Abstract TP50: Functional Recovery In Stroke: Performance On Verbal Fluency Task
BACKGROUND: The objective of this study is to investigate the brain activation patterns and relationship with verbal fluency performance in stroke recovery.
METHODS: Patients with ischemic stroke (N=19, mean age =64, 7F) and 17 healthy age-matched controls, participated in the study. Measures on a verbal fluency task were collected outside the scanner. Functional MR images were collected as subjects performed the same task(3T GE scanner). Task included alternating 20 second blocks of rest and word retrieval given a letter. Results from 19 acute patients(< 7 days from stroke onset - V1), of which 9 were also tested in the sub-acute stage(between 7 days and 6 months from stroke onset - V2), are reported here.
RESULTS: Acute patients showed significantly greater activation in several regions, including the right middle and inferior frontal gyrus, and de-activations in regions including left middle temporal and frontal gyri(p<.05, corrected for multiple comparisons). Beta values representing the intensity of BOLD signal were extracted from these significant activation clusters. There were significant differences in beta values in acute(p<.001 corrected) and sub-acute(p<.01 uncorrected) stages compared with healthy controls(Figure). Pearson r correlations computed between the beta values and normed verbal fluency scores did not show significant group difference in correlation between these measures.
CONCLUSIONS: Results suggest increased activation in acute stroke in right hemisphere language regions; healthy controls conversely show less activation in these regions. Additionally, activity in brain areas significantly correlated with behavior. Activation pattern in acute stroke however changes over time with patients in the sub-acute stage showing pattern similar to healthy controls. This is consistent with studies suggesting that activations in the acute stage tend to normalize over time likely due to areas prior to the stroke re-gaining function.
- © 2012 by American Heart Association, Inc.