Concussion and Mild Traumatic Brain Injury Notes

Introduction

• Concussion and mild traumatic brain injury (mTBI) are complex.
• The more you understand the physiology, the better you can assist people in returning to sport or daily life.

Understanding Concussion

• You don't need to hit your head to have a concussion.
• The main cause is the brain moving within the cerebral spinal fluid, causing a stretch injury.
• Jolts or shakes are the primary cause.
• Diagnosis is challenging as there are no definitive diagnostic tests.

Diagnosis

• Diagnosis relies on:
  • Mechanism of injury
  • Signs and symptoms
  • Cognitive function (memory), especially post-traumatic amnesia
  • Neurological assessment (balance, vision/oculomotor function)

Common Assessments

• SCAT6: Sideline Concussion Assessment Tool (used by sporting clubs)
• SCOAT: Sideline Concussion Office Assessment Tool (not yet validated)
• Post-Concussion Symptom Questionnaire
• Melbourne Pediatric Concussion Scale (for children)

Symptoms of Concussion

• Wide range of symptoms:
  • Common: Fatigue, headache, brain fog
  • Mood changes, irritability, sleep disturbances
  • Somatic (physical) symptoms: headache, dizziness, nausea, light/noise sensitivity, visual changes, tinnitus, brain fog
  • Attention, concentration, memory, and processing speed issues
  • Speech and language issues (rare)

Recovery

• 85-90% of concussions recover within 2-4 weeks.
• 15% may have long-term symptoms.

Red Flags - When to Seek Immediate Medical Attention

• Increasing severity of symptoms
• Confusion, agitation, or irritability (use Glasgow Coma Scale)
• Neurological neck pain
• Seizures or convulsions
• Any other neurological signs
• Loss of consciousness or changes in vision

Physiological Changes

• Metabolic changes occur in the brain without structural changes visible on scans.
• Understanding these changes helps in educating patients and reducing fear of catastrophizing, which can lead to long-term issues.

Metabolic Changes in the Brain

• Abrupt exit of potassium from the cell body and calcium rushes into the cell body.
• Blood vessels constrict resulting in decreased blood flow to the brain.
• Damage to brain cells' mitochondria leading to less energy production.
• Potential for glutamate production issues.
• Results in an energy or metabolic crisis: increased demand for energy/glucose but decreased supply.

Energy Requirements Pre and Post Injury

• Pre-injury: Brain uses 15-20% of the body's energy.
• Post-injury: Brain may require up to 80% of the body’s energy.

Impact of Insufficient Brain Energy

• The brain cannot cope with normal demands, leading to overwhelm.
• Normal brain functions:
  • Processing sensory inputs (light, noise)
  • Filtering information
  • Problem-solving
  • Managing emotions
• Energy crisis can make these functions feel overwhelming, similar to sleep deprivation combined with stress.
• These feelings can create stress, exacerbating the metabolic stress response.

Initial Management

• Calm down the stress response and allow the brain to heal.
• Rest (physical and cognitive) for 24-48 hours.
• Gradual increase in activities of daily living and cognitive activities (paced return to work/university).
• Progressive return to sport once daily life and work/school activities are managed.
• Strict rest beyond 48 hours is not recommended, as it can lead to cognitive deconditioning.
• Screens should be reintroduced after 48 hours, challenging the brain without exacerbating symptoms.

Role of Physiotherapy

• 70-80% of concussions recover on their own within 2-4 weeks, requiring minimal intervention.
• Physiotherapy can provide education, ensure appropriate rest, guide return to activities, and oversee return to sport (reflexes, balance).
• 30% of cases are more complex, requiring specialized physiotherapy.

Key Areas of Focus for Physiotherapy Assessment

• Autonomic Nervous System (ANS)
• Cervical Function
• Vestibular System
• Visual System
• Cognitive Function

Autonomic Nervous System (ANS)

• Addresses fight or flight response (sympathetic) and rest and digest (parasympathetic) systems.
• Symptoms of ANS dysfunction: dizziness, headache, orthostatic hypotension.
• Symptoms can overlap with neck and vestibular issues, so specific impairments need to be identified.

Reducing Metabolic Stress to Aid Recovery

• Early intervention aims to reduce anxiety (internal anxiety from concussion symptoms and external factors).
• Reassurance and validation of symptoms are crucial.
• Explanation of physiology: fatigue results from the brain needing more energy but not functioning at full capacity.
• Limiting sensory stimulation can help manage anxiety responses.

Trauma

• Identify trauma history (car accidents, domestic violence, assault).
• Psychological trauma may be associated with the injury.
• Referral to a psychologist may be needed to manage trauma symptoms and anxiety, which can reduce metabolic stress and encourage recovery.

Heart Rate and Exercise

• Pushing heart rate beyond manageable levels increases metabolic stress.
• Restricted blood flow to the brain may trigger symptoms when returning to exercise too early.

Importance of Exercise

• Exercise is medicine for neurological disorders, and important for concussion recovery.
• Benefits:
  • Improves energy metabolism in the brain.
  • Aids wakefulness and sleep cycles.
  • Inhibits apoptosis (neuronal cell death).
  • Promotes angiogenesis (new brain pathways).
  • Improves cerebral blood flow in response to cognitive demands.
  • Enhances inflammatory response.

Assessing Exercise Tolerance

• Use the Buffalo Concussion Treadmill Test (or modified version) to determine safe exercise levels.
  • Monitor symptoms and heart rate during progressive increase in exertion.
  • If symptoms increase by three or more points on a visual analog scale (0-10), stop the test.

Prescribing exercise

• Calculate 90% of the threshold heart rate from the treadmill test as the initial target.
• Exercise daily for 20 minutes at this target heart rate (except on bad days).
• Increase the target heart rate by 5 beats per minute every three days without symptom exacerbation.
• Continue until the individual can reach 85% of their age-predicted maximum heart rate before considering return to sport.

Other Ways to Improve Autonomic Nervous System Function

• Yoga, meditation, mindfulness
• Better sleep-wake cycles
• Biofeedback
• Encourage at least some form of exercise, even if not reaching the target heart rate.
• Diet may also play a significant role in concussion recovery; watching this space for further research.

Dizziness

• Dizziness is a very common symptom, often second to headaches or fatigue.
• Physiotherapists have a significant role in managing dizziness.
• Vestibular function is important to assess and clear.

Vestibular System

• Dizziness can stem from autonomic function or vestibular issues.
• Always rule out Benign Paroxysmal Positional Vertigo (BPPV).
• BPPV can be more complex post-concussion, involving multiple canals or both ears, and prone to recurrence.
• Empower patients to self-treat BPPV.
• Vestibular dysfunction post-concussion can have prolonged recovery times.

Vestibular Assessment

• Thorough assessment to rule out vestibular hypofunction or gaze stability and balance issues.
• Unilateral hypofunction is less common, but impaired gaze stability is frequent.
• Address central integration of visual and vestibular inputs.
• Use a dynamic visual acuity chart to assess gaze stability (vision with head still vs. moving at 120 bpm).

Balance

• Assess balance, considering central integration of vestibular information.
• Use functional gait assessment or HiMAT (High-Level Mobility Assessment Tool), especially for return to sport.
• Balance and gaze stabilization issues increase the risk of subsequent concussion.

Types of Vestibular Dysfunction Post-Concussion

• BPPV
• Central sensory processing deficits (integration of vestibular information)
• Sensitization or 3PD (persistent postural-perceptual dizziness): over-sensitization to motion; associated with anxiety.
• Labyrinthine concussion: concussion of the inner ear (its existence is debated).
• Inner ear tear: rare, requires ENT follow-up.
• Peripheral hyperfunction of the inner ear: rare.

Visual Changes

• Visual changes are common post-concussion.
• Refer to an orthoptist, optometrist, or neuro-ophthalmologist.
• Common issues:
  • Convergence insufficiency (eyes coming together)
  • Accommodation insufficiency (changing focus from near to far)
  • Saccades (jumping eyes between targets)
  • Smooth pursuit (following a target)
• Ocular motor assessment is important, as changes are visible in the acute stage.
• Many issues resolve within three months, but refer if unresolved.

Referral Guidelines

• Orthoptist: binocular vision changes.
• Optometrist: monocular vision assessment.
• Neuro-ophthalmologist: vision changes after brain injury or neurological conditions.
• Blurred vision, trouble reading, difficulty concentrating, and visual memory issues, can indicate the need for vision assessment.

Cervical Spine

• Symptoms of cervical spine injury: dizziness, headache, nausea, blurred vision.
• Cervical spine has interconnections to the vestibular system, contributing to balance and dizziness.
• Whiplash can also cause vision changes.
• Suboccipital muscles connect the neck to the eyes.
• Cervical spine has a high density of proprioceptors (250 in the suboccipital space), important for head positioning and balance.

Assessment

• Assess neck function, particularly proprioception and deep neck flexor strength.
• Use the cervical joint position error test to assess proprioception post-whiplash injury.
• Whiplash injuries increase concussion risk due to head jolting.

Cognitive Function

• Metabolic stress response impacts cognitive function.
• Occupational therapy or speech pathology can assist with return to activities.
• Cognitive dual-tasking is important for return to sport, especially under physical metabolic stress.
• Train split-second decision-making skills by incorporating cognitive tasks during exercise.
• Involve the interdisciplinary team.

Fatigue and Sensory Overload

• Can cause dizziness.
• Reduce metabolic stress response to manage.

Outcome Measures

• Symptom questionnaires (e.g., Rivermead Post Concussion Symptoms Questionnaire, Dizziness Handicap Inventory)
• Balance-related outcome measures (e.g., Functional Gait Assessment, HiMAT)
• VOMS (Vestibular Ocular Motor Screen)
• Dynamic Visual Acuity
• Buffalo Concussion Treadmill Test
• Cervical tests (e.g., neck proprioception test)
• Pain assessment (pain increases metabolic stress)

Persisting Post-Concussion Symptoms

• Assess: autonomic, cervical, vestibular, cognitive, and visual domains.
• Consider:
  • Cognitive vulnerabilities
  • Mood disorders
  • PTSD
  • Chronic pain patterns
  • Previous brain injuries
  • Family or work situations
  • Compensability
• A team approach is often needed.

Interdisciplinary Team

• Medical: medication management, clearance for driving/return to work.
• Occupational therapy: return to daily activities/work, visual assessments, cognitive therapy.
• Speech therapy: address aphasia and cognitive communication issues.
• Psychology: manage stress and anxiety.

Assessment and Management

• Create a problem list and prioritize impairments.
• Set functional goals.
• Clear for BPPV first.
  • For BPPV the Epley maneuver is a treatment that can be effective in resolving vertigo.
• Consider energy needs and incorporate necessary activities into broader goals.
• Liaise with the interdisciplinary team.
• Address anxiety and stress.
• Use outcome measures.

Key Tips from Physio

• Refer to the interdisciplinary team as needed.
• Start regular aerobic exercise early (after 48 hours).
• Reassure and educate patients.
• Protect ANS function: prioritize sleep, meditation, and relaxation.
• Plan for return to play/work with clear expectations.

Returning to Sport (Children)

• Australian Institute of Sport recommends:
  • 14 days symptom-free at rest before contact training.
  • Minimum of 21 days from the time of concussion before competitive contact sport.
  • If in doubt, sit them out.

Returning to Sport (Adults)

• Assess symptom rating and physical capabilities, particularly in the mentioned key domains prior to contact sports.

Resources

• Concussion and brain health position statement 2024 (Australian Institute of Sport, APA, Association for EPs).
• Brain and Interview Australia.
• Living concussion guidelines from the Brain Institute in Ontario.