scholarly journals Pregabalin Rectifies Aberrant Brain Chemistry, Connectivity, and Functional Response in Chronic Pain Patients

2013 ◽  
Vol 119 (6) ◽  
pp. 1453-1464 ◽  
Author(s):  
Richard E. Harris ◽  
Vitaly Napadow ◽  
John P. Huggins ◽  
Lynne Pauer ◽  
Jieun Kim ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Chronic Pain ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Human Brain ◽  
Default Mode Network ◽  
Brain Regions ◽  
Resonance Imaging ◽  
Chronic Pain Patients ◽  
Pain Patients

Abstract Background: Chronic pain remains a significant challenge for modern health care as its pathologic mechanisms are largely unknown and preclinical animal models suffer from limitations in assessing this complex subjective experience. However, human brain neuroimaging techniques enable the assessment of functional and neurochemical alterations in patients experiencing chronic pain and how these factors may dynamically change with pharmacologic treatment. Methods: To identify the clinical action of pregabalin, a proven analgesic, the authors performed three complementary brain neuroimaging procedures: (proton magnetic resonance spectroscopy, functional magnetic resonance imaging, and functional connectivity magnetic resonance imaging) in 17 chronic pain patients diagnosed with fibromyalgia. Results: The authors found that pregabalin but not placebo reduces combined glutamate + glutamine levels within the posterior insula (pregabalin P = 0.016; placebo P = 0.71). Interestingly, reductions in clinical pain were associated with reductions in brain connectivity of this structure to brain regions within the default mode network during pregabalin (r = 0.82; P = 0.001) but not placebo (r = −0.13; P = 0.63). Response of default mode network regions to experimental pain was also reduced with pregabalin (P = 0.018) but not placebo (P = 0.182). Perhaps most importantly, baseline values for all three neuroimaging markers predicted subsequent analgesic response to pregabalin but not placebo. Conclusions: The results of this study suggest that pregabalin works in part by reducing insular glutamatergic activity, leading to a reduction of the increased functional connectivity seen between brain regions in chronic pain states. The study also supports a role for human brain imaging in the development, assessment, and personalized use of central-acting analgesics.

Altered Functional Connectivity within Default Mode Network in Patients with Transient Ischemic Attack: A Resting-State Functional Magnetic Resonance Imaging Study

2019 ◽  
Vol 48 (1-2) ◽  
pp. 61-69 ◽  
Author(s):  
Tingting Zhu ◽  
Lingyu Li ◽  
Yulin Song ◽  
Yu Han ◽  
Chengshu Zhou ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Transient Ischemic Attack ◽  
Default Mode Network ◽  
Resting State ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ischemic Attack

Default mode network (DMN) is an important functional brain network that supports aspects of cognition. Stroke has been reported to be associated with functional connectivity (FC) impairments within DMN. However, whether FC within DMN changes in transient ischemic attack (TIA), an important risk factor for stroke, remains unclear. Forty-eight TIA patients and 41 age- and sex-matched healthy controls (HCs) were recruited in this study. Using resting-state functional magnetic resonance imaging seed-based FC methods, we examined FC alterations within DMN in TIA patients, tested its associations with clinical information, and further explored the ability of FC abnormalities to predict follow-up ischemic attacks. We found significantly decreased FC of left middle temporal gyrus/angular gyrus both with medial prefrontal cortex (mPFC) and posterior cingulate cortex/precuneus (PCC/Pcu) and significantly decreased FC among each pair of mPFC, left PCC, and right Pcu in patients with TIA as compared with HCs. Moreover, the connectivity between mPFC and left PCC could predict future ischemic attacks of the patients. Collectively, these findings may provide insights into further understanding of the underlying pathological mechanism in TIA, and aberrant FC between the hubs within DMN may provide a reference for the imaging diagnosis and early intervention of TIA.

Functional Connectivity Magnetic Resonance Imaging Reveals Rapid and Reversible Changes in the Brain Following Induction of Psoriasiform Dermatitis in Mice

2018 ◽  
Vol 3 (2) ◽  
pp. 59-64
Author(s):  
Xiping Liu ◽  
Yasutomo Imai ◽  
Yan Zhou ◽  
Sebastian Yu ◽  
Rupeng Li ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Skin Inflammation ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Mri Imaging ◽  
Resonance Imaging ◽  
Mouse Ear ◽  
The Brain

Functional connectivity magnetic resonance imaging (fcMRI), a specific form of MRI imaging, quantitatively assesses connectivity between brain regions that share functional properties. Functional connectivity magnetic resonance imaging has already provided unique insights into changes in the brain in patients with conditions such as depression and pain and symptoms that have been reported by patients with psoriasis and are known to impact quality of life. To identify the central neurological impact of psoriasiform inflammation of the skin, we applied fcMRI analysis to mice that had been topically treated with the Toll-like receptor agonist, imiquimod (IMQ) to induce psoriasiform dermatitis. Brain insula regions, due to their suggested role in stress, were chosen as seed regions for fcMRI analysis. Mouse ear and head skin developed psoriasiform epidermal thickening (up to 4-fold, P < .05) and dermal inflammation after 4 days of topical treatment with IMQ. After fcMRI analysis, IMQ-treated mice showed significantly increased insula fc with wide areas throughout the brain, including, but not limited to, the somatosensory cortex, anterior cingulate cortex, and caudate putamen ( P < .005). This reflects a potential central neurological impact of IMQ-induced psoriasis-like skin inflammation. These data indicate that fcMRI may be valuable tool to quantitatively assess the neurological impact of skin inflammation in patients with psoriasis.

scholarly journals Functional Connectivity of Nucleus Accumbens and Medial Prefrontal Cortex With Other Brain Regions During Early-Abstinence Is Associated With Alcohol Dependence and Relapse: A Resting-Functional Magnetic Resonance Imaging Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Xia Yang ◽  
Ya-jing Meng ◽  
Yu-jie Tao ◽  
Ren-hao Deng ◽  
Hui-yao Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Brain Regions ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Anterior Cortex ◽  
The Right

Background: Alcohol dependence (AD) is a chronic recurrent brain disease that causes a heavy disease burden worldwide, partly due to high relapse rates after detoxification. Verified biomarkers are not available for AD and its relapse, although the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) may play important roles in the mechanism of addiction. This study investigated AD- and relapse-associated functional connectivity (FC) of the NAc and mPFC with other brain regions during early abstinence.Methods: Sixty-eight hospitalized early-abstinence AD male patients and 68 age- and education-matched healthy controls (HCs) underwent resting-functional magnetic resonance imaging (r-fMRI). Using the NAc and mPFC as seeds, we calculated changes in FC between the seeds and other brain regions. Over a follow-up period of 6 months, patients were measured with the Alcohol Use Disorder Identification Test (AUDIT) scale to identify relapse outcomes (AUDIT ≥ 8).Results: Thirty-five (52.24%) of the AD patients relapsed during the follow-up period. AD displayed lower FC of the left fusiform, bilateral temporal superior and right postcentral regions with the NAc and lower FC of the right temporal inferior, bilateral temporal superior, and left cingulate anterior regions with the mPFC compared to controls. Among these FC changes, lower FC between the NAc and left fusiform, lower FC between the mPFC and left cingulate anterior cortex, and smoking status were independently associated with AD. Subjects in relapse exhibited lower FC of the right cingulate anterior cortex with NAc and of the left calcarine sulcus with mPFC compared to non-relapsed subjects; both of these reductions in FC independently predicted relapse. Additionally, FC between the mPFC and right frontal superior gyrus, as well as years of education, independently predicted relapse severity.Conclusion: This study found that values of FC between selected seeds (i.e., the NAc and the mPFC) and some other reward- and/or impulse-control-related brain regions were associated with AD and relapse; these FC values could be potential biomarkers of AD or for prediction of relapse. These findings may help to guide further research on the neurobiology of AD and other addictive disorders.

scholarly journals Altered Functional Connectivity within and between Brain Modules in Absence Epilepsy: A Resting-State Functional Magnetic Resonance Imaging Study

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Cui-Ping Xu ◽  
Shou-Wen Zhang ◽  
Tie Fang ◽  
Ma Manxiu ◽  
Qian Chencan ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Resting State ◽  
Brain Regions ◽  
Absence Epilepsy ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Superior Frontal Gyrus

Functional connectivity has been correlated with a patient’s level of consciousness and has been found to be altered in several neuropsychiatric disorders. Absence epilepsy patients, who experience a loss of consciousness, are assumed to suffer from alterations in thalamocortical networks; however, previous studies have not explored the changes at a functional module level. We used resting-state functional magnetic resonance imaging to examine the alteration in functional connectivity that occurs in absence epilepsy patients. By parcellating the brain into 90 brain regions/nodes, we uncovered an altered functional connectivity within and between functional modules. Some brain regions had a greater number of altered connections and therefore behaved as key nodes in the changed network pattern; these regions included the superior frontal gyrus, the amygdala, and the putamen. In particular, the superior frontal gyrus demonstrated both an increased value of connections with other nodes of the frontal default mode network and a decreased value of connections with the limbic system. This divergence is positively correlated with epilepsy duration. These findings provide a new perspective and shed light on how functional connectivity and the balance of within/between module connections may contribute to both the state of consciousness and the development of absence epilepsy.

scholarly journals Integrative Models of Brain Structure and Dynamics: Concepts, Challenges, and Methods

2021 ◽  
Vol 15 ◽  
Author(s):  
Siva Venkadesh ◽  
John Darrell Van Horn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Electrical Activity ◽  
Temporal Resolution ◽  
Network Structure ◽  
Brain Structure ◽  
Brain Regions ◽  
Resonance Imaging ◽  
Structure And Dynamics

The anatomical architecture of the brain constrains the dynamics of interactions between various regions. On a microscopic scale, neural plasticity regulates the connections between individual neurons. This microstructural adaptation facilitates coordinated dynamics of populations of neurons (mesoscopic scale) and brain regions (macroscopic scale). However, the mechanisms acting on multiple timescales that govern the reciprocal relationship between neural network structure and its intrinsic dynamics are not well understood. Studies empirically investigating such relationships on the whole-brain level rely on macroscopic measurements of structural and functional connectivity estimated from various neuroimaging modalities such as Diffusion-weighted Magnetic Resonance Imaging (dMRI), Electroencephalography (EEG), Magnetoencephalography (MEG), and functional Magnetic Resonance Imaging (fMRI). dMRI measures the anisotropy of water diffusion along axonal fibers, from which structural connections are estimated. EEG and MEG signals measure electrical activity and magnetic fields induced by the electrical activity, respectively, from various brain regions with a high temporal resolution (but limited spatial coverage), whereas fMRI measures regional activations indirectly via blood oxygen level-dependent (BOLD) signals with a high spatial resolution (but limited temporal resolution). There are several studies in the neuroimaging literature reporting statistical associations between macroscopic structural and functional connectivity. On the other hand, models of large-scale oscillatory dynamics conditioned on network structure (such as the one estimated from dMRI connectivity) provide a platform to probe into the structure-dynamics relationship at the mesoscopic level. Such investigations promise to uncover the theoretical underpinnings of the interplay between network structure and dynamics and could be complementary to the macroscopic level inquiries. In this article, we review theoretical and empirical studies that attempt to elucidate the coupling between brain structure and dynamics. Special attention is given to various clinically relevant dimensions of brain connectivity such as the topological features and neural synchronization, and their applicability for a given modality, spatial or temporal scale of analysis is discussed. Our review provides a summary of the progress made along this line of research and identifies challenges and promising future directions for multi-modal neuroimaging analyses.

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