Differential eye movements in mild traumatic brain injury versus normal controls.
OBJECTIVE
Objective measures to diagnose and to monitor improvement of symptoms following mild traumatic brain injury (mTBI) are lacking. Computerized eye tracking has been advocated as a rapid, user friendly, and field-ready technique to meet this need.


METHODS
Eye-tracking data collected via a head-mounted, video-based binocular eye tracker was used to examine saccades, fixations, and smooth pursuit movement in military Service Members with postconcussive syndrome (PCS) and asymptomatic control subjects in an effort to determine if eye movement differences could be found and quantified.


METHODS
Sixty Military Service Members with PCS and 26 asymptomatic controls.


METHODS
The diagnosis of mTBI was confirmed by the study physiatrist's history, physical examination, and a review of any medical records. Various features of saccades, fixation and smooth pursuit eye movements were analyzed.


RESULTS
Subjects with symptomatic mTBI had statistically larger position errors, smaller saccadic amplitudes, smaller predicted peak velocities, smaller peak accelerations, and longer durations. Subjects with symptomatic mTBI were also less likely to follow a target movement (less primary saccades). In general, symptomatic mTBI tracked the stepwise moving targets less accurately, revealing possible brain dysfunction.


CONCLUSIONS
A reliable, standardized protocol that appears to differentiate mTBI from normals was developed for use in future research. This investigation represents a step toward objective identification of those with PCS. Future studies focused on increasing the specificity of eye movement differences in those with PCS are needed.
Departments of Physical Medicine and Rehabilitation (Drs Cifu and Carne) and Biomedical Engineering (Drs Wetzel and Gitchel), Virginia Commonwealth University; Physical Medicine and Rehabilitation Program Office of the Department of Veterans Affairs (Dr Cifu); and Department of Mathematics and Computer Science, University of Richmond (Drs Wares and Hoke), Richmond, Virginia.
David X
DX
Cifu
Joanna R
JR
Wares
Kathy W
KW
Hoke
Paul A
PA
Wetzel
George
G
Gitchel
William
W
Carne
D000328:Adult; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D008889:Military Personnel; D038223:Post-Concussion Syndrome / Q000503:physiopathology*; D012438:Saccades / Q000502:physiology; D055815:Young Adult