The Symbol Digit Modalities Test (SDMT) Has Been the Standard Cognitive Measure Used in Multiple Sclerosis (MS) Clinical Trials: How Does It Correlate with Computerized Cognitive Screening Tools? (P4.169)

Abstract

OBJECTIVE: To explore the correlations between SDMT and NeuroTrax computerized cognitive testing domains. BACKGROUND:Cognitive impairment is common in MS patients. Routine cognitive screening in MS care is not common. The SDMT is frequently used in MS clinical trials to measure cognitive impairment, but is not commonly used in routine care. MS impacts cognition domains differently depending upon plaque size, burden, and location. Easily utilized objective cognitive screens are needed to evaluate the cognitive impact of MS independent of EDSS or MRI. SDMT, a single score cognitive measure, does not provide information about individual cognitive domains or the presence/degree of impairment in multiple domains. Computerized cognitive screening tools have recently become available. These tools provide scores for individual cognitive domains. DESIGN/METHODS: Retrospective review of consecutive MS patients referred for cognitive testing in the course of routine clinical care evaluated with both oral version of SDMT & NeuroTrax testing on the same day. RESULTS: 113 MS patients mean age 48.9±11.3yrs, 85% female. Standardized SDMT score (Centofani, 1975 age norms) significantly (p's<.001) correlated with NeuroTrax Global Cognitive Score (GCS; r=.64) and 7 domain index scores: executive function r=.60, memory r=.58, attention r=.56, visual spatial processing r=.47, information processing speed r=.45, motor skill: r=.40 and verbal function r=.35. CONCLUSIONS: The highest correlations were for domains tapped by SDMT. This provides support for the construct validity of this computerized tool. Computerized cognitive testing may provide an easy independent, objective screening tool that taps into broader sets of cognitive domains, giving individual scores for multiple cognitive domains and a global score. By comparison, evaluation with SDMT screening tool provides one cognitive score related to fewer cognitive domains. Additional studies of cognitive screening tools and correlation to previously utilized clinical trial measures are necessary to facilitate widespread acceptance and incorporation of these tools into routine MS care and patient management. Study Supported by: no outside support

Disclosure: Dr. Zarif has nothing to disclose. Dr. Gudesblatt has received personal compensation for activities with Biogen Idec, Medtronic Inc., Teva Neuroscience, Genzyme Corp., Novartis and Sanofi-Aventis Pharmaceuticals Inc. as a consultant and/or speaker. Dr. Bumstead has received personal compensation for activities with Biogen Idec and Teva Neuroscience. Dr. Buhse has received personal compensation for activities with Biogen Idec, Teva Neuroscience, Bayer Pharmaceuticals Corporation, and Questcor. Dr. Buhse has received research support from Bayer Pharmaceuticals Corporation. Dr. Fafard has nothing to disclose. Dr. Sullivan has received personal compensation for activities with Genzyme Corp. as a consultant. Dr. Wilken has received personal compensation for activities with Biogen Idec and Sention, Inc. Dr. Wilken received research support from Biogen Idec and Cephalon, Inc. Dr. Doniger has received personal compensation for activities with NeuroTrax Corp. as an employee. Dr. Chahda has nothing to disclose.