WK4 - Head Injury Recognition and Management Flashcards
How many athletes admitted to continue playing after being hit in the head?
30%
What % of athletes had knowledge of concussions and the complications of head injuries?
43%
What percentage of athletes sought medical clearance for RTP? And what % returned to training?
34%
25%
What percentage of players felt that time off for rehab was too long?
75%
What is the past definition of a ‘concussion’?
A clinical syndrome characterized by immediate and transient post-traumatic impairment of neural function (altered consciousness, vision or equilibrium), any trauma-induced alteration in mental status that may/may not include loss of consciousness.
What is the current definition for ‘sport-related concussions’?
-Evolving injury
-Acute change rapidly based on clinical signs and symptoms which may reflect underlying physiological injury in brain
-Impairment of higher cerebral function
-Considered one of most complex injuries to diagnose, assess and manage
- Potential for further harm
What considerations are made for ‘sports-related concussions’?
whether it is the acute damage or is it the aftereffects of the damage
whether it is the concussion part of TBI spectrum with lesser degrees of diffuse structural change that are typically seen in TBI OR due to the result of reversible physiological change?
List the characteristics of sports-related concussion.
- evolving injury
- acute: change rapidly based on clinical signs/symptoms that may reflect underlying injury in brain
- impairment of higher cerebral function
- considered among most complex injuries in sports medicine to diagnose, assess and manage
- potential for further harm
Define sport-related concussion.
the rapid onset of short-lived impairment of neurological function that resolved spontaneously
- could be mins or hrs –> require followup
Effects of Sports-related concussions.
May result in neuropathological changes but acute clinical signs and symptoms largely reflect a functional disturbance rather than a structural injury.
- no abnormality is seen on standard structural neurimaging studies
What are physiological characteristics of the brain?
- one of softest biologic materials
- resistance to changing shape (viscoelastic) when slow or transient pressure is applied BUT can deform easily from shearing forces
- Shear modulus of brain tissue is several orders of magnitude lower than Bulk modulus of brain tissue
- differing mechanical properties of grey and white matter (Water Hammer theory)
If head is constrained to exclude any rotational motion, it is difficult to produce traumatic unconsciousness. True or false and state why.
TRUE
angular acceleration (rotation) of head can cause axonal injury in brain proportional to degree of coronal plane –> doesn’t necessarily need impact
What 2 components happen in nearly every concussion?
linear and rotational acceleration
Define Young’s Modulus.
measures resistance of solid to a change in its length
Define Shear Modulus.
measures resistance of motion of planes within a solid parallel to each other
Define Bulk Modulus.
Measures resistance of solids or liquids to changes in their volume
Why are there differing mechanical properties of grey and white matter?
- repeated blows to head may distribute forces through incompressible CSF
- causes shear forces at intersection between grey and white matter, possible breakdown of blood-brain barrier and haemorrhage
What is the Water Hammer Theroy?
The region of brain exposed to highest force is base of sulcus where “water-hammer” force must dissipate if brain integrity is retained
- causing haemorrhage at angles (leaves iron behind)
Why do white/grey matter affect forced applied to brain?
Differing rigidity features of grey and white matter result in shearing at intergace as non-compressible CSF is driven into sulci
Difference in normal vs female soccer player brain volume?
Brain volume in normal women increases 2-3% or remains the same but female soccer players were experiencing increased sulcal volume even without concussion (just from forces)
Concussion can occur with or without loss of consciousness. True or false.
True
What is the proximal cause of diffuse brain injury in general and concussion?
Rapid rotational loading of head and neck about craniocervical junction and torso
What to do when concussive incident occurs on field?
Recognise - signs
Remove player from field/play
Rest
Refer them to Dr
Risk Reduction
RTS
Keep calm and watch the game.
SIDELINE EVALUATION!!!
What is the importance of recognising injury and mechanisms? e.g. from sideline evaluations
- I should know if athlete is behaving abnormally from observing the game.
- assessment of symptoms
- cognitive and cranial nerve function
- balance
- serial assessments
What is the Glasgow Coma Scale designed for?
for people in hospital to monitor those with severe head injury, want to achieve a 15.
What are the 3 categories of the Glasgow Come Scale?
Eye opening
- spontaneous 4
- to loud voice 3
- to pain 2
- none 1
Verbale response
- oriented 5
- confused, disoriented 4
- inappropriate words 3
- incomprehensible sounds 2
- none 1
Best motor response
- obeys 6
- localised 5
- withdraws (Flexion) 4
- abnormal flexion posturing 3
- extension posturing 2
- none 1
Explain the process of NRL Removal from Play.
Player must be immediately removed from play with any of the following observations by an Club staff member, whether observe directly or indirectly.
What is Cat1 of the valuation for determining concussion?
Must leave field and cannot return as there is indication of higher brain function
- loss of consciousness
- no protective action while falling to ground
- impact seizure or tonic posturing
- confusion, disorientation
- memory impairment
- balance disturbance
- dazed/blank/vacant stare or not normal selves
- behavioural change atypical of player
Why is ‘no protective action while falling to ground’ part of the Cat1 of evaluating concussion?
no effect to protect themselves means they were most likely concussed at the time of impact
Why is ‘impact seizure or tonic posturing’ part of Cat1 of evaluating concussions?
- hyperactivity of brainstem, NOT epilepsy
- immediate sequelae of concussive brain injury
- legs extended, arms in bear hug position, spasming and jerking
- potentially due to facial contact, activating afferent pathways of physiological mechanisms.
e.g. diving reflex - submersion in water activates reflex, resulting in decreased HR
What are the characteristics of the ‘Fencing’ response?
- no protective action during fall to ground (indicates magnitude/localisation of impact)
- resembles asymmetrical tonic neck reflex in human infants
- mechanical forces of sufficient magnitude on midbrain to elicit a fencing response (caution in guiding RTP)
Meaning of mechanical forces in ‘fencing’ response.
Mechanical forces to head may stretch cerebellar peduncles and activate LVN
- means that a lot of torsion loading on neck going through brainstem which was sufficient enough to cause this response
What is Cat2 of the evaluation process of concussions?
Requires immediate removal from play for further assessment (may still be able to RTP)
List characteristics of Cat2 of the Evaluation process of concussions.
- loss of responsiveness (player motionless for 2-3s/until support staff arrive
- possible tonic posturing or impact seizure
possible balance disturbance directly observed - SCAT 5 carried out
What is the Maddocks Score test?
memory test - ability to recall and also form new memories, indication of higher brain functioning
When is the Maddocks score used?
Only validated for sideline diagnosis of concussion only and is not used for serial testing
What questions are asked in the Maddocks Score test?
What venue are we at today?
Which half is it now?
Who score last in this match?
What team did you play last week/game?
Did you team win the last game?
What is the Balance Error Score System (BESS)?
most commonly used low-technology balance assessment for those with sports-related concussion
Require pre-test scores to know how athlete normally performs on the test
Process:
- standing within square with feet together, hands on hips and eyes closed
- hold for 20s, numbers of errors are observed.
What are the errors in BESS?
- lifting hands off iliac crest
-opening eyes (when inappropriate) - stepping, stumbling or falling
- moving hip more than 30deg of FLEX or ABD
- lifting the forefoot or heel
- remaining out of the testing position for more than 5 seconds
What is the Tandem Gait Test?
assesses balance and stability through movement, can be used during medical clearance for RTP
- Suspected concussed athlete walk 3m along straight line using alternate heel-toe gait, turn, and return to starting as quickly as possible
- 4 trials done, best retained
- Should be completed in 14 seconds
- Fail if step off line, separation between heel and toe, touch/grab examiner or an object to stabilise
- Can be used together with another concurrent memory test – etc reciting months of the year
What is the Sway Test?
Measures static balance
- out of 100
- perfect = 100
Effects of concussion…
cause balance problems by adversely affecting either NCS or inner ear balance mechanism
dizziness can be a variety of reasons
e.g. vestibular, visual, cardiovascular
Define epidural hematoma.
- arterial blood, life threatening
- very rapid, within an hour or 2
- dura peels off skull, blod placing pressure on brain
Define subdural heamtoma.
- venous blood, will be slow and may not present for a while
- dura attached to skull
What happens if there is clear diagnosis of brain injury or concussion?
NO RTP!! and SCAT5 required.
SCAT5 required to be cleared to play after removal from play
What is the theory of the consequences of concussions?
Repeated trauma to head could cause damage to microtubules –> release of tau proteins which clump together and find their way into damaged structures of brain.
Similar to those seen in late-stage Alzheimer’s patients but in different brain areas
List some characteristics of the consequence of concussions.
- tends to accumulate in emotional brain - memory stage
- behavioural symptoms
- thalamus is the region that undergoes changes to repeated head injury
- psychopathic deterioration after multiple repeated head injuries (1 dose may not cause this damage)
- 1-2 concussions = 1.5x more likely to suffer depression
- > 2 = more likely to suffer depression, cognitive deficits, memory problems and earlier onset of Alzheimers
- chronic traumatic encephalopathy
- reinjury implications
What are the effects of concussion on behaviour symptoms?
- emotional lability, aggression, violent outbursts
- due to anatomical regions associated with emotions being damaged due to concussion
- repeated damage could lead to long-term issues
Explain the neurophysiology of a concussion.
trauma = excessive extracellular K+
–> increased demand for glucose followed by marked metabolic depression which can take weeks to resolve
Explain the cascade of injury-induced concussions.
dramatically alters cell env where neighbouring cells that are not directly and irreversible damaged are rendered extremely vulnerable to secondary insults (2nd impact/head injury)
= compromises ability to exhibit therapeutic plasticity
- consider more recovery time if recurring head injuries are present
Persistent Post-Concussion Symptoms (PPCS).
SYmptoms persist for >2wks after initial insult in adults and >4wks in children
- dizziness/fatigue etc
Understanding cause of symptoms can help attain treatment
Why do we get PPCS?
Heart is innervated by both thoracic (CNS) and by the head (PNS)
- Injury to head may interfere with PNS
- Upsets balance between CNS and PNS
- Autonomic dysfunction could explain why head injuries cause ongoing issues
* Concussion could damage parasympathetic nervous system
* Affects homeostatic balance
* PNS and SNS don’t align properly, improper responses due to autonomic dysfunction
* Eg. HR does not respond appropriately to exercise/standing up really quickly feel dizzy as a response
Why do we get PPCS?
Heart is innervated by both thoracic (CNS) and by the head (PNS)
- Injury to head may interfere with PNS
- Upsets balance between CNS and PNS
- Autonomic dysfunction could explain why head injuries cause ongoing issues
- Concussion could damage parasympathetic nervous system
- Affects homeostatic balance
- PNS and SNS don’t align properly, improper responses due to autonomic dysfunction
*Eg. HR does not respond appropriately to exercise/standing up really quickly feel dizzy as a response
What is orthostatic hypotension?
- low BP and lightheadedness
- may be useful tool to judge their RTP
What is the importance of HR variability?
- greater HRV suggests that ANS is appropriately responding to requirements of the environment
- lower HRV - ANS not modulating HR as efficiently
- amygdala is believed to be major efferent source of modulation of autonomic, endocrine, and cardiovascular response (look into HRV devices - even HR monitor)
Why is sleep importance for recovery of concussion/head injuries?
Brain recovers during sleep by rinse Cycle (stage 3 non-rem sleep)
- opens up channels (similar to lymphatic systems since brain doesn’t have lymphatic system)
- drop in norepinephrine/adrenaline - biggest increase in growth hormone (for recovery)
- Cx spine is attached to brain - responsible for noradrenaline/adrenaline could be disrupted by concussion.
If can’t sleep…
- can’t get good cleaning process of brain
- disturbance of circadian rhythm
- hard to recover as waste clearance can’t occuring during sleep
Normalisation of sleep is important
What does ARL say to head injuries?
Under no circumstance should the player be allowed to continue playing or RTP during same game.
- eliminates potential 2nd hit syndrome and potential liability (cascade of events due to consecutive head injuries)
Explain SCAT5 for assessing head injury.
Not diagnostic
- event if they pass SCAT, could still have concussion
- consider patient in totality (DRABCD, 9 signs of concussion)
evolution of symptoms
Explain SCAT3 for assessing head injury.
standardised tool for evaluating injured athletes for concussion and used in athletes aged >13y
children <13y, use child SCAT3
designed for use by medical professionals
- pre-season testing can be useful for comparison to post-injury assessment and injury interpretation
What is the importance of safety protocol for concussion injuries?
have safe removal plan for injured athletes, paying attention to possibility of neck trauma
How are concussions evalutated?
Post-traumatic amnesia
- stuff they should regocnise
- e.g. girl, dog, football
- can also tell them random facts and see if they can recall it later
Retrograde amnesia
- ask them what happened in the game/past
Eye movement
- King-Devick Test can capture impairment of eye movements, attention, language and other areas that correlate with suboptimal brain function
Balance Test
What else do we need to consider in acute assessment of concussion/head injury?
BALANCE!
- heel to toe
- dominant foot to rear
- hands on hips
- eyes closed and test for 20s
- 5 errors suspect concussion
What happens after the athlete is symptom-free at REST?
a graduated aerobic exertional test to examine for return of symptoms
When asymptomatic after exertion then consider neuro-psych testing to compare baseline scores
List an example of a graduated aerobic exertional test.
Buffalo Test
- athletes with post-concussive symptoms were placed on treadmill to do aerobic exercise and assessed on when they felt their symptoms com one
- corresponding pulse rates would be their “threshold” for RTP/training