Objectifying eye movements during rapid number naming: Methodology for assessment of normative data for the King-Devick test

J Neurol Sci. 2016 Mar 15:362:232-9. doi: 10.1016/j.jns.2016.01.045. Epub 2016 Jan 22.

Abstract

Objective: Concussion is a major public health problem and considerable efforts are focused on sideline-based diagnostic testing to guide return-to-play decision-making and clinical care. The King-Devick (K-D) test, a sensitive sideline performance measure for concussion detection, reveals slowed reading times in acutely concussed subjects, as compared to healthy controls; however, the normal behavior of eye movements during the task and deficits underlying the slowing have not been defined.

Methods: Twelve healthy control subjects underwent quantitative eye tracking during digitized K-D testing.

Results: The total K-D reading time was 51.24 (±9.7) seconds. A total of 145 saccades (±15) per subject were generated, with average peak velocity 299.5°/s and average amplitude 8.2°. The average inter-saccadic interval was 248.4 ms. Task-specific horizontal and oblique saccades per subject numbered, respectively, 102 (±10) and 17 (±4). Subjects with the fewest saccades tended to blink more, resulting in a larger amount of missing data; whereas, subjects with the most saccades tended to make extra saccades during line transitions.

Conclusions: Establishment of normal and objective ocular motor behavior during the K-D test is a critical first step towards defining the range of deficits underlying abnormal testing in concussion. Further, it sets the groundwork for exploration of K-D correlations with cognitive dysfunction and saccadic paradigms that may reflect specific neuroanatomic deficits in the concussed brain.

Keywords: Brain concussion; Eye movement measurements; Eye movements; Saccades.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brain Concussion / diagnosis*
  • Clinical Decision-Making
  • Eye Movements / physiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Names*
  • Neuropsychological Tests
  • Reference Values
  • Severity of Illness Index*
  • Young Adult