Diagnosis

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Diagnosis of concussion is the first critical step in successful management leading to improved outcomes and prevention of further injury. The Living Concussion Guidelines adheres to the 2023 American Congress of Rehabilitation Medicine (ACRM) diagnostic criteria for concussion or uncomplicated mTBI (i.e., mTBI with no neuroimaging abnormality present).1 The full article can be accessed here. Click here to view a visual representation of the ACRM diagnostic criteria taken from the article, and here to view a visual representation of clinical signs, acute symptoms, and lab findings. 

The purpose of the initial medical assessment is to establish the diagnosis of concussion by ruling out other conditions with similar symptom profiles such as more severe forms of TBI, cervical spine injuries and medical and neurological conditions.2 The need for neuroimaging should also be determined using the Canadian CT Head Rule (Figure 1.1).3,4 Symptoms should be formally documented at the time of the initial assessment for the purpose of subsequent comparative analysis in the event of prolonged symptoms. Blood-based biomarkers5 are still considered investigational and therefore are not recommended for use in diagnosing/assessing patients in the ED or PCP’s office.

Once a diagnosis of concussion is established, Primary Care Provider’s (PCP’s) should provide patients and their support person with written, verbal and/or pictorial education regarding management and prognosis.6 Follow-up by a PCP should be arranged for all patients with a diagnosed concussion to monitor progress and ensure that the patient's symptoms are improving according to expected timelines. PCPs may also consider referral to a regulated healthcare professional if necessary. 

References supporting introduction:

  1. Silverberg ND, Iverson GL; ACRM Brain Injury Special Interest Group Mild TBI Task Force members:, et al. The American Congress of Rehabilitation Medicine Diagnostic Criteria for Mild Traumatic Brain Injury. Arch Phys Med Rehabil. 2023;104(8):1343-1355.
  2. Parachute. Canadian Guideline on Concussion in Sport. In. Toronto: Parachute; 2017.
  3. Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001;357(9266):1391-1396
  4. Sharp AL, Nagaraj G, Rippberger EJ, et al. Computed Tomography Use for Adults with Head Injury: Describing Likely Avoidable Emergency Department Imaging Based on the Canadian CT Head Rule. Academic Emergency Medicine. 2017;24:22-30
  5. Mondello S, Schmid K, Berger RP, et al. The Challenge of Mild Traumatic Brain Injury: Role of Biochemical Markers in Diagnosis of Brain Damage. Medicinal Research Reviews. 2014;34(3):508-531. 
  6. Nygren-de Boussard C, Holm LW, Cancelliere C, et al. Nonsurgical interventions after mild traumatic brain injury: a systematic review. Results of the International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch Phys Med Rehabil. 2014;95(3 Suppl):S257-264.
1.1

Suspected concussion should be recognized as soon as possible and referred to a physician/nurse practitioner for diagnosis confirmation.

Context

While other experts beyond physicians and nurse practitioners may effectively recognize concussion, referral should be made to a physician/nurse practitioner who can access the healthcare resources and infrastructure needed to fully assess and care for a patient following concussion.

Level of Evidence A
( recognition )
Level of Evidence C
( referral for diagnosis )
Last updated  
1.2

The primary care provider should conduct a comprehensive review of every patient who has sustained concussion/mTBI (see Appendix 1.1). The assessment should include taking a history using a standardized concussion symptom inventory tool (including cognition screening), a physical examination, and a review of mental health status.

Context

A comprehensive history of a patient with a suspected concussion should include the use of a standardized tool with concussion specific measures. This allows for consistent and standardized assessment of the patient with the ability to follow and monitor the progression of the patient’s recovery. A physical examination should look for objective signs of dysfunction following concussion and examine for other potential diagnosis. A review of mental health status should be conducted as there is evidence that pre-injury psychiatric history or disorder is a predictor of persistent post-concussion symptoms and disability following concussion.

References supporting context:

  1. Booker, J., Sinha, S., Choudhari, K., Dawson, J., & Singh, R. Description of the predictors of persistent post-concussion symptoms and disability after mild traumatic brain injury: The shefbit cohort. British Journal of Neurosurgery. 2019;33(4), 367–375.
  2. Campbell-Sills, L., Jain, S., Sun, X., Fisher, L. B., Agtarap, S. D., Dikmen, S., Nelson, L. D., Temkin, N., McCrea, M., Yuh, E., Giacino, J. T., & Manley, G. T. Risk factors for suicidal ideation following mild traumatic brain injury: A track-TBI study. Journal of Head Trauma Rehabilitation. 2020;36(1).
  3. Cnossen, M. C., Winkler, E. A., Yue, J. K., Okonkwo, D. O., Valadka, A. B., Steyerberg, E. W., Lingsma, H. F., Manley, G. T., & the TRACK-TBI Investigators. Development of a prediction model for post-concussive symptoms following mild traumatic brain injury: A track-tbi pilot study. Journal of Neurotrauma. 2017;34(16), 2396–2409.
Level of Evidence A
( taking a history, physical examination, and review of mental health status )
Level of Evidence B
( using a standardized concussion symptom inventory tool (including cognition) )
Last updated  
1.3

The need for neuroimaging on acute presentation (within 24-48 hours post-injury) should be determined according to the Canadian CT rule (see Figure 1.1), noting that patients who are anticoagulated or who have bleeding disorders require extra consideration. Patients presenting at the post-acute phase deemed to require neuroimaging should ideally be scanned using MRI. Plain skull x-rays are not recommended.

Context

For patients who fulfill the Canadian CT rule criteria, CT scanning is the most appropriate investigation for the exclusion of neurosurgically significant lesions, such as hemorrhage, within the acute phase (< 48 hours after injury). However, there is low value of CT scan in the post-acute phase (>48 hours after injury). Instead, an MRI has an increased ability compared to CT scan in the subacute phase for identifying evidence of intracranial trauma. Patients with bleeding disorders or who are taking direct oral anticoagulant treatment or a vitamin K antagonist require extra attention as they have an increased risk of hemorrhage. While there is evolving literature about blood biomarkers such as glial fibrillary acidic protein (GFAP) and S100 calcium binding protein B (S100B), use of these as diagnostic tools is currently difficult to implement and does not have strong enough evidence to warrant changing current practices.

References supporting context:

  1. Cipriano, A., Park, N., Pecori, A., Bionda, A., Bardini, M., Frassi, F., Lami, V., Leoli, F., Manca, M. L., Del Prato, S., Santini, M., & Ghiadoni, L. Predictors of post-traumatic complication of mild brain injury in anticoagulated patients: Doacs are safer than vkas. Internal and Emergency Medicine. 2021;16(4), 1061–1070.
  2. Riccardi, A., Spinola, B., Minuto, P., Ghinatti, M., Guiddo, G., Malerba, M., & Lerza, R. (2017). Intracranial complications after minor head injury (MHI) in patients taking Vitamin K antagonists (VKA) or direct oral anticoagulants (doacs). The American Journal of Emergency Medicine. 2017;35(9), 1317–1319.
  3. Turcato, G., Zannoni, M., Zaboli, A., Zorzi, E., Ricci, G., Pfeifer, N., Maccagnani, A., Tenci, A., & Bonora, A. Direct oral anticoagulant treatment and mild traumatic brain injury: Risk of early and delayed bleeding and the severity of injuries compared with Vitamin K antagonists. The Journal of Emergency Medicine. 2019;57(6), 817–824.
  4. Gill, J., Latour, L., Diaz-Arrastia, R., Motamedi, V., Turtzo, C., Shahim, P., Mondello, S., DeVoto, C., Veras, E., Hanlon, D., Song, L., & Jeromin, A. Glial fibrillary acidic protein elevations relate to neuroimaging abnormalities after mild TBI. Neurology. 2018;91(15).
  5. Giza, C. C., McCrea, M., Huber, D., Cameron, K. L., Houston, M. N., Jackson, J. C., McGinty, G., Pasquina, P., Broglio, S. P., Brooks, A., DiFiori, J., Duma, S., Harezlak, J., Goldman, J., Guskiewicz, K., McAllister, T. W., McArthur, D., Meier, T. B., Mihalik, J. P., … Svoboda, S. Assessment of blood biomarker profile after acute concussion during combative training among US Military Cadets. JAMA Network Open. 2021;4(2).
  6. Mondello, S., Sorinola, A., Czeiter, E., Vámos, Z., Amrein, K., Synnot, A., Donoghue, E., Sándor, J., Wang, K. K. W., Diaz-Arrastia, R., Steyerberg, E. W., Menon, D. K., Maas, A. I. R., & Buki, A. Blood-based protein biomarkers for the management of traumatic brain injuries in adults presenting to emergency departments with mild brain injury: A living systematic review and meta-analysis. Journal of Neurotrauma. 2017;34, 1–21.
  7. Okonkwo, D. O., Puffer, R. C., Puccio, A. M., Yuh, E. L., Yue, J. K., Diaz-Arrastia, R., Korley, F. K., Wang, K. K., Sun, X., Taylor, S. R., Mukherjee, P., Markowitz, A. J., Jain, S., Manley, G. T., Adeoye, O., Badjatia, N., Boase, K., Bodien, Y., Bullock, R., … Zafonte, R. Point-of care platform blood biomarker testing of glial fibrillary acidic protein versus S100 calcium binding protein B for prediction of traumatic brain injuries: A transforming research and clinical knowledge in Traumatic Brain Injury Study. Journal of Neurotrauma. 2020;37(23), 2460–2467.
  8. Yue, J. K., Korley, F. K., Winkler, E. A., Sun, X., Puffer, R. C., Deng, H., Choy, W., Chandra, A., Taylor,, S. R., Ferguson, A. R., Huie, J. R., Rabinowitz, M., Puccio, A. M., Mukherjee, P., Vassar, M. J., Wang, K. K. W., Diaz-Arrastia, R., Okonkwo, D. O., Jain, S., … TRACK-TBI Investigators. Association between plasma GFAP concentrations and MRI abnormalities in patients with CT-negative traumatic brain injury in the TRACK-TBI cohort: a prospective multicentre study. Lancet Neurol. 2019;18, 953–961.
Level of Evidence B
( Canadian CT rule )
Level of Evidence B
( anticoagulation or bleeding disorders )
Level of Evidence B
( MRI )
Level of Evidence C
( x-ray )
Last updated  
1.4

Patients presenting to hospital/clinic acutely with concussion can be safely discharged for home observation if they meet the following clinical criteria:

  • Normal mental status (alertness/behavior/cognition) with clinically improving post-concussive symptoms.
  • No clinical risk factors indicating the need for CT scanning or normal CT scan result if performed due to presence of risk factors.

Context

Normal mental status should be specifically assessed to ensure safe discharge. Clinical factors such as persistent abnormal GCS, focal neurological deficit, vomiting/severe headache, presence of coagulopathy, persistent drug or alcohol intoxication, presence of multi-system injuries, presence of concurrent medical problems, or age > 65 years may indicate clinical risk factors warranting continued hospital observation.

Level of Evidence B
( first bullet )
Level of Evidence B
( second bullet )
Last updated  
1.5

Once an appropriate evaluation of the patient has been completed, upon discharge, provide the patient (and support person) with written and verbal information (see printable handout and online resource for patients and families) regarding concussion management including:

  • Symptoms and signs of acute deterioration and when to seek urgent follow-up (e.g., worsening or new symptoms).
  • Typical post-concussive symptoms and reassurance about anticipated recovery.
  • Lifestyle advice to assist recovery.
  • A discharge report and a written copy of the information provided to the patient for primary care provider.

Context

It is important to provide written information for patients to refer to following discharge in the case of impaired cognition. A copy of the written information should also be provided to the primary care provider to refer to as guidance with respect to the education and information the patient has received. Provide patients with education/advice about acute management of symptoms in the recovery period and to manage expectations regarding recovery

Level of Evidence C
( first bullet )
Level of Evidence B
( second bullet )
Level of Evidence B
( third bullet )
Level of Evidence C
( fourth bullet )
Last updated  
Assessment (Appendix 1.1)
Acute Concussion Evaluation (ACE): Physician/Clinician Office Version
appendix-1-1.pdf
Assessment (Table 1.2)
Table 1.2 Key Features of mTBI Assessment in an Emergency Department or Doctor’s Office
Informational Tool
Canadian CT Head Rule
Assessment (Appendix 1.2)
Abbreviated Westmead Post Traumatic Amnesia Scale (A-WPTAS)
appendix-1-2.pdf
Management
Manitoba Adult Concussion Network Post-Concussion Education Sheet
Assessment (Appendix 1.5)
The Rivermead Post Concussion Symptoms Questionnaire
appendix-1-5.pdf
Assessment (Appendix 1.6)
Post-Concussion Symptom Scale
appendix-1-6.pdf
Management (Table 1.1)
Table 1.1 Risk Factors Influencing Recovery Post mTBI
Assessment (Algorithm 1.1)
Algorithm 1.1 Initial Diagnosis/Assessment of Adult mTBI
Assessment
Sport Concussion Assessment Tool (SCAT5)
Assessment
Ohio State University TBI Identification Method
Assessment And Management
Centre for Effective Practice Diagnosing and Managing Concussion Tool
Management
Concussion Information for Patients and Families
To learn more about strengths and limitations of the evidence informing each recommendation, click here.

Carney N, Ghajar J, Jagoda A, et al. Concussion guidelines step 1: systematic review of prevalent indicators. Neurosurgery. 2014;75 Suppl 1:S3-15.

PRISMA: 21/27

Associated with recommendations 1.1 and 1.4

Davis GA, Makdissi M, Bloomfield P, et al. International consensus definitions of video signs of concussion in professional sports. Br J Sports Med. 2019;53(20):1264-1267.

AGREE II: 93/161

Associated with recommendations 1.1 and 1.2

Patricios J, Fuller GW, Ellenbogen R, et al. What are the critical elements of sideline screening that can be used to establish the diagnosis of concussion? A systematic review. Br J Sports Med. 2017;51(11):888-894. 

AMSTAR 2: 15/20

Associated with recommendations 1.1 and 1.2

Broglio SP, Harezlak J, Katz B, et al. Acute Sport Concussion Assessment Optimization: A Prospective Assessment from the CARE Consortium. Sports Med. 2019;49(12):1977-1987.

STROBE: 17/23

Associated with recommendation 1.2

Coscia A, Stolz U, Barczak C, Wright N, Mittermeyer S, Shams T, Epstein S, & Kreitzer N. Use of the Sports Concussion Assessment Tool 3 in emergency department patients with psychiatric disease. Journal of Head Trauma Rehabilitation. 2021;36(5).

STROBE: 21/23

Associated with recommendation 1.2

Dagher JH, Richard-Denis A, Lamoureux J, de Guise E, Feyz M. Acute global outcome in patients with mild uncomplicated and complicated traumatic brain injury. Brain Inj. 2013;27(2):189-199.

DOWNS & BLACK: 16/32

Associated with recommendation 1.2

Fuller GW, Cross MJ, Stokes KA, et al. King-Devick concussion test performs poorly as a screening tool in elite rugby union players: a prospective cohort study of two screening tests versus a clinical reference standard. British Journal of Sports Medicine 2019;53:1526-1532.

STROBE: 22/23

Associated with recommendation 1.2

Fuller GW, Tucker R, Starling L, Falvey E, Douglas M, Raftery M. The performance of the World Rugby Head Injury Assessment Screening Tool: a diagnostic accuracy study. Sports Med Open. 2020;6(1):2.

STROBE: 18/23

Associated with recommendation 1.2

Garcia G-G P, Broglio S P, Lavieri M S, McCrea M, & McAllister T. Quantifying the value of multidimensional assessment models for acute concussion: An analysis of data from the NCAA-dod care consortium. Sports Medicine. 2018;48(7), 1739–1749.

STROBE: 19/23

Associated with recommendation 1.2

Hartwell JL, Spalding MC, Fletcher B, O'mara MS, Karas C. You cannot go home: routine concussion evaluation is not enough. Am Surg. 2015;81(4):395-403.

DOWNS & BLACK: 14/32

Associated with recommendations 1.2 and 1.4

Miller KJ, Ivins BJ, Schwab KA. Self-reported mild TBI and postconcussive symptoms in a peacetime active duty military population: effect of multiple TBI history versus single mild TBI. J Head Trauma Rehabil. 2013;28(1):31-38.

DOWNS & BLACK: 18/32

Associated with recommendation 1.2

Meares S, Shores EA, Smyth T, Batchelor J, Murphy M, Vukasovic M. Identifying posttraumatic amnesia in individuals with a Glasgow Coma Scale of 15 after mild traumatic brain injury. Arch Phys Med Rehabil. 2015;96(5):956-959.

DOWNS & BLACK: 14/32

Associated with recommendation 1.2

Silverberg ND, Luoto TM, A-hman J, Iverson GL. Assessment of mild traumatic brain injury with the King-Devick Test in an emergency department sample. Brain Inj. 2014;28(12):1590-1593.

DOWNS & BLACK: 14/32

Associated with recommendation 1.2

Ayaz SI, Thomas C, Kulek A, et al. Comparison of quantitative EEG to current clinical decision rules for head CT use in acute mild traumatic brain injury in the ED. Am J Emerg Med. 2015;33(4):493-496.

DOWNS & BLACK: 15/32

Associated with recommendations 1.3 and 1.4

Cipriano A, Park N, Pecori A, Bionda A, Bardini M, Frassi F, Lami V, Leoli F, Manca M L, Del Prato S, Santini M, & Ghiadoni L. Predictors of post-traumatic complication of mild brain injury in anticoagulated patients: Doacs are safer than vkas. Internal and Emergency Medicine. 2021;16(4), 1061–1070.

STROBE: 18/23

Associated with recommendation 1.3

Ip IK, Raja AS, Gupta A, Andruchow J, Sodickson A, Khorasani R. Impact of clinical decision support on head computed tomography use in patients with mild traumatic brain injury in the ED. Am J Emerg Med. 2015;33(3):320-325.

DOWNS & BLACK: 14/32

Associated with recommendations 1.3 and 1.4

Klein A P, Tetzlaff J E, Bonis J M, Nelson L D, Mayer A R, Huber D L, Harezlak J, Mathews V P, Ulmer J L, Sinson G P, Nencka A S, Koch K M, Wu Y-C, Saykin A J, DiFiori J P, Giza C C, Goldman J, Guskiewicz K M, Mihalik J P, … Meier T B. Prevalence of potentially clinically significant magnetic resonance imaging findings in athletes with and without sport-related concussion. Journal of Neurotrauma 2019;36(11), 1776–1785.

STROBE: 16/23

Associated with recommendation 1.3

Sharp AL, Nagaraj G, Rippberger EJ, et al. Computed Tomography Use for Adults With Head Injury: Describing Likely Avoidable Emergency Department Imaging Based on the Canadian CT Head Rule. Acad Emerg Med. 2017;24(1):22-30.

DOWNS & BLACK: 15/32

Associated with recommendation 1.3

Turcato, G., Zannoni, M., Zaboli, A., Zorzi, E., Ricci, G., Pfeifer, N., Maccagnani, A., Tenci, A., & Bonora, A. (2019). Direct oral anticoagulant treatment and mild traumatic brain injury: Risk of early and delayed bleeding and the severity of injuries compared with vitamin K antagonists. Journal of Emergency Medicine, 57(6), 817-824. 

STROBE: 19/23

Associated with recommendation 1.3

Eliyahu L, Kirkland S, Campbell S, Rowe BH. The Effectiveness of Early Educational Interventions in the Emergency Department to Reduce Incidence or Severity of Postconcussion Syndrome Following a Concussion: A Systematic Review. Acad Emerg Med. 2016;23(5):531-542.

PRISMA: 21/27

Associated with recommendation 1.5

Nygren-de Boussard C, Holm LW, Cancelliere C, et al. Nonsurgical interventions after mild traumatic brain injury: a systematic review. Results of the International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch Phys Med Rehabil. 2014;95(3 Suppl):S257-264.

PRISMA: 17/27

Associated with recommendation 1.5

Hoek AE, Joosten M, Dippel DWJ, et al. Effect of Video Discharge Instructions for Patients With Mild Traumatic Brain Injury in the Emergency Department: A Randomized Controlled Trial. Ann Emerg Med. 2021;77(3):327-337.

Downs and Black: 22/28

Associated with recommendation 1.5