Traumatic Brain Injury [Guest Lecture] Flashcards
List the protective coverings of the brian from outside in
Scalp/Hair [2-6mm thick, thinner at temporal fossa]
Dura mater [inelastic]
Arachnoid mater [elastic]
Pia mater [vessels]
Define TBI
Sudden external trauma that causes injury to the brain
Describe the difference between an closed and open/penetrating TBI
closed = everything says inside
open = tissue can escape the site, ex. GSW, stab wound, etc
Describe the difference between a focal and diffuse TBI
Focal = pinpoint, severity depends on locaiton
Diffuse = widespread, “storm in their head” “everything bothers me” “cant get a hold on it”, angry, HA, easily agitated
Type of Injury:
- Forceful blow to resting, moveable head
- Max injury at point of cranial impact
- Contusion w/w/o skull fx
- Ex. hit over head with a bat
Coup Injury
Describe a coup injury
- Forceful blow to resting, moveable head
- Max injury at point of cranial impact
- Contusion w/w/o skull fx
- Ex. hit over head with a bat
Type of Injury:
- Moving head
- Injury is opposite of impact
- Frontal and temporal lobes
- Ex. Run into fence and land on face, injury to back of brain
Contracoup Injury
Describe a contracoup injury
- Moving head
- Injury is opposite of impact
- Frontal and temporal lobes
- Ex. Run into fence and land on face, injury to back of brain
Type of Injury:
- Whiplash injury
- Multiple areas of the brain injuried: temporal, frontal, occipital
- Ex. MVA, Quarterback sacked
Coup/Contracoup Injury
Describe a coup/contracoup injury
- Whiplash injury
- Multiple areas of the brain injuried: temporal, frontal, occipital
- Ex. MVA, Quarterback sacked
Describe the function of teh CSF
- Shock absorber
- Dissipates forces
- Acts as a buffer
Describe primary damage post TBI
Combination of all the forces on the brain tissue i.e.
- Compression/swelling
- Tensile/stretching
- Shearing/tearing (hard/slow recovery)
Type of force: axon tearing
Shearing or diffuse axonal injury (DAI)
Describe secondary damage post TBI
- Brain swelling resulting in cerebral edema, increased ICP, seizure, and hypoxic ischemic injury
- Anoxia or no oxygen
- Hypo/hypertension
- Hematoma/compression
List the types of hematoma
- Epidural = b/t skull and ura
- Subdural = b/t dura and arachnoid
- Intracerebral = w/in cerebrum
List the top causes of TBI
- MVA
- Violence/GSW/War
- Falls
- Sports injuries
- Pedestrian/cycling accident
- OD/Poisoning
- Drowning
- Carelessness
Type of brain injury:
- No loss of consciousness
- Experiences changes in one of the following areas: physical, cognitive, behavioral
- Ex. concussion
Mild Brain injury
Describe second impact syndrome
Second impact syndrome occurs when a secondary TBI occurs shortly after a primary TBI. This results in loss of autoregulation of the blood supply to the brain which causes swelling, and can be fatal
Describe the physiology behind second impact syndrome
When the second impact occurs there is excitotoxicity due to lack of cerebroregulation
- Na/K pump disrupted > Ca leaks into vessels > Lactic acid/H+ ion build up > lactate (salt) > decrease pH/increase acidity > blow off excess CO2
- Brain detects acid change > increased breathing, HR, vasodilation
Describe the sequence of events involved with second impact syndrome
Initial concussion impairs normal brain function
Second impact unleashes series of metabolic events
Loss of autoregulation of blood vessels in the brain
Congestion, vasodilation, and large increase in BF
Large increase in ICP
Herniation of brain structures through foramen magnum
List the long term consequences of repetitive mild TBI
Neurodegenerative diseases
Mild cognitive impairment
Alzheimer’s
Chronic Traumatic Encephalopathy
Depression
Type of brain injury:
- Loss of consciousness (minutes to hours)
- Confusion (days to weeks)
- Changes in physical, cognitive, behavioral traits (months-permanent)
- Can make complete recovery and compensate for deficits
Moderate TBI
Type of brain injury:
- Coma or prolonged unconsciousness
- Can recover
- Deficits in physicallity, congition, and behavior are permanent
Severe TBI
List the factors that contribute to the amount of improvement made s/p TBI
Extent of injury
Neuroplasticity
Describe the ways the brain makes adapatations s/p TBI
- Old pathways can take new routes
- Uninjured neurons can tak over via regenerative or collateral sprouts
- The brain reorganizes to store new information
- New connections can be formed
Describ ethe Glasgow Coma Score and it’s cut off scores
It is a scale that looks at eye opening, verbal repsonse, and motor response to assess severity of injury in the field and the ability to recover
< 8 = poor px
> 12 = good chance of recovery
Max score = 15
Level of consciousness: unresponsive but aroused by strong stimulus
Stupor
Level of consciousness: unconscious, unaware, unarousable, absnet sleep/wake cycle
Coma
Level of consciousness: unconscious and unaware but have sleep/wake cycle and periods of alertness
vegetative state
Level of consciousness: don’t recover within 30 days
persistent vegetative state (PVS)
Level of consciousness: Aware and awake but can’t move or communicate except by blinking
Locked-in syndrome
Describe the Rancho Los Amigos recovery classification system
Assess the level of cognitive functioning by looking at the whole person from information gathered across disciplines
The scale goes to 10
You can jump levels
LOOK AT LEVELS CHART
