title: Capturing saccades in multiple sclerosis with a digitized test of rapid number naming.
abstract: The King-Devick (K-D) test of rapid number naming is a visual performance measure that captures saccadic eye movements. Patients with multiple sclerosis (MS) have slowed K-D test times associated with neurologic disability and reduced quality of life. We assessed eye movements during the K-D test to identify characteristics associated with slowed times. Participants performed a computerized K-D test with video-oculography. The 25-Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) and its 10-Item Neuro-Ophthalmic Supplement measured vision-specific quality of life (VSQOL). Among 25 participants with MS (age 37 ± 10 years, range 20-59) and 42 controls (age 33 ± 9 years, range 19-54), MS was associated with significantly longer (worse) K-D times (58.2 ± 19.8 vs. 43.8 ± 8.6 s, P = 0.001, linear regression models, accounting for age). In MS, test times were slower among patients with higher (worse) Expanded Disability Status Scale scores (P = 0.01). Average inter-saccadic intervals (ISI) were significantly longer in MS participants compared to controls (362 ± 103 vs. 286 ± 50 ms, P = 0.001), and were highly associated with prolonged K-D times in MS (P = 0.006). MS participants generated greater numbers of saccades (P = 0.007). VSQOL scores were reduced in MS patients with longer (worse) K-D times (P = 0.04-0.001) and longer ISI (P = 0.002-0.001). Patients with MS have slowed K-D times that may be attributable to prolonged ISI and greater numbers of saccades. The K-D test and its requisite eye movements capture VSQOL and make rapid number naming a strong candidate efferent visual performance measure in MS.
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Hainline
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.|Department of Rehabilitation Medicine, New York University School of Medicine, New York, NY, USA.
authors.forename: John-Ross
authors.initials: JR
authors.lastname: Rizzo
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.|Department of Rehabilitation Medicine, New York University School of Medicine, New York, NY, USA.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Hudson
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.|Department of Rehabilitation Medicine, New York University School of Medicine, New York, NY, USA.|Department of Electrical and Computer Engineering, New York University Tandon School of Engineering, New York, NY, USA.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Dai
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Birkemeier
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.
authors.forename: Jenelle
authors.initials: J
authors.lastname: Raynowska
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Nolan
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.
authors.forename: Lisena
authors.initials: L
authors.lastname: Hasanaj
authors.affiliation: Department of Electrical and Computer Engineering, New York University Tandon School of Engineering, New York, NY, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Selesnick
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Frohman
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.|Department of Ophthalmology, New York University School of Medicine, New York, NY, USA.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA.|Department of Ophthalmology, New York University School of Medicine, New York, NY, USA.|Department of Population Health, New York University School of Medicine, New York, NY, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY, 10016, USA. janet.rucker@nyumc.org.|Department of Ophthalmology, New York University School of Medicine, New York, NY, USA. janet.rucker@nyumc.org.
authors.forename: Janet C
authors.identifier: http://orcid.org/0000-0002-0397-0999
authors.initials: JC
authors.lastname: Rucker
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D009275:Names; D009483:Neuropsychological Tests; D011788:Quality of Life / Q000523:psychology; D012438:Saccades / Q000502:physiology*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Inter-saccadic Interval; King–Devick Test; Multiple sclerosis; Rapid number naming; Saccades