Introduction

Concussion is a brain injury. Defined by a complex pathophsyiological process affecting the brain, induced by biomechanics forces

• Can be caused either:

  • direct blow to head, face, neck elsewhere

  • Impulsive force transmitted to the head

    • linear and/or rotational

• Results in rapid onset of short-lived impairment of neurological function that resolves spontaneously:

  • however, in some cases sx and sg may evolve over number of minutes to hours

• May result in neuropathological changes

• Functional rather than structural injury

  • no abN seen on standard structural neuro-imaging studies

• Results in graded set of clinical symptoms

  • may or may not involve LOC

Majority (80-90%) resolve in a short 7-10 day period.

 Time period may be longer in children and adolescents

• Clinical syndrome of biomechanically induced alteration of brain function.

  • Typically affecting:

    • memory and orientation

  • May involve LOC

• 1.6-3.8/million sports related mild TBI (mTBI) in USA/year

  • Many don't get medical attention - 50% unreported

Symptoms and signs of acute concussion

• assessment of range of domains; including clinical symptoms, physical signs, cognitive impairment, neurobehavioral features, and sleep disturbance.

• Detailed concussion history; important part of assessment of injured athlete and per-participation physical exams.

• SCAT3 and child SCAT 3

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Domains:

1. Symptoms

   1. Somatic (headache)

   2. Cognitive (feeling like in a fog)

   3. and/or emotional symptoms (lability)

2. Physical signs

   1. LOC

   2. Amnesia

3. Behvioural changes

   1. irritability

4. Cognitive impairment

   1. slowed reaction times

5. Sleep disturbance

   1. insomnia

If any one present -> suspect concussion

On-field/sideline assessment of acute concussion

When player shows any features of concussion:

• Player evaluated by healthcare professional

  • attention to exclude cervical spine injury

• disposition must be determined in a timely manner

  • if no healthcare prof. available then exclude from practice or play and transferred to HC prof.

• First aid -> SCAT3

• Athlete not be left alone following injury -> serial monitoring/assessment for first few hours

• A player with diagnosed concussion should not be allowed to return to play on day of injury

Neurocognitive testing

• Neurophysciological not considered mandatory at baseline

  • but may be useful

  • insufficient evidence

• may be used to assist RTP decisions

Concussion management

• Cornerstone = physical and cognitive rest until acute symptoms resolve

• graded programme of exertion prior to medical clearance and RTP

• 24-48hrs of complete rest in the acute period may be of benefit

• Low level exercise for those who are slow to recover may be of benefit

  • optimal timing following injury for initiation of this treatment is currently unknown

Graduated RTP protocol

• Stepwise approach:

• continue to proceed to the next level if asymptomatic at the current level

• Each step 24h long

• 1 week to progress through (@ minimum)

• If symptoms recur then drop back to previous level they were asymptomatic

• Symptom free means - no pharmacological therapy 'masking' effects - e.g. paracetamol/ibuprofen for headaches, anti-emetics

Same day RTP:

NO RETURN TO PLAY ON DAY OF CONCUSSIVE INJURY SHOULD OCCUR

• data that demonstrate collegiate/high school athletes demonstrate NP deficits post injury may not be evident on sidelines and are more likely to have delayed onset of symptoms

Difficult or persistently symptomatic concussion patient

• Persistent symptoms >10d 10-15% concussions

• symptoms not speicific to concussion

  • consider other pathologies

Modifiers:

Significance of LOC

• Associated with specific early cognitive deficits, it has not been noted as a measure of injury severity

• Prolonged (>1min) LOC would be considered as a factor that may modify management

Significance of motor/convulsive phenomena

• Vareity of immediate motor phenomena/convulsive movements may accompany concussion

• dramatic but benign

• no specific management beyond the standard treatment of underlying concussive injury

Depression

depressed mood following concussion may reflect underlying pathophysiological abN consistent with limic-frontal model of depression

Child/Adolescent athlete

• evaluation and management same for >= 13yo to adult

• children report concussion symptoms different

• age-appopriate symptom checklist

• child SCAT3 - 5-12yo

• no RTP should occur before child/adolescent able to return to school

• 'cognitive rest' - limit exertion with ADL that may exacerbate symptoms

• school attendance and activities may also need to be modified

• more conservative approach often required

Elite vs non-elite

• manage the same

Chronic traumatic encephalopathy

• unknown incidence in athletic population

• Tauopathy -> pathological aggregation of tau protein

Protective equipement

• no good clinical evidence that protective equipment will prevent concussion

• mouthguards

  • protect oro-facial/dental injuries

• Biomechanical reduction in force to brain with headgear and helmet but not translated to show dec. in concussion incidence

• skiing and snowboarding -> helmets provide protection against head and facial injury

• Other sports -. cycling, motor, equestrian -> protective helmets may prevent other forms of head injury

Risks of premature return to play

Short term

• possibility of SIS (second impact syndrome) o rdiffuse cerebral swelling

• SIS = Individual sustains a second head injury before symptoms completely cleared

  • Loss of autoregulartion of brain's blood supply

  • vascular engorgemnet

  • inc. intracranial pressure

  • brain herniation

• Debate rages

  • related to prior head injury or separate pathophysiological malignant brain oedema

  • Limited cases of SIS in literature

  • more common in boxers and athletes \<18yo

• May predispose an athlete to worse concussion

• decreases cognitive ability and reaction time

  • inc. risk of second brain impact or injury to other body parts

• Prolong symptoms and neurocognitive recovery

2012 Evidence based guideline: Zurich

:: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Summary of evidence-based guideline update: Evaluation and management of concussion in sports Neurology 2013;80:2250-2257

What factors increase or decrease concussion risk?

• Age

  • unable to find link

• Sex

  • male>female

  • more males included in study

  • females: more concssion in soccer/basketball cf. male

• Type of sport

  • Rugby and American football worst

  • lowest:

    • baseball

    • softball

    • volleyball

    • gymnastics

• Equipment

  • highly probable that headgear use has a protective effect on concussion incidence in rugby

%% check references: 18,19%%

• no compelling evidence that mouth guards protect athletes from concussion

  • ? hard football helmet

• Position

  • Data insufficient

  • Body checking in ice hockey inc. risk

• Athlete related factors

  • BMI >27 inc. risk

  • training time \<3hrs/week inc. risk

For athletes suspected of having sustained concussion what diagnostic tools are useful in ID those with concussion?

• Post-Concussion Symptom Scale (PCSS) or Graded Symptom Checklist (GCS)

  • Accureateely ID concession in athletes

    • Sens 64-89%, Spec 91-100%

• Standardised assessment of Concussion (SAC)

  • 6-minute administration to assess 4 neuro-cognitive domains

    • orientation

    • immediate memory

    • concentration

    • delayed re-call

  • non-phsyicians at sideline

  • Sens 80-94%, Spec 76-91%

Tools for predicting inc. risk for severe or prolonged early impairments, neurologic catastrophe or chronic neurobehavioral impairment

• No studies found to be predictive in sports

Predictors of recurrent concussion

• History of concussion = highly probable risk factor for recurrent concussion

• increased risk in first 10 days after initial concussion

Predictors of chronic neurobehavioral impairment

• Prior concusison

• Increasing exposure

• Data insufficient to determine whether prior concussion exposure associated with chronic conginitve impairment in amateur athletes

Practice recommendations:

Preparticipation counseling:

1. understand risks of concussion so that may provide accurate information to parents and athletes

2. disseminate accurate information regarding concussion risks to school systems, sports authorities, parents, athletes

Suspected concussion:

Use of checklists and screening tools

1. Instructed in proper administration of standardised validated sideline assessment tools

2. Tools should be utilised for those suspected of concussion

3. Baseline testing may be useful

4. Immediately remove from play any athlete suspected of concussion to minimise risk of further injury

5. Athlete should not be permitted to return to play until assessed by experienced health care provider

Return to play

Age effects

1. younger athletes should be managed more conservatively

Graded physical activity

1. individualise graded plans for return to play

2. carefully monitored clinically based approach

++ Need to check:

++18. Hollis SJ, Stevenson MR, McIntosh AS, Shores EA, Collins MW, Taylor CB. Incidence, risk, and protective fac- tors of mild traumatic brain injury in a cohort of Australian nonprofessional male rugby players. Am J Sports Med 2009; 37:2328–2333.

++19. Kemp SPT, Hudson Z, Brooks JHM, Fuller CW. The epidemiology of head injuries in English professional rugby union. Clin J Sport Med 2008;18:227–234.

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