Human brain mapping
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Human brain mapping · Apr 2016
FMRI of spinal and supra-spinal correlates of temporal pain summation in fibromyalgia patients.
Fibromyalgia syndrome (FM) is a debilitating chronic pain condition, which afflicts primarily females. Although the etiology of this illness is not completely understood, FM pain is thought to rely on enhanced pain sensitivity maintained by central mechanisms. One of these mechanisms is central pain amplification, which is characterized by altered temporal summation of second pain (TSSP). ⋯ FM subjects, however, required significantly lower stimulus intensities than NC to achieve similar TSSP. fMRI analyses of perceptually equal TSSP identified similar brain activity in NC and FM subjects; however, multiple areas in the brainstem (rostral ventromedial medulla and periaqueductal grey region) and spinal cord (dorsal horn) exhibited greater activity in NC subjects. Finally, increased after-sensations and enhanced dorsal horn activity was demonstrated in FM patients. In conclusion, the spinal and brainstem BOLD responses to TSSP are different between NC and FM patients, which may indicate alterations to descending pain control mechanisms suggesting contributions of these mechanisms to central sensitization and pain of FM patients.
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Human brain mapping · Apr 2016
Brain network dysregulation, emotion, and complaints after mild traumatic brain injury.
To assess the role of brain networks in emotion regulation and post-traumatic complaints in the sub-acute phase after non-complicated mild traumatic brain injury (mTBI). ⋯ Functional interactions of the executive and salience networks were related to emotion regulation and complaints after mTBI, with a key role for the bilateral frontal network. These findings may have implications for future studies on the effect of psychological interventions.
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Human brain mapping · Apr 2016
Intrinsic functional connectivity of periaqueductal gray subregions in humans.
The periaqueductal gray matter (PAG) is a key brain region of the descending pain modulation pathway. It is also involved in cardiovascular functions, anxiety, and fear; however, little is known about PAG subdivisions in humans. The aims of this study were to use resting-state fMRI-based functional connectivity (FC) to parcellate the human PAG and to determine FC of its subregions. ⋯ FC analysis of predefined subregions revealed that the ventolateral(VL)-PAG was supfunctionally connected to brain regions associated with descending pain modulation (anterior cingulate cortex (ACC), upper pons/medulla), whereas the lateral (L) and dorsolateral (DL) subregions were connected with brain regions implicated in executive functions (prefrontal cortex, striatum, hippocampus). We also found sex differences in FC including areas implicated in pain, salience, and analgesia including the ACC and the insula in women, and the MCC, parahippocampal gyrus, and the temporal pole in men. The organization of the human PAG thus provides a framework to understand the circuitry underlying the broad range of responses to pain and its modulation in men and women.