.milly1/sandbox

Due to the unceasing prevalence of concussions, understanding the mechanism of injury in mild traumatic brain injuries (mTBI) is a vital aspect for preventing and treating neurological impairments. There are two fundamental mechanisms that can cause concussions: impact and impulsive (acceleration) forces. The most common force associated with concussions is impact force, in which the head comes into contact with a foreign body outside of the skull. Impulsive or acceleration force, can occur without contact from a physical object. During a concussion, the brain experiences a pressure gradient in which there is a difference in pressure between the coup portion (impact side of brain) and contrecoup portion (opposite side of impact) of the brain. Peak positive pressure forms at the coup site while the contrecoup side of the impact experiences peak negative pressure, or low pressure.

Anatomical Considerations
Concussions also exhibit a strong correlation between rotational acceleration and stress and strain, most notably shear stress. Shear stress is extremely threatening to the brainstem and midbrain due to the anatomical resistance of movement in the area causing detrimental strain, or deformation of the brain tissue.

Physiologically, the most damaging effects are deformation of neuron membranes, disturbances in neurotransmission, and axon damage. Axons transmit information in the form of electrical impulses to other neurons, causing the extent of axon damage to be strongly associated with the amount of neurological impairment. Furthermore, injury to the hippocampus appears to be a major contributor to neuropsychological impairments. The hippocampus plays a significant role in memory and retention of knowledge; subsequently, damage to this area is observed to lower verbal IQ scores as well as decrease intelligence scores.