Etiology and Pathogenic Mechanism of Traumatic Brain Injury
The Human brain can get injured form traffic accidents, engineering accidents, violent wounds, firearm injury etc. These cause scalp laceration, skull fracture, intra-cerebral haemorrhaging, and so on. The consequences are serious sequelae, such as rigid limbs, hemiplegia, unconsciousness, vegetative state, reduction of self-care ability, requiring long-term nursing, change of behaviour, vague language expression, amnesia, fall of computing power, slow response, epilepsy, spasm. Accelerated motion and impact on the head can cause cerebral tissue injury as well. When the head suffers an impact on a hard object rapidly, or sudden decelerated motion are common cause of cerebral trauma. The side which suffers the impact or opposite brain tissue impact with solid protuberant skull can be easily injured. Accelerate/decelerate injuries are also called contralateral blast injury.
Serious traumatic brain injury drags, sprains or avulses encephalic nerve, blood vessel and other tissues, thus, neural pathway can be hurt, there will be haemorrhage, oedema. Encephalic haemorrhage and oedema make the cerebral contents get larger, while cranial cavity cannot get larger ,therefore, intra-cranial pressure will go up, brain tissue will get injured further. The intensified intra-cranial pressure causes cerebral hernia by pushing the brain downward, driving upper brain tissue and brainstem into the pore canal nearby. Epencephalon and brainstem may translocate toward spinal cord through the pore canal of basis cranii. The brainstem is vital to breath and heartbeat, so cerebral hernia is often lethal.
The Major Traumatic Brain Injury Syndrome
The Traumatic brain injury syndrome is the focusing or dispersion of injured brain tissue, different injury part of traumatic brain injury can cause different symptoms, those special focal symptoms can help doctors to distinguish the type of injury. The focal symptoms include motor, sensation dysfunction, and accompanied with speech, vision, hearing abnormality. Dispersive traumatic brain injury usually effect memory, sleep or cause unconsciousness and coma. Generally, the injured brain tissue and the degree of injury effect patients' prognosis directly. Because many cerebral functions are undertaken by different parts of brain, the injuries on less important part of brain won't cause any sequelae.