Functional neuroanatomy of sustained attention and exogenous alerting following naturalistic recovery from moderate-to-severe traumatic brain injury.
Published: 2005
Language: eng
Number of pages: 100
Description: Sustained attention (SA) refers to the endogenous ("top-down") control of attentional resources to implement goal-directed behaviour over time. SA relies on a right-lateralized frontal-thalamic-parietal brain network, with dorsolateral prefrontal cortex (DLPFC) as the primary substrate for supervisory control. Traumatic brain injury (TBI) causes frontal damage and SA deficits. Neuroplastic mechanisms and/or the existence of alternate (degenerate) systems offer possible routes for recovery of endogenous control, with the additional possibility of attentional re-engagment though exogenous ("bottom-up") stimulation (e.g. via alerting tones). This fMRI study revealed recovered sustained attention in five patients who sustained significant TBI at least one year ago. Rather than right DLPFC, patients activated right ventrolateral and medial PFC including anterior cingulate. Thalamic and parietal SA network components were preserved. In contrast to control subjects, alerting cues did not reduce "top-down" activations in TBI patients. These findings suggest that sustained attention in patients recovered from TBI is mediated by alternate prefrontal regions.
Notes: Thesis (M.A.)--University of Toronto, 2005.

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Source: Masters Abstracts International, Volume: 44-01, page: 0268.

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