Evaluation of multisensory responses (oculomotor, vestibular, and reaction time) in 3, 8 and 15 days after mild traumatic brain injury

Abstract

Background Despite the prevalence of mild traumatic brain injury (mTBI, concussion) in a wide range of occupational, sport, and military settings, accurate diagnosis and optimal treatment of concussive injuries are delayed by several challenging obstacles. Ability to measure the multisensory functional integrity of numerous neuroanatomical pathways with multiple tasks (oculomotor, vestibular and reaction time) can capture impairments of brain function. Methods 106 mTBI patients and 300 control subjects were tested in the vestibular labs at 2 military hospitals. Patients were tested 3 times at average 2.5, 8.5 and 15.8 days post-injury. All patients completed a health history questionnaire, a dizziness handicap index (DHI), a functional gait index (FGI), and Trail Making Tests (TMTs) and were assessed by a battery of tests with video-oculography (I-Portal VOG) comprised of a head mounted, high speed eye tracking system on a rotary chair device (I-Portal Neuro-Otologic Test Center). The individuals in the study performed multiple tests including saccades, antisaccade, pursuit tracking, nystagmus, optokinetic, vestibular motion, and reaction time. Results No single test was sufficiently predictive to have separation between controls and mTBI subjects but results from a computer controlled rotational head impulse test (crHIT), antisaccade and predictive saccade were highly correlated with mTBI for the first test session. Longitudinally, for example, 74% of patients in session 1, 56% in session 2% and 51% in session 3 had in crHIT gain or absolute asymmetry above 95% of the respective control's distribution. Conclusion These results suggest that vestibular, oculomotor and reaction time tests using can provide an objective and reliable method of capturing and quantifying abnormal response in patients with mTBI. In addition, this type of testing can be used to monitor the recovery process.