DISCUSSION ON ...

SPORTS

CONCUSSION

Dr Isstelle JoubertSports Meds, UFS

1st year, 2011

SURFACE ANATOMY:

Cerebrum:

largest + developmentally advanced portion

controls higher functions

• speech, emotion, integration of sensory stimuli,

• initiation of final common pathways for movement

• fine control of movement

left hemisphere• controls the majority of functions on right side of the body

right hemisphere • controls most of functions on left side of the body• injury to left: sensory and motor deficits on right side, vice versa

Cerebrum

Cerebellum

Parietal Lobe

Occi-pital lobe

Frontal lobe

Temporal lobe

PonsMedulla

Brainstem

Spinal Cord

Surface anatomy of the Brain

o frontal: planning, organizing, problem solving and selective attention

• prefrontal cortex: personality, behaviour and emotions

• back of frontal lobe: pre-motor, motor areas - produce / modify

movement

o parietal: primary sensory cortex

controls sensation (touch and pressure) +

fine sensation (judgment of texture, weight, size, and shape)

• damage to R: visuo-spacial deficits, difficult in new / familiar places

• damage to L: inability to understand spoken / written language

SURFACE ANATOMY:

o temporal: differentiate smells + sounds

help in sorting new information / short-term memory

• right lobe: visual memory (i.e., memory for faces and pictures)

• left lobe: verbal memory (i.e., memory for words and names)

o occipital:

• visual information - reception, recognition of shapes, colours

damage: visual deficits

SURFACE ANATOMY:

Cerebellum:

second largest area of brain

controls

• reflexes, balance and

aspects of movement /

coordination

Brain Stem:

automatic functions

• breathing, digestion and heart beat

• alertness and arousal (the state of being awake)

SURFACE ANATOMY:

Internal structure of

brain

Spinal cord

Medulla oblongata

Cerebrum

Midbrain

Diencephalon

Cerebellum

Pons

VASCULAR SUPPLY OF THE BRAIN

DEFINITION – SPORTS CONCUSSION:

 

type of minor head injury

complex patho-physiological process affecting the brain

process is induced by traumatic bio-mechanical forces

(brukner and khan 2009)

trauma-induced change in mental state

a mild form of brain injury

with or without loss of consciousness

(Patricios & Kohler et al, 2010)

 

DEFINITION: 

Consensus statement on Concussion in Sport

(Zurich Nov 2008)

common features:

direct blow being a causative factor;

rapid onset of neurologic impairment of short duration

neuropathological changes - functional > structural

graded set of clinical symptoms with / without LOC

structurally normal neuro-imaging studies

 

SYNONYMS: 

brain concussion

mild head injury

minor head injury

mild or minimal traumatic brain injury

(Signoretti et al, 2010)

 

INCIDENCE: 

varies - level of play / different management protocols

reported in all sports

studied most widely in American football

mostly ice hockey + American football

(Meehan, Bachur, 2009)

 

1.74 million concussions annually USA (2010) CDC

football: 10% in US College athletes

20% in US high school athletes each season

 

INCIDENCE: 

sex of athlete (soccer)

2 – 4 % concussions in male

3 – 5% in female players

non-reporting of concussions

American football, only 47%, reported the injury

(Meehan, Bachur, 2009) 

INCIDENCE: 

level of play

4 – 14% in sport at school level

3 – 23% at adult level

(Shuttleworth-Edwards & Noakes et al, 2008)

level of play

higher level of play – associated:

increased strength and body size

increased impact and momentum

increased competitiveness

longer seasons

 

 

PATHOPHYSIOLOGY: 

precise mechanism - not clear

neurological deficit due to biomechanical injury

• shearing forces

• external forces transferred

• to intracranial contents

usually transient in character

(brukner and khan 2009)

 

 

 

PATHOPHYSIOLOGY:

 

shearing force -> diffuse axonal injury

functional > structural injury

molecular level:

• in-flux of Ca2+ , out-flux of K+

• due to depolarization

• caused by excitatory neurotransmitters

such as glutamate, acetylcholine and aspartate

mitochondrial dysfunction

inflammatory responses

therefore changes in cellular physiology

  (Hayes & Dixon, 1994)

PATHOPHYSIOLOGY:

 

restore pre-injury cell physiology + metabolism

cell metabolism increase drastically:

“hyper-metabolism”

sodium-potassium-pump is in overdrive

to increase the glucose metabolism

to restore neuronal membrane potential

↑ cell metabolism + ↓ blood flow +

disrupted glucose-supply-and-demand

= energy crisis (cellular level)

concussion symptoms and signs

  (Patricios & Kohler et al, 2010)

 

 

MECHANISMS OF INJURY: 

coup injury

direct blow to head - max injury at point of impact

contre-coup injury

direct blow to head - max injury opposite site of impact

combined contre-coup injuries

No one type is more

serious than the other type

MECHANISMS OF INJURY:

 

3 types of stresses :

compressive or crushing force

shearing

force across parallel organization of brain tissue

tensile stress

pulling / stretching of brain tissue

Uniform compressive stress –

fairly well tolerated by neural tissue

POSSIBLE COMPLICATIONS OF CONCUSSION:

intracranial space occupying lesion ↑ ICP due to damage to veins / arteries with bleeding -

epidural / subdural / intracerebral  second impact syndrome  

impact convulsions   

post-concussion syndrome 

chronic traumatic encephalopathy 

risk of 2nd concussion

Late complications

Early complications

Early complications

intracranial space occupying lesion  

second impact syndrome (1st in 1984)

• athlete suffers another blow to head

• before the previous concussion resolved completely

• increased brain oedema from first injury didn’t disappear

• 2nd injury increases the oedema + ICP further

• existence of syndrome questioned (Ropper 2009)

• current literature recommend: concussed athletes do not

RTP until / after all Sx and neuro-abN have resolved 

Early complications

impact convulsions   

• seizures not common

• not associated with structural damage

• good outcome

• anti-convulsant - not indicated

 

Late complications

post-concussion syndrome

• Sx / Tx persist : few days to weeks

• patient feels disturbed and debilitated

• mostly in young concussed athletes

• should rest completely from cognitive (thinking processes)

and physical stress

chronic traumatic encephalopathy

• boxing - repeated concussions

• eventually cognitive dysfunction

• ? genetic factors could play a role (Apo E4 genes)

Late complications

risk of 2nd concussion

• very controversial statement

• risk factors not clear

• athlete’s style of play predispose him to concussion

• age and level of play - expose athletes to greater forces

• ? one brain injury - ↑ susceptibility for another injury

(Schulz and Marshall, 2004)

 

SYMPTOMS AND SIGNS ASSOCIATED WITH CONCUSSION

reported in the concussed athlete

by the athlete self

observed by family members, coaches or teammates

Physical CognitiveEmotional / behavioural

Sleep disturbances

headache /LOC

poor concentration

depression drowsy

dizziness amnesia irritability insomniadisturbed

vision“foggy”

disturbed mood

increased sleep

light & noise sensitive

“slowed down” aggressiondifficulty getting to

sleep

Nausea & vomiting

difficulty remembering

new informationnervousness  

fatigue disorientation anxiety  poor balance      

seizures      

MANAGEMENT OF CONCUSSION:

Before the game: 

Pre participation evaluations

Preparedness before onset of the game

 

Immediate management of the injured player: 

Exclude serious head and spinal injury,

ATLS approach

Remove player from field of play

Assess severity of head injury

 

MANAGEMENT OF CONCUSSION:

Early management:

Decide on :

• urgent referral or not

• return to play or not

• baseline symptom analysis

Hospital management

Post-injury discharge information

Follow-up consultations

Neuropsychological evaluations 

Late management

Return to play indications

 

neuro-psychological evaluations:

traditional DSST - digit symbol substitution testing

newer computerised testing like ImPACT

• assess degree of recovery – baseline / data

• serial evaluations by an experienced

• clinical assessment of brain’s ability to process information

SCAT2 assessment forms

Acute Concussion Evaluation Forms (Gioia & Collins of CDC)

CogState Sport as used by SA Rugby Union

• neuropsychologist part of holistic management team

• not via internet or telephone conversations

MANAGEMENT OF CONCUSSION:

neuro-psychological evaluations:

ImPACT (Immediate Post concussion assessment and cognitive testing)

software program - University of Pitsburgh Medical Centre

baseline test: brain processing, speed, memory, visual and motor skills

some schools request baseline

does not prevent concussion - detect subtle cognitive impairment

aid to clinical decision - aid in determining safe return to play

measure performance variability

baseline data not affected by

disease, medication, practice effects or malingering

WHAT IS NEW IN CONCUSSIONS...? 

Prevention possibilities

Evaluation possibilities

Medication possibilities

Management possibilities

Fighting the Ghosts

ethical values - address violence, fair play and respect for other players

muscle conditioning:

• appropriate level of exercise tolerance

• reduction of adiposity

• increased flexibility, strength and aerobic capacity

prevention of fatigue:

• earlier substituting of fatigued player

• attention to recovery of previous head injuries

• attention to fitness, nutrition and hydration

mouth guard /helmets: ↓ severity of concussion, doesn’t prevent

• fit snugly, not move easily on head during the game

• secured with neck + chin strap; tested to safety standards

rules:

• prevent front-on tackling / techniques of going to ground during a tackle

Prevention possibilities...

Evaluation possibilities... CogState

Impact

SCAT

steroids

anti-oxidants

glutamate receptor antagonists

hyperbaric oxygen

hypothermia

calcium channel blockers

Medication possibilities...

Management possibilities...

education of athletes, trainers or coaches and parents

implementing the baseline testing that is available

“winna-mania” – player, coach, parent, media

“winning isn’t everything, it’s the only thing”

“play the man, leave the ball”

Fighting the Ghosts...

THE TAKE HOME MESSAGE IS...

Concussion is real

and not always preventable,

but with the correct knowledge

and management tools applied

– the outcome is not necessarily poor...

REFERENCES:

Brukner & Khan. Clinical sports medicine 3rd revised ed. 2009(13)201-206

Hayes RL, Dixon CE. Neurochemical changes in mild head injury. Semin

Neurol 1994;14:25

Meehan WP & Bachur RG. Sport-Related Concussion. Pediatrics

2009;123:114-123

Patricios JS, Kohler RMN, Collins RM. Sports-related concussion relevant to

the South African rugby environment - A review. SAJSM 2010;22(4):88-94

Ropper A, Gorson H. Concussion. N Engl J Med. 2007;356:166–172

Schulz MR, Marshall SW et al. Bowling Incidence and risk factors for concussion in

high school athletes, North Carolina, 1996-1999. American Journal of

Epidemiology. 2004;160(10):937-944

Shuttleworth-Edwards AB, Noakes TD, Radloff S et al. The Comparative

Incidence of Reported concussions presenting for Follow-up management in SA

Rugby Union. Clinical Journal of Sport Medicine. Sept 2008;18(5):403-409

Signoretti S, Vagnozzi R, Tavazzi B et al. Biochemical and Neurochemical

Sequelae following mild traumatic brain injury: summary of experimental data and

clinical implications. Neurosurg focus. 2010;29(5):e1