The purpose of the study was to test the ability of oculomotor, vestibular, and reaction time (OVRT) metrics to serve as a concussion assessment or diagnostic tool for general clinical use.
Patients with concussion were high school-aged athletes clinically diagnosed in a hospital setting with a sports-related concussion (n = 50). Control subjects were previously recruited male and female high school student athletes from 3 local high schools (n = 170).
Video-oculography was used to acquire eye movement metrics during OVRT tasks, combined with other measures. Measures were compared between groups, and a subset was incorporated into linear regression models that could serve as indicators of concussion.
The OVRT test battery included multiple metrics of saccades, smooth pursuit tracking, nystagmoid movements, vestibular function, and reaction time latencies.
Some OVRT metrics were significantly different between groups. Linear regression models distinguished control subjects from concussion subjects with high accuracy. Metrics included changes in smooth pursuit tracking, increased reaction time and reduced saccade velocity in a complex motor task, and decreased optokinetic nystagmus (OKN) gain. In addition, optokinetic gain was reduced and more variable in subjects assessed 22 or more days after injury.
These results indicate that OVRT tests can be used as a reliable adjunctive tool in the assessment of concussion and that OKN results appear to be associated with a prolonged expression of concussion symptoms.
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Departments of Neurology (Drs Kelly and Synowiec and Mr Miller), Orthopaedic Surgery (Drs Akhavan and Snell and Ms Bauer), and Ophthalmology (Dr Happ), Allegheny General Hospital, Pittsburgh, Pennsylvania; Department of Neurosurgery, University of Pittsburgh Medical Center, Erie, Pennsylvania (Dr Quigley); and Neuro Kinetics, Inc, Pittsburgh, Pennsylvania (Drs Kiderman and Ashmore, Ms Oakes, and Messrs Eydelman, Gallagher, Dinehart, and Schroeder).
Corresponding Author: Kevin M. Kelly, MD, PhD, Department of Neurology, Allegheny General Hospital, 940 South Tower, 320 E. North Ave, Pittsburgh, PA 15212 (email@example.com).
A.K., Y.E., J.H.S., and R.C.A. are employees of and financial stakeholders in Neuro Kinetics, Inc (NKI), a for-profit, privately held company, and manufacturer of the equipment used in this study. C.W.G. and L.P.O. were former employees of NKI, and T.D. was temporarily employed by NKI for this project. K.M.K. and M.R.Q. received salary support from Department of Defense Rapid Innovation Fund Contract 81XWH-12-C-0205 by a subcontract to Allegheny General Hospital from NKI. K.M.K., S.A., M.R.Q., E.D.S., E.H., A.S.S., E.R.M., and M.A.B. used the equipment lent by NKI, for the conduct of the study, which was supported in part by US Department of the Treasury, Internal Revenue Service Qualifying Therapeutic Discovery Project Credit Grant 21.013 to NKI, and by the Department of Defense Rapid Innovation Fund Contract 81XWH-12-C-0205 awarded to NKI under which Allegheny General Hospital was subcontracted.