Traumatic Brain Injury

Epidemiology of Head Trauma

- occurs every 15 seconds

- 500,000 annual ED visits

- Accounts for 40% of traumatic deaths

Common causes

- Motor vehicle accidents

- falls

- assaults

What populations are most likely to get a TBI?

- Males 15-24

- elderly over 75

Secondary injury

delayed injury from hypoxia, ischemia, and release of neurotoxins

Hydrocephalus

clotted blood obstructs CSF outflow tracts and absorption of CSF, disrupts blood-brain barrier

Types of Injury

- Concussion

- Contusion

- Epidural hematoma

- Subdural hematoma

- Basilar skull fracture

- Diffuse axonal injury

Focal

in one place

hematoma

pooling of blood

epidural

around the dura (outer most layer of the brain)

subdural

below the dura (between the dura and arachnoid)

Mild traumatic brain injury

- period of LOC (loss of consciousness) < 30 minutes with a GCS of 13-25 after this LOC

- amnesia to the event

- alteration in mental status at the time of the event (dazed and confused)

Concussion

brief change in mental status with axonal swelling

moderate to severe brain injury

- contusion

- fractures

- bleeds

contusion

- bruising

- small bleeds (micro bleeding)

- cerebral edema

- deficits are based on lobe involved (can make injury look like a stroke)

fractures

- linear, comminuted, depressed, basilar

- defined on how they brake

bleeds

epidural, subdural, intracerebral

Neurologic exam

- decreased neurologic function is best predictor of brain injury

- pay attention to cranial nerves

Type of concussion

- grade 1-3

Grade 1 concussion

- confusion, no amnesia, no LOC

- remove from activity (may return when asymptomatic)

- 3 concussions in 3 months; no activity that risks head trauma for 3 months

Grade 2 concussion

- confusion and amnesia

- remove from activity for day

- recheck in 24 hours

- no activity for 1 week

- two grade 2 concussions in 3 months, no activity for 3 months

Grade 3 concussion

Loss of consciousness

- to ED for CT

- symptom free for 2 weeks, then another 30 days

- two grade 3 concussions, no activity for 3 months

post-concussive syndrome

- somatic symptoms

- cognitive trouble

- affective

somatic symptoms

- headache

- sleep disturbance

- dizziness

- vertigo

- nausea

- fatigue

- sensitivity to light or noise

cognitive

- attention

- concentration

- memory problems

affective

- irritability

- depression

- anxiety

- emotional lability

Linear

break in bone, but no shifting

Comminuted

break in bone and shifting of the bone

depressed skull fracture

- bone is broken and pushed in potentially causing bone fragments to break off into brain tissue

- 95% go to surgery

- antibiotics for infection

- brain tissue is involved

CSF leaks

- crack in the base of the skull (basilar fracture)

- allows CSF and blood to leak

- increases in ICT (inter cranial pressure)

Epidural hematoma

- laceration of dural arteries or veins (blood vessel)

- classically laceration of middle meningeal artery

- temporal bone fracture

- "lucid interval" followed by rapid deterioration

- acute bleed

- defined based on where it is

Subdural hematoma

- below the dura mater

- more seniors and have a high likelihood of death (60-80%)

- tearing of bridging veins, dial artery, or cortical veins

- damage to brain tissue

Traumatic subarachnoid hemorrhage

laceration of vessels in subarachnoid space

- the blood is getting into the main cerebral tissue

Intraventricular hemorrhage

- very severe TBI

- poor prognosis

Intracerebral hemorrhage

- parenchymal injuries from lacerations or contusions

- large deep cerebral vessel injury

hemorrhage

blood is coming out into brain tissue

Coup

direct skull impact

countercoup

opposite side of impact

coup and countercoup injuries

- due to negative pressure forces causing both vascular and tissue damage

Diffuse axonal injury

- damage to nerve cells in the connecting fibers of the brain

- large hit to the head that causes break down