Postconcussion Syndrome (Mild Traumatic Brain Injury)



  • Postconcussion syndrome (PCS) is a constellation of symptoms involving physical, cognitive, and/or behavioral symptoms persisting after a concussion (synonymous with mild traumatic brain injury [mTBI]) that may continue for weeks to years.
  • It is difficult to define when concussive symptoms transition to postconcussive syndrome. A recent consensus suggests persistent symptoms lasting >10 to 14 days in adults and 4 weeks in children (1).
  • PCS may present with any symptoms of concussion including:
    • Cognitive
      • Poor attention
      • Poor memory
      • Diminished academic/intellectual performance
      • Slowed response time
    • Physical
      • Headache
      • Nausea
      • Visual changes
      • Light or noise sensitivity
      • Dizziness and balance problems
      • Fatigue and sleep disturbance
    • Behavioral
      • Depression
      • Anxiety
      • Irritability/emotional lability
      • Apathy
      • Increased sensitivity to alcohol
  • Diagnosis is based on history and clinical symptoms.


The reported frequency of patients with concussion who develop PCS varies widely between 5% and 80%.

  • Largely due to difficulty differentiating postconcussion symptoms from PCS
  • 80–90% of individuals with concussion recover from postconcussion symptoms within 7 to 10 days, longer in children/adolescents. A diagnosis of PCS is made in patients with persistent concussive symptoms.

Predominant sex: Females are slightly more likely to experience prolonged symptoms following a concussive injury.

Etiology and Pathophysiology

  • Controversial; exact mechanism(s) unknown
  • Because the pathophysiology of PCS is not well understood and because of symptom overlap with other psychiatric conditions, PCS remains difficult to diagnose and to manage.
    • Only some individuals with mTBI develop PCS; it is unclear what causes postconcussion symptoms to persist, leading to PCS.
    • Behavioral factors are commonly associated with (and may play a role in) the development of PCS. It can be challenging to differentiate some preexisting behavioral disorders from PCS. Neuropsychiatry evaluation can be helpful.
    • Patients who reported high symptom burden following mTBI are at increased risk of PCS (2).

Risk Factors

  • Strongest predictor of prolonged recovery and development of PCS is severity of initial concussion symptoms (1).
  • Initial symptoms including retrograde amnesia, difficulty concentrating, disorientation, insomnia, loss of balance, sensitivity to noise, or visual disturbance (3)
  • Preexisting psychiatric disorders including depression, anxiety, personality disorder, and posttraumatic stress disorder (PTSD)
  • Preexisting expectation of poor outcomes following mTBI
  • Nonsport concussion/mTBI
  • Unclear if previous history of concussion(s) is a risk factor for PCS
  • Low socioeconomic status
  • Loss of consciousness is NOT predictive of PCS.

General Prevention

  • Early clinical evaluation and treatment can help reduce time of recovery. Identified concussion symptom constellations should be addressed and treated early.
  • Education of players, coaches, parents, and athletic trainers about concussion, PCS, and appropriate safety rules
  • Head injury precautions are advised. Evidence is lacking that these decrease incidence of mTBI/PCS.
  • Screening and intervention for preexisting comorbidities such as anxiety, depression, attention disorders, migraines, or insomnia early in concussion treatment may reduce the likelihood of transitioning from concussion to PCS.

Commonly Associated Conditions

  • PTSD
  • Anxiety
  • Depression
  • Fibromyalgia
  • Personality disorders (namely, compulsive, histrionic, and narcissistic)
  • ADHD

There's more to see -- the rest of this topic is available only to subscribers.