| Objective:To explore the spatiotemporal characteristics of language lateralization in chronic Broca’s aphasics without speech therapy during picture naming.Method:Five patients with chronic Broca’s aphasia and five matched right-handed healthy controls were recruited. The spatiotemporal changes of language cortical activation during picture naming were detected by magnetoencephalography (MEG). Language dominance were stratified by the laterality index (LI), which was defined to be left when the LI was more than0.1, right when the LI was less than0.1, and bilateral when the LI was between0.1and0.1.Results:During the275-400ms,400-600ms and600-800ms time windows, the aphasia group have significantly right lateralization of combined ROIs compared to the control group (P＜0.01). At each ROIs level, Broca’s area, Wernicke’s area, supramarginal gyrus, and premotor area have significantly right lateralization during the specific time windows in aphasia group compared to the control group (P<0.05).Conclusion:Chronic Broca’s aphasics have significantly right lateralization during language processing of picture naming. This right lateralization is associated with specific time windows and ROIs. Objective:To explore the mechanism of language lateralization reorganization in chronic Broca’s aphasics with Word Association Navigation Training (WANT), by detecting regions of interest (ROIs) activity and their language laterality during language processing before and after training.Method:Five patients with chronic Broca’s aphasia were recruited for a ten-day intensively Word Association Navigation Training. The behavioral assessments were conducted by Western Aphasia Battery (WAB), Standard Language Test of Aphasia (SLTA), Mini-Communicative Activity Log (Mini-CAL) and picture naming tasks before and after WANT. The neural activity during language processing using a delayed picture naming task before and after WANT were detected by MEG. Language laterality of region of interests (ROIs) activity was compared before and after WANT. Results:The behavioral performances of patients with chronic Broca’s aphasia were improved after WANT. The correct number of picture naming,"repetition","naming" and "AQ" of WAB,"speaking" and "calculating" of SLTA were extremely significantly improved after training (P<0.01);"spontaneous speech" of WAB,"listening" of SLTA were significantly improved after training (P<0.05). During275-400ms time window, neural activity of language related brain regions showed left lateralization after WANT, the difference was significant (P＜0.05). Before training, during150-275ms and275-400ms, the activation of right Broca homologous area was significantly higher than Broca’s area (P＜0.05), during275-400ms,400-600ms time windows, the activation of Wernicke homologous area, right supramarginal gyrus, and right premotor area were significantly higher than Wernicke’s area, left supramarginal gyrus, and left premotor area respectively (P＜0.05). After training, these differences between right brain areas and left brain areas were not observed (P>0.05).Conclusion:Word Association Navigation Training induces left lateralization reorganization of neural activity during language processing in patients with chronic Broca’s aphasia. This reorganization effectively improves speech function.
|
PDF Full Text Request