title: Comparison and utility of King-Devick and ImPACT® composite scores in adolescent concussion patients.
abstract: The King-Devick (KD) oculomotor test has recently been advocated for sideline diagnosis of concussion. Although visual processing and performance are often impaired in concussion patients, the utility of KD as a concussion diagnostic tool is not validated.
  
  
  OBJECTIVE
  To examine the diagnostic value of KD, by comparing KD with post-concussion symptom scale (PCSS) and ImPACT® composite scores. We hypothesized that KD would be correlated with visual motor speed/memory (VMS, VIS) and reaction time (RT), because all require cognitive visual processing. We also expected parallel changes in KD and PCSS across recovery.
  
  
  METHODS
  Thirty-five concussed individuals (12-19 y; 18 females, 17 males) were evaluated with PCSS, ImPACT® composite and KD scores over four clinical visits (V).
  
  
  RESULTS
  KD times improved with each visit (ΔV1-V2: 7.86±11.82; ΔV2-V3: 9.17 ± 11.07; ΔV3-V4: 5.30 ± 7.87 s) and paralleled improvements in PCSS (ΔV1-V2: 8.97 ± 20.27; ΔV2-V3: 8.69 ± 14.70; ΔV3-V4: 6.31 ± 7.71), RT (ΔV1-V2: 0.05 ± 0.21; ΔV2-V3: 0.09 ± 0.19; ΔV3-V4 0.03 ± 0.07) and VMS (ΔV1-V2: -5.27 ± 6.98; ΔV2-V3: -2.61 ± 6.48; ΔV3-V4: -2.35 ± 5.22). Longer KD times were associated with slower RT (r = 0.67; P<0.0001) and lower VMS (r = -0.70; P<0.0001), respectively.
  
  
  CONCLUSIONS
  Cognitive visual performance testing using KD has utility in concussion evaluation. Validation would further establish KD as an effective ancillary tool in longitudinal concussion management and research.
authors.affiliation: Sanford School of Medicine, University of South Dakota, 1400 W. 22nd St., Sioux Falls, SD 57105, United States. Electronic address: Brian.Tjarks@usd.edu.
authors.forename: B Joel
authors.initials: BJ
authors.lastname: Tjarks
authors.forename: Jason C
authors.initials: JC
authors.lastname: Dorman
authors.forename: Verle D
authors.initials: VD
authors.lastname: Valentine
authors.forename: Thayne A
authors.initials: TA
authors.lastname: Munce
authors.forename: Paul A
authors.initials: PA
authors.lastname: Thompson
authors.forename: Shanna L
authors.initials: SL
authors.lastname: Kindt
authors.forename: Michael F
authors.initials: MF
authors.lastname: Bergeron
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000175:diagnosis*; D001924:Brain Concussion / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D053483:Eye Movement Measurements; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011597:Psychomotor Performance; D011930:Reaction Time; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Diffuse axonal injury; Neuropsychological tests; Oculomotor dysfunction; Post-concussion syndrome; Return to play; Traumatic brain injury; Visual-motor deficits