Abstracts

Rationale: No effective interventions exist to improve memory impairment present in over half of PWE. CR has been shown to be effective in patients with chronic neurologic conditions. Some neuroimaging studies have applied fMRI to investigating the effects of CR on neural plasticity in MS, PD, and TBI to demonstrate significant network changes. However, to date, there are no published neuroimaging data on CR’s effects on neural plasticity in PWE. Our goal was to determine if CR induces cortical plasticity in verbal memory tested with fMRI verbal paired associates learning task. Based on previous neuroimaging studies in PWE and in CR in other populations, we hypothesized that there would be increased activations in the left lateral frontal, temporal and anterior cingulate regions post-CR compared to pre-CR. Methods: Out of 9 patients who participated in CR, 5 (3 female) also underwent pre-/post-CR fMRI. FMRI: verbal paired-associate learning task presented 60 related word pairs across read and generate conditions. Read: both words were presented and subjects were instructed to read the second word aloud. Generate: the first word and the first letter of the second word followed by asterisks were presented, and subjects said the second word aloud. A post-fMRI recognition test was performed.  Data were preprocessed in a standard pipeline in AFNI. Group spatial independent component analysis was carried out using Group ICA fMRI Toolbox yielding 41 components per group. Noise-related correlations were discarded, and components correlated with the task time-series meeting a threshold of at r = 0.15 were retained. Paired sample t-tests were performed to compare spatial activations for pre- and post-CR, with voxelwise uncorrected p-value set at ≤ 0.01 and minimum voxel threshold set at 20. Results: Generate: post-CR scans revealed increased spatial activation in the left inferior frontal gyrus (IFG) and decreased activation in the left superior temporal gyrus. There was also increased activation in the anterior cingulate gyrus and decreased activation in the left cerebellar tonsil. Read: post-CR scans revealed changes in the default mode network via decreased activation in the right cingulate, right middle temporal gyrus, right supramarginal gyrus, and increased activation in the left cuneus. There was also increased activation in the left IFG in the read condition. For behavioral data, read condition percent correct improved from 69.4% to 82.8% from pre- to post- (p = 0.03) and generate percent correct improved from 77.8% to 78.3% (p > 0.05). Conclusions: CR program demonstrated improvements in neural circuits that support verbal memory and language processing and articulation centers. Additionally we demonstrated increased cingulate gyrus response to the CR program, which has been seen in other functional imaging studies of CR in other conditions. Funding: Department of Neurology, University of Alabama at Birmingham