Saccadic Eye Movements in Mild Traumatic Brain Injury: A Pilot Study

Objective: To investigate whether repeat saccadic reaction time (SRT) measurements using a portable saccadometer is useful to monitor patients with mild traumatic brain injury (mTBI). Methods: Seven patients with newly-diagnosed mTBI and five age-matched controls were prospectively recruited from an Emergency Department. Saccadic eye movements, symptom self-reporting and neuropsychological tests were performed within one week of injury and again at follow-up three weeks post-injury. Control patients underwent saccade recordings at similar intervals. Results: Median saccade reaction times were significantly prolonged within one week post-injury in mTBI compared to controls. At follow-up assessment there was no significant between-groups difference. Changes in median SRT between the two assessments were not statistically significant. Four of the seven mTBI patients showed significantly increased SRT at follow-up; three of the mTBI patients and all controls showed no significant change. Among the three mTBI patients with persistent decreased SRT, two experienced loss of consciousness and reported the greatest symptoms, while the third was the only subject with significant decrease in neuropsychological testing scores at both assessments. Conclusion: In three of seven mTBI patients, saccadic eye movements remained delayed within three weeks post-injury. These three patients also showed persistent symptoms or no improvement on neuropsychological testing. This pilot study using a portable saccadometer suggests that comparing SRT from three weeks post-injury to that within one week of injury may be useful for early detection of a subpopulation at risk of persistent disability from mTBI. This finding suggests that further investigation in a large study population is warranted.