Objective: Speeded Saccadic Eye Movement Predicts Symbol Digit Modalities Test Performance in Multiple Sclerosis

Background: Multiple sclerosis is an autoimmune demyelinating disease with estimates of cognitive impairment above 30% in pediatric and 50% in adult patients. The SDMT, a widely-used screening tool that measures speeded information processing, has been used to track cognitive decline in MS. The K-D test is a brief measure of saccadic eye movement speed using a timed number naming test, commonly used for the detection of mild traumatic brain injury. Here, we tested the sensitivity of the K-D test in MS and its association with performance on the SDMT.

Design/Methods: Adult and pediatric patients with clinically-definite MS were consecutively recruited through the NYU Langone MS Comprehensive Care Center. All participants completed the SDMT and K-D at a single visit.

Results: A total of 30 participants completed the assessments ranging in age from 13 to 72 years (mean 38 ± 19 years), were 74% female, and with an EDSS range 0.0 to 6.5. Relative to age normative data, the K-D indicated greater impairment than the SDMT (74% vs. 48%, respectively). Controlling for age, both tests were significantly correlated (r=0.44, p =0.02), demonstrating a close contribution of oculomotor function to SDMT performance.

Conclusions: The K-D test is sensitive to detecting impairment in MS across the lifespan. Performance on the SDMT is closely associated with oculomotor function in MS.

Study Supported by: The Lourie Center for Pediatric Multiple Sclerosis

Summary Points:

  • K-D Test is sensitive to detecting impairment in MS across the lifespan.
  • K-D Test performance is correlated with SDMT performance demonstrating close contribution of oculomotor function.
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