NPch15 Traumatic Brain Injury Flashcards
(62 cards)
1
Q
Traumatic brain injury
A
An alteration in brain function or pathology due to external force
- Physical trauma
2
Q
What are two types of TBI?
A
- Closed head injury (CHI)
- Penetrating head injury (PHI)
3
Q
Acquired Brain Injury
A
Any type of damage to the brain that occurs after birth
- TBI is the most common type of ABI among people under 50 yrs
- Other aetiologies, like stroke belong under ABI
4
Q
Epidemiology of TBI - how common is it?
A
- Most common cause of brain damage in children and young adults
- Recent data suggest approximately 85,000 people per year in the Netherlands (underestimate - many not hospitalised)
- Increasing rate of TBI in older people due to ageing population and higher survival rates
5
Q
Incidence
A
- Peak ages: 15-24 yrs, first 5 yrs and elderly
- Men sustain TBIs twice as frequently as women (men engage in behaviours that result in TBI more often)
6
Q
What are risk factors contributing to TBI?
A
- Lower SES, uneployment, and lower education (probably because of the behaviours these people engage in)
- Alcohol and substance abuse significantly contribute to TBI incidence (no enough reflexes to stop the fall, agression)
7
Q
What are main causes of TBI?
A
Falls, transportation-related injuries (cars, motorbikes) and blows to the head caused by violence
8
Q
What are long-term implications of TBI?
A
- Long-term mortality associated with age, lack of independence, and tube feeding
- Late-life dementing illnesses and neuropsychochiatric sequlae common
- Specific risks in retired athletes, e.g. rugby or American football
9
Q
How can we distinguish between the different phases TBI is in, in regard to recovery?
A
- Acute phase (which lasts up to 1 month)
- The subacute phase (lasting up to 6 months)
- The chronic phase
10
Q
Classification
How do we classify TBI based on severity? What are the different effects?
A
- TBI severity spectrum
- Mild impacts leave no lasting effects
- Severe TBIs can lead to prolonged coma and extensive brain damage
- Severity correlated with long-term social and cognitive effects
- Glasgow coma scale (GCS)
11
Q
What is Glasgow Coma Scale? What are the 3 domains? How do you interpret the score?
A
- Used to test the spontaneous reaction of a patient to being addressed or having pain stimuli applied
↪ Helps mp the severity of impairments of consciousness (3-15 point scale) - Three domains:
1. Eye opening
2. Motor response
3. Verbal response - For each you can get a rating and based on that they decide the severity of the injury
- Low score = more severe, high score = less severe
- Criticism: when it is administered differs - not ideal to predict longer term outcomes = might be incorrect
12
Q
What is Post-Traumatic Amnesia? How do we split in two types?
A
Post-Traumatic Amnesia - loss of memory due to TBI
- The moment of accident forms a dividing line between the two parts of PTA
1. Retrograde Amnesia
2. Anterograde Amnesia
13
Q
Retrograde amnesia
A
Amnesia about the time prior to the accident and the accident itself
- over time, RA ‘shrinks’ and the remaining amnesia concerns the period shortly before the accident
↪ result of interruption in the consolidation process
14
Q
Anterograde amnesia
A
Occurs after the accident, as a result of which new info cannot be stored
15
Q
What is PTA predictive of? How is PTA correlated with severity of TBI?
A
- Duration of PTA often correlated with GCS but offers finer scalping
- PTA more predictive of long-term cognitive status and neuroimaging findings (compared to GCS)
- Most predictive of long-term cognitive status
- Helps determine the presence and severity of a TBI
- Increasing duration of PTA corresponds to more severe injury
16
Q
What are some non-behavioural measures of TBI?
A
- Neuroimaging and electrophysiological measures like EEG used for damage assessment
- CT scans commonly used in acute stages for their cost-effectiveness and availability
- MRI is preferable in subacute (stable phase) and chronic stages for its predictive power
17
Q
What is neuropathology of TBI?
A
- Effects develop over various timeframes, from mins to years
- Very complex to find the biomarker (changes over time - graph) so difficult to predict outcomes
- Nature of impairments depends on the timing of assessment
18
Q
Penetrating head injuries
Causes of penetrating head injuries
A
- Leading cause: gunshot wounds
- But also, everyday objects like ball-point pens, chopsticks, door keys, etc
19
Q
Penetrating head injuries
Mortality and severity
A
- PHI mortality 6.6 times higher than Closed Head Injury
- 36% dead on arrival or die in emergency unit
- 41% of admissions for survivable injuries die within first 48 hours
- 52% of survivors are severly affected
20
Q
Penetrating head injuries
Types of injuries resulting in PHI
A
- Objects embedded in head (problematic: if you remove might cause imflammation which could result in epilepsy)
- '’Through-and-through’’ injuries: both entry and exit wounds
- Bone fragments often driven into the brain (tangential injury)
- affect how they present problems but also their extent of recovery
21
Q
Penetrating head injuries
What does neuropathology asses in case of PHI? Why is it important to have this info?
The second question ties to the next flashcard
A
- Advanced imaging techniques show type and extent of PHI damage
- Key issues: penetration location, trajectory, fragment scattering
↪ Affects the behavioural outcome
22
Q
Penetrating head injuries
What factors affect the outcome PHI is going to have?
A
- Physical qualities like speed, wobble, and malleability affect extent of damage
- The speed and physical qualities of the object is most closely associated with the extent of tissue damage
- High-velocity (>300 m/s) causes more extensive tissue damage (gunshot wounds)
↪ Immediate problems - Delayed effects like post-traumatic epilepsy and increased risk for cancer are associated with worse outcomes
↪ Long term problems
23
Q
Penetrating head injuries
What could the tissue damage in PHI result in?
A
- Extensive blood loss can lead to hypotension and hypovolemia, worsening primary damage
- Local and general cerebral oedema and intracranial haematomas may develop
24
Q
Penetrating head injuries
Neuropsychological effects
A
- Deficits depend on lesion site and clinical history (previous problems?)
- General impairments, including issues with attention and memory
- Short-term memory is especially likely to be compromised, regardless of injury location
- Larger lesions generally result in more widespread deficits
25
# Penetrating head injury
How does PHI progress? What is permanent damaged and what improved with time?
- Rapid gains observed in the first year or two post-injury
- Further improvement is slow and mainly due to learned accommodations
- Cognitive impairments like language disorders may improve but sensory defects (lower level...?) like visual blind spots presist
- General effects of brain damage, such as distractibility, may improve but not return to pre-injury levels
26
Closed head injuries
| Definition, consequences, stages of damage
- Non-penetrating injuries (falls, blunt head trauma etc.)
- CHI typically results in more generalised brain injury
- Damage occurs in stages: **initial impact** followed by **secondary physiological processes**
- Long-term effects can take months to years to fully develop (mainly in mild TBI because they often don't become apparent immediately)
27
# Closed head injuries
What are the factors that determine the extent of damage?
- Severity of injury dictates the extent of damage
- Biomechanics crucial in determining primary and secondary effects
28
# Closed head injury - primary effects
What is Diffuse axonal injury (shearing)? What is the cause?
- White matter (axons) injuries diffused over the brain
- Frontal or lateral impact often results in DAI
- Often the result of rotating forces that cause axons to become torn or damaged (because of opposing forces)
↪ often combined with microhaemorrhages and axonal degeneration
29
# Closed head injuries - primary effects
What is affected if there is axonal damage (shearing) in the corpus callosum?
- Damage to the corpus callosum - some axonal extension can be missing
↪ Damage extends far from focal site due to axonal disruption and inflammation
- Leads to atrophy and corresponding neuropsychological dysfunction
- Diminished speed of processing due to hemisphere integration issues
30
# Closed head injury - primary effects
Biomechanical features resulting from DAI
- Shearing forces tear delicate vasculature
- Hemosiderin, an iron-laden residue, shows in MRI for subacute and chronic injuries
- Contusions (local bruising) or subdural haematoma concerning due to pressure on the brain surface
31
# Closed head injuries - primary effects
Coup and Contrecoup lesions
| Another complication that can happen
1. Various mechanical forces resulting from a blow to the head cause TBI
2. A coup is damage at the site of impact
3. Pressure resulting from a coup (where the injury happens) may push the brain to the opposite end or side of the skull, producing a contrecoup
- Leads to injury in both sides
32
# Closed head injuries
What secondary injuries (effects) can be observed? What can be seen on brain scans?
- Secondary Brain Injury: As damaging as initial injury due to physiological processes
- Factors: Elevated intracranial pressure (ICP), brain swelling (edema - bleeding from some part of the brian), insufficient oxygen (hypoxia), insufficient blood supply (ischemia) - necrosis of brain tissue, fever (pyrexia), and infection
- Brian scans look similar to Demensia patients who have also an increase of the volume of ventricles and the gyri and sulci increase as a sign of cell loss
33
# Closed head injuries
Cognitive and mental impact
- **Reduced mental speed**, **attention** (related to slowing of info processing), cognitive efficiency
- Impact on high-level reasoning and executive functions
- Impaired memory (difficulty with remembering recent info, coming up with words, remembering appointments...)
- Complaints of confusion, irritability, distractibility (attention) and **fatigue**
- Social cognition changes: emotionally flat, not taking others into consideration, unable to adapt to social situations
34
# Closed head injuries
Sensory alterations
- Impaired sense of smell (Anosmia)
- Visual impairments: visual acuity reduced, field defects, double vision, prosopagnosia
- Dizziness and balance problems
- Hearing Defects: tinnitus, hyperacusis
- Sensory hypersensitivity
35
Types of CHI based on severity
1. Mild TBI
2. Moderate TBI
3. Severe TBI
36
# Closed head injury
The most important association in mild TBI
Complex association between severity and outcome
37
Is there a specific classification of mild TBI/concussion?
- Controversy over definition and symptom duration
- No universally agreed classification
- Much more agreeablness on moderate and severe TBI's classification
38
# Mild TBI
Criteria of the American Congress of Rehabilitation Medicine
(ACRM) for mild TBI?
- Any period of loss of consciousness (LOC) lasting for 30 minutes or less
- Any loss of memory for events immediately before or after the accident (Post-Traumatic Amnesia, PTA) not exceeding 24 hours
- Any alteration in mental state at the time of the accident (e.g., feeling dazed, disoriented, confused)
- Focal neurological deficits that may or may not be transient
39
# Mild TBI
Epidemiology
- Over 1.5 million documented TBIs annually; ~80% are mild TBI (extremely common)
- Stats based on hospital records, but an estimated 25% never visit the ER, likely making the real rate higher
- Approximately half of the cases meeting research criteria for mTBI are never formally diagnosed
40
# Mild TBI
Neuropathology
- Mechanical Forces and Cellular Changes: Mechanical forces that alter cellular physiology and anatomy, especially affecting the axons
- Physiological Disruptions: Potentially permanent cellular function changes and acute inflammatory reactions, especially in white matter
41
# Mild TBI
How does mTBI progress and what can it result in?
- Cognitive issues may not manifest until days or weeks aften an accident due to other injuries or medication
- Most individuals recover within hours to weeks, particularly after sports concussions, but a small percentage have long-term issues
- Even with cognitive improvement, symptoms like headaches, fatigue, and dizziness persist in many patients
- Studies suggest that reaction time and neurophysiological measures may reveal subtle, long-term mTBI affects better
42
# Mild TBI
Why is it difficult to predict the outcomes? What can actually help to predict them?
- Interactions between cognitive, emotional, and behavioural factors, that were present before the injury, make predictions challenging
- Inconsistent findings on the role of Loss of Consciousness (LOC) in predicting cognitive outcomes
- Post-Traumatic Amnesia (PTA), life events, and emotional distress can be predictive but lose strength over time
- Age over 40, pre-existing conditions, and history of brain illness are red flags - the best predictors
- Self-reported cognitive issues are more strongly related to emotional state and premorbid traits than actual cognitive
impairments
43
# Mild TBI
Post-concussion syndrome
| Definition, causes, cogniform disorder
- Immediate symptoms and persistent symptoms lasting beyond 3 months, not consistent with formal assessments
- Does not mean it's malingering
- Symptoms may be maintained or worsened by stress or depressive reactions at the time of the accident
- Outcomes affected by a range of neurological, physical, and psychological factors (inadequate coping style, catastrophising)
- Premorbid personality or psychiatric disorders can contribute to the chronicity of postconcussion symptoms
- *Cogniform disorder* - patients with excessive cognitive complaints and/or unexpectedly poor cognitive performance given their severity of their injury (unconscious)
44
# Mild TBI
Whiplash syndrome
- Common in car accidents
- Typical symptoms include neck pain, occipital headache, back pain, and upper limb pain (but the symptoms are very varied)
- Patients unlikely to meet criteria for concussion or mild TBI, most likely no actual brain injury in majority of cases
- Mixed views on whether neck abnormalities can be objectively demonstrated
- Discrepancies in evaluating the validity of complaints
- Chronic pain is the most common persistent complaint (that's mostly what distinguishes it from post-concussion syndrome)
- Impact on sleep and cognitive function, mostly attention and memory, dizziness
45
# Mild TBI
Cognitive deficits in mild TBI
- Early Stages Post Mild TBI: Moderate to severe communication, perceptual, or conceptual disturbances
- Symptoms clear up for most but subtle defects may remain
- Attention problems are most common, include poor concentration, distractibility, and mental fatigue
- Sensory and perceptual issues often reported, including visual incoordination, photophobia (not able to deal with bright lights), dizziness, deafness, or tinnitus
46
# Mild TBI
Non-cognitive Impairments
- Headaches are common, even in post-acute stage
- Dysphoria and fatigue are very common
- 35% prevalence of depression
47
What is **moderate TBI** and what is its epidemiology?
- Definitions vary in clinical criteria, including GCS scores (GCS score: 9-12 usually)
- Few specific studies on moderate TBIs compared to mild or severe
- 8-10% of all TBIs are moderate; some reviews suggest 7-28%
48
# Moderate TBI
Cognitive deficits
- Ongoing cognitive deficits at six months, especially in **information processing speed**
- Short-term memory deficits are common
- Frontal and/or temporal bruising often results in behavioural changes (hyperorality, saying inappropriate jokes or vulgar comments...)
- Temporal lobe damage may result in learning disorders or affective changes (lot of ups and downs but even completely flat mood)
49
# Moderate TBI
Progression and Outcome
- Patients generally function independently
- Many return to work but differ from their former selves
- Reduced initiative in non-routine activities (related to frontal lobes deficit)
- Emotional processing impaired, affecting relationships and motivation (lack the drive to engage, lack of insight in how affected they are especially 1 or 2 years after the injury)
50
What is severe TBI and what is its epidemiology?
- GCS score of 8 or less, loss of consciousness for 30 min or more, PTA for more than 24 h
- Less than 10% of TBI victims are severely injured but present substantial societal costs
51
# Severe TBI
Cognitive deficits
- **Executive dysfunction**: Impulsivity, lack of self-determination, lack of self-awareness
- **Memory deficits**: Problems with long-term and short-term memory
- **Communication**: Problems with word finding, reduced logical coherence and context awareness
52
# Severe TBI
Non-cognitive impairments
- Depression and anxiety are very common in TBI patients, regardless of injury severity (more common later on when they gain more insight)
- Tendency for these conditions to intensify over time
- Often a reaction to physical and cognitive limitations
- Higher rates of mania, paranoia, and schizophrenic-like symptoms
- Increased personality disorders: borderline, avoidant, paranoid, OCD, narcissistic
53
# Severe TBI
Progression: Initial phase
- Most patients show some progress but struggle with the severe impact of Traumatic Brain Injury (TBI)
- Gradual improvement in physical status and cognition
- Severe injuries lead to long-term pervasive deficits
- Improvement in learning and other cognitive functions occurs but seldom reaches normal levels
54
# Severe TBI
Progression: >1 year
- Improvement continues but at a slower pace, relying on new learning and compensatory strategies
- Emotional and psychosocial aspects show minor improvements but largely remain static
55
# Severe TBI
Outcome
- Reduced level of independence in daily activities and employment
- Often persistent physical complaints e.g., headaches, dizziness, fatigue, pain
- Return to previous employment levels is rare
- Emotional and physical burdens placed on families
- Social isolation and caregiver depression are common
56
What other factors determine outcomes? - Moderators
1. Age
2. Repeated TBI
3. Polytrauma
4. Alcohol use
57
How can age act as a moderator of the outcome of TBI?
- TBI most frequent in under 35s, impacting social and employment outcomes
- Early age TBI needs more intensive education and has poorer vocational outcomes
- Increased odds of adverse outcomes, especially post-65
- Aging brain characteristics contribute to worse outcomes, not just injury severity
- Risk of cognitive decline (e.g. dementia) increases nearly 5 times for each 10 years of age
- Increased rates of depression, psychotic disorders, and dementia in older patients
58
# Moderators
What is repeated TBI? What does it result in?
- Second or more mild concussions have increasingly negative cognitive effects
- A single TBI doubles the risk of future head injury
- Chronic Traumatic Enceohalopathy (CTE)
59
Chronic Traumatic Encephalopathy
- Confirmed presence in athletes with repeated concussions
- Subconcussive injuries can evolve into significant brain damage over time
60
How can we demostrated CTE with boxing as an extreme example?
- Even without KO history, boxers experience cognitive and motor symptoms
- 20% of professional boxers develop CTE
- MRI shows cerebral atrophy in boxers
- High frequency of neuropathological abnormalities confirmed
61
# Moderators
Polytrauma
- Head injuries often accompanied by trauma to other body parts
- Impacts severity of neurobehavioral conditions
- Cognitive deficits affect polytrauma outcomes
- Multiple skeletal injuries hinder rehabilitation benefits for head-injured patients
62
# Moderators
Alcohol and Substance Use
- TBI patients with prior alcohol abuse have poorer neuropsychological outcomes
- Alcohol and polysubstance abuse are major contributors to the incidence of TBI
- Fronto-temporo-limbic injury decreases impulse control and judgment, increasing likelihood of further substance abuse
- Alcohol exacerbates severity of head injury, neuropathological changes, and outcomes, even accounting for other variables like vehicle crush and demographics
