title: Test-retest reliability of fMRI during nonverbal semantic decisions in moderate-severe nonfluent aphasia patients.
abstract: Cortical reorganization in poststroke aphasia is not well understood. Few studies have investigated neural mechanisms underlying language recovery in severe aphasia patients, who are typically viewed as having a poor prognosis for language recovery. Although test-retest reliability is routinely demonstrated during collection of language data in single-subject aphasia research, this is rarely examined in fMRI studies investigating the underlying neural mechanisms in aphasia recovery. The purpose of this study was to acquire fMRI test-retest data examining semantic decisions both within and between two aphasia patients. Functional MRI was utilized to image individuals with chronic, moderate-severe nonfluent aphasia during nonverbal, yes/no button-box semantic judgments of iconic sentences presented in the Computer-assisted Visual Communication (C-ViC) program. We investigated the critical issue of intra-subject reliability by exploring similarities and differences in regions of activation during participants' performance of identical tasks twice on the same day. Each participant demonstrated high intra-subject reliability, with response decrements typical of task familiarity. Differences between participants included greater left hemisphere perilesional activation in the individual with better response to C-ViC training. This study provides fMRI reliability in chronic nonfluent aphasia, and adds to evidence supporting differences in individual cortical reorganization in aphasia recovery.
authors.affiliation: Harold Goodglass Boston University Aphasia Research Center, Department of Neurology, Boston University School of Medicine and the Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA. kurlandj@bu.edu
authors.forename: Jacquie
authors.initials: J
authors.lastname: Kurland
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Naeser
authors.forename: Errol H
authors.initials: EH
authors.lastname: Baker
authors.forename: Karl
authors.initials: K
authors.lastname: Doron
authors.forename: Paula I
authors.initials: PI
authors.lastname: Martin
authors.forename: Heidi E
authors.initials: HE
authors.lastname: Seekins
authors.forename: Andrew
authors.initials: A
authors.lastname: Bogdan
authors.forename: Perry
authors.initials: P
authors.lastname: Renshaw
authors.forename: Deborah
authors.initials: D
authors.lastname: Yurgelun-Todd
mesh_terms: D000368:Aged; D001039:Aphasia, Broca / Q000175:diagnosis* / Q000503:physiopathology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000503:physiopathology; D003143:Communication Devices for People with Disabilities; D003657:Decision Making / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D009416:Nerve Regeneration / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009633:Nonverbal Communication; D010101:Oxygen Consumption / Q000502:physiology*; D012660:Semantics; D012984:Software