The King-Devick test (KDT) and visual contrast sensitivity test (VCS) in migraine: the effect of migraine attack on rapid eye movements and visual sensitivity (S43.004)

Objective: To detect an alteration in central nervous system function using KDT and VCS by demonstrating a difference during a migraine attack compared to the inter-ictal (between attack) phase.

Background: Migraine is characterized by head pain and symptoms including photophobia and cognitive dysfunction during attacks. The KDT is a timed rapid number naming test that evaluates saccadic eye movements, attention, information processing, and is highly sensitive to altered cerebral function. The VCS measures the ability to visually discern details at low contrast level. KDT and VCS have been shown to correlate with neurologic dysfunction in various neurological diseases.

Design/Methods: We included adult subjects with episodic or chronic migraine with or without aura (less than 25 headache days/month). We enrolled on-site Mayo Clinic employees, and the KDT and VCS were performed by the same examiner to minimize bias. For each participant, we performed KDT and VCS testing during headache phase of migraine attack, and inter-ictal non-headache phases. Power analysis suggests a sample size of 26 subjects is needed to detect an effect size of 0.8 for both KDT and VCS, with an 80% power and a significance level at 0.05. Subjects served as their own controls.

Results: We collected data on 28 subjects. There was a statistically significant difference in the performance of KDT during the migraine attack compared to the inter-ictal baseline. On average, the KDT score was 6.3 seconds longer during the migraine attack compared to the interictal baseline. For VCS (both 100% and 2.5% contrast sensitivity), there was no significant difference between the migraine attack and the inter-ictal baseline.

Conclusions: This study provides objective and quantitative data demonstrating altered cerebral function during migraine attacks. The KDT could be an effective tool to understand migraine pathophysiology, to document the true interictal state, as well as to characterize migraine associated disability during and between attacks.

Disclosure: Dr. Chiang has nothing to disclose. Dr. Starling has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alder, Amgen, Eli Lilly & Company, eNeura. Dr. Dodick has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Acorda, Allergan, Amgen, Alder, Dr Reddy’s, Merck, Dr Reddy’s, Promius, eNeura, Eli Lilly & Company, Insys therapeutics, Autonomic Technologies, Teva, Xenon, Tonix, Trigemina, Boston Scientific, GBS, Colucid, Zosano, Laydenburg Thalmann, Biocentric, Biohaven, Magellan, Pfizer (Japan), Charleston Laboratories. Royalties: Oxford University Press and Cambridge University Press (Book Royalty). Uptodate — editorial/honoraria. CME companies honoraria/publishing honoraria/royalites: Chameleon Communications, Medscape, WebMD, Academy for Continued Healthcare Learning, Haymarket Medical Education, Miller Medical Communications, Global Scientific Communications, HealthLogix, Academy for Continued Healthcare Learning, Meeting LogiX, Health LogiX, . Dr. VanderPluym has nothing to disclose.