CONTACT US: Contact info
|
Citation |
Shah-Basak P, Urbain C, Wong S, Da Costa L, Pang EW, Dunkley B, Taylor M. J. Neurotrauma 2018; 35(2): 267-277. |
|
Affiliation |
The Hospital for Sick Children , Diagnostic Imaging, Toronto, Ontario, Canada ; margot.taylor@sickkids.ca. |
|
Copyright |
(Copyright © 2018, Mary Ann Liebert Publishers) |
|
DOI |
|
PMID |
29020848 |
|
Abstract |
Millions of North Americans suffer a concussion or a mild traumatic brain injury annually and are at risk of cognitive, emotional and physical sequelae. While fMRI studies have provided an initial framework for examining functional deficits induced by concussion, particularly working memory and attention, the temporal dynamics underlying these deficits are not well understood. We used magnetoencephalography (MEG), a modality with millisecond temporal resolution, in conjunction with a 1-back visual working memory (VWM) paradigm using scenes from everyday life to characterize spatiotemporal functional differences at specific VWM stages, in adults who did or did not suffer a recent concussion. MEG source-level differences between groups were determined by whole-brain analyses during encoding and recognition phases. Despite comparable behavioural performance, abnormal hypo- and hyperactivation patterns were found in brain areas involving frontoparietal, ventral occipitotemporal, temporal and subcortical areas in concussed patients. These patterns and their timing varied as a function of VWM stage-wise processing, linked to early attentional control, visuoperceptual scene processing and VWM maintenance and retrieval processes. Parietal hypoactivation, starting at 60ms during encoding, was correlated with symptom severity, possibly linked to impaired top-down attentional processing. Hyperactivation in the scene-selective occipitotemporal areas, the medial temporal complex, specifically the right hippocampus and orbitofrontal areas during encoding and/or recognition, lead us to posit inefficient but compensatory visuoperceptual, relational and retrieval processing. Although injuries sustained after the concussion were considered 'mild', these data suggest that they can have prolonged effects on early attentional and VWM processes. Language: en |
|
Keywords |
ADULT BRAIN INJURY; COGNITIVE FUNCTION; ELECTROPHYSIOLOGY; TRAUMATIC BRAIN INJURY |