Traumatic Brain Injury Flashcards
What is a TBI?
A TBI is caused by a bump, blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain.
What group of individuals are at highest risk for a TBI? Age?
Young males (TBI is leading cause of death for individuals aged 1-34)
Old >65
What are 4 risk factors for TBI death or hospitalizations?
- Male gender
- Older age
- Previous TBI
- Drug/Alchohol Use
What scale is most commonly used to classify the severity of a TBI?
Glasgow Coma Scale
Has good prognostic value
What are 3 issues/drawbacks of the Glasgow coma scale?
- Score affected by intoxication
- Intubation can alter scoring between mild and moderate
- Not scorable if patient cannot understand examiner’s language
What is the best predictor of outcomes in patients with TBI?
Depth and duration of unconsciousness
Post traumatic amnesia is assessed via what 2 tools?
- Galveston Orientation Amnesia Test (GOAT)
Scores ≥75 twice within 48 hours - Orientation Log
Scores ≥ 25 on 2 consecutive days
What are the 4 characteristics associated with PRIMARY injury following a TBI?
- Occurs at moment of impact
- Focal – bleeding, bruising or penetrating injury isolated to a portion of the brain
- Diffuse – brain tissue suffers more widespread damage
- People can experience both at the same time
What are the 7 characteristics associated with SECONDARY injury following a TBI?
- Triggered by primary injury; causes even more damage to brain
- Usually diffuse, but can also be delayed focal events
- Inflammation
- Cell receptor-mediated dysfunction
- Free radical and oxidative damage
- Calcium or other ion-mediated cell damage
- Cerebral Edema
What 4 things occur as a result of a TBI?
- Contusions (bruising)
- Diffuse Axonal Injury (shearing and widespread injury)
- Open Head Injury (skull fracture)
- Bleeding
Where dose the coup and countercoup injury take place?
- Coup – at site of impact
2. Contrecoup – opposite impact site
What is an epidural/extradural hematoma/hemorrhage? What can it cause? Mortality?
- Bleeding between the skull and the dura
- Can cause increase in iCP and brain shifting
- Typically arterial, spreads quickly
- Mortality 15-20%
What is the most common area to experience a epidural/extradural hematoma/hemorrhage?
Most common in temporal region as bone is thin
What is the treatment and prognosis of a epidural/extradural hematoma/hemorrhage?
Treatment: evacuation via burr hole or craniotomy
Prognosis: more favorable if patient was conscious immediately following injury vs. comatose throughout
What is typically the first symptom of a epidural/extradural hematoma/hemorrhage?
Fixed and dilated pupil on side of injury due to oculomotor nerve compression
What is a subdural hematoma/hemorrhage? When do symptoms typically appear? Most common in what age groups?
- Bleeding between the dura and the brain
- Usually venous
- Symptoms may appear immediately or be delayed
- Most common in elderly and very young children
What is the most deadly of all head injuries? Mortality?
Acute subdural hematoma
Mortality: 60-80%
How is a subdural hematoma treated?
Craniotomy with dural incision to remove blood clot and control bleeding
What is a subarachnoid hemorrhage? Signs and symptoms? Mortality?
- Bleeding into subarachnoid space
- Can occur from a ruptured blood vessel (non-traumatic) or from a severe blow to the head
- Signs and Symptoms: severe headache, vomiting, confusion, altered consciousness, sometimes seizures
- Mortality Rate: 40-50%
What are the 3 most common complications following a subarachnoid hemorrhage?
Hydrocephalus
Seizures
Re-bleeding
What is an intraparenchymal hemorrhage?
Bleeding into the brain tissue
Sxs depend on location and size of hemorrhage
What are 2 consequences on an intraparenchymal hemorrhage?
Can elevate ICP
Can cause fatal herniations
What is an intraventricular hemorrhage? What percentage of TBIs does this occur in?
Bleeding into the ventricles
35% of moderate to severe TBI
What are three common CNS herniations? Symptoms of each?
- Subfalcine: common, headache and contralateral leg weakness
- Trasntentorial: CNIII paresis (ipsilateral pupil dilation), contralateral hemiparesion.
- Tonsillar: Obtundation (less than full awareness)
What is compressed by subfalcine, transtentorial and tonsillar herniations?
Subfalcine: compresses pericallosal arteries
Transtentorial: compresses PCA and oculomotor nerve
Tonsillar: compresses pons and medulla
What are 8 secondary mechanisms of injury in a TBI?
- Ischemia
- Hypoxia
- Hypotension
- Cerebral Edema
- Increased Intracranial
- Pressure
- Hypercapnia
- Acidosis
- Excitotoxicity
What are the 4 levels of consciousness?
Coma: No eye opening, no sleep/wake cycle (Level 1)
Vegetative State: return of sleep/wake cycle; no purposeful responses (Level 2)
Minimally Conscious State: inconsistent purposeful responses (Level 3)
Emerged into Consciousness
What is a coma?
State of unarousable unresponsiveness
No response to verbal, tactile, or noxious stimulation