Increased cerebral activation after behavioral treatment for memory deficits in MS

Abstract

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.

Cognitive rehabilitation in multiple sclerosis: A systematic review

“…After rehabilitation, patients showed increased brain fMRI response only in the cerebellum when compared with healthy subjects. Few years later Chiaravallotti et al 26 explored changes in cerebral activation during the execution of a word learning and a word recognition task after a behavioural memory intervention, the modified Story Memory Technique. Greater activation was evident in the treatment group during performance of a memory task within a widespread cortical network involving frontal and temporal regions; no significant changes were found in the cerebellum.…”

Use of Magnetic Resonance Imaging as Well as Clinical Disease Activity in the Clinical Classification of Multiple Sclerosis and Assessment of Its Course

“…[25][26][27][28] This may be explained at least in part by several factors: lesions in "eloquent" brain areas such as the optic nerves are more likely to be clinically expressed than lesions in less eloquent pathways; the degree of matrix and axonal destruction may vary; and the potential exists for rapid symptom recovery. [29][30][31][32][33][34][35][36][37][38] Even patients with progressive forms of MS, particularly those with Gd+ lesions indicating a subclinical relapse, may respond clinically to disease-modifying therapies (DMTs). For example, in a post hoc analysis of the Olympus trial of rituximab in PPMS, patients with Gd+ lesions had a significantly better response to treatment than those without Gd+ lesions.…”

Functional plasticity in MS

“…In agreement with the fact that the human brain can undergo plastic changes, several studies have shown that patients with MS experience a modulation of their activation patterns following structural tissue damage. [3][4][5][6] Such a functional reorganization mainly consists of increased activation of regions that are devoted to a given task and recruitment of additional areas that may or may not be part of the same network. These functional changes are thought to have a compensatory role, thus possibly explaining the weak relationship between MRI-detected tissue damage and patient clinical manifestations.…”

“…4 Interestingly, studies in cognitive rehabilitation in MS are increasing and have shown functional changes of "critical" brain networks following rehabilitative intervention. 5,6 Resting-state fMRI may also be used to study MS and other neurologic conditions. At rest, specific neural networks are active, such as the so-called default mode and visual processing networks.…”