Rapid number naming in chronic concussion: eye movements in the King–Devick test

Abstract

ObjectiveThe King–Devick (KD) test, which is based on rapid number naming speed, is a performance measure that adds vision and eye movement assessments to sideline concussion testing. We performed a laboratory‐based study to characterize ocular motor behavior during the KD test in a patient cohort with chronic concussion to identify features associated with prolonged KD reading times.MethodsTwenty‐five patients with a concussion history (mean age: 31) were compared to control participants with no concussion history (n = 42, mean age: 32). Participants performed a computerized KD test under infrared‐based video‐oculography.ResultsAverage intersaccadic intervals for task‐specific saccades were significantly longer among concussed patients compared to controls (324.4 ± 85.6 msec vs. 286.1 ± 49.7 msec, P = 0.027). Digitized KD reading times were prolonged in concussed participants versus controls (53.43 ± 14.04 sec vs. 43.80 ± 8.55 sec, P = 0.004) and were highly correlated with intersaccadic intervals. Concussion was also associated with a greater number of saccades during number reading and larger average deviations of saccade endpoint distances from the centers of the to‐be‐read numbers (1.22 ± 0.29° vs. 0.98 ± 0.27°, P = 0.002). There were no differences in saccade peak velocity, duration, or amplitude.InterpretationProlonged intersaccadic intervals, greater numbers of saccades, and larger deviations of saccade endpoints underlie prolonged KD reading times in chronic concussion. The KD test relies upon a diffuse neurocognitive network that mediates the fine control of efferent visual function. One sequela of chronic concussion may be disruption of this system, which may produce deficits in spatial target selection and planning of eye movements.

Saccadic impairment in chronic traumatic brain injury: examining the influence of cognitive load and injury severity

“…planning and execution of saccadic eye movements) and tracking (e.g. smooth pursuit) of visual targets (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38). For example, in a recent study using a cued saccadic RT paradigm to compare participants with remote mild TBI to uninjured controls, we found evidence for persistent saccadic impairment among those with multiple previous injuries and/or chronic symptoms, whereas asymptomatic participants with a single mild TBI performed similarly to controls (35).…”

The King–Devick test is a valid and reliable tool for assessing sport-related concussion in Australian football: A prospective cohort study

“…4 Increased latency and decreased accuracy of saccades (fast eye movements) is accepted to follow acute head trauma. 5,6 Thus, eye function tests are a robust measure for the identification of mTBI and SRC. 4 Heitger et al 3 demonstrated an increased number of saccades and poor motor movement timings with slower velocities of eye movements in subjects with post-concussion syndrome.…”

Quantitative Analysis of Smooth Pursuit Eye Movement Using Video-Oculography

“…Our system is, however, marred by the possible disadvantage of capturing target and eye movements at only 30 Hz; it may be insuffi cient to cope with rapid eye movements. In order to evaluate the rapid eye movement using VOG, recording at 250 to 500 Hz is required [13,14]. In this study, evaluation was performed by setting the evaluation criteria for the SPEM, excluding the site where rapid eye movements occur.…”