Traumatic Brain Injury Flashcards
Moderate to severe traumatic brain injury (TBI)
results from damage to brain tissue caused by an external mechanical force, can include:
loss of consciousness
post-traumatic amnesia (PTA)
positive neuroimaging, or
objective neurological findings attributed to TBI on physical or mental status examination
Uncomplicated mild traumatic brain injury (mTBI)
“concussion:
Involves a traumatically induced physiological disruption of brain function that results in a graded set of clinical symptoms that most often resolve spontaneously.
Alteration or loss of consciousness and other transient neurologic signs are typically used to define mTBI.
Primary Injury examples of TBI
skull fracture
contusion
subarachnoid hemorrhage
mechanical injury to axons and blood vessels.
Because of the anatomical arrangement of the brain and skull, focal injury is most common in the frontal and temporal lobes.
Diffuse axonal injury tends to be most prominent at the gray–white matter junctions.
Secondary Injury examples of TBI
Hypoxia
ischemia
swelling/edema
hypotension
mass lesions
increased intracranial pressure (ICP)
poor cerebral perfusion pressure.
Risk factors for TBI based on age
0-7 years: falls or child abuse
15-24: motor vehicle related injuries
65+ falls
Risk factors that increase the likelihood of persistent problems (>3 months post injury) after mTBI include:
- medical factors (prior neurological injury, recent/multiple mTBIs, chronic pain or medical conditions)
- demographic (female, less education)
- mental health (depression, substance use, misattribution bias)
- secondary gain (litigation, disability incentives)
Rates of TBIs
mild: 70-80%
moderate: 20%
severe: 15-20%
mTBI but with positive neuroimaging is called
complicated mTBI
Functional outcome after such injury tends to be similar to moderate TBI.
Classification of TBI severity can be accomplished using a combination of various indicators:
Glasgow Coma Scale (GCS) score
Time to follow commands (TFC)
Length of PTA
*however, no universally accepted TBI classification system exists
Recovery after moderate to severe TBI often takes more than
1 year
Two general approaches to cognitive rehabilitation
restorative skills training - focus on treatments intended to reinforce or directly improve specific cognitive domains
compensatory skills training - teach patients strategies to compensate and adapt to cognitive impairments
computer- based cognitive rehabilitation has very limited utility in improving function. Instead, broad-based, real-world training in problem solving and compensatory techniques tends to be the most effective treatment.
TBI neuropsychological expectations
“Hold tests” (vocabulary, information) are generally unaffected
Processing speed (most commonly impacted d/t impact on white matter integrity)
Complex attention problems (divided) - children who sustain moderate to severe TBI may develop secondary ADHD.
Possible visual spatial difficulties secondary to EF
Memory, again possible d/t EF - reduced processing speed, learning capacity, and organizational skills, thus leading to faulty encoding, storage, and retrieval.
Depression and anxiety are common following TBI
Chronic Traumatic Encephalopathy (CTE)
a unique distribution of p-tau accumulates in the depths of the cortical sulci, which in turn is associated with severe behavioral, cognitive and mood changes in older adulthood.
BUT Recent comprehensive literature reviews suggest that the neuropathological changes described in CTE are not unique to that condition, and that a sizable percentage of persons who have such changes will not develop dementia or commit suicide.
Glasgow Coma Scale (GCS)
A scale that assesses responsiveness in patients who have sustained brain injury.
There are three parameters: eye opening, motor response, and verbal response.
The scale ranges from 3 to 15, with scores of 8 or less indicating severe injury and scores over 13 associated with mild injuries.
It is common to use the term “complicated mild” with GCS over 13 in the context of positive acute neuroimaging findings.
In severe TBI, lower GCS (3 to 5) is clearly associated with increased mortality rates.
What is the best predictor of TBI prognosis?
PTA
Subdural hematoma (SDH)
Caused by rupture of bridging veins between sulci on the upper surface of the brain. In high-speed injuries, hematomas are commonly found in the frontal and anterior temporal lobes due to the skull and brain’s anatomical arrangement.
The primary role for neuroimaging in the acute phase following moderate to severe TBI?
neurosurgical planning (e.g., epidural or subdural hematoma causing significant midline shift)
as opposed to determining severity, which is done with GCS, TFC, and PTA.
Low stimulation protocols are commonly implemented during the acute phases of recovery following moderate to severe TBI primarily to
reduce the cerebral metabolic rate
Even when severely injured the brain will expend energy when exposed to external stimulation (e.g., noise, bright light, tactile stimuli).
Low stimulation protocols also result in less sensory processing demands on the individual and thus are primarily employed to reduce the cerebral metabolic rate.
Following mild TBI in children and adults, postconcussive symptoms persisting beyond a month have been found to benefit most from interventions aimed at…?
physical exercise - that does not worsen symptoms reduced postconcussive symptoms in “active rehabilitation” models.
Which combination of factors would generally have the most impact on long-term outcome following traumatic brain injury in a pediatric patient?
injury severity and psychosocial support
Compared to acceleration-deceleration brain injury, penetrating brain injury carries a higher risk for…?
seizure and infection
Penetrating head trauma typically results in blood-brain barrier compromise and the introduction of foreign matter into brain parenchyma (e.g., bullet fragments, bone shards, hair). These factors significantly increase the risk for infection and seizure relative to nonpenetrating injuries.
What are the most common physical complaints following moderate to severe traumatic brain injury in adults?
fatigue and sleep disturbances
What symptoms tend to contribute to poorer community re-entry in adults with severe TBI?
personality changes and behavioral problem
What cognitive domains will most likely generalize to real-world tasks using direct retraining techniques?
Attention, visual scanning, and spatial organization
Brain injury during which school years confers the most risk for a poor outcome?
Preschool. Children who sustain traumatic brain injury during infancy and early childhood have worse neuropsychological and functional outcomes than those injured in later childhood or the teenage years.
The most common sites of brain contusion in TBI due to jagged bony prominence abutting brain tissue in the cranial vaults are:
anterior temporal lobes and orbitofrontal regions abut jagged bony prominence
Brain regions most impacted by coup-countercoup injury?
Frontal and temporal lobes
