Types of Head Injuries

• closed head injury
• open head injury
• traumatic brain injury

• occurs when a person receives an impact to the head from an outside force, but the skull does not fracture or displace
• brain swells

• the brain may expand through any available opening in the skull (including eye sockets)
• can cause CNs controlling eye mm to be impaired (CN III impaired = pupil appears dilated)

in a closed head injury, when herniation or cranial compression occur

Open Head Injury

brain has room to swell, which can reduce compression of brain tissue and ICP

b/c skull is damaged or open, it can't protect the brain as it did before (exposed and vulnerable to infection and damage)

if skull is fractured or displace, bone fragments from the skull can enter the brain and cause further injury

open head injury w/ obvious skull deficits

helmet

• depressed
• compound
• basilar

• raccoon eyes
• battle's sign

broken piece moves in towards the brain (open or closed)

scalp is disrupted and the skull is fractured

located at base of skull (neck area) and may include the opening at the base of the skull

bruising around eye orbits

blood collects behind the ears and causes bruising

eyes and nose

Traumatic Brain Injury

• concussion
• contusion
• diffuse axonal injury
• coup-contrecoup injury
• second impact syndrome
• penetration
• locked-in syndrome
• shaken baby syndrome

injury is greatest in where the density difference is greatest

gray-white matter junction

any

• shaking or strong rotation of the head, or by rotational forces
• the stable brain lags behind any movement of the skull causing long tracts in the brain to stretch and then tear

MRI (not CT)

tracts are disrupted

white blood cells (this causes more damage when they mistakenly target both healthy and unhealthy tissue)

• temporary, permanent, localized, or widespread brain damage
• coma
• death

could have variety of functional impairments depending on where shearing occured

brain receives trauma from an impact or a sudden movement or momentum change

• become stretched or torn (causing hemorrhage)
• CN damage can also occur

• direct blow to head
• gunshot wound
• violent shaking of the head
• whiplash

both

concussions

20

dazed or punch drunk

may or may not b/c damage may only be microscopic, non-localized, but widespread

complex neurobehavioral syndrome

can cause diffuse axonal type injury resulting in permanent or temporary damage

few months to a few years

• may report problems w/ concentration, recent memory, abstract thinking
• dizziness, irritability, fatigue, double vision, and personality changes
• elderly pts are particularly affected by disequilibrium and chronic dizziness

direct impact to the head

localized bruise (bleeding) on the brain (macroscopic)

orbitofrontal cortex, anterior temporal lobe, and posterior portion of superior temporal gyrus area (w/ adjacent parietal area)

contusions that occur from the impact, w/ damage at the site of the blow as well as damage from "rebound" when the brain hits the opposite side of the brain

when the force impacting the head is not only great enough to cause a great contusion at the site of impact, but also is able to move the brain and cause it to slam into the opposite side of the skull, causing additional damage

recurrent TBI

a person sustains a second TBI before the damage from the 1st TBI has healed

from days to weeks following the 1st

no

brain swelling and widespread damage

b/c death can occur rapidly

• muscle spasms
• increased muscle tone
• rapidly changing emotions
• hallucinations
• difficulty thinking and learning

• impact of a bullet, knife, or other sharp object that forces hair, skin, bone, and other foreign fragments into the brain
• OR
• objects traveling at low rates of speed through the skull and brain that can ricochet w/in the skull, widening the area of damage

• occurs if an object enters the skull, goes through the brain and exits the skull
• --include effects of penetration injuries plus additional shearing, stretching, and rupture of brain tissue

• rare neurological condition in which a person can't physically move any part of the body except the eyes
• person is conscious and able to think
• vertical eye movements and eye blinking can be used to communicate w/ others and operate environmental controls

describes any trauma that occurs to the brain after birth

• TBI
• disease processes (brain tumors, stroke, infection, substance disease)
• anoxia

lack of blood supply to the brain

when the brain does not receive any oxygen

when the brain has insufficient oxygen

anoxic brain injury

anoxic brain injury

• near drwoning
• pts w/ myocardial infarctions who survive but whose brains are w/o O2 for too long
• unsuccessful attempts of suicide
• smoke inhalation
• chest trauma
• electrocution

• occur with or w/o open brain injury
• some kind of trauma causes vessels to leak

• subdural hematoma
• epidural hematoma
• subarachnoid hematoma
• intraparynchemal hematoma

collection of blood below the inner layer of the dura but external to the brain and arachnoid membrane

subdural hematoma

• appear soon after trauma (24-48 hrs)
• initial loss of consciousness, but then appear fine
• later, may become unconscious as bleeding in brain continues
• may report feeling drowsy, having bad headache, nausea, and/or vomiting
• may become confused and/or develop weakness of limbs on one side of the body and speech difficulties
• some have seizures

traumatic accumulation of blood b/w inner table of skull and dural membrane

a focused blow to the head, such as that produced by a hammer or baseball bat

an overlying fracture of the skull

blood vessels in close proximity to the skull fracture

• b/c underlying brain has usually been minimally injured, prognosis is excellent if treated aggressively
• outcome from surgical decompression and repair is related directly to pt's preoperative neurologic condition

• depend on severity of brain injury
• brief period of unconsciousness followed by a period of alert consciousness before returning to unconsciousness or even coma
• symptoms occur w/in minutes to hours
• confusion/dizziness/drowsiness/varied alertness
• severe headache
• nausea and/or vomiting
• seizures
• enlarged pupil in one eye
• weakness on one part of body, typically side opposite of enlarged pupil
• bruises around eyes/behind ears
• CSF draining from nose or ears
• SOB or changes in breathing

blood leaking into the CSF (bathing and circulating around the brain under the arachnoid)

• primarily headache (worst of pt's life)
• some dizziness

• blood pools in white matter of brain
• can cause diffuse axonal injury

white matter shear injury -- extensive loss of axons w/ extensive brain injury

head CT, MRI (subarachnoid by lumbar puncture - blood in CSF); cerebral angiography (exact location of bleed)

• craniotomy, blood evacuation, ICP monitoring
• meds: anti-seizure, diuretics to reduce swelling, hyperosmotic agents, anti-hypertensives, calcium channel blockers
• head of bed elevated to relieve cerebral pressure (reverse trendelenberg)
• hydrate, but avoid fluid overload