Longitudinal Evaluation of Cognitive Functioning in Pediatric Multiple Sclerosis (MS): Report from the U.S. Pediatric Multiple Sclerosis Network (S33.004)

OBJECTIVE: This study examined longitudinal changes in cognitive functioning among the pediatric multiple sclerosis (MS) population in the largest cohort to date representing the U.S. Network of Pediatric MS Centers. BACKGROUND: Pediatric MS is a rare variant of the adult-onset neurologic disease diagnosed under the age of 18 years, with an estimated frequency of 0.5 to 1.0 per 100,000. Studies have found that approximately one-third of children and adolescents with MS have some degree of cognitive impairment. Less is known concerning change in cognitive functioning over time, but initial studies have suggested a significant risk for decline over relatively short time periods. DESIGN/METHODS: Sixty-seven (67) individuals with pediatric MS (n=62) or clinically isolated syndrome (CIS, n=5), ranging in age from 8 to 17 years of age (mean age ± standard deviation = 14.37 ± 2.02), completed initial and follow-up neuropsychological testing after an average of 1.64 ± 0.63 years. The nine tests administered measure general intellect, attention and working memory, verbal memory, visuomotor integration, language, and executive functioning. RESULTS: Rate of cognitive impairment (defined as having one-third or more test scores in the impaired range) was 37% at baseline and 33% at follow-up, generally consistent with previous reports. Tests most commonly impaired were those for measures of visuomotor integration, speeded processing, and attention. In contrast to prior observations, most children and adolescents tested did not decline over two years, nor was there any clear pattern or signal for impairment on specific measures. CONCLUSIONS: Findings suggest that over short time frames, stable or even improved performances on measures of cognitive ability can occur in pediatric MS. Rather than leading to decline, pediatric MS may instead adversely affect cognitive functioning by interfering with expected age-appropriate gains. Study Supported by: The Lourie Foundation, Inc., National Multiple Sclerosis Society (10020073405), NIH R01N5071463, and the Slomo and Cindy Silvian Foundation. Disclosure: Dr. Krupp has received personal compensation for activities with Teva Neurosciences, Biogen Idec, EMD Serono, Betaseron/Bayer Healthcare Pharmaceuticals, Guidepoint Consultants, and Novartis. Dr. Krupp has received royalty payments from Genzyme Corporation, Bristol-Myers Squibb Company, Biogen Idec, and Johnson & Johnson. Dr. Krupp has received research support from EMD Serono and Biogen Idec. Dr. Charvet has received personal compensation for activities with Biogen Idec as a consultant. Dr. Charvet holds stock and/or stock options in Johnson & Johnson. Dr. O9Donnell has nothing to disclose. Dr. Cleary has nothing to disclose. Dr. Serafin has nothing to disclose. Dr. Parrish has nothing to disclose. Dr. Julian has received personal compensation for activities with Genentech Inc. as an employee. Dr. Baruch has nothing to disclose. Dr. Belman has nothing to disclose. Dr. Benedict has received personal compensation for activities with Actelion, Biogen Idec, Bayer, and Novartis. Dr. Benedict has received royalty payments from Psychological Assessment Resources. Dr. Benedict has received research support from Acorda, Biogen Idec, and Shire. Dr. Chitnis has received personal compensation for activities with Biogen Idec, Novartis, Sanofi-Aventis Pharmaceuticals, Inc., EMD Serono, and Teva Neuroscience as a consultant. Dr. Chitnis has received research support from Merck & Co., Inc. Dr. Ness has nothing to disclose. Dr. Rodriguez has nothing to disclose. Dr. Waubant has received personal compensation for activities with Roche Diagnostics Corporation, Biogen Idec, Sanofi-Aventis Pharmaceuticals Inc., Genzyme Corporation, and Novartis. Dr. Weinstock-Guttman has received personal compensation for activities with Biogen Idec, Teva Neuroscience, EMD Serono, Pfizer, Novartis, Genzyme, Sanofi-Aventis Pharmaceuticals, Inc., Mylan, and Acorda Therapeutics. Dr. Weinstock-Guttman has received research support from Biogen Idec, Teva Neuroscience, EMD Serono, Pfizer Inc, Novartis, Acorda, ITN, Questcor, Shire, Genzyme, Sanofi-Aventis Pharmaceuticals, Inc., National Multiple Sclerosis Society, the National Institutes of Health and Aspreva-Roche.