Concussions Final Exam

Concussions

All concussions are

neurological injuries

* rates and types are dependent on activity
* nature of activity
* higher risk at practice

What is a concussion?

no visual markers to help define (specific signs)

many definitions by organizations

American medical society for sports medicine

a traumatically induced transient disturbance of brain function and is caused by a complex pathological process

defines concussions as a mild traumatic brain injuries (mTBI), states all concussion are mTBIs but not all mTBIs are concussions

self limited in duration

on the less severe end of the TBI spectrum

Syndrome

a number of things have to be occuring

American academy of neurology

a clinical syndrome of biomechanically induced alteration of brain function, typically affecting memory and orientation, which may include loss of consciousness

include metabolic cascade, affected domains, focuses on functional deficits

may occur with loss of consciousness

NATA

adopted definition from the AAN due to widespread use in the literature

4th international conference on concussion in sport; zurich (2012)

concussion is the historical term representing low-velocity injuries that cause brain ‘shaking’ resulting in clinical symptoms that are not necessairly related to a pathological injury

is a subset of TBI and will be the term used in this documet

commotio cerebri= in other countries

a brain injury; a complex pathophysical processs affecting the brain, induced by biomechanical forces

Why are concussions difficult to define?

you can’t see them

Misconceptions

must require LOS

“ding” or “bell rung” common in sport

terminology may lead to under reporting

* 8% of HS identified a concussion hx when using the word “concussion”
* 25% when using “bell rung” or “being dinged”

What is it important that clinicians do

understand differences within definitions, terms and symptoms

must use concussion to acknowledge the injury

Why is it unknown how common concussions are

limited amount of info on younger athletes

ex. little league with no medical assistance

value of the surveillance data (NCAA and HS) is limited

Reasons for unknown how common

lack of recognition of consission, likely under reported

estimated 50% of concussion in HS football go unreported

“best” data from American football (NCAA and HS)

Which sport has the **highest** number of concussions per 10,000 NCAA athletes participating in games or practices

men: wrestling (12.4)

woman: soccer (6.5)

Which sport has the **lowest** number of concussions per 10,000 NCAA athletes participating in games or practices

men: baseball (0.7)

woman: volleyball (3.3)

Which sport has the highest number of concussions in high school sports

football- there is a big gap in maturity and size from freshman in HS to senior

Youth football (Kontos)

468 male youth FB players

11338 exposures (practice or game)

20 diagnosed concussion

head to head contact (45%)

6\.16 IR per 1000- games

.24 IR per 1000- practice

competitive environment in games causes an increase in concussions

How does youth football compare

overall IR ages 8-12 data is comparable with high school and collegiate samples

participation in games was associated with an increase of concussion compared with practices (higher than high school and college)

ED visits and deaths are ____ related

inversely

if you go to the ER you can be monitored

How have ED visits changed over the years

they have ultimately increased

Mike Webster

NFL player

claim against NFL for repetitive brain trauma

Bennet Omalu

examined Websters brain and found chronic traumatic encephalopathy (CTE)

Chronic traumatic encephalopathy

a progressive degenerative disease, diagnosed postmortem in people with a history of concussive and sub-concussive impacts

many players have died (many by suicide) from effects of CTE

How many concussion does CDC estimate in the US annually for sports related

3\.9 million

\
will increase because now more people are going to the doctor

Standard of care

preparticipatation testing

eligibility

on field evaluations

treatment

return to play standards

Negligence

behavior that creates unreasonable danger to others

usually happens from a failure to act

based on a uniformed standard of behavior

“reasonable person”

Four conditions of negligence

duty

breach

proximate cause

harm

Duty

obligation to conform to a particular standard of conduct toward another

* every person has a legal duty to exercise reasonable card to avoid harm to others
* may be created by case law or statute

Breach

by an act or omission that exposed others to harm

Violation of statutory duty

should be aware of state laws that regulate activity and job being performed

laws may regulate a standard of care

49 states have concussion legislation

What do violation of statutory duty generally require

athlete to be removed from play if they are suspected of having a concussion

obtain written medical authorization to return to activity

concussion education of coached, parents, and athletes

Alabama Law

requires each sport/ recreational organization to create a concussion and head injury information sheet that athletes and parents must sign every year

give coaches annual training on how to organize the symptoms of a concussion and the proper medical treatment

a youth athlete who is suspected of having suffered a concussion during a practice or came be immediately taken out of play & not allowed to return until cleared by a doctor

Standard of care terminology

reasonable person standard is minimum

if person has knowledge or skill superior to that of the ordinary person, the law adjusts the standard and required that the reasonable person be one within the same profession or skill set

expert witness

literature

rules

protocols

texts

Good Samaritan law

when there is no duty to go to the assistance

dont make it worse

does not immunize a health care provider if care was negligent

Proximate cause

reasonable connection between the act of negligence and the damages

caused or contributed to?

Assumption of Risk

express or implied consent to the risk of injury inherent in an activity prior to engaging

Cases

courts follow earlier decisions, allowing continuity and predictability in the legal system

limited published opinions on concussion litigation

Maldonado v. Gateway hotel

ambulance and medical monitoring is now required on site

professional boxer knocked out in fight, no medical attention, passes out in locker room again, significant brain injury and cognitive effects

Cerny v. Cedar Bluffs public school

player struck head on ground, played for a few more minutes went back to practice next week and suffered a second concussion, coach didnt recognize signs

coach won (1995)

You have a duty to protect the player

Pinson v state of TN

1984

collapsed and remained unconscious for 10 minutes after a blow to the head

dilated pupils, facial palsy, no control to left side of body

was able to return to play after 3 weeks got injured again and was in a coma

AT was found negligent

NFL concussion litigation

class action, settled in 2013

damages for football related brain injuries

negligence

* failing to disclose harmful effects
* failure to treat
* failure to establish rules (tackling and RTP)

fraud: concealed and misrepresented facts about effects of concussions

Developing a plan

very specific for what you need

talk about the people, equipment, specific to location, etc

What is the need for a plan

it is professional

recommended by: NCAA, NFHS, up to 10% of NCSS dont have one, 70% have EAP; 36% did not practice, 34% have AT present at all functions

Legal need

* ensure high quality of care
* standard of care
* the EAP defines the standard of care required
* forseeability??

Team approach

work together/ time critical

chaotic environment

EAP provides structure/ outlines

* response
* communication
* where to transfer?

in athletics, the first responder may vary

* AT, coach, parent with skills, EMT

implementation (rehearsal), equipment (calibrated annually, batteries), communication (phones), transportation, venue location, care facilities, documentation

Problem with concussions

each incident is unique

every impact is different

* speed
* direction
* mass
* anatomical location

Newtons Second Law

force= mass x acceleration

for a linear impact, as the force increases, acceleration increases, mass is constant

Rotational forces

Torque= moment of inertia x angular acceleration

skull begins to rotate before the brain rotates

increased rotational forces result in a greater amount of rotational head acceleration

Most head injuries will have both __ __and__ ____ forces

linear and rotational

What happens to kinetic energy

total kinetic energy that enters the head is equal to the total linear and angular energy dissipated to the head

What determines what the outcome is

speed of the object hitting the head, the velocity of the struck player and the point of impact on the head are important in hits to the head

Law of momentum conservation

how does muscle contraction and body alignment affect brain velocities

What happens with a larger mass of an object

the larger the mass of the striking object and the faster the velocity it strikes with, the more momentum that will be transferred to the players head and body

What happens if a player strikes with the head, neck and body in alignment

the resulting force is 1.67 times larger than if the hit was made from the upright position

How can you lessen the impact

precontracting the neck muscles before a head impact

this decreases peak head accelerations

Where are concussions mainly from

acceleration and deceleration forces placed on the brain during head impact

you can reduce by controlling head motion

Brain slosh

dynamics of the head result in injury to the brain

coup-contracoup brain injury

floating in fluid (CSF) in a rigid container

allows for acceleration an collision with the skull

Coup-contracoup brain injury

initial injury to the brain at site of force, and a resulting injury on the opposite side of the brain

Q collar

supposed to help protect the brain against brain slosh

but nytimes thinks it is more dangerous to wear one because they think they are invincible

Lessons from football method of analysis

in 1994, the NFL committee on mild TBI

review helmet data with NOCSAE (warning)

1st report examined 182 concussive and subconcussive hits that occurred between 1996 and 2001 (used video)

reconstructed forces with helmet sensors and crash test simulators

learn about HITS system

Impact frequency

number of hits in a season

conservitive estimates

* 900-1000 hits per season- college
* 520-652 hits per season- high school

Impact magnitude

may have thousands of hits with no concussion or a concussion could come from 1 hit

linear acceleration- similar between high school & college

collegiate athletes experience high impact forces more often (2x), not at higher risk

Statistics on football

line players had the most hits per season with “skilled” players receiving fewer

offensive backs have a higher probability of receiving a high magnitude impact

most concussions are results of top of head impact

Concussion threshold

cutoff scores have not been found helpful

threshold numbers may not be as helpful as impact on occurrence and long term outcome

many attempts to quantify minimum force

* animal research
* auto crashes
* anatomical models
* a single variable threshold has not been found

Pathophysiology neurometabolic cascasde

no macroscopic pathological findings associated with (mTBI) concussions

* cerebral edema
* subarachnoid hemorrhage
* contusions
* hematomas

symptoms must result from transient functional disturbance of neuronal and parenchyma cells rather than destruction

Neuometabolic cascade

accelerations result in a neurometabolic cascade of events

1sst is dysregulation of channels within the neuronal cell membrane that allows ion flux

results in a release of potassium neurotransmitters and excitatory animo acids (glutamate)

glutamate acts on several receptors= more depolarization & calcium influx= more ATP production (go to homeostasis)= glucose hypermetabolism at about 30 min post injury

then go to a hyper metabolic state at about 5-6 hours, up to 5 days

all results in more glycolysis and anaerobic respiration and local extracellular acidosis

Cerebral blood flow dynamics

post injury metabolism shifts to blood flow

* highly regulated, can change direction quickly
* inc in metabolic does not = inc in blood flow
* can dec after injury for up to 2+ hours
* head injuries cause decoupling

Blood brain barrier

regulated by intravascular and extravascular content of CNS

* role in neuronal protection & maintaining homeostasis
* breakdown can cause alzheimers, ALS, MS
* can result in further breakdown= abnormal brain activity, inflammation, metabolic distubances

leads to

* fluid excretion
* dec in perfusion pressure inc CBF
* maybe the cause of seizure activity

Immunoexcitotoxicity

neuroinflammatory response develops after mTBI

* macrophages/ monocytes= microglia in brain
* activated after damage, do repair, and go back to resting
* in multiple concussions they become destructive and are always activated
* very important to rest

Glasgow coma scale

based on eye opening, verbal performance, and motor response with a composite score

valid, effective for making assessment

can still have a high score with a concussion

Presentation

not all signs and symptoms are immediately available and develop over time

may go undiagnosed or mismanaged due to type number and severity of signs/ symptoms

Presentation signs and symptoms for serious TBI

decreasing LOC

deterioration in neurological function

decreasing HR or respirations

signs of a skull Fx

lateral weakness

sensory deficits

severe headache

vomiting

seizure

unequal pupils

Signs and symptoms

vary from patient to patient

need for individual response

symptoms may be grouped (somatic, sleep distrubance, emotional, cognitive)

heat illness, dehydration have similar symptoms so mechanism is very important

Signs observed by staff

dazed or stunned

confusion

forgets plays

unsure of game opponent

moves clumsily

answers questions slowly

LOC

behavior or personality changes

forgets prior events

forgets events after hit

Symptoms reported by athlete

headache- 83-86%

nausea

balance problems

dizziness- 65%

double vision

fuzzy vision

sensitivity to light/ noise

feeling sluggish

feeling foggy

change in sleep pattern

concentration problems

memory problems

History

most resolve in 7-10 days

children take longer to heal

prior history may have a more protracted healing

some have post concussion syndrome

presense of amnesia predicts

* fogginess
* dizziness

Age

more pronounced response in younger individuals

more edema in children= more sensitive to glutamate

younger children have weaker necks= more at risk with similar magnitude of force

slow recovery or pour outcome

Sex/ gender

females may be at greater risk

higher incidence per 1000 exposure

more acute symptoms

worse reaction times

decreased neck mass, less isom strength

more willing to report symptoms

Other factors

lower iq- more likely to have persistenst symptoms and post concussion syndrome

self diagnosed learning disability- perform worse on baseline

post concussion syndrome is neurological and psychological factors

Acute eval

most challenging aspect is recognizing the injury

individualized approach

baseline evaluations!!!

* concussion related symptoms
* balance
* neuropsychological function

immediate removal from play and evaluates

severe or worsening symptoms- transport

traditional injury evaluation

Acute eval history

mental status, amnesia

retrograde/ anteriograde

prior history

symptoms

duration

length of time out of activity

Acute eval symptom scales

one we use is SCAT 5

Acute eval neurological exam

level of consciousness

glascow coma scale

speech patter (difficulty finding words, innapropriate words, slurring)

cranial nerve eval

pupil size

visual acuity

coordination

vital signs

cervical spine and facial bone palpation

Acute exam assessment tools

standardized assessment of concussion (SAC)

sport concussion tool -scat

sideline assessment

postural stability and balance

ROM and strength

functional

3rd International conference on concussion in sport

“no abnormality on standard structural neuroimaging studies is seen in concussion”

Standard neuroimaging

shear strain and tissue deformation caused by rotational acceleration after *closed head injury* can result in diffuse axonal injury

What is the modality of choice in ED for acute brain injury, widely avaliable, able to detect fractures, intracranial hemorrhage and contusions?

CT (computed tomography)

Can CT scans detect concussions

no, they are limited in detecting axonal injuries, images are usually normal for concussions

What are CT scans used for

is used to rule out more significant pathologies acutely, no other imaging is indicated

Who are CT scans required for? (NOC)

patients with minor head injuries with: headache, vomiting, older than 60, drug or alcohol intoxication, persistent anterograde amnesia, visible trauma above the clavicle, seizure

Clinical rules

new orleans criteria (NOC) for determining the need for CT following mTBI

Clinical rules reequirement for patients with a minor head injury if

GCS score of 13-15 after witnessed loss of consciousness, amnesia or confusion

High Risk for Neurosurgical Intervention

* GCS lower than 15 at 2 hours after
* Suspected skull fracture
* Two + vomiting episodes
* 65 years or older

Medium risk for brain injury detection by CT imaging

* Reterograde amnesia of 30 or more minutes
* Dangerous mechanism

CHALICE Rule

selection of high-risk children

__CT scan for__: history (witness LOC, amnesia, drowsiness, 3+ vomits, suspicion of non-accidental injury, seizure)

__Exam__: GCS of less than 14, suspicion of penetrating or depressed skull injury, basal skull Fx, positive focal neurology, presence of bruise, swelling, or laceration

__Mechanism__: high speed traffic, fall of more than 3m, high speed injury/ projectile

Absence of CT abnormalities does not guarantee…

a good outcome, nor does presence reflect long term impairment

Which imaging is greater detail resolution than CT, more sensitive and specific, detect structural abnormalities earlier than CT?

MRI

Conventional MRI provides detail of __*___*__*and may identify* _____

intracranial and cerebral structure

occult lesions, typically visualized on CT

What injuries appear on MRI

diffuse axonal injuries

Quantitative MRI technique

allows measurement in the differences in white and grey matter density or volume

What does high density fiber tracking track

white matter fibers

What aids in the eval of the pathophysiolocial and functional changes

advanced functional techniques

Functional MRI

neuronal function during task performance

can detect changes in neuronal activation; blood volume, blood flow and blood oxygen

Magnetic resonance spectroscopy

Concentrations of chemical compounds in the brain

Higher magnetic field strength