Acquired Brain Injury (Exam 2) Flashcards
What is a Traumatic Brain Injury?
Bump, blow or jolt to the head that disrupts normal function of the brain
Who is at greatest risk of TBI?
- Older adults (>75)
- Infants
- Older adolescents/young adults (15-34)
- Males 2x as likely>females
In a moderate to severe TBI what is brain damage a result of?
- External forces (primary injury)
- Rapid acceleration/deceleration forces (primary injuries)
- Blast waves from an explosion (Blast injury)
What is a closed head injury (CHI)?
- Non penetrating head injuries
- Accelerating or decelerating blow
What damage can be done as a result of a CHI?
- Minor to severe & irreversible brain damage
- May see brainstem damage, contusions, diffuse white matter lesions, injury to blood vessels, damage to cranial nerves or CSF rhinorrhea
What is an open head injury and what causes it?
- Meninges have been breached
- Caused by:
- Penetrating head injuries
- May be caused by accelerating or decelerating force
What damage can be done as result of OHI?
Amount of functional damage depend on areas affected
What classifies a TBI as a primary injury?
Direct trauma to paraenchyma
What are the 2 ways a primary injury (TBI) can occur?
- Brain tissue come in contact with an object (skull, bullet, sharp object) can be OHI or CHI
OR - Rapid Acceleration/ Deceleration of the brain causing cortical disruption (diffusion axonal injury, tissue tearing, intracerebral hemorrhages)
Primary injuries are generally a (BLANK) injury and where do these injuries occur?
- Focal Injury
Occurring: - Anterior temporal poles
- Frontal poles
- Lateral & inferior temporal cortices
- Orbital frontal cortices
What is a coup-contrecoup injury and what TBI classification does it fall under?
- Brain bouncing causes diffusion axonal injury (DAI)
- Falls under primary injury
What is a diffuse axonal injury (primary injury)?
Microscopic injury of the white matter axons related to shear/stretch/ tensile strain
- Axons twist & tear at the gray & white matter junctions
Where do diffuse axonal injury typically occur?
- Parasagittal white matter of cerebral cortex
- Corpus callosum
- Brainstem (pontine mesencephalic junction)
T/F: Diffuse Axonal Injury is the predominant MOI in moderate to severe brain injury
True
- Acute medical management is to prevent secondary injury
- Intensive rehab warranted
Describe the grade of Diffuse Axonal Injury:
Grade 1
Grade 2
Grade 3
Grade 1: Microscopic level evidence in cortex
Grade 2: Grade I & corpus callousum
Grade 3: Grade 2 & brainstem lesion
What are the 3 mechanism of primary blast injury?
- Direct transcranial blast wave propagation
- Transfer of kinetic energy from blast wave through the vasculature, triggering pressure oscillations in the blood vessels leading to the brain
- Elevations in CSF or venous pressure caused by compression of the thorax & abdomen & by propagation of the shock wave through the blood vessels or CSF
What can cause a secondary blast injury?
Shrapnel & other object being hurled at a person
What can cause a tertiary blast injury?
Victim flung backwards & strikes an object/ground
What can cause a quaternary blast injury?
Can be caused by exposure to resulting fire/fumes/toxins from explosion
What causes a secondary injury and what happens as a result?
- Caused from the reaction to primary trauma
- Occurs over hours to days
- Secondary injuries cause metabolic cascade & secondary cell death
What is Metabolic Cascade? And what causes secondary cell death?
Metabolic Cascade: Excitotoxicity & free radical formation
Secondary cell death is caused by:
- Elevated ICP
- Herniation (Secondary to edema)
- Vascular changes (Hypoxia/ischemia and/or hemorrhage)
- Neurochemical changes
- Infections
What is ICP?
- Intracranial Pressure
- Pressure within the skull & on the brain comprised of a fixed volume of neural tissue, blood & CSF
What is the normal value of ICP?
5-19 mmHG
What are some causes of increased ICP with TBI?
- Hematoma (epidural, subdural or intracerebral)
- Swelling (inflammatory response)
- Increased blood volume due to vascular damage (creates mass effect or midline shift)
- Blockage of typical drainage of venous outflow
- Impaired reabsorption of CSF
What can cause a herniation?
- Increased ICP or edema can cause herniation
- Brain shifts across structures within the skull (Cerebral herniation)
What is the location and effect of subfalcine/Cingulate herniation?
- Location: Frontal/parietal brain extends under falx cerebri
- Effects: Compress anterior Cerebral A with hemiparesis LE > UE
What is the location & effect of Uncal herniation?
Location: CNIII, Cerebral peduncle, Reticular activating system (RAS), PCA
Effects: CNIII paralysis & pupillary dilation, contra-hemiparesis, coma, homonymous & hemianopia
What is the location & effect of central transtentorial herniation?
Location: Midbrain & pons, RAS
Effects: Decerebrate rigidity, Coma
What is the location & effect of Tonsillar herniation?
Location: Cerebellar tonsils, Indirect activation pathways, RAS, Vasomotor centers
Effects: Neck pain & stiffness, cerebellar sxm, flaccidity, coma, Alt HR, RR, BP
Where do cerebral contusions most frequently occur at?
- The poles
- Inferior frontal & temporal lobes
What are the 4 main types of hematoma and where do they occur?
- Epidural: between skull & dura
- Subdural: Under dura
- Subarachnoid: Between brain & meninges
- Intracerebral
What can hypoxia/hypotension be related to?
- Impaired cardio/respiratory function associated with the injury (Low blood pressure)
- Not adequate perfusion to the brain
What area are most affect by hypoxia/hypotension?
Watershed areas
What areas of the brain are most affected by anoxia?
- Hippocampus
- Basal Ganglia
- Cerebellum
Neurochemical changes occur as a result of an inflammatory result what are 3 way this occurs?
- Increased release of excitatory neurotransmitters, glutatmate (Exacerbates ion channel leakage increasing swelling & ICP)
- Membrane depolarization (non selective opening of calcium channels leading to abnormal accumulation of calcium & other ions within the cell causing cell death
- Release of free radicals & cytokines
What are some brain infections?
- Encephalitis (sub-dural/epidural)
- Meningitis (membranes surrounding the brain)
- Abscess (within the brain)
What can cause a fever?
- Damage to the brain that regulates temperature
OR - Infection
What is brain death?
- Irreversible cessation of all functions of the entire brain, including brainstem
- Person is in permanent coma, brainstem reflexes have stopped working, breathing has permanently stopped
- Electrocerebral silence (EEG w/ absence of electrical potential of cerebral organs over 2 microvolts)
What are the tests carried out to determine if someone is brain dead?
-Pupillary response
- Corneal reflex
- Snout reflex (pressure applied to forehead & nose is pinched to see if any movement)
- Cough reflex (thin plastic tube is placed down windpipe)
- Apnea (disconnected from ventilator)
Mild TBI:
LOC?
Alteration of consciousness?
Post Traumatic Amnesia?
GCS?
Neuroimaging ?
LOC: 0-30 min
Alteration of consciousness: Brief, <24 hr
Post Traumatic Amnesia: 0-1 day
GCS: 13-15
Neuroimaging: normal
Moderate TBI:
LOC?
Alteration of consciousness?
Post Traumatic Amnesia?
GCS?
Neuroimaging ?
LOC: >30 min but <24 hr
Alteration of consciousness: >24 hr
Post Traumatic Amnesia: >1 & <7 days
GCS: 9-12
Neuroimaging: Normal or Abnormal
Severe TBI:
LOC?
Alteration of consciousness?
Post Traumatic Amnesia?
GCS?
Neuroimaging ?
LOC: >24 hr
Alteration of consciousness: >24 hour
Post Traumatic Amnesia: >7 days
GCS: <9
Neuroimaging: Normal or Abnormal
What is involved in emergency evaluation of acute medical management of TBI?
- Priority: Airway, Breathing, Circulation (stabilize CV & respiratory systems for brain perfusions)
- Manage other high priority injuries
- Glasgow Coma Scale at scene
What is the Glasgow Coma Scale?
Widely accepted scale to document level of consciousness
What 3 areas are patients graded on using the Glasgow Coma Scale?
Eye opening: 1-4
Best Motor Response: 1-6
Best verbal response: 1-5
Using the GCS what score indicates:
Mild
Moderate
Severe
Mild: 13-15
Moderate: 9-12
Severe: 8 or less
What are some acute care goals of TBI management?
- Determine severity (neuroimaging)
- Minimize secondary brain damage
- Control for:
Elevated ICP, Edema, Cerebral blood flow & O2, hypotension, bleeding
When is ICP monitoring recommended?
- GCS = 8 or less
- Abnormality on CT
- SBP <90mmHg
- Age > 40 y/o
- Motor posturing
How is ICP measured?
- Extra ventricular drain
- Subdural bolt
- Fiber optic catheter
Name some ways to manage ICP
- sedating meds
- head position
- osmotherapy
- hypothermia
- barbituates
- induce pharmacological coma
- surgical decompression
What is normal cerebral perfusion pressure (CPP)?
Normal = 60-80 mmHg
How do you calculate CPP?
MAP-ICP
What are the goals of neurosurgery and the common ones?
Goals:
- Relieve pressure
- Evacuate blood
- Debridement
Surgeries:
- Craniotomy (burr holes)
- Cranioectomy
What is a craniotomy?
- Bone flap is removed
- (replaced after repair)
What is craniectomy?
Removal of part of the skull to relieve pressure
What is a cranioplasty?
Skull back on
What is the appropriate first aid when someone has a seizure?
- Ease person to floor
- Turn person gently to side
- Clear area
- Put something soft & flat under the head
- Remove glasses
- Loosen ties or anything around the neck
- Time the seizures
When should you call 911 if someone has a seizure?
- Never had one before
- Difficulty breathing or waking after
- Last longer than 5 min
- Has another one soon after 1st
- They are hurt
- Other health condition
- Happens in water
What is paroxysmal sympathetic hyperactivity or sympathetic storming and what does this result in?
- Sympathetic nervous system activity can become overactive after TBI
Results in:
- increase HR, RR, BP
- Diaphoresis
- Hyperthermia
- Posturing/hypertonia
- Teeth grinding
What is the PT management is a patient has sympathetic storming?
- Monitor patient
- Call MD & RN
- Terminate therapy for the day
What is the focus on in pharmacology in acute care?
- Focused on minimizing secondary injury
with the use of pharmacology how can reducing the rate of secondary injury be achieved?
Mannitol: diuretic used to reduce ICP
System management: HR, BP, RR
What is the management of Fx?
- Stabilization
- Immobilization
- Weight bearing precautions
What is the contracture prevention/management?
- Orthosis
- Serial casting
What are some caused of pediatric TBI?
- Falls
- Shaken baby syndrome
- Drowning
What scale is used for pediatric TBI?
Pediatric Glasgow Coma Scale (modified for children under 2)
Where is injury most like to occur in a pediatric TBI?
Temporal & orbitofrontal lobes
Why are infants less likely to have skull fx?
B/c pliancy of the skull
Describe the Rancho Los Amigos Levels of Cognitive Functioning (LOCF)
- Descriptive scale that classifies levels of cognitive & behavior recovery
- 8 categories/kevels
- Helps track change over time
- Develops & guides interventions
- Provides method of communication between professional
Describe Level 1: No response of LOCF
- Pt not responsive to any stimuli
- Appears in a deep sleep
- No sleep wake cycle
- Reflexive motor movement only
Describe Level 2: Generalized response of LOCF
- Inconsistent & non purposeful responses
- Limited Amt of repsonse
- Response is not specific to stimuli
Describe Level 3: Localized response of LOCF
- Response continues to be inconsistent
- Response is directly related to the type of stimulus presented
- May follow one step commands
- Visual tracking
Describe Level 4: Confused and agitated of LOCF
- Heightened state of activity
- Behavior is not purposeful & bizarre relevant to environment
- Pt is driven by confusion
- Attention is brief
- Memory is impaired
- Pt may be aggressive
- Unable to cooperate directly w/ treatment efforts
- Unable to learn new info
Describe Level 5: Confused and inappropriate of LOCF
- Pt is now able to follow simple commands consistently
- In a more complex environment/task the response are more random
- W/ structured environment may be able to socialize on an automatic level for short period
- Extremely distractible
- Verbalizations (inappropriate, confabulatory)
- Memory severely impaired
- Unable to learn new info
- Poor safety awareness
Describe Level 6 of LOCF (Confused - appropriate)
- Goal directed behavior w/ external input
- Recognizes basic needs & perform automatic task
- Shows carryover of re-learned tasks
- Follows simple command consistently
- able to follow a schedule
- Memory probs (long term is better than short term)
Describe Level 7 of LOCF (Automatic - Appropriate )
- Patient is now oriented in environment
- Follows daily schedule & routine in a robot-like way
- Unable to recall all details of daily events
- New learning possible w/ extra time
- Ongoing safety concerns & impaired judgment
Describe Level 8 of LOCF (Purposeful - appropriate)
- Able to recall & integrate past and recent events
- Aware of & responsive to environment
- Independent in the home
- Developing community reentry skills
- Shows carryover w/ new skills & no supervision required once skill is learned
