Week 8 - Trauma & Head Injuries Flashcards
head injuries can be…
- mild and have no permanent effects
2. life-threatening & cause massive brain damage & icnreased ICP
what are 3 types of head injuries
- concussion
- contrecoup
- contusion
what is a concussion
- a reversible interference in brain function resulting from a blow to the head
what are symptoms of a concussion (4)
- loss of conciousness
- disruption of neural function
- headache
- retrograde amnesia of events immeditaly following the blow
does permanent damage occur with one concussion
- no, typically brain imaging cannot detect permanent damage
what does multiple concussions cause
- act synergistically to produce permanent neurological impairment
describe symptoms following a consussion
- pts can have post-concussion symptoms that last 4-6 weeks
- ex. headache & insomnia
what is a contrecoup head injury
- a rebound injury
- when a blow causes the skull & brain to move backwards & the momentum causes the brain to hit the opposite side of the skull
provide an example of a contrecoup head injury
- a boxer gets punched in front of the head
- this causes the face to get blown back, and the brain to bounce off the back of the head
direct injury = front of head
contre coup = back of head
what is a contusion
- bruising of the brain tissue resulting from rupture of small blood vessels
what can a contusion cause
- depending on the severity of the blow, it can cause increased ICP
what are 4 types of skull fractures
- simple
- compound
- depressed
- basilar
what is a simple fracture of the skull
- break in the continuity of the bone
- but the wound (skin) remains closed
what is a compound fracture of the skull
- break in the continuity of the bone & the skin
- an open fracture where the brain tissue is exposed to the enviro
what is a risk of compound fracture
- risk of infection
what is a depressed fracture
- when a piece of bone is displaced below the level of the skull & compresses the brain
what causes a depressed fracture
- often something heavy falling on the head
what is a basilar fracture
- fracture that occurs at the base of the skull
what does a basilar fracture often involve?
- the ethmoid bone, specifically the ethmoid cirbriform plate
where is the cribriform plate found
- roof of the nasal cavity & is very fragile
what are signs of a basilar skull fracture
- leaking CSF thru the ear = otorrhea
- leaking CSF thru the nose = rhinorrhea
what are risks associated with basilar fractures
- risk of infection
- laceration of blood vessels or nerves due to sharp edges of the bone
why is there increased risk of infection w basilar fracture
- the nasal cavity contains lots of bacteria, and now that the ethmoid bone has broken, this bacteria has access to the brain
what are 2 categories of brain damage
- primary
2. secondary
what is primary brain damage
- direct injuries to the brain that occur immediately due to the impact
what are examples of primary brain damage (6)
- concussion
- contusion
- laceration
- hemorrhage
- hypoxia
- diffuse axonal lesion (shearing lesions)
what is secondary brain damage
- damage that results from subsequent:
- brain swelling
- intracranial hematomas
- infection
- ischemia
- hypoxia
what is an intracranial hematoma
- collection of blood in a tissue that results from ruptured blood vessels
when can intracranial hematomas occur
- immeditaley following an injury
- after some delay
what are 3 types of intracranial hematomas
- epidural
- subdural
- intracerebral
what is an epidural hematoma
- bleeding above the dura mater, between the dura mater & bones of the cranium (which are typically firmly attached)
what is a subdural hematoma
- accumulation of blood within the potential space between the dura & arachnoid mater
describe the onset of symptoms for a subdural hematoma (3)
- can occur within 24 hrs after injury (acute)
- can develop slowly, about a week after (subacute)
- or weeks later (chronic)
what is an intracerebral hematoma
- accumulation of blood within the cerebrum
what can cause an intracerebral hematoma
- contusion
- shearing injury
- stroke
what manifestations does primary damage to the head often cause
- focal injuries = symptoms based on what part of the brain was effected
what do secondary injuries often result in
- increased ICP
list 4 other symptoms of head injuries
- seizures
- cranial nerve damage
- otorrhea, otorrhagia, rhinorrhea
- fever
how can head injuries cause seizures
- the blood & inflammation can irritate neural tissue = lose electrical control = seizures
- also the release of K+ from damaged neurons
what is cranial nerve damage common in
- basilar fractures
what is otorrhea, otorrhagia, and rhinorrhea
- CSF of blood leaking from the ear or nose
what 2 signs does otorrhea, otorrhagia, and rhinorrhea cause
- raccoons eye = bruising around the eyes
- battle sign = bruising behind the ear
what do otorrhea, otorrhagia, and rhinorrhea cause
- increases the risk of infection
how can head injuries cause fever
- infection
- hypothalamic impairment (important role in temp)
what can mask the early signs of increased ICP? (2)
- alcohol & drugs
how do drugs & alcohol mask the signs of increased ICP
- have similar symptoms
2. causes dehydration
how does dehydration associated w alcohol mask the signs of increased ICP
- makes the injury seem better in the beginning bc dehydration = decreased P
- but, once the alcohol is metabolized it produces a vasodilator = increased P by dilating vessels in the brain
what complication may occur if there is increased ICP?
- pressure on brainstem =
1. decreased cough reflex
2. decreased RR
= risk of pneumonia is the pt is laying prone
what can worsen neurological symptoms & brain damage
- hypoxemia
