Brain trauma and Increased ICP

Question 1

Various brain injuries

Answer 1

• Concussion: transient neurological deficit induced by brain trauma
• Contusion: bruise of the brain

Question 2

Skull fractures

Answer 2

• Linear: non-displaced
• Open or compound: overlying scalp is lacerated (predisposes to infection)
• Comminuted: multiple fractures
• Depressed: fragments indented thru normal width of skull. Laceration of underlying dura or brain may result in seizures or focal neuro deficits

Question 3

Epidural (extradural) hematoma

Answer 3

• Bleed btwn inner table and dura, due to bleeding of middle meningeal artery
• Most life threatening, ICP can get to 60 mmHg (normal: <20)
• 80% associated w/ skull fracture
• Usually localized to area btwn sutures, lentiform (lens) shape, smoothly encapsulated

Question 4

Subdural hematoma

Answer 4

• Bleed located btwn dura and arachnoid, usually bleeding from bridging veins (slow bleed)
• Often pan hemispheric and crescent shaped

Question 5

Intracerebral hematoma

Answer 5

• Located w/in the substance of the brain, often associated w/ penetrating injury or delayed from contusion
• Most commonly associated w/ focal neuro deficits (most threatening to normal function)

Question 6

Monroe-kellie doctrine

Answer 6

• Head is composed of 3 non-compressible volumes w/in the skull
• Brain substance and interstitial fluid (CSF)
• Vascular space (blood)
• And ventricular space (CSF)
• Increasing the amount of any one of these will lead to an increase in ICP
• CPP is cerebral perfusion pressure: the amount of pressure needed to perfuse the brain (normal is 50-60 mm Hg)
• CPP = MAP - ICP, CPP maintained by cerebral auto regulation

Question 7

Rx for increased ICP

Answer 7

• Hyperventilation: decreases pCO2 to vasoconstrictor brain blood vessels
• Pharmacologic diuresis using mannitol (draws water out of brain)
• Ventriculostomy/ventricular shunt
• Surgical removal of mass
• Removal of silent or injured areas of brain
• Hemicraniectomy
• Barbiturates to reduce brain metabolism rate

Question 8

Cushing’s triad

Answer 8

• Are signs of increased ICP
• Hypertension
• Bradycardia
• Respiratory irregularity

Question 9

Tentorial herniation

Answer 9

• Within the tenurial notch: brainstem and CN III
• Tentorial herniation of temporal lobe, followed by LP leads to uncal herniation
• Tentorial herniation of temporal lobe caused by lateralized mass
• Leads to unilateral compression of CN III, brainstem, and crus cerebri

Question 10

Glasgow coma scale (GCS)

Answer 10

• Assess head trauma victims
• Possible 15/15, 3 categories: eye, motor, verbalize
• Eyes: 4- opens spontaneously, 3- to voie, 2- to pain, 1- none
• Motor: 6- responds to command, 5- localizes, 4- withdraws, 3- abnormal flexion, 2- abnormal extension, 1- none
• Verbalizes: 5- normal, 4- confused, 3- abnormal words, 2- abnormal sounds, 1- none
• ≤8 is “coma”