Understanding the Post-Concussion Symptom Scale.

In at least one way, the Pittsburgh Steelers were a step ahead of the rest of the NFL in the 90s as they began using a symptom scale to assess head injuries suffered by their players. The scale — known today as The Post-Concussion Symptom Scale (PCSS) — was developed as part of a larger concussion management program for the Steelers. It was eventually published in the scientific literature in 1998 in Journal of Head Trauma Rehabilitation, after which its use became much more widespread.

Thanks to the Pittsburgh Steelers’ pioneering use of this scale, other NFL teams eventually adopted it, acknowledging the importance of standardizing concussion assessment methods.

Today, the PCSS is used not only in the NFL but also in other professional and amateur sports leagues, as well as in a variety of medical settings. It remains an important tool for all clinicians who manage the rehab and recovery of concussion patients.

The Importance of Symptom Assessment in Concussion Patients.

Symptoms of concussion are non-specific. They are not unique to concussions alone. This can complicate diagnosis and treatment, as apparent concussion symptoms may also be attributed to other factors like cervical spine dysfunction, medication side effects, inflammatory disorders, or other non-mTBI causes.

Assessing the symptomatic presentation of patients has many benefits. Preventatively, it can be used for a healthy patient baseline. It can provide a baseline for concussed patients at the beginning of treatment. It also allows the clinician to monitor recovery, inform return-to-play decisions, and give the patient an easy-to-understand gauge of their progress from the time of their concussion to their discharge.

Finally, symptom assessment is a valuable metric for shaping a patient’s rehabilitation program, especially the exercise component, as it can determine whether to progress to higher-intensity physical activities and environments.

Remember that the signs and symptoms of a concussion do not always present at the same rate. While the symptomatic presentation may vary in quality, complexity, and intensity, most individuals will recover in the initial 4 weeks after a concussion.

They may present immediately or evolve over minutes or hours. Though they will commonly resolve within days, there is always a possibility of symptoms persisting longer than expected (even despite the clinicians’ best efforts to mitigate such prolongation). Current research suggests up to 30% of youth and adults may have symptoms that last longer than one month.

What is the PCSS?

The PCSS or Post-Concussion Symptom Scale has been recommended at both the Berlin and Amsterdam International Conferences on Concussion in Sport. It is included in the SCAT 6 sideline assessment tool but may also be used for in-clinic assessment.

The PCSS is a 22-item checklist designed to assess and track symptoms associated with concussions. Patients are asked to rate each of the 22 symptoms on a 7-point Likert scale ranging from 0-6. Higher scores indicate a higher severity of post-concussive symptoms (which may, in turn, predict a poorer prognosis when considering the expected time to return to play).

The symptoms included in the PCSS are as follows:

HeadacheSensitivity to noiseDrowsiness
Pressure in headFeeling slowed downMore emotional
Neck painFeeling like “in a fog”Irritability
Nausea or vomitingDon’t feel right (feeling off)Sadness
DizzinessDifficulty concentratingNervous/anxious
Blurred visionDifficulty rememberingTrouble falling asleep (if applicable)
Balance problemsFatigue or low energy
Sensitivity to lightConfusion


First and foremost, the PCSS provides a starting point for recovery. But it also serves as an important tool for tracking changes in symptoms over time, for better or for worse, and helps to determine when it is safe for an athlete to return to play.

The use of a standardized symptom checklist is crucial in accurately assessing and managing concussions. Before its development, no universally accepted method existed for evaluating and tracking concussion symptoms. This led to varying practices among medical professionals and teams, resulting in inconsistent diagnoses and return-to-play decisions.

Additionally, this standardized scale has allowed research on concussion management and rehabilitation to advance significantly. By tracking symptoms and recovery progress, medical professionals and researchers can identify patterns and trends, leading to a better understanding of how concussions affect the brain and how to treat them best.

Baseline Testing and the PCSS.

A thorough, multimodal baseline test should utilize the Post-Concussion Symptom Score. By establishing a baseline before an injury occurs, medical professionals can accurately compare post-injury symptoms to pre-injury levels. This can aid in diagnosis, making more informed return-to-play decisions, and better tracking recovery progress.

It is not uncommon for individuals to experience some of the 22 symptoms included in the PCSS without ever experiencing a concussion. According to one study published in the Journal of Neurotrauma, up to 40% of healthy, non-concussed athletes have one or more symptoms typically associated with a concussion.

According to the World Health Organization, up to three-quarters of the global population have experienced a headache in the past year.

Thus, non-specific symptoms like headaches (and note that all of the symptoms in the PCSS are non-specific to concussion) may already be a typical daily occurrence for patients before injury. Clinicians should remember this as they administer the PCSS to their injured patients. It is also worth noting that such pre-injury symptoms are most prevalent in adolescents.

Diagnosis and the PCSS.

First, let’s review the basic framework for concussion diagnosis. (If you are familiar with the updated diagnostic criteria below, skip to “Using the PCSS for Diagnosis”).

In 2023, Silverberg et al. published updated diagnostic criteria for mild traumatic brain injury (this is also the diagnostic criteria accepted in the Amsterdam Consensus Statement).

The criteria for diagnosis are as follows (Note: this is an abridgment. Please refer to the paper linked above for details).

Criteria 1:  A plausible mechanism of injury

Concussion results from a transfer of mechanical energy to the brain from external forces resulting from the (1) head being struck with an object; (2) head striking a hard object or surface; (3) brain undergoing an acceleration/deceleration movement without direct contact between the head and an object or surface; and/or (4) forces generated from a blast or explosion.

Criteria 2: Clinical Signs

The injury event causes an acute physiological disruption of brain function, as manifested by one or more of the clinical signs listed below.

i.   Loss of consciousness immediately following injury.

ii.  Alteration of mental status immediately following the injury (or upon regaining consciousness).

iii. Complete or partial amnesia for events immediately following the injury (or after regaining consciousness).

iv. Observation of acute neurologic sign(s) like motor incoordination upon standing, seizure, or tonic posturing immediately following injury.

Criterion 3: Acute Symptoms

The physiological disruption of brain function is manifested by 2 or more new or worsened symptoms from the list below.

i.   Acute subjective alteration in mental status: feeling confused, feeling disoriented, and/or feeling dazed.

ii.  Physical symptoms: headache, nausea, dizziness, balance problems, vision problems, sensitivity to light, and/or sensitivity to noise.

iii. Cognitive symptoms: feeling slowed down, “mental fog,” difficulty concentrating, and/or memory problems.

iv.  Emotional symptoms: uncharacteristic emotional lability and/or irritability.

The symptoms may be from one or more categories.

Criterion 4: Clinical Examination and Lab Findings

Supportive evidence of brain injury may include:

i.   Cognitive impairment on acute clinical examination.

ii.  Balance impairment on acute clinical examination.

iii. Oculomotor impairment or symptom provocation in response to vestibular-oculomotor challenge on acute clinical examination.

iv.  Elevated blood biomarker(s) indicative of intracranial injury.

Criterion 5: Neuroimaging

Trauma-related intracranial abnormalities on computed tomography or structural magnetic resonance imaging. Remember that for concussion (i.e., mild TBI), no abnormality will be observed on imaging.

Criterion 6: Not better accounted for by confounding factors

Confounding factors, including pre-existing and co-occurring health conditions, have been considered and determined to not fully account for the clinical signs, acute symptoms, and clinical examination and laboratory findings that are necessary for the diagnosis.

Using the PCSS for Diagnosis.

Although the PCSS is not a suitable standalone tool for diagnosing concussion, it may be helpful (as part of a multi-modal initial assessment) in making the diagnosis.

According to one recent study (Eagle et al., 2021), when patients are evaluated with the PCSS within the first 7 days after sports-related concussion, any score above 7 (with cognitive and emotional symptoms) indicates a higher likelihood of concussion.

Interestingly, when patients are evaluated 8-21 days post-concussion, the cutoff that differentiates healthy patients from those with concussion remains the same (PCSS score of 8 or greater with cognitive, emotional, and sleep symptoms)

Although the PCSS provides a “big picture” representation of the patient culminating in a final score that carries significance for diagnosis and prognosis, medical professionals need to assess each symptom individually and in relation to other symptoms to diagnose a concussion accurately.

Especially without a baseline test, the clinician should determine whether the evaluated symptoms differ from what the patient would consider typical. For instance, some patients may suffer from chronic headaches before concussion. Though they may rate headache on the PCSS as a 5/6 (say), this may not deviate from what they might consider normal pre-injury.

Especially when patients rate a symptom at the high end (4-6/6), it would be diligent for the clinician to inquire further into what the patient is experiencing and how it compares to their pre-injury status (or refer to their baseline test if available).

Prognosis and the PCSS.

According to the same study from Eagle et al., patients who are evaluated with PCSS within the first 7 days after sports-related concussion who score above 39 (with 23 or more of those points coming from cognitive symptoms) indicates a higher likelihood of prolonged recovery. 

Conversely, for patients who present later than one week and are evaluated within 8-21 days post-concussion, a PCSS score above 35 (with emotional symptoms) predicts protracted recovery.

Again, it should be emphasized that the PCSS is not adequate in itself for diagnosing concussion (just as the VOMS test is useful but not sufficient in diagnosis).

Nonetheless, it may be important for a patient’s initial assessment.

Strengths of the PCSS.

There are other tools available to the clinician for assessing symptoms on the sideline and in the clinic (e.g., The Rivermead Post-Concussion Symptoms Questionnaire, the Post-Concussion Symptom Inventory, etc.).

Some of these tools may indeed be useful. So why go with the PCSS? What sets the PCSS apart from the other options?

Specific for Sport-Related Concussions:

First and foremost, the PCSS was explicitly designed for use in sports-related concussions. This means it considers the unique symptoms commonly experienced by athletes after a concussion, such as balance problems and sensitivity to light and noise.

(This is a relative strength, of course. This may not be considered a significant strength if you are not typically working with an athletic patient population.)

Ease of Use:

The PCSS is easy to administer and score, making it accessible for healthcare professionals of all levels of experience. This also makes it easy to use for a diverse patient population who vary in levels of education, socioeconomic status, linguistic and cultural backgrounds, age, and disability.

Further, since concussion patients can often be functionally compromised when they first present to your clinic, the PCSS is valuable in that it exerts a relatively low cognitive and physical demand on your patient when administered.

Validity and International Use:

The PCSS is recognized globally as a research-validated, accurate instrument for assessing post-concussion symptoms. It was recommended at both the Berlin and Amsterdam International Conferences on Concussion in Sport, making it a globally recognized and accepted tool for assessing concussion symptoms. This allows for consistency in assessment across countries and, as stated above, leads to improved data collection and research outcomes.

Limitations of the PCSS.

Though the Post-Concussion Symptom Scale can be a helpful tool in diagnosing and clinically managing patients with concussion, it also has limitations (as every tool does). These are important to consider.

Some limitations include:

Subjective nature:

The PCSS relies on self-reported symptoms, which may be influenced by factors such as mood or psychological state. Patients may also over or under-report symptoms due to various reasons. This means that the scores on the PCSS may not always accurately reflect the patient’s true symptom severity.

Limited scope:

As mentioned earlier, the PCSS does not cover all possible concussion symptoms and, therefore, should be combined with other assessment tools for a more comprehensive evaluation.

Lack of baseline:

Unless the PCSS is completed first as a baseline test, interpretation of the scale post-injury can be challenging. Without a baseline score, it is difficult to determine how diverse pre-injury symptoms were from post-concussion symptoms. This may result in inaccurate assessment and limit the tool’s use to assist in initially determining diagnosis and prognosis.

In Summary.

The Post-Concussion Symptom Scale, though only a small part of the overall diagnostic and treatment framework, is nonetheless still of great importance for clinicians who manage patients with concussion. It is a valuable tool for diagnosing, assessing, and monitoring symptoms and predicting recovery rate.

While it has limitations, the PCSS is easy to administer, making it accessible to healthcare professionals of all experience levels and diverse patient populations. Its global recognition further strengthens its value in promoting consistency and improved data collection for research purposes.

The PCSS is a simple but valuable tool that should be used by every healthcare professional who manages patients with concussions, whether on the sideline or in the clinic.


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