Concussion: its recognition and management
Concussion: its recognition and management
FIA Institute Fellow - USA
RECOGNITION AND MANAGEMENT
FIA MEDICINE IN MOTOR SPORT SUMMIT 2010
Stephen E. Olvey, M.D.
Associate Professor Clinical Neurology/Neurosurgery
Director Neuroscience Intensive Care Unit
University of Miami/Miller School of Medicine
Fellow FIA Institute for Motor Sports Safety
WHY THIS IS A HOT TOPIC?
There are 250,000 - 300,000 sports related TBIs
reported annually in the U.S alone. Thousands more
Sports concussion is unique in that it is generally mild,
but carries a high risk of recurrent concussion and
subsequent illness due to early return to competition.
Long term dysfunction often follows repeated
concussions. (Mohamed Ali, Steve Young, Troy Aikman,
and more than a few racing drivers)
Annual cost in the United States exceeds 1 billion dollars.
>98% of sports related head injuries are concussions.
Misunderstanding of concussion still permeates the
Major health problem
No proven acute treatment. Injury must run its
Severity of the concussion not known until it has
resolved. The final outcome may take years.
Uncertainty about when it is safe to return to
Multiple criteria and guidelines exist; but these
are based primarily on subjective clinical factors
and the duration of impairment, they do not,
unfortunately correlate with outcome.
WHAT IS A CONCUSSION?
“A reversible injury to the brain due to
traumatic forces, resulting in amnesia
and/or loss of consciousness.”
Don’t need to have been unconscious
Don’t need to have directly hit your head
Don’t need to have been amnesic
Must have some concussion related symptoms
Normal routine CT or MRI
May or may not have post concussion symptoms
Repeated sub-clinical head accelerations will
likely become part of the definition in the near
Potassium, glutamate, and glucose are immediately
released from affected brain cells…
Calcium enters these disturbed cells in exchange for the
Neurotransmitter release occurs with loss of
autoregulation in the area of the brain affected…
Concomitant decrease in regional cerebral blood flow
with a resultant energy crisis…
Brain is vulnerable to further injury during this
period due to altered cerebral glucose
metabolism. (20 minutes to a few days?)
The hyperglycolysis that results, depletes cellular
ATP resulting in an energy crisis as decreased
blood flow limits body’s ability to supply enough
glucose to satisfy the supply/demand
relationship for brain function.
Results in seriously altered brain function
It has been shown that if there is too much
calcium influx, actual cell death may occur; seen
in the most severe forms of concussion
NOT JUST A BUMP ON THE HEAD
SUMMARY: There is a Triphasic metabolic
response in mild TBI:
Metabolic depression (days-weeks)
Metabolic recovery (days-weeks-mos.)
None of the above is directly related to the initial
WHAT HAPPENS IF CONCUSSED ANIMAL IS CONFINED POST INJURY?
WHAT HAPPENS IF AN ANIMAL IS CONFINED POST INJURY?
THE DICOTOMY OF RETURN TO
How much rest before how much activity?
There is a period of energy crisis and
vulnerability during which secondary insults
must be avoided---return to play issues
Post-traumatic physiological brain abnormalities
in humans can last days to months.
Clinical assessment is inadequate to quantify
post traumatic dysfunction.
Excessive activation or forced disuse of injured
brain can worsen the outcome---therapeutic
The developing brain is uniquely vulnerable to
trauma.--- It is different in kids!
THE TWO TYPES OF ACCELERATION
Translational acceleration- Total applied force
passes through the center of gravity of the head
(walking into a flag pole, hitting steering wheel
Angular acceleration- Force generates motion
around an axis (Whiplash, or left hook in
TWO TYPES OF ACCELERATION
Impulsive loading (whiplash, shaking baby, most open wheel crashes) and Impact
loading (skull vs. a rigid surface as happens in rally cars, stock cars)
Impact loading in general produces much higher forces than does impulsive loading.
Mild TBI may result from both.
Physical Signs of Mild TBI
Any loss of consciousness
Retrograde or anterograde amnesia
Seizure at time of impact (so-called impact seizure)
Inability to focus, easily distracted
Slurred speech, slow to answer questions
Disoriented, unsteady gait
Memory deficits, personality change
Emotionally unstable, inappropriate behavior
Delayed verbal and motor responses
Headache ( nearly always present)
Lack of awareness
Loss of balance
Feeling dazed, “dinghy”
Ringing in the ears (tinnitus)
Blurred or double vision (diplopia)
“Just not feeling right”
Examiner must have high index of
suspicion based on mechanism of injury,
velocity, in- car damage, helmet damage,
damage to surrounding area, etc.
Athletes themselves will under report
symptoms and out right lie to stay in the
ANY Symptoms or Signs: NO RETURN TO
ANY SPORTS ACTIVITY; whether
competition, or training
Driver or athlete should be medically
evaluated and monitored every 5 min. for
symptom/sign resolution or deterioration
for at least 1 hr.
WHEN IN DOUBT, SIT THEM
STATE OF THE ART
Neuro-psyche testing: ImPACT:
Immediate Post-Concussion Assessment
and Cognitive Testing
One of several available: Now used in
Indy Car, Formula 1, NASCAR, NFL, NHL,
World Cup Soccer, USSA, FISA, and FIFA.
Most extensively tested (Initially over
WHY USE NEUROPSYCH TESTING
Athletes with a mild TBI will often deny
Athletes may lack awareness of symptoms
Testing provides unique information
Trusting an athlete’s self-assessment is
Eliminates bias, favoritism, and revenge
Minimizes practice effects (can’t out smart the
Measures reaction time to 1/100 th Sec.
Can be administered in a group setting
Can be administered by a Nurse or Athletic
Trainer, even a PhD or MD
Now available for I-PHONE and other wireless
< 30 Minutes to administer
24/7 World wide reporting of the results
HOW TO USE ImPACT
Initial preseason baseline testing on all athletes
(now enough tests so not absolutely necessary)
Administer test as soon as practical following
incident (readings returned in matter of
Diagnosis confirmed if test determined to be
abnormal (more than 2 SD from baseline)
Repeat test at 48 hrs. and again at 7 days and
every 7 days until normal.
Provides a definitive guide for return to
EFFECT OF REPEATED MILD TBI ON
An athlete with more than three previous concussions is
9 x more likely to have associated amnesia either
anterograde or retrograde as well as post concussion
Retrograde amnesia: 10 x more likely to have a poor
Anterograde amnesia: 4.2 x more likely to have a poor
L.O.C. not predictive of outcome!!!
WHEN DO WE NEED CT/MRI?
Suspicion of a structural lesion: focal neurological signs,
evidence of significant impact i.e. helmet, cockpit
damage in racing
Seizure activity > 1 minute
Prolonged disturbance of consciousness or worsening
level of consciousness while under observation
Persistent clinical or cognitive symptoms, doesn’t
improve gradually over period of 2 to 3 weeks.
RETURN TO COMPETITION
Level 1. No activity, complete rest; once asymptomatic
proceed to level 2
Level 2. Light aerobic exercise such as walking or
Level 3: Sport-specific training (skating in hockey,
running in soccer, simulator, go-kart, family car in
Level 4: Return to sport with supervised private practice
with attention to consistent, competitive times or abilities
Level 5: Return to competition under observation during
practice then competition
Any re-occurrence of symptoms along the line, athlete
should go back to previous level!!!!
WHAT WE STILL DON’T KNOW
How many mild TBI’s are too many?
When is the brain really back to normal?
Is there effective pharmacotherapy?
Why some athletes are “brain injury prone”?
- The exact role of age/development
(kids and women are more vulnerable)
- The role of genetics, seems to run in families
- The role of other conditions (migraine, ADD)
WHAT HAVE WE LEARNED
Mild TBI can have long term effects
Most but not all athletes recover quickly
Age may be important in recovery
Neuropsychological testing is a useful tool
Management should involve multiple
Total inactivity is bad but, activity too soon is
Effect of Transfer Function
Correction: Case 1
Lf Ear Ref
Computed Lf Ear Ref
• CT scan of Specimen 1
(EShock1) showing position of
each ear mounted sensor.
• From C. Bass and R. Salzar,
Final Report 2008.
Stay inside and don’t do anything
Wear an approved/well fitted helmet (FIA 8860)
Head and Neck restraint SYSTEM in 4 wheel vehicles
Newer devices available for motorcycles (Leatt)
Something to “catch” the head.
Pad everything with energy absorbing material