Computerized Cognitive Training in Multiple Sclerosis: A Systematic Review and Meta-analysis

<i>Background</i>. Cognitive impairments are common in people with multiple sclerosis (MS). Systematic reviews reported promising evidence for various cognitive interventions in this population. Computerized cognitive training (CCT) has strong evidence for safety and efficacy in several populations, but its effects in MS have yet to be specified. <i>Objective</i>. We aimed to synthesize the evidence from randomized controlled trials (RCTs) investigating the effects of CCT on cognitive, psychosocial, and functional outcomes in adults with MS. <i>Method</i>. We searched MEDLINE, EMBASE, PsycINFO, CINAHL, and CENTRAL from inception to March 2019. We calculated standardized mean difference (Hedges' <i>g</i>) of change from baseline in untrained measures of cognition, individual domains, psychosocial functioning, and daily function between CCT and control groups using a random-effects model. <i>Results</i>. A total of 20 RCTs encompassing 982 participants (78% with relapsing-remitting MS) were included. The overall cognitive effect size was moderate (<i>g</i> = 0.30; 95% CI = 0.18-0.43), with no evidence of small-study effect or between-study heterogeneity (prediction interval = 0.17-0.44). Small to moderate effect sizes were found for attention/processing speed, executive functions, and verbal and visuospatial memory. Evidence for working memory, fatigue, and psychosocial and daily functioning were inconclusive. Cognitive effects waned without further training. <i>Conclusions</i>. CCT is efficacious for overall and key cognitive domains in adults with MS, but efficacy on other outcomes and in progressive subtypes remains unclear. Long-term and well-powered trials with diverse cohorts are needed to optimize and maintain the efficacy of CCT, investigate transfer to daily living, and determine who can benefit and whether CCT is a cost-effective strategy to attenuate cognitive decline in MS.