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

John Ross Rizzo, Todd E. Hudson, Weiwei Dai, Ninad Desai, Arash Yousefi, Dhaval Palsana, Ivan Selesnick, Laura J. Balcer, Steven L. Galetta, Janet C. Rucker

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish (US)
Pages (from-to)232-239
Number of pages8
JournalJournal of the Neurological Sciences
StatePublished - Mar 15 2016


  • Brain concussion
  • Eye movement measurements
  • Eye movements
  • Saccades

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology


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