Jamshid Ghajar MD, PhD, FACS, is a board certified neurosurgeon, Clinical Professor of Neurosurgery, Director of the Stanford Concussion and Brain Performance Center and President of the Brain Trauma Foundation in New York City and Palo Alto.

He completed the MD/PhD program at Cornell University Medical College. During his residency training in neurosurgery at New York Presbyterian Hospital, he invented and patented several neurosurgical devices that are currently used worldwide. After residency, he joined the faculty at the New York Presbyterian Hospital-Cornell Medical Center and was a founder of the Brain Trauma Foundation (BTF) in 1986. The mission of the BTF is to improve the outcome of patients with traumatic brain injury (TBI). He joined the neurosurgery faculty at Stanford in February 2014.

Learn more about the Stanford Concussion and Brain Performance Center:

Clinical Focus

  • Neurosurgery
  • Concussion, traumatic brain injury

Academic Appointments

Administrative Appointments

  • Clinical Professor of Neurological Surgery, Weill Cornell Medical College (2003 - 2014)
  • Chief of Neurosurgery, The Jamaica Hospital-Cornell Trauma Center. New York (1989 - 2014)
  • President, Brain Trauma Foundation (1995 - Present)
  • Clinical Professor of Neurosurgery, Stanford University Medical School (2014 - Present)
  • Director, Stanford Concussion and Brain Performance Center (2014 - Present)

Honors & Awards

  • Honorary Police Surgeon, New York Police Department (2007-2014)
  • Ellis Island Award, Ellis Island Award Committee (2013)
  • American Iranian Council Award, American Iranian Council (2001)

Boards, Advisory Committees, Professional Organizations

  • Committee on Trauma, American College of Surgeons (2012 - Present)

Professional Education

  • Board Certification: Neurosurgery, American Board of Neurological Surgery (1993)
  • Residency:New York Hospital - Cornell (1983) NY
  • Residency:New York Hospital - Cornell (1987) NY
  • Internship:New York Hospital - Cornell (1982) NY
  • Medical Education:Cornell University Medical College (1981)

Community and International Work

  • Brain Trauma Foundation, New York and Palo Alto


    Traumatic Brain Injury

    Partnering Organization(s)

    Indian Head Injury Foundation

    Populations Served

    Traumatic Brain Injury patients



    Ongoing Project


    Opportunities for Student Involvement



  • Jamshid Ghajar. "United States Patent 7,849,525 Apparatus for Reducing Brain and Cervical Spine Injury due to Rotational Movement", G-Brace, Dec 14, 2010
  • Jamshid Ghajar. "United States Patent 7,819,818 Cognition and Motor Timing Diagnosis Using Smooth Eye Pursuit Analysis", SyncThink, Oct 26, 2010
  • Jamshid Ghajar. "United States Patent 7,708,700 Method for Improving Cognition and Motor Timing", SyncThink, May 4, 2010
  • Jamshid Ghajar. "United States Patent 7,384,399 Cognition and Motor Timing Diagnosis and Training System and Method", SyncThink, Jun 8, 2008

Research & Scholarship

Current Research and Scholarly Interests

Principal Investigator,
“Concussion Definition Consortium – An Evidence Based Project”. Department of Defense. There are over 40 definitions of concussion but none are evidence based- i.e. come from well done studies. We will extract the most salient data from well run studies that are designed to give us a "snapshot" of what concussion is.

Principal Investigator,
“Multi-Dimensional Model for Brain Trauma”. The goal is to develop a dynamic model for concussion, validate it on a retrospective dataset, and design a second study to validate it on a prospective dataset. Department of Defense.

Principal Investigator,
“EYE-TRAC Advance”. Testing 10,000 subjects with normal and post concussive eye tracking. Military and civilian athletes are included. Department of Defense.

Principal Investigator,
B-TEC (Brain Trauma Evidence-based Consortium). Combines Stanford B-TEC clinical trials coordinating center with the Brain Trauma Foundation's B-TEC evidence-based center to promote and coordinate an evidence-based approach to the spectrum of brain trauma from concussion to coma.


2016-17 Courses


All Publications

  • Degradation of Binocular Coordination during Sleep Deprivation FRONTIERS IN NEUROLOGY Tong, J., Maruta, J., Heaton, K. J., Maule, A. L., Rajashekar, U., Spielman, L. A., Ghajar, J. 2016; 7


    To aid a clear and unified visual perception while tracking a moving target, both eyes must be coordinated, so the image of the target falls on approximately corresponding areas of the fovea of each eye. The movements of the two eyes are decoupled during sleep, suggesting a role of arousal in regulating binocular coordination. While the absence of visual input during sleep may also contribute to binocular decoupling, sleepiness is a state of reduced arousal that still allows for visual input, providing a context within which the role of arousal in binocular coordination can be studied. We examined the effects of sleep deprivation on binocular coordination using a test paradigm that we previously showed to be sensitive to sleep deprivation. We quantified binocular coordination with the SD of the distance between left and right gaze positions on the screen. We also quantified the stability of conjugate gaze on the target, i.e., gaze-target synchronization, with the SD of the distance between the binocular average gaze and the target. Sleep deprivation degraded the stability of both binocular coordination and gaze-target synchronization, but between these two forms of gaze control the horizontal and vertical components were affected differently, suggesting that disconjugate and conjugate eye movements are under different regulation of attentional arousal. The prominent association found between sleep deprivation and degradation of binocular coordination in the horizontal direction may be used for a fit-for-duty assessment.

    View details for DOI 10.3389/fneur.2016.00090

    View details for Web of Science ID 000377585200002

    View details for PubMedID 27379009

  • Clinical evaluation of concussion: the evolving role of oculomotor assessments NEUROSURGICAL FOCUS Sussman, E. S., Ho, A. L., Pendharkar, A. V., Ghajar, J. 2016; 40 (4)


    Sports-related concussion is a change in brain function following a direct or an indirect force to the head, identified in awake individuals and accounting for a considerable proportion of mild traumatic brain injury. Although the neurological signs and symptoms of concussion can be subtle and transient, there can be persistent sequelae, such as impaired attention and balance, that make affected patients particularly vulnerable to further injury. Currently, there is no accepted definition or diagnostic criteria for concussion, and there is no single assessment that is accepted as capable of identifying all patients with concussion. In this paper, the authors review the available screening tools for concussion, with particular emphasis on the role of visual function testing. In particular, they discuss the oculomotor assessment tools that are being investigated in the setting of concussion screening.

    View details for DOI 10.3171/2016.1.FOCUS15610

    View details for Web of Science ID 000373476500006

    View details for PubMedID 27032924

  • Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery Carney, N., Totten, A. M., OʼReilly, C., Ullman, J. S., Hawryluk, G. W., Bell, M. i., Bratton, S. L., Chesnut, R., Harris, O. A., Kissoon, N., Rubiano, A. M., Shutter, L., Tasker, R. C., Vavilala, M. S., Wilberger, J., Wright, D. W., Ghajar, J. 2016


    The scope and purpose of this work is 2-fold: to synthesize the available evidence and to translate it into recommendations. This document provides recommendations only when there is evidence to support them. As such, they do not constitute a complete protocol for clinical use. Our intention is that these recommendations be used by others to develop treatment protocols, which necessarily need to incorporate consensus and clinical judgment in areas where current evidence is lacking or insufficient. We think it is important to have evidence-based recommendations to clarify what aspects of practice currently can and cannot be supported by evidence, to encourage use of evidence-based treatments that exist, and to encourage creativity in treatment and research in areas where evidence does not exist. The communities of neurosurgery and neuro-intensive care have been early pioneers and supporters of evidence-based medicine and plan to continue in this endeavor. The complete guideline document, which summarizes and evaluates the literature for each topic, and supplemental appendices (A-I) are available online at, traumatic brain injuryRESCUEicp, Randomised Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of ICP.

    View details for DOI 10.1227/NEU.0000000000001432

    View details for PubMedID 27654000

  • Executive summary of concussion guidelines step 1: systematic review of prevalent indicators. Neurosurgery Carney, N., Ghajar, J., Jagoda, A., Bedrick, S., Davis-O'Reilly, C., du Coudray, H., Hack, D., Helfand, N., Huddleston, A., Nettleton, T., Riggio, S. 2014; 75: S1-2

    View details for DOI 10.1227/NEU.0000000000000434

    View details for PubMedID 24867198

  • Concussion guidelines step 1: systematic review of prevalent indicators. Neurosurgery Carney, N., Ghajar, J., Jagoda, A., Bedrick, S., Davis-O'Reilly, C., du Coudray, H., Hack, D., Helfand, N., Huddleston, A., Nettleton, T., Riggio, S. 2014; 75: S3-S15


    Currently, there is no evidence-based definition for concussion that is being uniformly applied in clinical and research settings.To conduct a systematic review of the highest-quality literature about concussion and to assemble evidence about the prevalence and associations of key indicators of concussion. The goal was to establish an evidence-based foundation from which to derive, in future work, a definition, diagnostic criteria, and prognostic indicators for concussion.Key questions were developed, and an electronic literature search from 1980 to 2012 was conducted to acquire evidence about the prevalence of and associations among signs, symptoms, and neurologic and cognitive deficits in samples of individuals exposed to potential concussive events. Included studies were assessed for potential for bias and confound and rated as high, medium, or low potential for bias and confound. Those rated as high were excluded from the analysis. Studies were further triaged on the basis of whether the definition of a case of concussion was exclusive or inclusive; only those with wide, inclusive case definitions were used in the analysis. Finally, only studies reporting data collected at fixed time points were used. For a study to be included in the conclusions, it was required that the presence of any particular sign, symptom, or deficit be reported in at least 2 independent samples.From 5437 abstracts, 1362 full-text publications were reviewed, of which 231 studies were included in the final library. Twenty-six met all criteria required to be used in the analysis, and of those, 11 independent samples from 8 publications directly contributed data to conclusions. Prevalent and consistent indicators of concussion are (1) observed and documented disorientation or confusion immediately after the event, (2) impaired balance within 1 day after injury, (3) slower reaction time within 2 days after injury, and/or (4) impaired verbal learning and memory within 2 days after injury.The results of this systematic review identify the consistent and prevalent indicators of concussion and their associations, derived from the strongest evidence in the published literature. The product is an evidence-based foundation from which to develop diagnostic criteria and prognostic indicators.GCS, Glasgow Coma ScaleLOC, loss of consciousnessPCE, potential concussive eventPTA, posttraumatic amnesiaSOT, Sensory Organization TestSSD, signs, symptoms, neurologic deficits, and cognitive deficits.

    View details for DOI 10.1227/NEU.0000000000000433

    View details for PubMedID 25006974

  • Predictive Visual Tracking: Specificity in Mild Traumatic Brain Injury and Sleep Deprivation MILITARY MEDICINE Maruta, J., Heaton, K. J., Mau, A. L., Ghajar, J. 2014; 179 (6): 619-625


    We tested whether reduced cognitive function associated with mild traumatic brain injury (mTBI) and sleep deprivation can be detected and distinguished using indices of predictive visual tracking. A circular visual tracking test was given to 13 patients with acute mTBI (recruited within 2 weeks of injury), 127 normal control subjects, and 43 healthy subjects who were fatigued by 26-hour sleep deprivation. Eye movement was monitored with video-oculography. In the mTBI-related portion of the study, visual tracking performance of acute mTBI patients was significantly worse than normal subjects (p < 0.001). In the sleep-deprivation-related portion of the study, no change was detected between the two baseline measures separated by 2 to 3 weeks, but the 26-hour sleep deprivation significantly degraded the visual tracking performance (p < 0.001). The mTBI subjects had substantially worse visual tracking than sleep-deprived subjects that could also be identified with different visual tracking indices, indicating possible different neurophysiological mechanisms. Results suggest that cognitive impairment associated with mTBI and fatigue may be triaged with the aid of visual tracking measures.

    View details for DOI 10.7205/MILMED-D-13-00420

    View details for Web of Science ID 000340806500006

    View details for PubMedID 24902128

  • Detecting eye movement abnormalities from concussion. Progress in neurological surgery Maruta, J., Ghajar, J. 2014; 28: 226-233


    An attention-based biomarker may be useful for concussion screening. A key role of attention is to generate time-based expectancies of specific sensory information, and it is postulated that postconcussion cognitive impairments and symptoms may stem from a primary deficit in this predictive timing mechanism. There is a close relationship between gaze and attention, but in addressing predictive timing, there is a need for an appropriate testing paradigm and methods to quantify oculomotor anomalies. We have utilized a continuous predictive visual tracking paradigm because human visual tracking requires predicting the temporal course of a stimulus and dynamically synchronizing the required action with the stimulus. We have shown that concussion patients often show disrupted gaze-target synchronization characterized by large gaze position error variability and overall phase advancement. Various attention components interact with visual tracking, and thus there is a possibility that different neurological and physiological conditions produce identifiable visual tracking characteristics. Analyzing neuromotor functions, specifically oculomotor synchronization, can provide a fast, accurate, and reliable assessment of cognitive functions. © 2014 S. Karger AG, Basel.

    View details for DOI 10.1159/000358786

    View details for PubMedID 24923406

  • Chronic Post-Concussion Neurocognitive Deficits. II. Relationship with Persistent Symptoms FRONTIERS IN HUMAN NEUROSCIENCE Maruta, J., Spielman, L. A., Yarusi, B. B., Wang, Y., Silver, J. M., Ghajar, J. 2016; 10


    Individuals who sustain a concussion may continue to experience problems long after their injury. However, it has been postulated in the literature that the relationship between a concussive injury and persistent complaints attributed to it is mediated largely by the development of symptoms associated with posttraumatic stress disorder (PTSD) and depression. We sought to characterize cognitive deficits of adult patients who had persistent symptoms after a concussion and determine whether the original injury retains associations with these deficits after accounting for the developed symptoms that overlap with PTSD and depression. We compared the results of neurocognitive testing from 33 patients of both genders aged 18-55 at 3 months to 5 years post-injury with those from 140 control subjects. Statistical comparisons revealed that patients generally produced accurate responses on reaction time-based tests, but with reduced efficiency. On visual tracking, patients increased gaze position error variability following an attention demanding task, an effect that may reflect greater fatigability. When neurocognitive performance was examined in the context of demographic- and symptom-related variables, the original injury retained associations with reduced performance at a statistically significant level. For some patients, reduced cognitive efficiency and fatigability may represent key elements of interference when interacting with the environment, leading to varied paths of recovery after a concussion. Poor recovery may be better understood when these deficits are taken into consideration.

    View details for DOI 10.3389/fnhum.2016.00045

    View details for Web of Science ID 000370120800001

    View details for PubMedID 26912999

  • Chronic Post-Concussion Neurocognitive Deficits. I. Relationship with White Matter Integrity FRONTIERS IN HUMAN NEUROSCIENCE Maruta, J., Palacios, E. M., Zimmerman, R. D., Ghajar, J., Mukherjee, P. 2016; 10


    We previously identified visual tracking deficits and associated degradation of integrity in specific white matter tracts as characteristics of concussion. We re-explored these characteristics in adult patients with persistent post-concussive symptoms using independent new data acquired during 2009-2012. Thirty-two patients and 126 normal controls underwent cognitive assessments and MR-DTI. After data collection, a subset of control subjects was selected to be individually paired with patients based on gender and age. We identified patients' cognitive deficits through pairwise comparisons between patients and matched control subjects. Within the remaining 94 normal subjects, we identified white matter tracts whose integrity correlated with metrics that indicated performance degradation in patients. We then tested for reduced integrity in these white matter tracts in patients relative to matched controls. Most patients showed no abnormality in MR images unlike the previous study. Patients' visual tracking was generally normal. Patients' response times in an attention task were slowed, but could not be explained as reduced integrity of white matter tracts relating to normal response timing. In the present patient cohort, we did not observe behavioral or anatomical deficits that we previously identified as characteristic of concussion. The recent cohort likely represented those with milder injury compared to the earlier cohort. The discrepancy may be explained by a change in the patient recruitment pool circa 2007 associated with an increase in public awareness of concussion.

    View details for DOI 10.3389/fnhum.2016.00035

    View details for Web of Science ID 000369850900001

    View details for PubMedID 26903842

  • Filling in the gaps: Anticipatory control of eye movements in chronic mild traumatic brain injury NEUROIMAGE-CLINICAL Diwakar, M., Harrington, D. L., Maruta, J., Ghajar, J., El-Gabalawy, F., Muzzatti, L., Corbetta, M., Huang, M., Lee, R. R. 2015; 8: 210-223


    A barrier in the diagnosis of mild traumatic brain injury (mTBI) stems from the lack of measures that are adequately sensitive in detecting mild head injuries. MRI and CT are typically negative in mTBI patients with persistent symptoms of post-concussive syndrome (PCS), and characteristic difficulties in sustaining attention often go undetected on neuropsychological testing, which can be insensitive to momentary lapses in concentration. Conversely, visual tracking strongly depends on sustained attention over time and is impaired in chronic mTBI patients, especially when tracking an occluded target. This finding suggests deficient internal anticipatory control in mTBI, the neural underpinnings of which are poorly understood. The present study investigated the neuronal bases for deficient anticipatory control during visual tracking in 25 chronic mTBI patients with persistent PCS symptoms and 25 healthy control subjects. The task was performed while undergoing magnetoencephalography (MEG), which allowed us to examine whether neural dysfunction associated with anticipatory control deficits was due to altered alpha, beta, and/or gamma activity. Neuropsychological examinations characterized cognition in both groups. During MEG recordings, subjects tracked a predictably moving target that was either continuously visible or randomly occluded (gap condition). MEG source-imaging analyses tested for group differences in alpha, beta, and gamma frequency bands. The results showed executive functioning, information processing speed, and verbal memory deficits in the mTBI group. Visual tracking was impaired in the mTBI group only in the gap condition. Patients showed greater error than controls before and during target occlusion, and were slower to resynchronize with the target when it reappeared. Impaired tracking concurred with abnormal beta activity, which was suppressed in the parietal cortex, especially the right hemisphere, and enhanced in left caudate and frontal-temporal areas. Regional beta-amplitude demonstrated high classification accuracy (92%) compared to eye-tracking (65%) and neuropsychological variables (80%). These findings show that deficient internal anticipatory control in mTBI is associated with altered beta activity, which is remarkably sensitive given the heterogeneity of injuries.

    View details for DOI 10.1016/j.nicl.2015.04.011

    View details for Web of Science ID 000373187100022