Persisting symptoms after concussion: Time for a paradigm shift

INTRODUCTION

The term postconcussion syndrome (PCS) has long been used to refer to symptoms occurring after the acute phase of concussion. This term has lost meaning over time, however, because of misunderstanding by patients and providers, overuse or inappropriate use, and misrepresentation in the media. At the International Congress of the Athlete Brain Health Foundation held in Park City, Utah in 2019, our workgroup advocated for new terminology—Persisting Symptoms after Concussion (PSaC). This term reflects our call for a paradigm shift in how all patients—not just athletes—are managed and treated when they do not recover within the typical time frame after concussion. We believe that this new terminology will shift focus to active rehabilitation with the goal of recovery and improved quality of life, regardless of duration of symptoms. Just as there has been a shift in terminology from “bell ringer” to “concussion” to emphasize the clinical importance of acute mild brain injury, we believe it is equally important to shift terminology that can guide the conceptualization and management of symptoms that linger or worsen beyond the expected time frame for recovery after concussion (see Table 1).

TABLE 1.

Definition: Persisting Symptoms after Concussion

Most concussion symptoms improve significantly within 1 month for otherwise healthy individuals. The number and severity of concussion symptoms are typically greatest within hours of the injury and gradually improve over days. Persisting symptoms after concussion are characterized by the following: Symptoms are not improving or are worsening in number and/or severity over days to weeks after injury. Persisting symptoms may be related to premorbid, comorbid, or resulting factors from the injury. These persisting symptoms may be present due to the injury itself but often are due to other biopsychosocial factors as well. Symptoms cause distress or disability more days than not. Symptoms interfere with partial or full return to typical activities such as school, work, sport, and/or social roles. Consultation with multidisciplinary brain injury professionals is recommended for individuals with persisting and disabling symptoms.

Precise terminology

Although originally intended to refer to symptoms that persist for a specific time frame after concussion, PCS became a generic diagnosis that has been applied at incorrect times, ranging from the day of injury to years after a concussion when vague new and unexplained symptoms arise. The term PCS provides no useful information about the specificity of symptoms, duration, course, or response to treatment. In fact, the term provides no information that can meaningfully guide rehabilitation.

Why change the term “syndrome”? According to Merriam‐Webster, ¹ syndrome refers to “a group of signs and symptoms that occur together and characterize a particular abnormality or condition.” The terminology provides no clinical information. In fact, at a 2003 meeting of the American Medical Informatics Association, Calvo and colleagues ² argued that using the term “syndrome” is a “knowledge representation problem” and that accurately depicting medical knowledge “is a highly complex endeavor.” They defined syndrome as “a recognizable complex of symptoms and physical findings which indicate a specific condition for which a direct cause is not necessarily understood” (p. 802). The use of syndrome in PCS is problematic because it implies that it is typical for a group of symptoms to occur in a cluster after concussion and that the group of symptoms either define the condition ¹ or that a cause is not understood. ²

Persistent versus persisting

Given the numerous factors that can mimic, exacerbate, or prolong symptoms after concussion, more precise terminology is needed to convey that individual symptoms occurring after concussion can and should be evaluated, identified, and actively treated. Although the terms persistent symptoms after concussion or persistent post concussion symptoms have been used in the medical literature as an alternative to PCS, both convey the same sense of defeatism or resignation about recovery potential. Turning again to Merriam‐Webster, persistent is defined as:

1. Existing for a long or longer than usual time, or continuously

2a. Continuing or inclined to persist in a course

2b. Continuing to exist despite interference or treatment.

As commonly used, the terminology “persistent symptoms” communicates that the symptoms are lasting longer than typical or even continuously and that the symptoms are likely to continue—even despite treatment or rehabilitation. As used in these clinical cases, “persistent” implies that symptoms are or will be unrelenting and unremitting. In contrast, “persisting” is defined by Merriam‐Webster as “to continue to exist especially past a usual, expected, or normal time.” Of significant importance, persisting does not imply that symptoms are unrelenting—just that they are lasting longer than expected. Most important, persisting conveys a sense of hope for improvement in symptoms and for recovery—and it communicates that active evaluation and rehabilitation can make a difference. This is particularly important, because patients' mistaken beliefs about many aspects of the injury are associated with duration and intensity of symptoms, even months later. ³ , ⁴

Postconcussion versus symptoms after concussion

Although the terms “postconcussion” and “symptoms after concussion” may seem to be semantically similar, we believe that “symptoms after concussion” conveys that not all symptoms that occur after a concussion are due to the concussion. Given the nonspecificity of many acute and postacute concussion symptoms, it is important to recognize that persisting symptoms, and particularly those occurring weeks or months after concussion, may have other causes. Fatigue is a common symptom of concussion. According to Harrison's Manual of Medicine, there are 15 disease categories of potential etiologies for general fatigue, and there are numerous examples within those categories of potential diseases, mental health disorders, nutrient deficiencies, lifestyle factors, and medication effects associated with fatigue. ⁵ Persisting fatigue after concussion, especially if it is persisting for weeks or months or increasing in severity, may not be because of the concussion, and lab work or other medical evaluation should be actively considered. Similarly, headaches and other symptoms that are persisting after concussion may have other causes that merit medical evaluation and active treatment. Just as patients may engage in misattribution of symptoms, we as health care providers are also guilty of assuming that symptoms that occur after concussion are due solely to the concussion when they may in fact be caused by preexisting, co‐occurring, or new medical concerns that require evaluation and treatment.

PCS and diagnostic specificity

Research studies have also highlighted the problematic nonspecificity of the term PCS by demonstrating how often it is indistinguishable from symptoms commonly reported in healthy controls or persons with other disorders. In a prospective study of PCS in patients who had experienced a mild traumatic brain injury (mTBI), researchers found that 59% of those who sustained an mTBI met International Classification of Diseases, Tenth Revision (ICD‐10) criteria for PCS 1 month after injury and that 38% met criteria at 1 year. ⁶ Of note, however, 31% of the noninjured controls also met criteria for PCS; in other words, nearly one third of the sample who did not have a concussion met criteria for PCS. A study of symptom‐reporting in adolescents with attention‐deficit/hyperactivity disorder showed that 28.8% of boys and 47.1% of girls met ICD‐10 criteria for PCS without recent concussion. ⁷ When nearly as many healthy individuals without a concussion meet the criteria for diagnosing symptoms of concussion, PCS as a diagnostic entity has such low specificity that it is of limited to no value in guiding treatment. Changing the terminology to PSaC is needed to emphasize the importance of active evaluation of persisting symptoms resulting in an active, individualized plan for rehabilitation. Rather than just advocating for change in terminology, this is a call to action for health care providers to identify specific symptoms that are persisting after concussion, refer patients to multidisciplinary brain injury experts, and consider alternative etiologies for persisting symptoms.

As health care providers who work with individuals who have sustained TBIs, we always respect the brain injury. We believe that it is critical to appropriately assess and treat symptoms in order to facilitate recovery and improve quality of life. In the case of the mildest form of brain injury—concussion—most individuals typically recover clinically within days to a few weeks without any need for intervention or treatment other than evidence‐based clinical management recommendations. ⁸ Length of recovery may be affected by many factors including age, mechanism of injury, medical comorbidities, history of previous concussions, psychological factors, and stress. ⁹ As a result, some individuals will recover quite rapidly whereas others will have a longer recovery. Regardless of length of recovery, symptoms after a concussion are at their peak in the first hours and days after injury after which symptoms begin to gradually subside. When symptoms do not subside, undiagnosed issues or secondary factors that exacerbate concussion symptoms are likely at play. It is critical, however, to perform a new clinical evaluation to ensure nothing has been overlooked and that the initial concussion was treated correctly. We do not define persisting symptoms as those that are present beyond a specific time point, but rather by a recovery trajectory marked by symptoms that are not improving or are worsening in number and/or severity over days to weeks after injury.

It is also important to note that there seems to be great confusion about concussion diagnoses in general. We have seen many patients receive a diagnosis of PCS on the day of their concussion when their symptoms are in fact acute symptoms of concussion. Similarly, some who seek follow‐up care in the days after their initial injury receive a PCS diagnosis although they are still within the typical time frame of recovery. We advocate for the accurate diagnosis of acute and postacute concussion. When symptoms are not improving, are increasing, or new symptoms are appearing approximately 1 month after injury, we advocate for diagnosing PSaC, identifying the specific symptoms that are persisting, and creating an active plan for evaluation of those specific symptoms, including consultation with multidisciplinary brain injury experts.

Maxims for providers

Based on the authors' experience, we suggest the following considerations be central in the clinical evaluation of patients with persisting symptoms after concussion:

Maxim 1. Respect the brain injury

When working within the clinical framework of a likely PSaC diagnosis, the provider is first encouraged to ensure that the brain injury itself has been assessed and treated appropriately. A patient who may arrive from another clinic with the PCS label may have never had an appropriate or thorough workup of the initial injury and its symptoms. A thorough history and physical examination (including a thorough neurological examination) are imperative with consideration for further testing as needed. Treatments offered should be reviewed for appropriateness, timing, and completeness.

When symptoms are persisting after concussion and not improving, or symptoms are increasing in frequency or intensity in the absence of a new injury, multidisciplinary evaluation by clinicians with expertise in brain injury is critical. Evaluating and identifying specific persisting symptoms for active treatment and development of an action plan based on restoration of function is crucial to prevent unnecessary suffering by patients who have experienced a concussion. This new evaluation requires a good clinical assessment to ensure that no factors associated with the original injury have been missed (eg, cervical spine injury). It is also important for the clinician to step back from the reported symptoms and examine secondary factors that may be contributing to the persisting symptoms. A recent consensus statement on sport‐related concussion delineated multiple symptoms that should be the focus of targeted treatment after concussion, including fatigue, mental health concerns, headaches and migraines, sleep dysfunction, and vestibular/oculomotor disturbance. ¹⁰ All of these individually or in combination can contribute to persisting symptoms and perceived lack of recovery, and all of these symptoms are treatable.

Maxim 2. Understand the injury in context

Providers treat people, not conditions. Thus, it is critical to understand PSaC in the lives of individual patients. This approach will help with not only treatment but with patient education. There are numerous preinjury risk factors for the development of PSaC, which include family and personal history of mood disorder (such as depression or anxiety disorders), inadequate social or family support, prior concussion, perfectionism, hypervigilance, and significant personal and environmental stressors. ¹⁰ , ¹¹ Postinjury factors including pain, litigation status, posttraumatic stress, and concurrent mood symptoms have also been found to be related to risk of PSaC development. ¹²

Maxim 3. Observe how the patient views the injury

It is critical to evaluate and examine misconceptions patients have about concussion and concerns related to their long‐term health. Many patients receive misleading and inaccurate information from media sources and/or at the time of their initial evaluation in which expectations may be set that they have permanent brain damage or will face an inevitable neurodegenerative disorder. Receiving such news would understandably trigger hopelessness, anxiety, and dysphoria and contribute to catastrophizing around any symptoms experienced after concussion. Patients who receive accurate information and education about concussion shortly after injury and have positive expectations generally recover more quickly. ¹³

In addition, much can be learned through understanding a patient's coping style when faced with PSaC. Coping styles can be protective or harmful in injury recovery. Problem‐solving coping strategies and resilience are associated with decreased symptoms, whereas emotion‐focused strategies and anxiety sensitivity are related to increased symptoms. Patient beliefs or attributions about the causes and duration of their symptoms are powerful influencers of PSaC. Those who tend to attribute every symptom or difficulty (many of them common normal daily experiences) to a remote head injury may find it challenging to understand the gradual transition from injured to recovered, experiencing what Mittenberg and colleagues coined “expectation as etiology.” ¹⁴ Individuals recovering from concussion (as well as other conditions) also may experience a “good old days” bias in which the injured person reflects on their preinjury daily symptoms as very minimal compared to uninjured control groups. This biased perspective of a problem‐free life prior to injury artificially widens the gap between their current status and their desired status, leading to hopelessness on the part of the patient and presenting the provider with an unattainable treatment goal.

There are several cognitive‐behavioral frameworks that can explain how symptoms can be maintained after brain injury. The fear avoidance model suggests that symptoms are mistakenly interpreted as a sign of serious injury (catastrophizing) over which a patient has no control. The patient increasingly avoids activities that worsen symptoms because they conclude that it is worsening their condition (eg, causing more brain injury), though in reality avoidance of activity can lead to increased disability, social isolation, and depression. Patients may avoid cognitive exertion (cogniphobia) and/or physical exertion (kinesiophobia) in cases of PSaC.

Persisting symptoms after concussion are frustrating for everyone—for well‐intentioned health care providers, patients, and their families. In addition, these persisting symptoms may inadvertently lead to overmedicalization of concussion care. Well‐intentioned providers without primary expertise in brain injury may misinterpret persisting symptoms and attribute them only to the initial concussion injury itself—even months or years after a concussion. Symptoms of treatable medical conditions may be assumed to be concussion‐related and necessary medical evaluations may not be ordered. Patients may be referred for ineffective interventions or non‐evidence‐based treatments, and clinicians may communicate resignation by diagnosing PCS or persistent PCS.

In addition, an industry of expensive pseudo‐medicine techniques has proliferated which promises cures or more rapid recovery after concussion. This trend has also occurred in another brain disorder—dementia. A JAMA Viewpoint called attention to the rise of pseudo‐medicine. This term refers to “supplements and medical interventions that exist within the law and are often promoted as scientifically supported treatments, but lack credible efficacy data.” ¹⁵ Pseudo‐medicine has also increased in the sports concussion arena. ¹⁶ Although such interventions may be viewed as harmless, “these interventions are not ethically, medically, or financially benign for patients or their families.” Purveyors of these interventions may convince patients they have permanent brain damage due to concussion and that only expensive technologies and products can cure them. In contrast, education, reassurance, and evidence‐based clinical management are low‐tech, minimal cost, and yet highly effective interventions for facilitating recovery of concussion.

Maxim 4. Learn from other fields

Although PSaC may seem like a new and difficult diagnosis to treat, there are many valuable lessons to be learned from the chronic pain literature. Pain, described as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage” is common across many conditions, including PSaC and chronic pain of all types. Pain can occur from actual or threatened damage to nonneural tissue (nociceptive pain), by lesion or disease of the peripheral nervous system (neuropathic pain), or from altered nociception despite no clear evidence of actual or threatened tissue.

Our observations are not unique to mTBI. The chronic pain model has a rich empirical literature emphasizing the efficacy of education and reassurance. The disproportionate disability and suffering attributed to concussion is similar to chronic pain. As in the complex pain world, ensuring that the pain has been accurately assessed, identifying all the complex biopsychosocial factors, and using multidisciplinary treatment are essential to optimizing the patient's functional ability, improving quality of life, and reducing health care use. A comprehensive evaluation must address these factors, including anatomical and psychosocial contributors to pain, and this evaluation must result in a plan that best determines the content and timing of the treatment. A recent team physician consensus statement recommends that psychological factors including mood, catastrophizing, social pressures, and support system be evaluated and considered in the initial evaluation of acute pain and a more complete psychosocial history be gathered during evaluation of chronic pain, because these internal and external factors can affect the experience of pain. ¹⁷

CONCLUSION

Our primary concern is to help patients who are suffering but could move forward with reevaluation and active treatment. We strongly advocate for this change in terminology to provide a focus on recovery, including identification of treatable conditions and implementation of evidence‐based active recovery. Rather than using terminology that conveys that symptoms are unrelenting and untreatable, the term PSaC offers a way forward. This is an important conversation for patients, their families, and clinicians. Words matter—changing terminology to persisting symptoms after concussion communicates hope and a plan for recovery.

DISCLOSURES

Dr. Broshek provides consultation the United States Olympic & Paralympic Committee (fee paid to institution) and Sports Neuropsychology Society (Executive Director, part‐time, annual stipend); expert testimony. Dr Herring is senior medical advisor, The Sport Institute at University of Washington Medicine; member, NCAA Concussion Safety Advisory Group; team physician, Seattle Mariners; former team physician, Seattle Seahawks.

Broshek DK, Pardini JE, Herring SA. Persisting symptoms after concussion: Time for a paradigm shift. PM&R. 2022;14(12):1509‐1513. doi: 10.1002/pmrj.12884