A Behavioral Manipulation Engages Right Frontal Cortex During Aphasia Therapy

• Authors: Michelle L. Benjamin, University of Alabama Birmingham; Stephen Towler, University of Florida; Amanda Garcia, University of Florida; Hyejin Park, University of Florida; Atchar Sudhyadhom, University of California San Francisco; Stacy Harnish, Ohio State University; Keith McGregor, Emory University; Zvinka Zlatar, University of California San Diego; Jaime J. Reilly, University of Florida; John C. Rosenbek, University of Florida; Leslie J. Gonzalez, University of Florida; Bruce Crosson, Emory University
• Journal Title: Neurorehabilitation and Neural Repair
• Volume: Volume 28, Number 6
• Publisher: SAGE Publications (UK and US) | 2014-07-01, Pages 545-553
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1177/1545968313517754
• Subjects: Biology, Neuroscience; Health Sciences, Rehabilitation and Therapy; Health Sciences, Speech Pathology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Rehabilitation; Neurosciences & Neurology; aphasia; magnetic resonance imaging; fMRI; rehabilitation; rehabilitation of speech and language disorders; neuronal plasticity; MELODIC INTONATION THERAPY; NONFLUENT APHASIA; BRAIN-STIMULATION; RECOVERY; LANGUAGE; STROKE; TMS

Abstract

Background. An aphasia treatment was designed to shift laterality from the left to right lateral frontal lobe during word production by initiating word-finding trials with complex left-hand movements. Previous findings indicated successful relateralization. Objective. The current study was designed to ascertain whether the shift was attributable to the lefthand movement. Methods. Using stratified random sampling, 14 subjects were equally divided between Intention (IT) and Control (CT) treatments. CT was identical to IT, except with no left-hand movements. Both treatments trained picture naming (phases 1 and 2) and category-member generation (phase 3), each phase lasting 10 sessions. Functional magnetic resonance imaging of category member generation occurred at pretreatment, posttreatment, and 3-month follow-up. Results. IT shifted lateral frontal activity rightward compared with pretreatment both at posttreatment (t = -2.602, df = 6, P < .05) and 3-month follow-up (t = -2.332, df = 5, P < .05), but CT did not. IT and CT yielded similar changes for all picture-naming and category probes. However, IT patients showed gains for untrained category (t = 3.33, df = 6, P < .01) and picture-naming probes (t = 3.77, df = 5, P < .01), but CT patients did not. Conclusions. The rightward shift in lateral frontal activity for IT was because of the left-hand movements. IT evoked greater generalization than CT.