Traumatic Brain Injury

Question 1

What is a traumatic brain injury? What are the 4 ways it can manifest?

Answer 1

• An alteration in brain function caused by any external force rotating the brain to unphysiologically high rates of angular acceleration (> 2 x 10^5 degrees / second^2)

1. Any alteration in mental state at the time of injury
2. Any loss of memories for events before or after the injury
3. Any decreased level of consciousness
4. Any neurological deficits (transient or permanent)

Question 2

What are the most common causes of TBI?

Answer 2

• Transportation related collisions are most common cause (motorcycle accidents account for 40-60%)
• Others include slips and falls, assaults, sports, and explosions

Question 3

How is TBI diagnosed?

Answer 3

• Acute clinical criteria at time of event (neurological tests and observations)
• Ancillary tests: neuroradiology, lab tests, EEG, etc.
• Neuropsychological tests after acute phase, such as tests on choice reaction time, selective attention, task switching, etc.

Question 4

What are 10 symptoms of TBI?

Answer 4

1. Amnesia
2. Personality changes
3. Confabulation
4. Loss of consciousness
5. Slurred / incoherent speech
6. Blurry / double vision
7. Confusion
8. Dizziness
9. Headache
10. Photo / phonophobia

Question 5

What is mild traumatic brain injury? What are the grades of severity?

Answer 5

• Concussion: Most common type of closed head TBI
• Multiple concussions associated with increased risk of CTE, PD, and depression
• Grade 1: Confusion lasts less than 15 minutes and no LOC
• Grade 2: Confusion lasts over 15 minutes and no LOC
• Grade 3: LOC for seconds (IIIa) or minutes (IIIb)

Question 6

What are the 10 common symptoms of mTBI?

Answer 6

• Memory loss
• Fatigue
• Headaches
• Visual disturbances
• Poor attention / concentration
• Sleep disturbances
• Dizziness
• Irritability
• Depression
• Seizures

Question 7

Explain the Glasgow Coma Scale. What 3 aspects does it measure?

Answer 7

• A subjective behavioural assessment scale
• Serial assessment of presence, duration, and depth of impaired consciousness and coma
• Used to describe altered consciousness from mild confusional state to deep coma
• Highly reliable when used by trained persons but not valid

Eye opening (4 points)

• 4: Spontaneous
• 3: Opens to speech
• 2: Opens to pain
• 1: Does not open eyes

Best motor response (6 points)

• 6: Follows simple commands
• 5: Pulls hand away with pain
• 4: Pulls body part away with pain
• 3: Arms contract / abnormal flexion with pain
• 2: Body becomes rigid in an extended position with pain
• 1: Flaccid motor response to pressure

Best verbal response (5 points)

• 5: Tells examiner who he is, where he is and why, and the month and year
• 4: Response seems confused and disoriented
• 3: Random, incoherent speech
• 2: Makes sounds that can’t be understood
• 1: No noise
• Score of 13-15 = mild
• Score of 9-12: moderate
• score of 3-8: severe (coma)
• Injury severity is predictive of long term disability

Question 8

What are some issues with the Glasgow Coma Scale?

Answer 8

• Scalar number system: Numbers that contributed to it are lost
• Alcohol / drugs can mimic symptoms of brain damage
• Other injuries may prevent accurate assessment

Question 9

Explain the period following coma / impaired consciousness.

Answer 9

• Patient is confused and disoriented
• Post-traumatic amnesia is characterized by intellectual and behavioural disturbances (violence, emotional disturbance). Loss of episodic memories.
• Hallmark of PTA is amnesia where patient is unable to record events in a continuous or connected manner.
• Duration of PTA defined as from the time of injury until return of continuous memory and includes period of coma / impaired consciousness
• PTA is one of the best predictors of outcome following TBI and is more accurate than GCS

Question 10

How do the LOC and PTA scales grade TBI severity?

Answer 10

LOC:
Mild: less than 30 mins
Moderate: 30 min - 24 hours
Severe: More than 24 hours

PTA:
Mild: Less than 24 hours
Moderate: 1-7 days
Severe: More than 7 days

Question 11

How may CT scans be useful for detecting TBI?

Answer 11

• Can detect blood
• Has nearly perfect sensitivity (99-100%)
• Specificity of 48-77% for injury requiring neurosurgical intervention

Question 12

What are 4 reasons that TBI in athletics are underreported?

Answer 12

1. Potential lost opportunity for sports career advancement
2. Scholarship and other educational advancements potentially lost
3. Coaches attempt to keep key players on playing field
4. Parents who place pressure on their children to do well

Question 13

How is choice reaction time impaired after a concussion?

Answer 13

• Choice RT: Timed choice responses
• Concussed subjects found to be significantly slower than normal controls, especially after 1st month of injury
• At 3 months, concussed subjects still do not obtain skin of controls
• No correlation between severity of concussion and RT: Even mild concussions can cause significant attentional and information processing impairments in the absence of any neurological problems
• Assessed with neuropsychological tests

Question 14

Discuss problems associated with sports-related TBI.

Answer 14

• Precise guidelines for which evaluation methods should be used to determine full recovery do not exist yet: Players determine when they feel better but often return too soon
• Symptom recovery occurs in nearly 50% of athletes following returning to play or returning to learn

Question 15

What is focal brain injury? Name and describe the different types.

Answer 15

• Closed head injuries focused on one region of the brain that often produce bleeding without symptoms
• Contusions: Bruise of brain tissue. Preferentially affects frontal pole, inferior frontal lobes, temporal poles, lateral and inferior frontal lobes, and cortex above and below operculum of sylvan fissures
• Intracranial hematoma: Bleeding in brain. Most frequent cause of deterioration and death in patients initially lucid after TBI.
• Neuropsychologists not involved

Question 16

What are the two types of intracranial hematoma?

Answer 16

• Subdural: Blood accumulates in between dura mater and the brain as a result of tearing of bridging veins that cross the subdural space. Symptom progression takes days-weeks.
• Epidural: Blood accumulates in space between dura mater and skull as a result of tears in arteries. Faster symptom progression due to higher pressure / larger blood vessels.

Question 17

What is a diffuse brain injury? Provide an example.

Answer 17

• A brain injury that is diffused over a wide area.
• Traumatic axonal injury: Caused by stretching of axons due to brain distortion during movement
• Less than 15% stretch usually results in full recovery
• More than 15% stretch causes permanent axonal damage
• Right to left more damaging than front to back (damages CC)
• Neuropsychologists involved in this brain injury

Question 18

Explain the secondary, delayed phase of brain injury.

Answer 18

• Inflammatory cascade activation: Chemical environment of brain becomes toxic
• Edema: Swelling
• Ischemia: Loss of oxygen
• Reactive oxygen species: Change in chemical environment leads to programmed cell death
• Excitatory amino acids and ion release
• Disruption of axonal neurofilament organization impairs axonal transport and leads to axonal swelling, Wallerian degeneration (non-reversible), and transection (non-reversible segmentation of axon)
• Release of excitatory neurotransmitters Each, Glutamate, and Aspartate and Free radicals

Question 19

What are the top 5 symptoms experienced in post concussion syndrome? How long do these symptoms occur after injury?

Answer 19

• Within first few days following mTBI (acute period)

1. Sleep difficulties (80%)
2. Poor concentration (71%)
3. Irritability (66%)
4. Fatigue (64%)
5. Depression (63%)

• 5 symptoms experienced by 2/3

Question 20

What is neurocognitive disorder? What are the two types?

Answer 20

• When symptoms persist beyond acute period
• Mild: Neuropsychological test findings are 1-2 SDs below appropriate norms and patient can manage instrumental activities of daily living
• Major: Neuropsychological test findings 2 SDs below appropriate norms and patient is unable to manage instrumental activities of daily living

Question 21

How long do symptoms typically persist? What may cause symptoms that persist longer than 3 months?

Answer 21

• Typically resolve within a few weeks

- Over 3 months: somatic symptom disorder, PTSD, factitious disorder, malingering should be considered

Question 22

What is the 3-phase approach for those with post concussive disorder?

Answer 22

1. Symptom management and reduction
2. Cognitive restructuring: Training patients to think differently about nature of capabilities and experience
3. Preventative treatment

Question 23

What are the 2 axes of therapy for those with PCD?

Answer 23

1. Psycho-educational (clinical psychologist)

2. Cognitive-behavioural