"New technology that tracks the eye movements of patients may be a more accurate measure of brain injury than any other diagnostic measurements currently in use according to a study published in the journal Concussion http Dr. Uzma Samadani who recently joined Hennepin County Medical Center httpshcmcnews.orginternationallyrecognizedneurosurgeondruzmasamadanijoinshcmc in collaboration with researchers at the Steven and Alexandra Cohen Veterans Center at NYU Langone Medical Center developed the technology that can serve as a biomarker for concussion by tracking patients eye movements as they watch music videos.   The eye tracking technology works by having patients watch a music video for  seconds while eye movements are measured using a tracking camera.  Videos used in the study ranged from Disneys Puss in Boots to Wavin Flag by KNaan.  Multiple measures of each eyes movement followed by comparisons of their positions over time are used to distinguish between normal subjects and those with concussion. In the work led by Uzma Samadani MD PhD Charles Marmar MD and Eugene Laska PhD the investigators built a classifier based on  emergency room patients with brain injury and  uninjured healthy control subjects of similar age. A classifier is a mathematical model that converts a patients eye movement measures into a prediction of the concussive status of the individual. They then tested the models on a dataset of  subjects of whom  had concussions and found that the eye tracking test had an optimal sensitivity of  and specificity of . Typically a classifier produces a score and a subject is classified as having a concussion if the score exceeds a predefined threshold value. The accuracy of a biomarker is measured by plotting the probability of a true versus false positivity at each possible threshold value and the Area Under the Curve AUC is computed. A perfect biomarker has an AUC of . while a worthless marker  no better than the chance toss of a coin  has an AUC of ..  Most tests used clinically have AUCs greater than ..  For example serum troponin the most commonly performed blood test for heart attacks has an AUC ranging in various studies from . to ..  In this study the eye tracking based classifier had an AUC of . and a crossvalidated AUC of .. According to Dr. Samadani the major challenge for any technology proposed as a biomarker for concussion is first defining concussion.  When doctors look for a biomarker for heart attack it is relatively easy to check the accuracy of a potential candidate because they can perform a cardiac catheterization and confirm that the heart vessel is blocked and an attack has occurred.  There is no analogous capability with brain injury  there is no gold standard diagnostic no blood test and no imaging study for definitively concluding that a patient has experienced a concussion.  We use symptom severity scales and standardized cognitive examination assessments but the imperfect nature of these may result in incorrect subject classification. Potentially eye tracking may be more accurate than it appears because of its objective appraisal of a complicated process of coordination that may be impaired. The investigators defined concussion as  trauma to the head with a normal CT computed tomography scan of the brain  symptom severity score of  or greater on SCAT testing and  standardized assessment of concussion SAC score less than .  The symptom severity score measures the selfreported severity of  concussion symptoms ranging from headache to dizziness and irritability.  The SAC measures orientation memory and concentration  capabilities which have some variability even among uninjured healthy control subjects. In an accompanying editorial http that also appears in the journal Dr. Samadani proposes that eye tracking will help diagnose and classify brain injury and concussion particularly in patients with elevated pressure inside their skulls and disruption of pathways in the brain that control eye movements. The ultimate goal for brain injury said Dr. Samadani is to achieve the same level of diagnostic capability and care as currently exists for other medical conditions.  Right now when someone comes in to the emergency room with chest pain doctors perform an EKG blood test imaging and treatment.  With brain injury we need to be able to achieve the same level of care  to assess all aspects of the problem rigorously classify and treat accordingly.  We already know that there is much more to brain injury than what is seen on a CT scan.  Eye tracking tells us how well the brain is working regardless of how it looks and represents the beginning of a solution to this problem.  It is noninvasive inexpensive and extremely quick.  Testing does not require reading nor language skills which makes it useful for multiple patient populations. Commenting further on the study was Dr. David Cifu the Herman J. Flax M.D. Professor and Chair of Rehabilitation at Virginia Commonwealth University Senior TBI Specialist with the U.S. Department of Veterans Affairs and Principal Investigator of the VADepartment of Defense Chronic Effects of NeuroTrauma Consortium. This innovative research by Samadani and colleagues highlights a novel approach to objectively and rapidly support the diagnosis of acute concussion using a novel technique of assessing eye tracking. This publication may represent the first step in the development of a more exacting method of diagnosing and monitoring recovery from traumatic brain injury. Computerized assessment of eye tracking may represent the first truly useful biomarker of TBI. Brain injury is the number one cause of death and disability in Americans under age  according to the U.S. Centers for Disease Control and Prevention. Every year . million people suffer from a traumatic brain injury in the United States. Of those  die and  require hospital admission.  Internationally it is a leading cause of death in India and China where access to radiographic diagnostics is also limited. Dr. Samadani http_P_ is the Rockswold Kaplan endowed chair for traumatic brain injury at Hennepin County Medical Center and an Associate Professor of Neurosurgery at the University of Minnesota.  Dr. Marmar is the Lucius N. Littauer Professor and Chair of the Department of Psychiatry at NYU Langone Medical Center and Director of its Cohen Veterans Center httpnyulangone.orglocationscohenveteranscenter. Dr. Laska is a statistician at the Nathan Kline Institute for Psychiatric Research and a Research Professor of Psychiatry at the NYU School of Medicine http  Other coauthors of this study include Meng Li MA Meng Qian PhD Robert Ritlop M Eng Radek Kolecki MS Marleen Reyes BA Lindsey Altomare BA Je Yeong Sone Aylin Adem Paul Huang MD Douglas Kondziolka MD Stephen Wall MD and Spiros Frangos MD. Technology described in this paper has been licensed to Oculogica Inc. a neurodiagnostic startup company in which NYU Dr. Samadani and Robert Ritlop have an equity interest. The work was supported in part by the Steven  Alexandra Cohen Veterans Center http for the Study of PostTraumatic Stress and Traumatic Brain Injury at NYU Langone."