INVITED COMMENTARY
Is Rest the Best Intervention for Concussion? Lessons Learned from the Whiplash Model Neil Craton, MD, MHK and Oliver Leslie, MD Whiplash-associated disorder (WAD) is a clinical syndrome with an injury mechanism identical to that of concussion; the diagnostic criteria are essentially the same (20,24,33). However the management of whiplash is very different from the concussion algorithm. Concussion guidelines recommend rest (24), while WAD is managed with reassurance and a general return to regular activity (33). The whiplash literature emphasizes that rest, medicalization, and catastrophization adversely affect patient outcomes. Our concern is that the current construct of concussion represents a syndrome of multiple overlapping conditions, in which patients are vulnerable to the false attribution of everyday feelings to brain injury, when brain injury either has resolved or not transpired (6). The potential for iatrogenic disability is high, as patients are encouraged to pursue a course of treatment that emphasizes somatic hypervigilance and the adoption of a lifestyle that might perpetuate some of the very symptoms postulated to represent concussion itself. It is this slippery slope, from safe and reasonable acute head and neck injury management, into postconcussion syndrome (PCS) with its psychosocial underpinnings that we address in this article. In the current state of the concussion crisis or epidemic, we ask the question ‘‘Should concussion be managed like whiplash?’’ The sociocultural perspectives regarding whiplash and concussion are very different. The very existence of whiplash as a nosological entity has been challenged, whereas concussion is viewed as a bona fide epidemic or health care crisis. A recent review stated that concussion was a cause of death, disability, chronic traumatic encephalopathy, secondimpact syndrome, and epilepsy (35). Publications such as these contribute to fear and anxiety regarding this condition and facilitate catastrophic thinking among patients, their families, and their caregivers (19). While the current state of heightened awareness has facilitated efforts in injury prevention and invigorated research efforts into this important
Legacy Sport Medicine, Winnipeg, Manitoba, Canada; and Department of Family Medicine, University of Manitoba, Winnipeg, Manitoba, Canada Address for correspondence: Oliver Leslie, MD, Legacy Sport Medicine, Winnipeg, Manitoba, Canada; E-mail: [email protected]. 1537-890X/1304/201Y204 Current Sports Medicine Reports Copyright * 2014 by the American College of Sports Medicine www.acsm-csmr.org
condition, the current concussion milieu seems to have emphasized rare catastrophic injuries and overlooked the excellent prognosis of this condition (13). Conversely reviews of whiplash have emphasized that this is a benign condition with a favorable prognosis (23,33). Medicalization is considered to contribute to a worse prognosis. McClune et al. (23) stated the following regarding whiplash: Serious physical injury is rare; reassurance about good prognosis is important; overmedicalization is detrimental; recovery is improved by early return to normal preaccident activities, self-exercise I positive attitudes and beliefs are helpful in regaining activity levels; I rest and negative attitudes and beliefs delay recovery and contribute to chronicity.
A jarring example of the difference in philosophy regarding whiplash and concussion can be found in the controversial writings of Schrader et al. (31). This author called into question the entire syndrome of WAD. He stated that despite more than 1,600 publications about whiplash since 1996, no study that confirmed the nosological validity of the chronic whiplash syndrome could be identified. Schrader et al. (31) highlights the risk of overmedicalization causing a worse prognosis. Publications such as that of Schrader et al. (31) contributed to the general consensus to activate patients with whiplash after injury. Subsequently the medical community seems to endorse the activation of patients with whiplash. It is important to remember that virtually all of the patients who met the diagnostic criteria for WAD also would meet the current diagnostic criteria for concussion. In the acute setting, clinical evaluation to rule out catastrophic injury is imperative, given the morbidity and mortality associated with serious intracranial or cervical spine injury. However most patients with a head shake mechanism will improve quickly and spontaneously and return to school, work, and sport (14). A small proportion, however, will develop PCS. Our concern stems from the evidence indicating that a number of psychosocial factors influence the genesis and perpetuation of concussion symptom reporting particularly over the long term. There is substantial scholarship to support this position. This concern is greatest outside the realm of professional and collegiate athletics where organizations are supported by medical practitioners well versed in the subtleties of this syndrome. Current Sports Medicine Reports
Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
201
Despite issues with a lack of symptom specificity (3), the operational definitions of ‘‘rest,’’ and the issues surrounding ‘‘asymptomatic’’ status (1), the medical response to the sociological phenomenon of concussion has been to prescribe patient isolation in the form of withdrawal from school, work, and/or the interruption of common forms of communication. Patients with concussion are prescribed physical and cognitive rest (24). The current operational definition of rest is the avoidance of scholastic work, video games, concentration, attention, and text messaging (24). The recommendation for rest and social isolation of patients with concussion is curious. Few conditions in either the psychological or physical domain of medicine are treated in this fashion. Patients with significant traumatic brain injury (TBI) on neurosurgical wards are reactivated. Rest is known to have numerous deleterious effects on human health (17,19). Presumably an ‘‘energy crisis’’ in the acutely concussed brain justifies physical and cognitive rest (12,16,34). Moser et al. (26) stated that the ‘‘neurometabolic cascade’’ of concussion justified abstinence from school, work, homework, computers, texting, reading, Facebook, video games, drawing, driving, television, social activities outside, and travel outside the home even months after a concussion. It is not hard to believe that there are significant neurometabolic anomalies after massive hits in collision sport, where obvious manifestations of the central nervous system dysfunction and cognitive impairment are observed. But is there an ‘‘energy crisis’’ in the brain of patients who meet the current diagnostic criteria of concussion, who manifest one symptom after head shake? Is there evidence of this cascade in a person heading a soccer ball or sustaining a body check to the chest and sustaining an impulsive force to the head? Much of our understanding of concussion pathophysiology comes from experiments where rodents are exposed to TBI. Manifestations of TBI include neuronal depolarization, release of excitatory neurotransmitters, changes in glucose and calcium metabolism, altered cerebral blood flow, and impaired axonal function (12,16,34). This ‘‘energy crisis’’ is postulated to be correlated with the neurobehavioral abnormalities seen in concussion and renders the brain vulnerable to cognitive and physical activity. However many of these experiments have used disproportionately high-energy TBI. Takahashi et al. (34) used an impact of 600 gIcmj1 delivered to the vertex of the mouse skull that induced arrest of movement for up to 8 min, apnea, and bradycardia as well as altered electroencephalography recordings and seizures. This is the equivalent of a male adult being hit by a 2,100-kg force. The rationale for rest probably is rooted in fear that cognitive and physical activity would jeopardize the brain during this neurometabolic crisis. The symptoms currently attributed to TBI on the 22-item Likert scale used in concussion guidelines were thought to be reflective of this crisis. Symptoms such as loss of consciousness, amnesia, and confusion after high-intensity collisions in contact sport may be associated with such neurometabolic findings. However we wonder whether an individual who is sad and irritable after a simple head shake would manifest such a crisis (3). We are concerned that the current state of knowledge does not justify the notion of an ‘‘energy crisis’’ in the brain of many patients following a simple head shake. Silverberg and Iverson (32) have concluded that psychological factors play a role in the development of PCS from 202
Volume 13 & Number 4 & July/August 2014
the outset and greater emphasis on predisposing factors from the psychological domain should be considered in the management of this syndrome. While there is no evidence that psychosocial factors cause concussion, many authors consider PCS to be influenced strongly by psychosocial factors (4,8,15,29). Parental influences and a patient’s psychosocial milieu affect PCS symptoms reporting (15,27). We assert that these psychological factors would be affected negatively by removing a patient from school, work, and normal patterns of communication. Wood et al. (36) demonstrated that preinjury anxiety and difficulty processing emotion (alexithymia) are mediators for the development of PCS. Stress, anxiety, depression, and all-or-nothing behavior are associated with the risk of PCS (10). The patient’s psychological makeup influences PCS substantially (22,25,28). For individuals predisposed to anxiety, depression, and all-or-none thinking, further problems would be associated with the catastrophization and medicalization inherent in current concussion management and media reports. Military research indicates that significant psychological modifiers often influence PCS symptom reporting. PCS rarely occurred in the absence of depression, traumatic stress, possible symptom exaggeration, or poor effort on testing (18). Lange et al. (18) concluded that clinicians cannot assume, uncritically, that PCS symptom endorsement is indicative of a brain injury. Donnell et al. (9) showed that Vietnam veterans with generalized anxiety disorder, major depressive disorder, posttraumatic stress disorder, and somatization disorder endorsed symptoms of PCS more than veterans with a history of mild TBI. Given that psychological factors have such a strong influence on symptom reporting, we question the social isolation and avoidance of regular daily activity recommended by concussion consensus guidelines. Rest has been not demonstrated clearly to be an efficacious treatment for concussion (7,11). Retrospective data indicate that the recommendation to pursue rest does not help recovery (11). There are publications suggesting that cognitive rest helps limit the duration of postconcussion symptoms, particularly in the pediatric literature (2,26). Majerske et al. (21) noted that a high level of activity after concussion could lead to poorer performance on cognitive tests. However they used a retrospective chart review to estimate activity with a post hoc activity intensity scale. Such estimates cannot come close to discerning the actual amount of physical and cognitive activity performed by a patient. Articles such as these neither provide satisfactory operational definitions of cognitive rest nor account for the lack of specificity of concussion symptoms. Gibson et al. (11) concluded that prolonged periods of cognitive rest should be approached cautiously, but their article also used a retrospective estimate of cognitive activity. In a recent systematic review, Schneider et al. (30) concluded that the current evidence is so poor that it does not justify the prescription of either rest or activity for a patient with concussion. In the absence of proven efficacy and given the psychological influence on prolonged postconcussion symptom reporting, is rest the right treatment? If ‘‘rest until asymptomatic’’ is not based on evidence or practically attainable, is pursuit of regular activity, even in the face of ongoing symptoms warranted? While the concussion literature would suggest that we do not know Invited Commentary
Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
whether patients can be activated after concussion without negatively affecting the brain (30), the management of patients with whiplash serves as a useful example here. Are patients with whiplash harmed by pursuing usual activities even when they have symptoms, as advocated by current guidelines? The evidence suggests that education, exercise, and mobilization are effective modalities to treat WAD (33). The population of patients who has sustained such an injury reinforces the generally benign natural history of the head or neck shake syndrome. Paradoxically Cote and Soklaridis (5) have noted that ‘‘too much health care too early after the injury’’ can be associated with delayed recovery and the development of chronic pain and disability in the management of patients with whiplash. These findings suggest that clinicians may be contributing to disability by intervening unnecessarily. Cote and Soklaridis (5) conclude that ‘‘medicalization, iatrogenesis, and moral hazard all adversely affect patient outcomes.’’ Catastrophization has been associated with pain reporting, disability, and lower pain threshold or tolerance levels. In patients with whiplash, catastrophization has been demonstrated to perpetuate symptoms and minimize the effect of somatic interventions (23). We assert that this is operative in the current concussion milieu. Being told to stay home and that a text message may damage your brain must be quite alarming to patients. Medical hypervigilance and repeated testing for a brain injury could be perceived catastrophically, particularly in a patient with preinjury psychological risk factors who is exposed to sensational media reports regarding the potential long-term effects of repeated head shake. Health care practitioners need to consider the risk of iatrogenic disability in their management strategies. We assert that the prescription of cognitive and physical rest after concussion requires much more research before it can be endorsed. Removal from sport until comprehensive medical assessment is required, as patients may have an impairment prohibiting safe participation in sport or high-risk employment. The consequences associated with missed major intracranial or cervical spine injury are significant. However the multitude of host psychosocial factors that influence PCS could be affected adversely by social isolation and the avoidance of simple forms of communication. The prescription of rest has insufficient support in the literature to continue to recommend it. The data used to establish guidelines for patients with whiplash, virtually all of whom could be diagnosed with concussion, provide reassurance for the practice of early return to normal preinjury activities outside the realm of contact sport. While head injury prevention and health promotion remain fundamental responsibilities of the medical community, we must be aware of the medicalization and catastrophization inherent in the current concussion zeitgeist as we try to minimize the impact of this important condition.
References 1. Alla S, Sullivan SJ, McCrory P. Defining asymptomatic status following sports concussion: fact or fallacy? Br. J. Sports Med. 2012; 46:562Y9. 2. Brown NJ, Mannix RC, O’Brien MJ, et al. Effect of cognitive activity level on duration of post-concussion symptoms. Pediatrics. 2014; 133:e299Y304. 3. Cassidy JD, Cancelliere C, Carroll LJ, et al. Systematic review of selfreported prognosis in adults after mild traumatic brain injury: results of the
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International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch. Phys. Med. Rehabil. 2014; 95:S132Y51. 4. Clarke LA, Genat RC, Anderson JF. Long-term cognitive complaint and post-concussive symptoms following mild traumatic brain injury: the role of cognitive and affective factors. Brain Inj. 2012; 26:298Y307. 5. Cote P, Soklaridis S. Does early management of whiplash-associated disorders assist or impede recovery? Spine (Phila Pa 1976). 2011; 36:S275Y9. 6. Craton N, Leslie O. Time to re-think the Zurich guidelines?: a critique on the consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport, held in Zurich, November 2012. Clin. J. Sport Med. 2014; 24:93Y5. 7. de Kruijk JR, Leffers P, Meerhoff S, et al. Effectiveness of bed rest after mild traumatic brain injury: a randomised trial of no versus six days of bed rest. J. Neurol. Neurosurg. Psychiatry. 2002; 73:167Y72. 8. Dean PJ, O’Neill D, Sterr A. Post-concussion syndrome: prevalence after mild traumatic brain injury in comparison with a sample without head injury. Brain Inj. 2012; 26:14Y26. 9. Donnell AJ, Kim MS, Silva MA, Vanderploeg RD. Incidence of postconcussion symptoms in psychiatric diagnostic groups, mild traumatic brain injury, and comorbid conditions. Clin. Neuropsychol. 2012; 26:1092Y101. 10. Edmed S, Sullivan K. Depression, anxiety, and stress as predictors of postconcussion-like symptoms in a non-clinical sample. Psychiatry Res. 2012; 200:41Y5. 11. Gibson S, Nigrovic LE, O’Brien M, Meehan WP 3rd. The effect of recommending cognitive rest on recovery from sport-related concussion. Brain Inj. 2013; 27:839Y42. 12. Giza CC, Hovda DA. The neurometabolic cascade of concussion. J. Athl. Train. 2001; 36:228Y35. 13. Godbolt AK, Cancelliere C, Hincapie CA, et al. Systematic review of the risk of dementia and chronic cognitive impairment after mild traumatic brain injury: results of the International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch. Phys. Med. Rehabil. 2014; 95:S245Y56. 14. Guskiewicz KM, McCrea M, Marshall SW, et al. Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003; 290:2549Y55. 15. Hou R, Moss-Morris R, Peveler R, et al. When a minor head injury results in enduring symptoms: a prospective investigation of risk factors for postconcussional syndrome after mild traumatic brain injury. J. Neurol. Neurosurg. Psychiatry. 2012; 83:217Y23. 16. Katayama Y, Becker DP, Tamura T, Hovda DA. Massive increases in extracellular potassium and the indiscriminate release of glutamate following concussive brain injury. J. Neurosurg. 1990; 73:889Y900. 17. Knight J, Nigam Y, Jones A. Effects of bedrest 1: cardiovascular, respiratory and haematological systems. Nurs. Times. 2009; 105:16Y20. 18. Lange RT, Brickell T, French LM, et al. Risk factors for postconcussion symptom reporting after traumatic brain injury in U.S. military service members. J. Neurotrauma. 2013; 30:237Y46. 19. Leddy JJ, Sandhu H, Sodhi V, et al. Rehabilitation of concussion and postconcussion syndrome. Sports Health. 2012; 4:147Y54. 20. Leslie O, Craton N. Concussion: purely a brain injury? Clin. J. Sport Med. 2013; 23:331Y2. 21. Majerske CW, Mihalik JP, Ren D, et al. Concussion in sports: postconcussive activity levels, symptoms, and neurocognitive performance. J. Athl. Train. 2008; 43:265Y74. 22. McCauley SR, Wilde EA, Miller ER, et al. Preinjury resilience and mood as predictors of early outcome following mild traumatic brain injury. J. Neurotrauma. 2013; 30:642Y52. 23. McClune T, Burton AK, Waddell G. Evaluation of an evidence based patient educational booklet for management of whiplash associated disorders. Emerg. Med. J. 2003; 20:514Y7. 24. McCrory P, Meeuwisse W, Aubry M, et al. Consensus statement on Concussion in Sport V The 4th International Conference on Concussion in Sport held in Zurich, November 2012. J. Sci. Med. Sport. 2013; 16:178Y89. 25. McNally KA, Bangert B, Dietrich A, et al. Injury versus noninjury factors as predictors of postconcussive symptoms following mild traumatic brain injury in children. Neuropsychology. 2013; 27:1Y12. 26. Moser RS, Glatts C, Schatz P. Efficacy of immediate and delayed cognitive and physical rest for treatment of sports-related concussion. J. Pediatr. 2012; 161:922Y6. 27. Olsson KA, Lloyd OT, Lebrocque RM, et al. Predictors of child postconcussion symptoms at 6 and 18 months following mild traumatic brain injury. Brain Inj. 2013; 27:145Y57.
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28. Ponsford J, Cameron P, Fitzgerald M, et al. Predictors of postconcussive symptoms 3 months after mild traumatic brain injury. Neuropsychology. 2012; 26:304Y13. 29. Ryan LM, Warden DL. Post concussion syndrome. Int. Rev. Psychiatry. 2003; 15:310Y6. 30. Schneider KJ, Iverson GL, Emery CA, et al. The effects of rest and treatment following sport-related concussion: a systematic review of the literature. Br. J. Sports Med. 2013; 47:304Y7. 31. Schrader H, Stovner LJ, Eisenmenger W. Doubtful nosological validity of the chronic whiplash syndrome [in German]. Orthopade. 2012; 41:147Y52. 32. Silverberg ND, Iverson GL. Etiology of the post-concussion syndrome: physiogenesis and psychogenesis revisited. NeuroRehabilitation. 2011; 29:317Y29.
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33. Spitzer WO, Skovron ML, Salmi LR, et al. Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining ‘‘whiplash’’ and its management. Spine (Phila Pa 1976). 1995; 20:1SY73S. 34. Takahashi H, Manaka S, Sano K. Changes in extracellular potassium concentration in cortex and brain stem during the acute phase of experimental closed head injury. J. Neurosurg. 1981; 55:708Y17. 35. Tator CH. Concussions and their consequences: current diagnosis, management and prevention. CMAJ. 2013; 185:975Y9. 36. Wood RL, O’Hagan G, Williams C, et al. Anxiety sensitivity and alexithymia as mediators of postconcussion syndrome following mild traumatic brain injury. J. Head Trauma Rehabil. 2013; 29:E9YE17.
Invited Commentary
Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
Is Rest the Best Intervention for Concussion? Lessons Learned from the Whiplash Model Neil Craton, MD, MHK and Oliver Leslie, MD Whiplash-associated disorder (WAD) is a clinical syndrome with an injury mechanism identical to that of concussion; the diagnostic criteria are essentially the same (20,24,33). However the management of whiplash is very different from the concussion algorithm. Concussion guidelines recommend rest (24), while WAD is managed with reassurance and a general return to regular activity (33). The whiplash literature emphasizes that rest, medicalization, and catastrophization adversely affect patient outcomes. Our concern is that the current construct of concussion represents a syndrome of multiple overlapping conditions, in which patients are vulnerable to the false attribution of everyday feelings to brain injury, when brain injury either has resolved or not transpired (6). The potential for iatrogenic disability is high, as patients are encouraged to pursue a course of treatment that emphasizes somatic hypervigilance and the adoption of a lifestyle that might perpetuate some of the very symptoms postulated to represent concussion itself. It is this slippery slope, from safe and reasonable acute head and neck injury management, into postconcussion syndrome (PCS) with its psychosocial underpinnings that we address in this article. In the current state of the concussion crisis or epidemic, we ask the question ‘‘Should concussion be managed like whiplash?’’ The sociocultural perspectives regarding whiplash and concussion are very different. The very existence of whiplash as a nosological entity has been challenged, whereas concussion is viewed as a bona fide epidemic or health care crisis. A recent review stated that concussion was a cause of death, disability, chronic traumatic encephalopathy, secondimpact syndrome, and epilepsy (35). Publications such as these contribute to fear and anxiety regarding this condition and facilitate catastrophic thinking among patients, their families, and their caregivers (19). While the current state of heightened awareness has facilitated efforts in injury prevention and invigorated research efforts into this important
Legacy Sport Medicine, Winnipeg, Manitoba, Canada; and Department of Family Medicine, University of Manitoba, Winnipeg, Manitoba, Canada Address for correspondence: Oliver Leslie, MD, Legacy Sport Medicine, Winnipeg, Manitoba, Canada; E-mail: [email protected]. 1537-890X/1304/201Y204 Current Sports Medicine Reports Copyright * 2014 by the American College of Sports Medicine www.acsm-csmr.org
condition, the current concussion milieu seems to have emphasized rare catastrophic injuries and overlooked the excellent prognosis of this condition (13). Conversely reviews of whiplash have emphasized that this is a benign condition with a favorable prognosis (23,33). Medicalization is considered to contribute to a worse prognosis. McClune et al. (23) stated the following regarding whiplash: Serious physical injury is rare; reassurance about good prognosis is important; overmedicalization is detrimental; recovery is improved by early return to normal preaccident activities, self-exercise I positive attitudes and beliefs are helpful in regaining activity levels; I rest and negative attitudes and beliefs delay recovery and contribute to chronicity.
A jarring example of the difference in philosophy regarding whiplash and concussion can be found in the controversial writings of Schrader et al. (31). This author called into question the entire syndrome of WAD. He stated that despite more than 1,600 publications about whiplash since 1996, no study that confirmed the nosological validity of the chronic whiplash syndrome could be identified. Schrader et al. (31) highlights the risk of overmedicalization causing a worse prognosis. Publications such as that of Schrader et al. (31) contributed to the general consensus to activate patients with whiplash after injury. Subsequently the medical community seems to endorse the activation of patients with whiplash. It is important to remember that virtually all of the patients who met the diagnostic criteria for WAD also would meet the current diagnostic criteria for concussion. In the acute setting, clinical evaluation to rule out catastrophic injury is imperative, given the morbidity and mortality associated with serious intracranial or cervical spine injury. However most patients with a head shake mechanism will improve quickly and spontaneously and return to school, work, and sport (14). A small proportion, however, will develop PCS. Our concern stems from the evidence indicating that a number of psychosocial factors influence the genesis and perpetuation of concussion symptom reporting particularly over the long term. There is substantial scholarship to support this position. This concern is greatest outside the realm of professional and collegiate athletics where organizations are supported by medical practitioners well versed in the subtleties of this syndrome. Current Sports Medicine Reports
Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
201
Despite issues with a lack of symptom specificity (3), the operational definitions of ‘‘rest,’’ and the issues surrounding ‘‘asymptomatic’’ status (1), the medical response to the sociological phenomenon of concussion has been to prescribe patient isolation in the form of withdrawal from school, work, and/or the interruption of common forms of communication. Patients with concussion are prescribed physical and cognitive rest (24). The current operational definition of rest is the avoidance of scholastic work, video games, concentration, attention, and text messaging (24). The recommendation for rest and social isolation of patients with concussion is curious. Few conditions in either the psychological or physical domain of medicine are treated in this fashion. Patients with significant traumatic brain injury (TBI) on neurosurgical wards are reactivated. Rest is known to have numerous deleterious effects on human health (17,19). Presumably an ‘‘energy crisis’’ in the acutely concussed brain justifies physical and cognitive rest (12,16,34). Moser et al. (26) stated that the ‘‘neurometabolic cascade’’ of concussion justified abstinence from school, work, homework, computers, texting, reading, Facebook, video games, drawing, driving, television, social activities outside, and travel outside the home even months after a concussion. It is not hard to believe that there are significant neurometabolic anomalies after massive hits in collision sport, where obvious manifestations of the central nervous system dysfunction and cognitive impairment are observed. But is there an ‘‘energy crisis’’ in the brain of patients who meet the current diagnostic criteria of concussion, who manifest one symptom after head shake? Is there evidence of this cascade in a person heading a soccer ball or sustaining a body check to the chest and sustaining an impulsive force to the head? Much of our understanding of concussion pathophysiology comes from experiments where rodents are exposed to TBI. Manifestations of TBI include neuronal depolarization, release of excitatory neurotransmitters, changes in glucose and calcium metabolism, altered cerebral blood flow, and impaired axonal function (12,16,34). This ‘‘energy crisis’’ is postulated to be correlated with the neurobehavioral abnormalities seen in concussion and renders the brain vulnerable to cognitive and physical activity. However many of these experiments have used disproportionately high-energy TBI. Takahashi et al. (34) used an impact of 600 gIcmj1 delivered to the vertex of the mouse skull that induced arrest of movement for up to 8 min, apnea, and bradycardia as well as altered electroencephalography recordings and seizures. This is the equivalent of a male adult being hit by a 2,100-kg force. The rationale for rest probably is rooted in fear that cognitive and physical activity would jeopardize the brain during this neurometabolic crisis. The symptoms currently attributed to TBI on the 22-item Likert scale used in concussion guidelines were thought to be reflective of this crisis. Symptoms such as loss of consciousness, amnesia, and confusion after high-intensity collisions in contact sport may be associated with such neurometabolic findings. However we wonder whether an individual who is sad and irritable after a simple head shake would manifest such a crisis (3). We are concerned that the current state of knowledge does not justify the notion of an ‘‘energy crisis’’ in the brain of many patients following a simple head shake. Silverberg and Iverson (32) have concluded that psychological factors play a role in the development of PCS from 202
Volume 13 & Number 4 & July/August 2014
the outset and greater emphasis on predisposing factors from the psychological domain should be considered in the management of this syndrome. While there is no evidence that psychosocial factors cause concussion, many authors consider PCS to be influenced strongly by psychosocial factors (4,8,15,29). Parental influences and a patient’s psychosocial milieu affect PCS symptoms reporting (15,27). We assert that these psychological factors would be affected negatively by removing a patient from school, work, and normal patterns of communication. Wood et al. (36) demonstrated that preinjury anxiety and difficulty processing emotion (alexithymia) are mediators for the development of PCS. Stress, anxiety, depression, and all-or-nothing behavior are associated with the risk of PCS (10). The patient’s psychological makeup influences PCS substantially (22,25,28). For individuals predisposed to anxiety, depression, and all-or-none thinking, further problems would be associated with the catastrophization and medicalization inherent in current concussion management and media reports. Military research indicates that significant psychological modifiers often influence PCS symptom reporting. PCS rarely occurred in the absence of depression, traumatic stress, possible symptom exaggeration, or poor effort on testing (18). Lange et al. (18) concluded that clinicians cannot assume, uncritically, that PCS symptom endorsement is indicative of a brain injury. Donnell et al. (9) showed that Vietnam veterans with generalized anxiety disorder, major depressive disorder, posttraumatic stress disorder, and somatization disorder endorsed symptoms of PCS more than veterans with a history of mild TBI. Given that psychological factors have such a strong influence on symptom reporting, we question the social isolation and avoidance of regular daily activity recommended by concussion consensus guidelines. Rest has been not demonstrated clearly to be an efficacious treatment for concussion (7,11). Retrospective data indicate that the recommendation to pursue rest does not help recovery (11). There are publications suggesting that cognitive rest helps limit the duration of postconcussion symptoms, particularly in the pediatric literature (2,26). Majerske et al. (21) noted that a high level of activity after concussion could lead to poorer performance on cognitive tests. However they used a retrospective chart review to estimate activity with a post hoc activity intensity scale. Such estimates cannot come close to discerning the actual amount of physical and cognitive activity performed by a patient. Articles such as these neither provide satisfactory operational definitions of cognitive rest nor account for the lack of specificity of concussion symptoms. Gibson et al. (11) concluded that prolonged periods of cognitive rest should be approached cautiously, but their article also used a retrospective estimate of cognitive activity. In a recent systematic review, Schneider et al. (30) concluded that the current evidence is so poor that it does not justify the prescription of either rest or activity for a patient with concussion. In the absence of proven efficacy and given the psychological influence on prolonged postconcussion symptom reporting, is rest the right treatment? If ‘‘rest until asymptomatic’’ is not based on evidence or practically attainable, is pursuit of regular activity, even in the face of ongoing symptoms warranted? While the concussion literature would suggest that we do not know Invited Commentary
Copyright © 2014 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
whether patients can be activated after concussion without negatively affecting the brain (30), the management of patients with whiplash serves as a useful example here. Are patients with whiplash harmed by pursuing usual activities even when they have symptoms, as advocated by current guidelines? The evidence suggests that education, exercise, and mobilization are effective modalities to treat WAD (33). The population of patients who has sustained such an injury reinforces the generally benign natural history of the head or neck shake syndrome. Paradoxically Cote and Soklaridis (5) have noted that ‘‘too much health care too early after the injury’’ can be associated with delayed recovery and the development of chronic pain and disability in the management of patients with whiplash. These findings suggest that clinicians may be contributing to disability by intervening unnecessarily. Cote and Soklaridis (5) conclude that ‘‘medicalization, iatrogenesis, and moral hazard all adversely affect patient outcomes.’’ Catastrophization has been associated with pain reporting, disability, and lower pain threshold or tolerance levels. In patients with whiplash, catastrophization has been demonstrated to perpetuate symptoms and minimize the effect of somatic interventions (23). We assert that this is operative in the current concussion milieu. Being told to stay home and that a text message may damage your brain must be quite alarming to patients. Medical hypervigilance and repeated testing for a brain injury could be perceived catastrophically, particularly in a patient with preinjury psychological risk factors who is exposed to sensational media reports regarding the potential long-term effects of repeated head shake. Health care practitioners need to consider the risk of iatrogenic disability in their management strategies. We assert that the prescription of cognitive and physical rest after concussion requires much more research before it can be endorsed. Removal from sport until comprehensive medical assessment is required, as patients may have an impairment prohibiting safe participation in sport or high-risk employment. The consequences associated with missed major intracranial or cervical spine injury are significant. However the multitude of host psychosocial factors that influence PCS could be affected adversely by social isolation and the avoidance of simple forms of communication. The prescription of rest has insufficient support in the literature to continue to recommend it. The data used to establish guidelines for patients with whiplash, virtually all of whom could be diagnosed with concussion, provide reassurance for the practice of early return to normal preinjury activities outside the realm of contact sport. While head injury prevention and health promotion remain fundamental responsibilities of the medical community, we must be aware of the medicalization and catastrophization inherent in the current concussion zeitgeist as we try to minimize the impact of this important condition.
References 1. Alla S, Sullivan SJ, McCrory P. Defining asymptomatic status following sports concussion: fact or fallacy? Br. J. Sports Med. 2012; 46:562Y9. 2. Brown NJ, Mannix RC, O’Brien MJ, et al. Effect of cognitive activity level on duration of post-concussion symptoms. Pediatrics. 2014; 133:e299Y304. 3. Cassidy JD, Cancelliere C, Carroll LJ, et al. Systematic review of selfreported prognosis in adults after mild traumatic brain injury: results of the
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