What is post concussion syndrome?

Post-Concussion Syndrome: Definition, Symptoms, and Management

Post-concussion syndrome (PCS) is a complex condition characterized by the persistence of concussion-related symptoms for weeks to months after the initial head injury, affecting approximately 15-20% of concussion patients and significantly impacting morbidity, mortality, and quality of life.

Definition and Diagnostic Criteria

Post-concussion syndrome lacks a universally accepted definition, but several diagnostic frameworks exist:

• World Health Organization (WHO): Presence of 3 or more symptoms after head injury including headache, dizziness, fatigue, irritability, difficulty concentrating, memory impairment, insomnia, and reduced tolerance to stress/emotional excitement/alcohol (no specified duration) 1

• DSM-IV: 3 or more symptoms persisting for at least 3 months, including fatigue, disordered sleep, headache, dizziness, irritability, anxiety/depression, personality changes, and apathy 1

• Recent Proposed Definition: Cognitive, physical, or emotional symptoms lasting longer than expected, with a threshold of 1-6 weeks of persistent symptoms 1

Common Symptoms

PCS presents with a constellation of symptoms across multiple domains:

Physical Symptoms

• Headache (most common)
• Dizziness
• Fatigue
• Blurred vision
• Sleep disturbances
• Neck pain
• Noise and light sensitivity

Cognitive Symptoms

• Difficulty concentrating
• Memory problems
• Slowed thinking
• Executive function impairment
• Mental fogginess

Emotional/Behavioral Symptoms

• Irritability
• Anxiety
• Depression
• Emotional lability
• Personality changes
• Reduced stress tolerance

Epidemiology and Risk Factors

• Approximately 15-20% of concussion patients develop PCS, though objective cognitive assessments suggest the incidence may be higher 1
• 40% of patients report 3 or more symptoms at 3 months post-injury 2
• Risk factors for developing PCS include:
  • High early symptom burden
  • History of multiple concussions
  • Pre-existing psychiatric conditions (anxiety, depression)
  • Longer duration of unconsciousness or amnesia
  • Younger age 3
  • Age over 40 years
  • Lower educational/socioeconomic status
  • Female gender
  • Prior head injuries 4

Pathophysiology

PCS likely results from:

• Ongoing neurometabolic dysfunction after traumatic brain injury 5
• Regulatory and autoregulatory physiological dysfunction 5
• Altered cerebral autoregulation
• Autonomic nervous system dysregulation
• Disrupted sleep and circadian rhythms

Assessment and Evaluation

• The Rivermead Postconcussion Symptoms Questionnaire (RPQ) provides useful quantification of symptom severity 2
• Neuropsychological testing typically demonstrates difficulties with attention and memory 1
• Standard structural neuroimaging (CT, MRI) is typically normal 1

Management Approaches

Based on current guidelines, management of PCS should focus on identifying and treating underlying symptom generators:

1. Physical/Exercise Interventions:

   • Graded physical exercise: Weak recommendation but beneficial for both early and late-phase disorders after concussion 1, 3
   • Vestibular rehabilitation: Weak recommendation for patients with vestibular symptoms 1
   • Manual treatment of neck and spine: Weak recommendation for those with cervical symptoms 1

2. Cognitive and Psychological Interventions:

   • Psychological treatment: Weak recommendation for addressing anxiety, depression, and other emotional symptoms 1
   • Early information and advice: Weak recommendation but important for setting expectations 1
   • Cognitive rehabilitation: For persistent cognitive symptoms 6

3. Multidisciplinary Approach:

   • Interdisciplinary coordinated rehabilitative treatment: Weak recommendation but often necessary for complex cases 1
   • Vision therapy: Good clinical practice recommendation based on consensus (no strong evidence) 1

4. Return to Activities:

   • Athletes with 3+ concussions in a season or PCS symptoms >3 months should be considered for prolonged time away from sports 1
   • Elective surgery should be delayed at least 4 weeks after concussion 7

Prognosis

• Most patients experience symptom resolution within 7-10 days 1
• 80-90% experience full recovery within one month 1
• Approximately 10% remain symptomatic beyond 3 months 1
• Patients with PCS have significantly higher symptom scores than those without (mean RPQ 19.1 vs. 1.2) 2

Clinical Pitfalls to Avoid

1. Overlooking comorbidities: PCS symptoms are nonspecific and may be attributable to other factors; assess for pre-existing and co-existing conditions 1

2. Recommending prolonged rest: Extended rest leads to deconditioning and may cause secondary effects including depressive symptoms 5

3. Failing to provide adequate education: Patient education about expected recovery is essential for managing expectations

4. Missing treatable conditions: Many patients with persistent symptoms have treatable conditions that should be identified and addressed 1

5. Ignoring the impact on academics/work: PCS can significantly impact academic performance in students and work productivity in adults 1

6. Premature return to high-risk activities: Returning to contact sports or other high-risk activities before full recovery increases risk of second-impact syndrome, especially in younger patients 1

7. Dismissing symptoms as purely psychological: Despite historical controversy, the organic basis of PCS is well-documented through neuropathologic, neurophysiologic, neuroimaging, and neuropsychologic studies 4