What is the diagnostic approach for a concussion?

Diagnosing Concussion: A Systematic Approach

Concussion should be diagnosed using a comprehensive assessment that includes evaluation of signs and symptoms, cognitive function, balance testing, and oculomotor/vestibular examination, with no single test being sufficient for diagnosis.

Definition and Recognition

Concussion is a traumatic brain injury induced by biomechanical forces that:

• Results from direct or indirect transmission of force to the head
• Causes immediate and transient brain dysfunction
• Typically presents with rapid onset of short-lived neurological impairment
• Reflects functional rather than structural injury (normal standard neuroimaging)
• Results in a range of clinical signs and symptoms that may or may not involve loss of consciousness 1

Diagnostic Approach

Step 1: Initial Assessment (On-Field/Sideline)

• Remove athlete from play immediately when concussion is suspected 1
• Assess for red flags requiring emergency evaluation:
  • Glasgow Coma Scale < 15 at 2 hours post-injury
  • Suspected skull fracture
  • Worsening headache
  • Irritability on examination
  • Seizures or convulsions
  • Prolonged loss of consciousness (>30 seconds)
  • Focal neurological deficits 1

Step 2: Comprehensive Evaluation

1. Symptom Assessment

   • Use standardized symptom checklist to document:
     • Physical symptoms (headache, dizziness, nausea, light/noise sensitivity)
     • Cognitive symptoms (confusion, feeling foggy, difficulty concentrating)
     • Emotional symptoms (irritability, sadness, nervousness)
     • Sleep disturbances 1

2. Neurological Examination

   • Perform elemental neurological exam with emphasis on:
     • Mental status and orientation
     • Cranial nerve assessment
     • Oculomotor/ophthalmologic evaluation:
       • Smooth pursuits
       • Saccades (rapid eye movements)
       • Vestibular ocular reflex (VOR)
       • Near point convergence
       • Accommodation 1, 2
     • Vestibular assessment:
       • Balance testing (Balance Error Scoring System)
       • Coordination
       • Gait assessment 1

3. Cognitive Assessment

   • Evaluate:
     • Orientation
     • Immediate and delayed recall
     • Concentration (digits backward, months backward)
     • Processing speed 1
   • Consider standardized tools like Standardized Assessment of Concussion (SAC) 1

4. Musculoskeletal Assessment

   • Evaluate craniocervical and upper shoulder girdle complex
   • Assess for cervical strain (associated condition) 1, 2

Step 3: Supplementary Testing (When Indicated)

1. Neuroimaging

   • CT scan is indicated within first 24-48 hours if:
     • Glasgow Coma Scale < 15
     • Suspected skull fracture
     • Worsening headache
     • Focal neurological deficits 1
   • MRI may be appropriate if symptoms persist beyond 48 hours 1

2. Neuropsychological Testing

   • Not required for all concussions but helpful for:
     • Persistent symptoms
     • Complex cases
     • Return-to-play decisions
     • Baseline comparison when available 1, 3

3. Exercise Tolerance Testing

   • Buffalo Concussion Treadmill Test to assess exertional symptoms 2

Concussion Subtypes Identification

Evaluate for predominant subtype presentation to guide management 1:

1. Cognitive: Attention, memory, processing speed deficits
2. Ocular-motor: Visual disturbances, convergence insufficiency
3. Headache/migraine: Headache as primary symptom
4. Vestibular: Dizziness, balance problems, spatial disorientation
5. Anxiety/mood: Emotional symptoms predominate

Common Pitfalls to Avoid

1. Relying solely on loss of consciousness

   • LOC occurs in less than 10% of concussions 1
   • Absence of LOC does not rule out concussion 1

2. Dismissing subtle symptoms

   • Avoid terms like "ding" or "bell rung" that minimize injury 1
   • Even mild symptoms warrant evaluation 1

3. Premature return to play

   • Never allow same-day return to play after diagnosed concussion 1
   • Athletes should never return while symptomatic 1

4. Inadequate follow-up

   • Monitor for deterioration or delayed symptoms
   • Assess for persisting symptoms that may indicate prolonged recovery 1

5. Missing associated conditions

   • Sleep disturbances
   • Cervical strain
   • Pre-existing conditions that may complicate recovery 1, 4

Special Considerations for Children and Adolescents

• Recovery course is typically longer than in adults 1
• More conservative approach to return-to-play is warranted 1
• Academic accommodations may be necessary during recovery 1
• Consider referral if symptoms persist beyond 4 weeks 1

By following this systematic approach to concussion diagnosis, clinicians can ensure appropriate identification, management, and monitoring to optimize recovery and minimize potential long-term consequences.