An fMRI-Based Visual Cognition Paradigm for Detection of Command-Following and Communication (P7.183)

OBJECTIVE: Develop and test a novel fMRI visual cognition paradigm for detection of covert command-following and communication in healthy subjects for eventual neurodiagnostic use in patients with disorders of consciousness. BACKGROUND: Severe, acquired brain injury may result in a disorder of consciousness (DOC, i.e. vegetative, minimally conscious, or post-traumatic confusional state [VS, MCS, PTCS]). Impairments in language and/or motor function may mask command-following and communication behaviors in persons with DOC and lead to a high rate of misdiagnosis. Unbiased measures of consciousness that are independent of motor and language output impairment are essential for diagnostic, prognostic, and treatment purposes. Past studies have used functional Magnetic Resonance Imaging (fMRI) and motor/spatial imagery tasks to detect covert command-following and communication in persons with DoC, but these imagery paradigms require high working memory demands and patients with significant sensory and motor deficits have reduced capacity to activate expected regions during imagery tasks. DESIGN/METHODS: Fifteen healthy control subjects were recruited for an event-related fMRI study that interrogated the left occipito-temporal junction (i.e. visual word form area) and the right fusiform gyrus (i.e. the parahippocampal place area) in response to commands to look at the word “YES” or a cityscape scene, respectively. RESULTS: Group and individual subject results indicated that across all regions of interest, and conditions, nearly all peaks (91 of 96) reached statistical significance, suggesting detection of command following and communication in these subjects. CONCLUSIONS: fMRI paradigms that rely on visual discrimination can be used to assess covert command following and communication in healthy subjects and these paradigms may have clinical utility in detecting these behaviors in patients with disorders of consciousness who have severe speech and motor impairments. Study Supported by: Department of Education (NIDRR TBI Model Systems Grant H133A120085) and The James S. McDonnell Foundation Disclosure: Dr. Guller has nothing to disclose. Dr. Pan has nothing to disclose. Dr. Iyer has nothing to disclose. Dr. Leung has nothing to disclose. Dr. Cohn has nothing to disclose. Dr. Fuchs has nothing to disclose. Dr. Haley has nothing to disclose. Dr. O9Neil-Pirozzi has nothing to disclose. Dr. Giacino has nothing to disclose. Dr. Stern has nothing to disclose.