title: Objectifying eye movements during rapid number naming: Methodology for assessment of normative data for the King-Devick test.
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.
authors.affiliation: Department of Physical Medicine & Rehabilitation, NYU School of Medicine, New York, NY, United States; Department of Neurology, NYU School of Medicine, New York, NY, United States.
authors.forename: John-Ross
authors.initials: JR
authors.lastname: Rizzo
authors.affiliation: Department of Physical Medicine & Rehabilitation, NYU School of Medicine, New York, NY, United States; Department of Neurology, NYU School of Medicine, New York, NY, United States.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Hudson
authors.affiliation: Department of Electrical & Computer Engineering, NYU Tandon School of Engineering, New York, NY, United States.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Dai
authors.affiliation: Department of Neurology, NYU School of Medicine, New York, NY, United States.
authors.forename: Ninad
authors.initials: N
authors.lastname: Desai
authors.affiliation: Department of Physical Medicine & Rehabilitation, NYU School of Medicine, New York, NY, United States.
authors.forename: Arash
authors.initials: A
authors.lastname: Yousefi
authors.affiliation: Department of Mechanical Engineering, NYU Tandon School of Engineering, New York, NY, United States.
authors.forename: Dhaval
authors.initials: D
authors.lastname: Palsana
authors.affiliation: Department of Electrical & Computer Engineering, NYU Tandon School of Engineering, New York, NY, United States.
authors.forename: Ivan
authors.initials: I
authors.lastname: Selesnick
authors.affiliation: Department of Neurology, NYU School of Medicine, New York, NY, United States; Department of Population Health, NYU School of Medicine, New York, NY, United States; Department of Ophthalmology, NYU School of Medicine, New York, NY, United States.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.affiliation: Department of Neurology, NYU School of Medicine, New York, NY, United States; Department of Ophthalmology, NYU School of Medicine, New York, NY, United States.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
authors.affiliation: Department of Neurology, NYU School of Medicine, New York, NY, United States; Department of Ophthalmology, NYU School of Medicine, New York, NY, United States. Electronic address: janet.rucker@nyumc.org.
authors.forename: Janet C
authors.initials: JC
authors.lastname: Rucker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001924:Brain Concussion / Q000175:diagnosis*; D000066491:Clinical Decision-Making; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009275:Names; D009483:Neuropsychological Tests; D012016:Reference Values; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Brain concussion; Eye movement measurements; Eye movements; Saccades