MILITARY MEDICINE, 179, 11:1250, 2014
CT Positive Brain Injury in Mild TBI Patients Presenting With Normal SAC Scores Brian O’Neil, MD, FACEP*; Rosanne Naunheim, M D f; COL Robert DeLorenzo, MC USA t
ABSTRACT Introduction: Traumatic brain injury accounts for over 1 million U.S. emergency department visits annually. A significant percentage of patients undergo CT scans to exclude intracranial bleeds. The Standardized Assessment of Concussion (SAC) is designed to rapidly determine whether a concussion has occurred, (0-30 scale, where >25 is considered normal). Although not intended to be used in isolation, results in the normal range are considered an indication of low suspicion of brain injury. This study evaluated the relationship between CT findings of structural injury (CT+) and performance on the SAC. Methods: We performed a prospective observational study on mild head-injured patients presenting to the emergency department who underwent CT scans and had SAC evaluations. Results: We enrolled 368 patients, of which 66 were read by a neuroradiologist as positive (CT+), with an average age of 46.7, and an average Glasgow Coma Scale of 14.85. 38.2% of these CT+ patients had a SAC score >25. There were no significant differences between time of injury and CT scan or SAC for those with high or low SAC scores. Both high and low SAC groups contained similar CT+ abnormalities (e.g., hematomas). Conclusions: These results indicate that a normal SAC score alone does not exclude intracranial injury.
INTRODUCTION T raum atic brain injury accounts for over 1.3 m illion em er gency departm ent (ED) visits annually w ithin the U nited States w ith the m ajority o f these visits are for m ild in ju ry .1'2 T reatm ent decisions (e.g., transport to a traum a center or em ergency neurosurgery) are both tim e sensitive and depen dent on the severity and type o f injury. T herefore, it is critical that m edical providers both at the scene o f the injury and in the ED be able to rapidly and accurately determ ine the severity o f the traum atic injury. For those head-injured patients seen in the ED , a signifi cant percentage undergo C T scans to exclude intracranial bleeds. C urrent decision rules for the use o f CT scanning in TB I have high sensitivity at the expense o f poor specificity,3 w hich together w ith other factors (e.g., local practice p at terns) and high risk associated w ith m issed intracranial lesions results in a high incidence o f CT scanning. On the other hand, concern about risk o f unnecessary radiation expo sure and overuse o f CT scanning o f m ild TBI patients4'5 further com plicate the decision path in the ED. O ther clinical tools are available in outpatient settings to assist the clinician in screening for and diagnosing concus sion, especially in those cases (e.g., sports arena or m ilitary)
*Department of Emergency Medicine, School of Medicine, Wayne State University, 4201 St. Antoine, University Health Center 6-G, Detroit, MI 48201. ■(Division of Emergency Medicine, Washington University School of Medicine, 660 So. Euclid, Box 8072, St. Louis, MO 63110. fMedical Corps, U.S. Army Institute for Surgical Research, Tactical Combat Casualty Care Research Program, 3698 Chambers Pass, Building 3611, Fort Sam Houston, TX 78234. The opinions or assertions are those of the authors and do not necessarily reflect the position of the Army Medical Department or the Department of Defense. doi: 10.7205/MILMED-D-13-00585
1250
w here CT scans are not readily available. O ne such tool is the Standardized A ssessm ent o f Concussion (SA C), a sports sideline evaluation tool designed to determ ine w hether or not a concussion has occurred. It has been show n to be sensi tive to determ ining the presence o f a concussive injury within the acute phase o f injury in distinguishing concussed from nonconcussed football players.6-8 T he SAC has been identi fied as a sensitive tool for concussion assessm ent by the A m erican A cadem y o f N eurology.9 The SAC is utilized by the m ilitary as the objective score o f the 2-part M ilitary A cute C oncussion Evaluation (M A CE). It has been show n to be sensitive to the im m ediate effects o f m ild traum atic brain injury, with som e studies dem onstrating sensitivity w hen adm inistered w ithin 6 to 12 h o u rs,1011 and other studies show ing sensitivity extending to 24 h o u rs.12-14 The SAC has also been show n to be sensitive to concussive injury in the E D se ttin g ,15 studied in lim ited tim e intervals, and in m ore current studies for w ide age ranges and tim e intervals up to 72 h o u rs,16 although only evaluated at 3 to 6 hours post injury. A recent survey o f certified athletic trainers found that 44% used the SAC as part o f their sideline evaluation of student athletes suspected o f m T B I.17 A lthough the SAC (M A CE) is not intended to be used in isolation for the determ ination o f the existence o f concussion, or for the need for further evaluation, w hen results fall within the norm al range, it is considered to be an indication o f low suspicion o f brain in ju ry .18 Since the SAC is typically used in nontraditional clinical settings such as football gam e side lines or by the m ilitary, and not the ED , there is little data relating CT scan results to SAC scores. The purpose o f this study is to evaluate the relationship betw een CT findings of structural injury and perform ance on the SAC in a population o f head-injured patients presenting to the E D w ith little or no clinical evidence o f im pairm ent.
MILITARY MEDICINE, Vol. 179, November 2014
CT Positive Brain Injury in mTBI Patients Presenting With Normal SAC Scores
METHODS AND DESIGN Subjects The data was collected at EDs across the United States, in a multisite study of mTBI, clinical symptomatology, and brain electrical activity, (as part of BrainScope, Bethesda, Maryland, validation prospective trial, funded in part by a contract from the Department of Defense, No. W911QY-12C-0004; EEG data not presented here). The majority of the patients were recruited from Brooke Army Medical Center, University of Maryland (R Adams Cowley Shock Trauma Center), University of Virginia Medical Center, Washington University, and Detroit Receiving Hospital Wayne State University (Sinai Grace Hospital). The study was conducted in a convenience sample composed of subjects suspected of a traumatically induced structural brain injury and for whom a CT scan was ordered as part of their standard clinical evaluation to access brain injury. Candidates for study were subject to inclusion/exclusion criteria below. Once identified, the research staff recruited the subject for the study through an informed consent process.
Inclusion Criteria Males and females between the ages of 18 and 80, who were suspected of a traumatically induced structural brain injury and/or clinical manifestations of functional brain injury as a result of insult to the head from an external force, e.g., the head being struck by an object, the head striking an object, and/or the brain undergoing an acceleration/deceleration movement without direct external trauma to the head. The acute, suspected traumatically induced structural brain injury needed to occur within the 24 hours preceding admission to the ED, and receipt of a CT scan for assessment of brain injury.
Exclusion Criteria Subjects were excluded from the study if they had forehead, scalp, or skull abnormalities or other conditions that pre vented correct application of the electrode headset on the skin. Subjects with dementia. Parkinson’s disease, multiple sclerosis, seizure disorder, brain tumors, history of brain surgery, mental retardation, psychiatric disorder for which there is a prescribed psychiatric medication taken on a daily basis, substance dependence, history of transient ischemic attack or stroke within the last year, currently receiving dialysis or in end-stage renal disease, active fever defined as greater than 100°F or 37.7°C, or suffering from an open head injury were excluded. In addition, subjects with Glasgow Coma Scale (GCS)
CT Positive Brain Injury in Mild TBI Patients Presenting With Normal SAC Scores Brian O’Neil, MD, FACEP*; Rosanne Naunheim, M D f; COL Robert DeLorenzo, MC USA t
ABSTRACT Introduction: Traumatic brain injury accounts for over 1 million U.S. emergency department visits annually. A significant percentage of patients undergo CT scans to exclude intracranial bleeds. The Standardized Assessment of Concussion (SAC) is designed to rapidly determine whether a concussion has occurred, (0-30 scale, where >25 is considered normal). Although not intended to be used in isolation, results in the normal range are considered an indication of low suspicion of brain injury. This study evaluated the relationship between CT findings of structural injury (CT+) and performance on the SAC. Methods: We performed a prospective observational study on mild head-injured patients presenting to the emergency department who underwent CT scans and had SAC evaluations. Results: We enrolled 368 patients, of which 66 were read by a neuroradiologist as positive (CT+), with an average age of 46.7, and an average Glasgow Coma Scale of 14.85. 38.2% of these CT+ patients had a SAC score >25. There were no significant differences between time of injury and CT scan or SAC for those with high or low SAC scores. Both high and low SAC groups contained similar CT+ abnormalities (e.g., hematomas). Conclusions: These results indicate that a normal SAC score alone does not exclude intracranial injury.
INTRODUCTION T raum atic brain injury accounts for over 1.3 m illion em er gency departm ent (ED) visits annually w ithin the U nited States w ith the m ajority o f these visits are for m ild in ju ry .1'2 T reatm ent decisions (e.g., transport to a traum a center or em ergency neurosurgery) are both tim e sensitive and depen dent on the severity and type o f injury. T herefore, it is critical that m edical providers both at the scene o f the injury and in the ED be able to rapidly and accurately determ ine the severity o f the traum atic injury. For those head-injured patients seen in the ED , a signifi cant percentage undergo C T scans to exclude intracranial bleeds. C urrent decision rules for the use o f CT scanning in TB I have high sensitivity at the expense o f poor specificity,3 w hich together w ith other factors (e.g., local practice p at terns) and high risk associated w ith m issed intracranial lesions results in a high incidence o f CT scanning. On the other hand, concern about risk o f unnecessary radiation expo sure and overuse o f CT scanning o f m ild TBI patients4'5 further com plicate the decision path in the ED. O ther clinical tools are available in outpatient settings to assist the clinician in screening for and diagnosing concus sion, especially in those cases (e.g., sports arena or m ilitary)
*Department of Emergency Medicine, School of Medicine, Wayne State University, 4201 St. Antoine, University Health Center 6-G, Detroit, MI 48201. ■(Division of Emergency Medicine, Washington University School of Medicine, 660 So. Euclid, Box 8072, St. Louis, MO 63110. fMedical Corps, U.S. Army Institute for Surgical Research, Tactical Combat Casualty Care Research Program, 3698 Chambers Pass, Building 3611, Fort Sam Houston, TX 78234. The opinions or assertions are those of the authors and do not necessarily reflect the position of the Army Medical Department or the Department of Defense. doi: 10.7205/MILMED-D-13-00585
1250
w here CT scans are not readily available. O ne such tool is the Standardized A ssessm ent o f Concussion (SA C), a sports sideline evaluation tool designed to determ ine w hether or not a concussion has occurred. It has been show n to be sensi tive to determ ining the presence o f a concussive injury within the acute phase o f injury in distinguishing concussed from nonconcussed football players.6-8 T he SAC has been identi fied as a sensitive tool for concussion assessm ent by the A m erican A cadem y o f N eurology.9 The SAC is utilized by the m ilitary as the objective score o f the 2-part M ilitary A cute C oncussion Evaluation (M A CE). It has been show n to be sensitive to the im m ediate effects o f m ild traum atic brain injury, with som e studies dem onstrating sensitivity w hen adm inistered w ithin 6 to 12 h o u rs,1011 and other studies show ing sensitivity extending to 24 h o u rs.12-14 The SAC has also been show n to be sensitive to concussive injury in the E D se ttin g ,15 studied in lim ited tim e intervals, and in m ore current studies for w ide age ranges and tim e intervals up to 72 h o u rs,16 although only evaluated at 3 to 6 hours post injury. A recent survey o f certified athletic trainers found that 44% used the SAC as part o f their sideline evaluation of student athletes suspected o f m T B I.17 A lthough the SAC (M A CE) is not intended to be used in isolation for the determ ination o f the existence o f concussion, or for the need for further evaluation, w hen results fall within the norm al range, it is considered to be an indication o f low suspicion o f brain in ju ry .18 Since the SAC is typically used in nontraditional clinical settings such as football gam e side lines or by the m ilitary, and not the ED , there is little data relating CT scan results to SAC scores. The purpose o f this study is to evaluate the relationship betw een CT findings of structural injury and perform ance on the SAC in a population o f head-injured patients presenting to the E D w ith little or no clinical evidence o f im pairm ent.
MILITARY MEDICINE, Vol. 179, November 2014
CT Positive Brain Injury in mTBI Patients Presenting With Normal SAC Scores
METHODS AND DESIGN Subjects The data was collected at EDs across the United States, in a multisite study of mTBI, clinical symptomatology, and brain electrical activity, (as part of BrainScope, Bethesda, Maryland, validation prospective trial, funded in part by a contract from the Department of Defense, No. W911QY-12C-0004; EEG data not presented here). The majority of the patients were recruited from Brooke Army Medical Center, University of Maryland (R Adams Cowley Shock Trauma Center), University of Virginia Medical Center, Washington University, and Detroit Receiving Hospital Wayne State University (Sinai Grace Hospital). The study was conducted in a convenience sample composed of subjects suspected of a traumatically induced structural brain injury and for whom a CT scan was ordered as part of their standard clinical evaluation to access brain injury. Candidates for study were subject to inclusion/exclusion criteria below. Once identified, the research staff recruited the subject for the study through an informed consent process.
Inclusion Criteria Males and females between the ages of 18 and 80, who were suspected of a traumatically induced structural brain injury and/or clinical manifestations of functional brain injury as a result of insult to the head from an external force, e.g., the head being struck by an object, the head striking an object, and/or the brain undergoing an acceleration/deceleration movement without direct external trauma to the head. The acute, suspected traumatically induced structural brain injury needed to occur within the 24 hours preceding admission to the ED, and receipt of a CT scan for assessment of brain injury.
Exclusion Criteria Subjects were excluded from the study if they had forehead, scalp, or skull abnormalities or other conditions that pre vented correct application of the electrode headset on the skin. Subjects with dementia. Parkinson’s disease, multiple sclerosis, seizure disorder, brain tumors, history of brain surgery, mental retardation, psychiatric disorder for which there is a prescribed psychiatric medication taken on a daily basis, substance dependence, history of transient ischemic attack or stroke within the last year, currently receiving dialysis or in end-stage renal disease, active fever defined as greater than 100°F or 37.7°C, or suffering from an open head injury were excluded. In addition, subjects with Glasgow Coma Scale (GCS)
