Brain imaging and behavior
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Brain Imaging Behav · Jun 2012
ReviewFunctional MRI of mild traumatic brain injury (mTBI): progress and perspectives from the first decade of studies.
Mild traumatic brain injury (mTBI) represents the great majority of traumatic brain injuries, and is a common medical problem affecting cognitive and vocational functioning as well as quality of life in some individuals. Functional MRI (fMRI) is an important research method for investigating the neuroanatomic substrates of cognitive disorders and their treatment. Surprisingly, however, relatively little research has utilized fMRI to examine alterations in brain functioning after mTBI. ⋯ Finally, we address fMRI evaluations of response to behavioral or pharmacological challenges and interventions targeting cognitive and behavioral sequelae of mTBI. The review concludes with identification and discussion of gaps in current knowledge and future directions for fMRI studies of mTBI. The authors conclude that fMRI in combination with related methods can be expected to play an increasing role in research related to studies of pathophysiological mechanisms of the sequelae of mTBI as well as in diagnosis and treatment monitoring.
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Brain Imaging Behav · Jun 2012
Structural integrity and postconcussion syndrome in mild traumatic brain injury patients.
The presence of a postconcussion syndrome (PCS) induces substantial socio-professional troubles in mild traumatic brain injury (mTBI) patients. Although the exact origin of these disorders is not known, they may be the consequence of diffuse axonal injury (DAI) impacting structural integrity. In the present study, we compared structural integrity at the subacute and late stages after mTBI and in case of PCS, using diffusion-weighted imaging (DWI). ⋯ Moreover, we observed that mTBI patients with PCS had greater and wider structural impairment than patients without PCS. These damages persisted over time for PCS patients, while mTBI patients without PCS partly recovered. In conclusion, our results strengthen the relationship between structural integrity and PCS.
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Brain Imaging Behav · Jun 2012
Introduction to the brain imaging and behavior special issue on neuroimaging findings in mild traumatic brain injury.
Contemporary neuroimaging methods and research findings in mild traumatic brain injury (mTBI) are reviewed in this special issue. Topics covered include structural and functional neuroimaging techniques with a particular emphasis on the most contemporary research involving magnetic resonance imaging (MRI). Future research directions as well as applied applications of using neuroimaging techniques to define biomarkers of brain injury are covered.
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Brain Imaging Behav · Jun 2011
Comparative StudyReevaluating brain networks activated during mental imagery of finger movements using probabilistic Tensorial Independent Component Analysis (TICA).
The cerebral and cerebellar networks involved in execution and mental imagery of the same sequential finger movements performed with the non-dominant hand were assessed by 3T functional magnetic resonance imaging using multivariate model-free analysis. Eight right-handed healthy volunteers successively performed execution and mental imagery tasks (sequential thumb to fingers opposition). The same data were analyzed by using (1) the linear General Model (p < 0.05 corrected), and (2) probabilistic tensorial independent component analysis (TICA). ⋯ TICA also showed concomitant activation of (1) a cerebello-thalamo-cortical network during motor execution, and (2) a control executive network during imagination. TICA therefore allows precise identification of the brain networks collaborating in the same performance. TICA constitutes a valuable tool to assess and improve detection of brain networks engaged in mental imagery in comparison with GLM.
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Brain Imaging Behav · Jun 2010
Default network response to a working memory challenge after withdrawal of continuous positive airway pressure treatment for obstructive sleep apnea.
Lower working memory performance and altered brain activity have been reported in studies of obstructive sleep apnea (OSA) patients. However, little is known about the effect of treatment of OSA on brain function, particularly effects on default network processing. We previously reported increased brain response to a working memory challenge in active regions and decreased response in relatively deactivated a priori regions of interest (ROIs) following withdrawal of continuous positive airway pressure (CPAP) treatment. ⋯ Significant further deactivation relative to the treatment adherent baseline was observed in the majority of these ROIs during the withdrawal condition. The magnitude of deactivation during withdrawal was significantly associated with better working memory performance in the posterior cingulate and right postcentral gyrus, and greater sleepiness in the left and right medial frontal gyrus. Results suggest that default network functions are further suspended as a result of a shifting of attention towards a more difficult active task in the context of lowered attentional capacity related to sleepiness.