Lecture 1 – Sports Related Concussions January 11, 2021
Concussion: damage that occurs to the brain’s neural and glial networks from a force
translated to the body
Incidence of Concussions (NCAA)
• Men’s football (1st) à highest annual national estimate
o More athletes typically in football à higher rate
• Women’s soccer (2nd) and basketball (3rd)
o Physiological differences?
o Women more likely to speak to trainers about having a concussion?
• Men’s basketball (4th)
Mechanism
1. Linear (translational) acceleration
a. Head snaps forward
2. Rotational (angular) acceleration
a. Head turns to side very quickly à primary mitigator for
concussions
3. Impact deceleration
a. Head hits the ground
4. Impact deceleration secondary to the head striking an opposing
player’s body
a. Head to knee
Coup and Contre-coup Injuries
• Frontal and temporal lobes at increased risk for concussive injury
o Frontal lobe hits running backs knee (initial contact made) à coup
o Temporal lobe sloshes back (contact force on occipital bone) à contre-coup
• Frontal lobe = executive and high-level cognitive function
• Temporal lobe = memory and language function
Neurometabolic
• Increase in extracellular potassium
• Increased demand of energy to establish
homeostasis
• Build-up of lactate to decrease activity of brain
• Decrease in cerebral blood flow
Sport Concussion Assessment Tool (SCAT-5)
• State months in reverse order
• Memory recall task
• Reverse number recall task
• State months in reverse order
• Balance task (i.e., single leg stance)
, • Concussed individuals may do well on all tasks à important to identify these people
• Can use more lab-based measures à determine specific deficits from concussion
Chronic Traumatic Encephalopathy (CTE) Symptoms
• Typically associated with individuals later in life (50s-70s)
• Can be associated with people younger in age (18)
• Smaller brain (atrophy), larger ventricles
• Progressive decline of memory and cognition
• Depression and suicidal behaviour
• Poor impulse control and aggressiveness
• Parkinsonism
• (eventually) dementia
• Motor neuron disease (similar to ALS)
Causes of CTE
1. Repetitive brain trauma that occurs with/without symptomatic concussion
2. Athletes in contact sports may experience many subconcussive impacts
3. Mild traumatic brain injury (mTBI) from a force transmitted to the head à collision
between brain and skull or strain on tissue and vasculature of brain
4. Strong link between concussion and CTE
CTE: Neural Pathological Investigation
• Top left: whole mount section of frontal cortex showing very focal deposition of tau
protein around small blood vessels
• Bottom left: shows dense tau immunoreactive NFTs around small blood vessels and
extensive tau immunoreactive neurites in neuropil immediately surrounding the
area
• Distinct from other similar brain disorders à distinguishing feature is damage to
neural and glial networks around small vessels in deep folds of brain
Neuropsychological Assessment for Concussion
• Evaluate executive function à Trail making task or Ray-Osterreith Complex Figure
Test à may not be reliable
Neuropsychological-Neurophysiological Assessment
• ERP measures cognition
1. Event-related brain potentials (ERPs) averaged electrical brain responses to
time-locked stimuli
2. N2pc = ERP component related to the focusing of visuospatial attention
3. P300 = measure of stimulus classification processing speed
Study
• Used football players 9 months removed from last concussive episode in 3 groups
1. Athletes never diagnosed with concussion
2. Athletes with one confirmed concussion
Concussion: damage that occurs to the brain’s neural and glial networks from a force
translated to the body
Incidence of Concussions (NCAA)
• Men’s football (1st) à highest annual national estimate
o More athletes typically in football à higher rate
• Women’s soccer (2nd) and basketball (3rd)
o Physiological differences?
o Women more likely to speak to trainers about having a concussion?
• Men’s basketball (4th)
Mechanism
1. Linear (translational) acceleration
a. Head snaps forward
2. Rotational (angular) acceleration
a. Head turns to side very quickly à primary mitigator for
concussions
3. Impact deceleration
a. Head hits the ground
4. Impact deceleration secondary to the head striking an opposing
player’s body
a. Head to knee
Coup and Contre-coup Injuries
• Frontal and temporal lobes at increased risk for concussive injury
o Frontal lobe hits running backs knee (initial contact made) à coup
o Temporal lobe sloshes back (contact force on occipital bone) à contre-coup
• Frontal lobe = executive and high-level cognitive function
• Temporal lobe = memory and language function
Neurometabolic
• Increase in extracellular potassium
• Increased demand of energy to establish
homeostasis
• Build-up of lactate to decrease activity of brain
• Decrease in cerebral blood flow
Sport Concussion Assessment Tool (SCAT-5)
• State months in reverse order
• Memory recall task
• Reverse number recall task
• State months in reverse order
• Balance task (i.e., single leg stance)
, • Concussed individuals may do well on all tasks à important to identify these people
• Can use more lab-based measures à determine specific deficits from concussion
Chronic Traumatic Encephalopathy (CTE) Symptoms
• Typically associated with individuals later in life (50s-70s)
• Can be associated with people younger in age (18)
• Smaller brain (atrophy), larger ventricles
• Progressive decline of memory and cognition
• Depression and suicidal behaviour
• Poor impulse control and aggressiveness
• Parkinsonism
• (eventually) dementia
• Motor neuron disease (similar to ALS)
Causes of CTE
1. Repetitive brain trauma that occurs with/without symptomatic concussion
2. Athletes in contact sports may experience many subconcussive impacts
3. Mild traumatic brain injury (mTBI) from a force transmitted to the head à collision
between brain and skull or strain on tissue and vasculature of brain
4. Strong link between concussion and CTE
CTE: Neural Pathological Investigation
• Top left: whole mount section of frontal cortex showing very focal deposition of tau
protein around small blood vessels
• Bottom left: shows dense tau immunoreactive NFTs around small blood vessels and
extensive tau immunoreactive neurites in neuropil immediately surrounding the
area
• Distinct from other similar brain disorders à distinguishing feature is damage to
neural and glial networks around small vessels in deep folds of brain
Neuropsychological Assessment for Concussion
• Evaluate executive function à Trail making task or Ray-Osterreith Complex Figure
Test à may not be reliable
Neuropsychological-Neurophysiological Assessment
• ERP measures cognition
1. Event-related brain potentials (ERPs) averaged electrical brain responses to
time-locked stimuli
2. N2pc = ERP component related to the focusing of visuospatial attention
3. P300 = measure of stimulus classification processing speed
Study
• Used football players 9 months removed from last concussive episode in 3 groups
1. Athletes never diagnosed with concussion
2. Athletes with one confirmed concussion
