title: Bedside functional brain imaging in critically-ill children using high-density EEG source modeling and multi-modal sensory stimulation.
abstract: Acute brain injury is a common cause of death and critical illness in children and young adults. Fundamental management focuses on early characterization of the extent of injury and optimizing recovery by preventing secondary damage during the days following the primary injury. Currently, bedside technology for measuring neurological function is mainly limited to using electroencephalography (EEG) for detection of seizures and encephalopathic features, and evoked potentials. We present a proof of concept study in patients with acute brain injury in the intensive care setting, featuring a bedside functional imaging set-up designed to map cortical brain activation patterns by combining high density EEG recordings, multi-modal sensory stimulation (auditory, visual, and somatosensory), and EEG source modeling. Use of source-modeling allows for examination of spatiotemporal activation patterns at the cortical region level as opposed to the traditional scalp potential maps. The application of this system in both healthy and brain-injured participants is demonstrated with modality-specific source-reconstructed cortical activation patterns. By combining stimulation obtained with different modalities, most of the cortical surface can be monitored for changes in functional activation without having to physically transport the subject to an imaging suite. The results in patients in an intensive care setting with anatomically well-defined brain lesions suggest a topographic association between their injuries and activation patterns. Moreover, we report the reproducible application of a protocol examining a higher-level cortical processing with an auditory oddball paradigm involving presentation of the patient's own name. This study reports the first successful application of a bedside functional brain mapping tool in the intensive care setting. This application has the potential to provide clinicians with an additional dimension of information to manage critically-ill children and adults, and potentially patients not suited for magnetic resonance imaging technologies.
authors.affiliation: Department of Critical Care Medicine, Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Danny
authors.initials: D
authors.lastname: Eytan
authors.affiliation: Division of Neurology, Department of Paediatrics, Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Pang
authors.affiliation: Department of Biomedical Physiology and Kinesiology, Behavioural and Cognitive Neuroscience Institute, Simon Fraser University, Burnaby, Canada.
authors.forename: Sam M
authors.initials: SM
authors.lastname: Doesburg
authors.affiliation: Division of Neurology, Department of Paediatrics, Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Vera
authors.initials: V
authors.lastname: Nenadovic
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, Department of Critical Care Medicine, Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Bojan
authors.initials: B
authors.lastname: Gavrilovic
authors.affiliation: Department of Critical Care, David and Stacey Cynamon Chair in Critical Care Medicine, The Hospital for Sick Children, Department of Anaesthesia, University of Toronto, Toronto, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Laussen
authors.affiliation: Department of Critical Care, Neuroscience and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Guerguerian
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001930:Brain Injuries / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D010775:Photic Stimulation
keywords: Bedside cerebral function; Brain injury; Children; Electroencephalography (EEG); Evoked potentials; Neuroimaging; Pediatrics