Concussion Flashcards
What does SRC stand for?
Sport related concussion
Sport related concussion is classified as what type of traumatic brain injury?
Mild
Symptoms and signs of an SRC may present _
Immediately, or evolve over minutes or hours, and commonly resolve within days, but may be prolonged
Clinical symptoms and signs can be variable, which sign did people believe you had to exhibit to have a concussion that is false?
Losing consciousness
What are the three subsets of clinical presentation in sports related concussions?
Symptoms, cognitive deficits, motor deficits
Describe the symptom category of concussion clinical presentation
what the person experiences from a subjective perspective (can’t measure this)
Physical, mental, emotional
Physical (ex. Headache)
Mental (ex. Brain fog)
Emotional (irritability, sadness, anxiety)
Describe the 3 main cognitive deficits in concussions
Orientation, memory and concentration
Orientation (dizziness, aka where am I in space)
Memory (doesn’t remember details)
Concentration (reduced ability to perform tasks because they have hard time with focus)
Describe the 2 components of motor deficits in concussions
- coordination and balance (unsteady, which may relate to dizziness)
- Can compare coordination with usual normal, people don’t always have trouble just walking
What tool is typically used to assess symptoms of a concussion? How long does it take to do and when would you do it?
SCAT6
Sport concussion assessment tool
- Around 15 minutes, done in the first week of injury otherwise it loses some validity.
The brain is a tethered organ what is the anchored to?
Spinal cord
Aside from being anchored to the spinal cord, what other structural properties does the brain have?
- texture like a nearly ripe avocado
- hangs out in cerebrospinal fluid (around 1/2 cup or 4 oz), roughly the consistency of water and protective but not too deep
- high water content ~75%
The brain has a high water content: what does this mean mechanically? Does the water level ever change?
Water impacts compressibility, can’t squish brain very easily because of high water content
- Since Breanne doesn’t compress very easily, you don’t just hit the brain and get a bruise (more severe TBI)
- HYDRATION LEVEL CHANGES THROUGHOUT LIFE
What is the grey matter and where is it located?
Cell bodies
On outside of brain mostly, some right near center
What is the white matter and where is it located?
Myelinated axons, mostly on inside
What is the mechanism of injury of concussions?
- external force applied in diff ways
1. Moving object strikes head
2. Your head strikes something that is stationary
3. No context with the head, external force is applied to some part of body, head ACCELERATES and then DECELERATES (ex.car accident, whiplash)
What is im common between all the MOI of concussion?
Some mechanical energy is transferred to brain and brain fails in absorbing it
Describe what happens when you accelerate/decelerate head
Head whipping around axis of rotation
- specifically leads to angular acceleration of the brain inside the skull
What 2 examples did Krista use to understand angular acceleration of the head/concussion MOI
Tennis ball in sock, a couple is cell body and axon, ball is brain
* AXON STRETCHES with angular acceleration
Brain as jello cheesecake, cell bodies are jello, axons and white matter are stiffer cheesecake, inner brain is graham crust ** diff densities in brain react differently
In concussion, structural distortion leads to
Functional issues/disturbance, manifests in metabolic things
What happens when axons are stretched? (1 word)
Mechanoporation
Mechanoporation leads to
Ion balance disruption
Description mechanoporation it in detail
- opens up channels through which ions travel through
- when you take channels that allow for transport and you stretch them, you open up gates and increase their opening size = interrupts tightly controlled system
- get large flow of sodium and calcium into cell, and large flow of potassium out
- homeostasis out of balance, nerves will want to restore it (pumps need a lot of atp to do this though)
= ELEVATED ENERGY DEMAND
What effect does calcium influx have on the mitochondria?
- calcium blocks/impairs its ability to create energy
= Primary energy mechanism doesn’t work - we want a lot of oxidative process and energy generation at mitochondria, now there is a shift to anaerobic system
Why is a shift to anaerobic in the brain a bad thing?
- if you rely on anaerobic glycolysis you need glucose from blood flow
- cerebral blood flow is greatly reduced following a concussion so you feed system effectively
How does the time to clinical recovery symptom wise differ from physiological recovery of concussion?
People tend to still have physiological impact that outlasts symptom recovery
What timeline could we expect for cerebral blood flow recovery?
Will be done symptoms in around 2 weeks but cerebral blood flow could be disrupted up to 30 days or even a year
* Quite variable, no exact values mentioned in lecture
What structural injury can go along with a concussion if there’s a great enough force?
Skull fracture if hit with fast moving projectile
What’s an intercranial hematoma?
Blood collection in brain, pooling/bleed is underneath or outside the dural matter
- can’t expand to accommodate that, so we get increased pressure, will try to push brain outside
- in extreme cases could lead to death
- if you have a hole in skull brain might come out
What are signs/symptoms we should watch out for,that might indicate an ER visit
- severe/crippling headache that just gets worse, may reflect buildup of blood inside skull
- vomiting
- impaired pupil response ( tells you there is something very wrong in brain, esp if only in one side)
- fluid leaks and bruising (fluid can escape through any hole, eyes ears nose)
From a cardiovascular perspective, what else is impacted with concussion?
Heart rate variability
aka variability between each beat, healthier to have more variability and here we have less
Describe how heart rate variability is affected with a concussion
- HRV is decreased
- tells us we have a change in balance in the autonomic system (sns and pns)
- increase in sns activity and less pns
What are some consequences of changes HRV in concussion?
- sns will affect other things like digestion and broader body symptoms/immune system changes all because there is a shift to SNS
- becomes difficult to sleep (can’t close eyes, feel too awake)
- anxiety and higher stress
Which part of the neuron lies in the grey matter of the brain?
Cell bodies
Review: why is energy demand elevated in concussion
- causes ion imbalance
- as we stretch apart axons, we get mechanoporation and open up spaces that cause dysregulated ion flow
Why is it difficult for this energy demand to be met?
- problem cause we can’t meet the demand
- need more glucose, need to switch to anaerobic
- calcium interferes with mitochondria, get a switch to anaerobic
- lack of cerebral blood flow (which will carry glucose to hungry brain)
- high demand and low capacity to deal with it
What is the relative risk of concussion for participants wearing protective equipment vs standard or no equipment? What does this mean?
0.82
82% risk relative to 100% risk of the person who does not wear equipment/18% risk of the person who does not wear equipment/18% less risk
What was the p value of risk of concussion in protective vs non protective equipment? What does this mean?
0.30, not statistically significant
- confidence interval is also very large
Why might protective equipment data be statistically insignificant for concussion risk?
- people could be more reckless with the equipment on, false sense of security
- poorly fit helmet
- weight of helmet
What is the relative risk and p value of superficial head injury (not concussion) in participants who wore interventional protective equipment compared to no equipment?
0.41 59% less risk
P smaller than 0.0001 (very significant!), confidence interval also smaller
Based on relative risk, p value, and CI of protective equipment on superficial injury vs concussion, what can we assume?
- would probably help superficial I jury risk BUT helmet may not reduce risk of concussion
- helmet stops contact but not acceleration and deceleration
- might reduce energy of impact but impact is still there (unless very good helmet ex double layer)
How long does it typically take to be symptom free in ADL?
14 days
How long does it typically take to return to sport after concussion?
Around 20 days
* Need more research on para sport athletes
What are some factors that might influence concussion recovery/prognosis?
- how serious injury is
- age (children tend to have longer recovery than adults)
- sex (females generally have more concussion per same sport, can also influence recover time (prognosis)
- concussion history (more likely to happen if happened before)
What does PPCS stand for?
Persistant post- concussion symptoms (extended symptoms)
What is the prevalentlce of PPCS? How long would your symptoms have to be to call it this?
30% of children and adults
* Lower number in athlete because better fitness and blood flow/ might take recovery more seriously because they want to get back to sport/underreporting
Symptoms >4 weeks
When and by who is the SCAT 6 used?
Not by lay ppl, health care professionals
Acute, on field
What would we want to know physiologically to assess recovery?
Cerebral blood flow, ion balance/imbalance, source of energy for brain (ie. Anaerobic or aerobic), HR variability
What symptom presentation would we look at to assess concussion recovery?
Balance & coordination, ADL functionality, cognition tests, vision tests and sensitivity to light, emotional tests
The return to sport protocol is a multistage process, lasting around _. What happens when the symptoms get worse?
24 hrs per stage (usually up to 48)
When symptoms get worse, go back to previous stage
What is the first stage of return to sport?
Active rest with symptoms present (can do ADL like walking, prob not mental activities)
What is stage 2 of return to sport?
Light aerobic
- still have symptoms but focusing on not making them worse
- watching HR with monitor, up to 55% MHR and then increase up to 70%
- activities you can do are walking, light resistance exercise, stationary bike (limited head movement)
Describe stage 3 of return to sport
Sport-specific exercise
- can do sport-specific activities but individually (low risk)
- running, direction changes, general movement, maybe some dribbling or shooting
- cognitive load increases here
In stages 4-6, what are the 3 main differences between the earlier stages of return to sport?
- risk of physical contact introduced
- symptom free
- monitored
Describe stage 4 of return to sport
- non contact but with team
- risk that someone will fall into you/hit you on purpose
- higher intensity
- greater physical and cognitive load
Describe stage 5 of return to sport
Full contact practice
- need medical clearance to enter stage * might also need 5-6 clearance, for higher risk sports would need clearance earlier than non contsct
What is stage 6 of return to sport?
Return to competition
- building and constantly assessing status
If you had no setbacks, what is the minimum length of time return to sport would take?
6-8 days, constantly assessing
What components/benefits of exercise also benefit concussion patients?
Psychological
Social
Physiological
Normalization of autonomic function (HR variability, pns-sns, normalization of cerebral blood flow)
What does BCTT stand for? What is its main purpose?
Buffalo concussion treadmill test
- measure the amount of aerobic exercise that is safe to perform
What do we use to assess baseline concussion symptoms?
VAS (visual analogue scale)
1-10 scale, 10 is bad, threshold is 7
Looks at headache, sensitivity to light, dizziness, general feelings
Describe the exercise protocol in BCTT
- person walking on treadmill (speed set at average walking pace/5ish kph)
-incline increased 1% each minute
What is measured during BCTT and how often?
Every minute, HR, RPE out of 20, and VAS is assessed
What marks the end of the BCTT test?
- HR 90% of age- predicted max
- RPE 17/2
- VAS symptoms have increased by 3
What does the BCTT tell us?
- heart rate at end of test can be used to mark a safe threshold to exercise at, gives you a safe training load
- after 12 weeks we run the test again, should see improvements in all measures
