Post-Concussion Syndrome

Introduction[edit | edit source]

Post-concussion syndrome (PCS) occurs when symptoms resulting from a concussion, also known as a mild traumatic brain injury (mTBI), persist beyond the expected timeframe of recovery, although there is disagreement among the literature as to the exact duration of symptoms necessary for this diagnosis (many sources state duration of one month). [1] The transition from concussion to post-concussion syndrome is poorly understood at this stage[2].

The most common post-concussive symptom is headache, followed by dizziness - more often a sense of disequilibrium and imbalance than objective vertigo[3].

Head and brain.jpg

The WHO International Classification of Diseases, 10th Revision (ICD-10) defines PCS as: [1]

  • History of head trauma with loss of consciousness preceding symptom onset by a maximum of 4 weeks.
  • Symptoms in 3 or more of the following symptom categories:
  1. Headache, dizziness, malaise, fatigue, altered noise tolerance
  2. Irritability, depression, anxiety, emotional lability
  3. Subjective concentration, memory, or intellectual difficulties without neuropsychological evidence of marked impairment
  4. Insomnia
  5. Reduced alcohol tolerance
  6. Preoccupation with above symptoms and fear of brain damage with hypochondriacal concern and adoption of sick role

The DSM-IV defines PCS as: [1]

  • A history of head trauma that has caused significant cerebral concussion. Note: The manifestations of concussion include loss of consciousness, posttraumatic amnesia, and less commonly, the post-traumatic onset of seizures. The specific method of defining this criterion needs to be established by further research.
  • Evidence from neuropsychological testing or quantified cognitive assessment of difficulty in attention (concentrating, shifting focus of attention, performing simultaneous cognitive tasks) or memory (learning or recall of information).
  • Three (or more) of the following occur shortly after the trauma and last at least 3 months:
  1. Becoming fatigued easily
  2. Disordered sleep
  3. Headache
  4. Vertigo or dizziness
  5. Irritability or aggression on little or no provocation
  6. Anxiety, depression, or affective instability
  7. Changes in personality (e.g., social or sexual inappropriateness)
  8. Apathy or lack of spontaneity
  • The symptoms in criteria B and C have their onset following head trauma or else represent a substantial worsening of pre-existing symptoms.
  • The disturbance causes significant impairment in social or occupational functioning and represents a significant decline from a previous level of functioning. In school-age children, the impairment may be manifested by a significant worsening in school or academic performance dating from the trauma.
  • The symptoms do not meet criteria for Dementia Due to Head Trauma and are not better accounted for by another mental disorder (e.g. Amnestic Disorder Due to Head Trauma, Personality Change Due to Head Trauma).
[4]
[5]

Clinical Presentation[edit | edit source]

[6]

Studies suggest that 21-59% of paediatric patients (age 18 and younger) who experience a concussion will develop persistent symptoms lasting longer than one month.[7] Post-concussion dysfunction (PCD), are subcategorised into physiological PCD, vestibulo-ocular PCD and Cervicogenic PCD[8]. Some of the most common and debilitating symptoms experienced by patients after a concussion are those involving dysfunction of the oculomotor and vestibular systems.[7]

Symptoms of Physiological PCD is characterized by :[8]

  • Headache that worsens with physical and cognitive exertion
  • Nausea
  • Vomiting,
  • Sensitivity to light and sound,
  • Dizziness,
  • Fatigue,
  • Poor concentration
  • Slow speech


Symptoms of Vestibulo-ocular dysfunction (VOD) may include, but are not limited to:[7]

  • Vertigo
  • Dizziness
  • Motion sensitivity
  • Postural or gait imbalances
  • Blurred vision
  • Gaze instability
  • Disequilibrium
  • Diplopia


Symptoms of Cervicogenic PCD include:[8]

  • Painful and/or stiff neck
  • Limited range of motion,
  • Occipital headache triggered by neck movements,
  • Dizziness
  • Postural issues.


Studies have shown that post-traumatic headaches (PTH) are one of the many symptoms of PCS. PTHs are more prevalent post mild TBI, AKA concussions. These headaches usually resolve within the first 3 months of injury, although some develop chronic headaches.[9] Also, a systematic review suggests a positive correlation between concussion injury and gait deviation in patients individuals who have suffered a concussion[10].

Types of Post Traumatic Headaches[9]

Tension Occipital Neuralagia Migraine Cluster
- pressure, dull ache, or tightness

Variety of distributions

- 85% of PTH

-constant or intermittent

- Ache, pressure, stabbing, or throbbing pain

- nuchal occipital, parietal, temporal, frontal, periorbital, or retroorbital distribution (greater form) or lateral/around the ear (lesser form).

- Can be seen unrelated to injury

- can occur post mild TBI

- Individuals across all age groups can develop variety of transient neurological sequelae, perhaps due to vasospasms. Five clinical types: hemiparesis; irritability, somnolence a confusional state and vomiting; transient blindness and brainstem signs

- Extremely rare

- classified as one of the Trigeminal- autonomic cephalgias

- involves the Trigeminal-vascular system with associated unilateral pain

Low CSF Pressure Supraorbital and Infraorbital Neuralgia Whiplash and Cervicogenic Other
-A result of intracranial hypotension due to CSF leak

-can be caused by minor trauma- cough/sneeze or major trauma- significant impact on the spinal axis

- Caused by a Injury of the supra/infra orbital branch

- Symptoms include tingling, shooting, burning, or aching pain with decreased or altered sensation +/- decreased sweating along the nerve distribution

- Caused by neck injuries which are common with head trauma

-Often described as unilateral throbbing +/- pressure-like pain, originating in the Occipital region, then radiating anteriorly to the Temporo-parietal areas.

- can have migraine-like qualities

- Cervicogenic headaches often go hand in hand with whiplash injuries

- Sub-dural/eidural heamatomas associated with headache due to space occupying lesion

- often in children/young adults after sustaining a trivial injury without LOC

- Often complains of persisting headache with nausea, vomiting and memory impairment

Risk Factors for Developing Post-Concussion Syndrome[edit | edit source]

Initial injury severity does not appear to correlate with likelihood of developing post-concussion syndrome[2]. However, a history of past concussions does appear to correlate likelihood of PCS development[11].

A study comparing children and adolescents with sport-related concussions who had short recovery times (30 days or less) to those who developed post-concussion syndrome, found that PCS was more likely to occur in:[7]

  • Patients who reported amnesia at the time of concussion
  • Patients diagnosed with Vestibulo-ocular dysfunction (double the average recovery time as those without VOD, and 4X higher odds of developing PCS)
  • Patients with higher PCSS scores (concussion severity indicator)

Other Risk Factors identified in the literature: Age, gender (female), previous concussion, previous migraine, loss of consciousness at the time of injury.[7]

Assessment[edit | edit source]

Treadmill testing

Treadmill testing can differentiated between alteration of brain metabolism (i.e. physiological PCD) and neural subsystem (i.e. vestibule-ocular PCD or cervicogenic PCD).[8]

  • Patients may be considered as recovered when they have minimal to no symptoms at rest and attain maximal exertion without worsening of symptoms. This is when they can safely return to physical activities.[8]
  • If patients still have symptoms 3 weeks after the injury and experience symptoms during the treadmill test may have physiological PCD.[8]
  • If patients still have symptoms at rest three weeks after their injury, but they don't experience any symptoms during the treadmill test, additional examination is necessary to identify whether their symptoms could be due vestibulo-ocular PCD or cervicogenic PCD.[8]

[12]

Vestibulo-ocular clinical exam:

Involves standardizes techniques such as the evaluation of extra-ocular movement, smooth pursuits, near-point convergence (NPC), horizontal and vertical saccades, and the vestibulo-ocular reflex (VOR).[7] In addition to vestibular and visual dysfunction, other potential causes of persistent dizziness can include cervical spine dysfunction, post-traumatic migraine, and autonomic dysfunction.[13]

Outcome Measures[edit | edit source]

Useful self-report measures for evaluating patients with vestibular symptoms associated with a concussion:[13]

Dizziness Handicap Inventory (DHI) [14]

  • 25 item questionnaire measuring self-perceived disability due to unsteadiness and dizziness. Items are scored from 0-100, with higher scores indicating a greater perceived level of disability. Clinically significant change = 18 or more.

Activities-specific Balance Confidence Scale (ABC) [15]

  • 16-item questionnaire in which patients rate their confidence in their balance during activities of daily living. Items are scored from 0-100, with 100 being complete confidence that they will not lose their balance during a task. Increased risk for falls = score of 67 or less.

Post-Concussion Symptoms Scale (PCSS) [16]

  • 22-item questionnaire requiring patients to rate various symptoms of concussion, vestibular and otherwise, on a scale from 0-6.

Visual Vertigo Scale (VVS)[17]

  • Condition-specific, 15-item questionnaire which assesses a patient’s perceived severity of vertigo symptoms over the past month. The scale measures the frequency of vertigo, imbalance, dizziness, and other autonomic and anxiety-related symptoms. Scored out of a total of 60, higher scores indicates increased symptom severity.


Treatment[edit | edit source]

When symptoms of concussion such as dizziness, vertigo, and imbalance fail to recover spontaneously, vestibular rehabilitation can be used effectively to aid in the normalization of a patient’s vestibular responses. Vestibular rehab involves the use of specific exercises that aim to alleviate symptoms of vestibular dysfunction, as well as improve balance and the overall function of the patient.[13]

Dynamic Gaze Stability[edit | edit source]

The ability to maintain focus while the head is in motion, controlled primarily by the vestibular ocular reflex (VOR), cervical ocular reflex (COR), smooth pursuit, and optokinetic responses. Impairments in the VOR are often seen after an injury to the vestibular system.

  1. Exercise: “X1” and “X2” viewing - Patient focuses on a target (first stationery, then moving) while the head is rotated. Progressions can include increasing speed, and introducing coordination tasks [13]
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Postural Control[edit | edit source]

Static and dynamic balance controlled through combined input from the visual, vestibular, and somatosensory systems - can often become impaired following a concussion. Thorough testing needs to be performed to assess all three contributing systems and how they are functioning together for a particular patient. Exercise components:[13]

  1. Beginning with basic environments and progress to more complex ones
  2. Eyes open versus eyes closed
  3. Head turns and tilts
  4. Stable versus unstable surfaces
  • Other Aspects of PCS Treatment
[20]
  1. Pacing techniques
  2. Graded, sub-symptom exertional exercise [13] 
  3. Binasal Occlusion (BNO). Partial occluders (scotch tape, nail polish, or electrical tape) can be added to spectacle lenses to suppress abnormal visual motion in the peripheral field. In patients with Visual Motion Sensitivity (VMS), BNO can improve both subjective visual perception and objective performance with sensorimotor tasks.[21]

Considerations:[13]

  • It is important to clear patients of Benign Paroxysmal Positional Vertigo (BPPV) prior to beginning vestibular rehab exercises, as it can have its own effect on a patient’s balance and is treated with a specific repositioning protocol.
  • Patients should also be screened for cervicogenic dizziness (symptoms caused by cervical spine dysfunction, which should be relieved with manual cervical traction).
  • Vestibular rehab is most effective for patients whose headaches are well-controlled, therefore close monitoring of symptoms and treatment coordination with physicians can be important
  • A patient does not need to be made dizzy by an exercise in order to improve
  • Many mTBI patients require very basic visual targets.

Resources[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 Guidelines for Concussion/mTBI and Persistent Symptoms: Second Edition. Ontario Neurotrauma Foundation. Available from: http://onf.org/documents/guidelines-for-concussion-mtbi-persistent-symptoms-second-edition Last accessed: 30/08/2016
  2. 2.0 2.1 Harmon KG, Drezner JA, Gammons M, Guskiewicz KM, Halstead M, Herring SA, Kutcher JS, Pana A, Putukian M, Roberts WO. American Medical Society for Sports Medicine position statement: concussion in sport. Br J Sports Med. 2013 Jan;47(1):15-26. doi: 10.1136/bjsports-2012-091941. Erratum in: Br J Sports Med. 2013 Feb;47(3):184. PMID: 23243113.
  3. Mullally, William J., MD. Concussion. The American journal of medicine. 2017;130(8):885–92.
  4. Appalachian Regional Healthcare System. What is Post-Concussion Syndrome? . Available from: http://www.youtube.com/watch?v=x59vYzLuQR8 [last accessed 30/08/2016]
  5. Betteryears.com. Post-Concussion Syndrome Myths and Facts. Available from: http://www.youtube.com/watch?v=srCc6dDWSnY [last accessed 30/08/2016]
  6. Physical Therapy Nation. Dynamic Visual Acuity Test. Available from: http://www.youtube.com/watch?v=AfghWx3IInE [last accessed 30/08/2016]
  7. 7.0 7.1 7.2 7.3 7.4 7.5 Ellis MJ, Cordingley D, Vis S, Reimer K, Leiter J, Russell K. Vestibulo-ocular dysfunction in pediatric sports-related concussion. J Neurosurg Pediatr. 2015 https://pubmed.ncbi.nlm.nih.gov/26031619/ [cited 2016 May 31]; 16:248-255.
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Ellis MJ, Leddy JJ, Willer B. Physiological, Vestibulo-ocular and cervicogenic post-concussion disorders: An evidence-based classification system with directions for treatment [Internet]. Taylor & Francis. [cited 2023Apr16]. Available from: https://www.tandfonline.com/doi/abs/10.3109/02699052.2014.965207?journalCode=ibij20
  9. 9.0 9.1 Seifert TD. & Evans RW. Posttraumatic Headache: A Review. Curr Pain Headache Rep.2010, 14: 292. https://doi.org/10.1007/s11916-010-0117-7
  10. Manaseer TS, Gross DP, Dennett L, Schneider K, Whittaker JL. Gait deviations associated with concussion: a systematic review. Clinical journal of sport medicine. 2020 Mar 1;30:S11-28.
  11. Tator CH, Davis HS, Dufort PA, Tartaglia MC, Davis KD, Ebraheem A, Hiploylee C. Postconcussion syndrome: demographics and predictors in 221 patients. J Neurosurg. 2016 Nov;125(5):1206-1216. doi: 10.3171/2015.6.JNS15664. Epub 2016 Feb 26. PMID: 26918481.
  12. What is the Buffalo Concussion Treadmill Test? | concussion questions (2020) [Internet]. YouTube. YouTube; 2020 [cited 2023Apr16]. Available from: https://www.youtube.com/watch?v=eJAGdLszgIg
  13. 13.0 13.1 13.2 13.3 13.4 13.5 13.6 Gurley JM, Hujsak BD, Kelly JL. Vestibular rehabilitation following mild traumatic brain injury. NeuroRehabilitation. 2013 [cited 2016 May 31]; 32:519-528.Available from: https://pubmed.ncbi.nlm.nih.gov/23648606/
  14. Jacobson GP, Newman CW. The development of the Dizziness Handicap Inventory. Arch Otolanryngol Head Neck Surg. 1990;116:424–427. Available from: https://pubmed.ncbi.nlm.nih.gov/23648606/
  15. Powell LE and Myers AM. (1995). "The Activities-specific Balance Confidence (ABC) Scale." Journals of Gerontology. Series A, Biological Sciences and Medical Sciences 50A(1): M28-34. Available from: https://pubmed.ncbi.nlm.nih.gov/7814786/
  16. Aubry M, Cantu R, Dvorak J, Graf-Baumann T, Johnston K, Kelly J, et al. Summary and agreement statement of the First International Conference on Concussion in Sport, Vienna 2001. Recommendations for the improvement of safety and health of athletes who may suffer concussive injuries. Br J Sports Med. 2002 Feb;36(1):6-10. Available from: https://pubmed.ncbi.nlm.nih.gov/11867482/
  17. Dannenbaum E, Chilingaryan G et al. Visual vertigo analogue scale: an assessment questionnaire for visual vertigo. J Vestib Res. 2011. 21(3): 153-159. Available from: https://pubmed.ncbi.nlm.nih.gov/21558640/
  18. UMHealthSystem. Gaze Stabalization VOR x1 - 2014. Available from: http://www.youtube.com/watch?v=dA_r_dsui6s [last accessed 30/08/2016]
  19. UMHealthSystem. Gaze Stabilization VOR x 2 - 2014. Available from: http://www.youtube.com/watch?v=aVz_ZD103as [last accessed 30/08/2016]
  20. St Joseph's London. Concussion/mTBI - Dealing with vision changes: Bi-Nasal Occlusion. Available from: http://www.youtube.com/watch?v=JSFIkCWCwMc [last accessed 30/08/2016]
  21. Yadav NK, Ciuffreda KJ. Effect of binasal occlusion (BNO) and base-in prisms on the visual-evoked potential (VEP) in mild traumatic brain injury (mTBI). Brain Inj. 2014 [cited 2016 May 31]; 28 (12): 1568-1580. Available from: https://pubmed.ncbi.nlm.nih.gov/25058498/