Increased cerebral activation after behavioral treatment for memory deficits in MS

Nancy D. Chiaravalloti, Glenn Wylie, Victoria Leavitt, John DeLuca

Deficits in new learning and memory are common in persons with multiple sclerosis (MS), though few studies have examined the efficacy of memory retraining in MS. Previous research from our laboratory has demonstrated that the modified Story Memory Technique (mSMT) significantly improves new learning and memory in MS. The present double-blind, placebo-controlled, randomized clinical trial was designed to examine changes in cerebral activation following mSMT treatment. Sixteen individuals with clinically definite MS were randomly assigned to treatment (n = 8) or placebo-control (n = 8) groups, matched for age, education, and disease characteristics. Baseline and follow-up fMRI was collected during performance of learning and memory tasks. No baseline activation differences on fMRI were seen between groups. After treatment, greater activation was evident in the treatment group during performance of a memory task within a widespread cortical network involving frontal, parietal, precuneus, and parahippocampal regions. All participants in the treatment group showed increased activation in frontal and temporal regions in particular. In contrast, the control group showed no significant changes in cerebral activation at follow-up. A significant association was found between increased activation in the right middle frontal gyrus and improved memory performance post-treatment. The increased activation seen likely reflects increased use of strategies taught during treatment when learning new information. This study is the first to demonstrate a significant change in cerebral activation resulting from a behavioral memory intervention in an MS sample. Behavioral interventions can show significant changes in the brain, validating clinical utility.