CNS Trauma.pdf

CNS Trauma A CNS trauma is an acquired injury of the brain/spinal cord by an external force. Most of the traumas on the head or spine are minor (not leading to any dysfunction). The trauma location could be anterior (frontal), posterior (occipital), Lateral (temporal), base of skull, or multiregiona...

CNS Trauma A CNS trauma is an acquired injury of the brain/spinal cord by an external force. Most of the traumas on the head or spine are minor (not leading to any dysfunction). The trauma location could be anterior (frontal), posterior (occipital), Lateral (temporal), base of skull, or multiregional. The severity of the trauma depends on the force of damage. Fractures could happen with severe trauma. Injury could be Direct/penetrating trauma (skull only or + brain exposure) or Indirect/closed trauma (no skull/brain exposure). The epidemiology of the CNS trauma is difficult to estimate because: A. Many patients die on the site of the accident (thus not counted). Up to 40% of people who were exposed to acute severe head trauma die before reaching the hospital. B. The classification from one protocol to the other differ. C. Sometimes the investigations cannot be well documented (because of the poor equipment availability). The incidence is variable (mostly mild trauma → Moderate → Severe). The most common head injury fatalities are caused by firearms. The people who are at high risk include: A. The young (less than 35) are more exposed (because they take the risk). Infants (accidental) and elderly (falls) can also occur B. Men (2 times more than women) C. Low income individuals (because they take the risk to get income) D. Unmarried individuals. E. Residents of inner cities (as compared to rural areas) F. Individual with history of drug abuse and previous head trauma. Mechanisms of brain insults include: A. Blunt injury (contusion) ------ Motor vehicle and assaults are the most common. Others include falls. B. Penetrating materials injury (displacement of a piece of bone or a foreign body penetrating the skull) ------ For example, Gunshots, stabbing, explosion, falling on sharp objects, or accidental. The two major signs that determine the severity are: 1. Battle’s sign ------ Found behind the ear (mastoid ecchymosis) most likely indicate fracture of the auditory canal or the temporal bone (base of skull). 2. Raccoon sign ------ Mostly fracture of the orbit. 3. Other signs include CSF leak (indicate rupture and leakage) from the nose (roof of the frontal sinus trauma most commonly) or the external auditory canal (can be from temporal bone). The Glasgow coma scale is usually used for assessment of severity (usually the first few days then investigations follow). Clinical findings The most important symptoms clinically found are pain. Nausea/vomiting (because of disturbance of the brain) can be because of increase intracranial pressure (but not always). Higher mental function is also one of the major signs that we should also look for (in minor trauma, consciousness may not be impaired). Dysmnesia may occur during the time of the trauma. It may occur after the trauma (anterograde) or before the trauma (retrograde). Bruises of the brain may be complicated with edema. The pupils (mydriasis) are one of the important structures to indicate the severity of the trauma (because of the damage of the cranial nerves related to the eye). Decortication/ Decerebration may also occur (bad prognosis). Classification We classify the trauma to two types: 1. Direct, which is due to the force causing the trauma: A. Focal ------ Often Coup (first hit)/ contrecoup (second hit). We may deal with local contusion (damage of the area without opening of the trauma) or hemorrhage (EDH, SDH, ICH) may be seen. Middle meningeal artery rupture is more commonly seen in EDH. In SDH, there is rupture of the bridging veins and the progression is slow (over days). B. Diffuse ------ neuronal dysfunction in the whole brain and can’t localize. Concussion and axonal injury (moderate/diffuse) may be seen. Usually no anatomy damage. May involve brainstem. 2. Indirect, which is secondary to factors caused by the trauma that can worsen the case (e.g. hypoxia, low perfusion, and edema) Primary and Secondary brain injury Abdulrahman Algwaiz Sarahah: https://goo.gl/gbxaXx