Resting state connectivity correlates with drug and placebo response in fibromyalgia patients

AbstractFibromyalgia is a chronic pain syndrome characterized by widespread pain, fatigue, and memory and mood disturbances. Despite advances in our understanding of the underlying pathophysiology, treatment is often challenging. New research indicates that changes in functional connectivity between brain regions, as can be measured by magnetic resonance imaging (fcMRI) of the resting state, may underlie the pathogenesis of this and other chronic pain states. As such, this parameter may be able to be used to monitor changes in brain function associated with pharmacological treatment, and might also be able to predict treatment response.We performed a resting state fcMRI trial using a randomized, placebo-controlled, cross-over design to investigate mechanisms of action of milnacipran (MLN), a selective serotonin and norepinephrine reuptake inhibitor (SNRI), in fibromyalgia patients. Our aim was to identify functional connectivity patterns at baseline that would differentially predict treatment response to MLN as compared to placebo. Since preclinical studies of MLN suggest that this medication works by augmenting antinociceptive processes, we specifically investigated brain regions known to be involved in pain inhibition.15 fibromyalgia patients completed the study, consisting of 6 weeks of drug and placebo intake (order counterbalanced) with an interspersed 2 week wash out period. As a main finding we report that reductions in clinical pain scores during MLN were associated with decreased functional connectivity between pro-nociceptive regions and antinociceptive pain regions at baseline, specifically between the rostral part of the anterior cingulate cortex (ACC) and the insular cortex (IC), as well as between the periaqueductal gray (PAG) and the IC: patients with lower preexisting functional connectivity had the greatest reduction in clinical pain. This pattern was not observed for the placebo period. However a more robust placebo response was associated with lower baseline functional connectivity between the ACC and the dorsolateral prefrontal cortex.This study indicates that ACC–IC connectivity might play a role in the mechanism of action of MLN, and perhaps more importantly fcMRI might be a useful tool to predict pharmacological treatment response

Altered fMRI restingâ state connectivity in individuals with fibromyalgia on acute pain stimulation

BackgroundFibromyalgia is a chronic widespread pain condition, with patients commonly reporting other symptoms such as sleep difficulties, memory complaints and fatigue. The use of magnetic resonance imaging (MRI) in fibromyalgia has allowed for the detection of neural abnormalities, with alterations in brain activation elicited by experimental pain and alterations in resting state connectivity related to clinical pain.MethodsIn this study, we sought to monitor state changes in resting brain connectivity following experimental pressure pain in fibromyalgia patients and healthy controls. Twelve fibromyalgia patients and 15 healthy controls were studied by applying discrete pressure stimuli to the thumbnail bed during MRI. Restingâ state functional MRI scanning was performed before and immediately following experimental pressure pain. We investigated changes in functional connectivity to the thalamus and the insular cortex.ResultsAcute pressure pain increased insula connectivity to the anterior cingulate and the hippocampus. Additionally, we observed increased thalamic connectivity to the precuneus/posterior cingulate cortex, a known part of the default mode network, in patients but not in controls. This connectivity was correlated with changes in clinical pain.ConclusionsThese data reporting changes in restingâ state brain activity following a noxious stimulus suggest that the acute painful stimuli may contribute to the alteration of the neural signature of chronic pain.What does this study/add?In this study acute pain application shows an echo in functional connectivity and clinical pain changes in chronic pain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122449/1/ejp832_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122449/2/ejp832.pd

The impact of pain on systemic rheumatic diseases

Abstract Pain is associated with the different types of rheumatic syndromes because it is often the most troubling symptom of patients affected by any of these diseases. Some risk factors clearly play a major role in the clinical expression of pain and related syndromes, including genetics, age, gender, co-morbidities, traumas and psychological patterns, but there are no specific clinical, laboratory or neuroimaging markers that can indicate why and when a patient's localised pain will become chronic and widespread. Any type of pain must be treated not only appropriately, but also rapidly because the likelihood of developing some form of chronic pain is related to the duration of the peripheral pain stimulus. Chronic pain inevitably has a major impact on patients' quality of life because the loss of function undermines their ability to do everyday activities. Pain can be most effectively treated by carefully selecting various pharmacological and non-pharmacological interventions based on the characteristics of the pain itself, disease factors, psychological coping abilities, and lifestyle

A tale of two cities - the effect of low intensity conflict on prevalence and characteristics of musculoskeletal pain and somatic symptoms associated with chronic stress

Although both acute and chronic stress leads to pain, the precise characteristics of this association have not been well defined. Sderot is an Israeli town exposed to repeated missile attacks. Ofakim, a town of similar demographic and socioeconomic characteristics, had not been targeted, as of the period of our study. We examined the occurrence and characteristics of pain and related somatic symptoms in Sderot and Ofakim. Methods. One thousand and twenty-four individuals in Sderot and 1006 in Ofakim were interviewed regarding pain, somatic symptoms, mood, trauma-exposure, and general health status. Results. Significantly higher levels of trauma-related symptoms and somatic symptoms were noted in Sderot compared with Ofakim (p<0.001). Chronic widespread pain (CWP) was more common in Sderot (11.1%) than Ofakim (8.3%; OR 1.37, p=0.038). Women were more likely (13.9% vs. 9.3%; OR 1.45,p=0.06) than men (8.9% vs. 7.3%, OR 1.24, p=037) to experience CWP in Sderot vs. Ofakim. Amongst males, chronic regional pain (CRP) was more common in Sderot (19.2%) than in Ofakim (14.2%; p=0.036). Pain, severity in Sderot was significantly higher than in Ofakim (p<0.001). Conclusions. Similar to previous studies that have suggested that chronic stress is associated with chronic pain, this study demonstrates significantly increased rates of somatic complaints, including pain, fatigue and IBS-like symptoms, among individuals in Sderot compared with Ofakim, as well as significantly higher rates of trauma-related symptoms. Thus, a fibromyalgia-like symptoms cluster was more likely to be found in Sderot compared with Ofakim. Widespread pain was reported as being significantly more frequent by inhabitants of Sderot compared with Ofakim. These results have relevance to both the general population and for populations enduring chronic stress