Imaging brain mechanisms in chronic visceral pain

Abstract

Chronic visceral pain syndromes are important clinical problems with largely unmet medical needs. Based on the common overlap with other chronic disorders of visceral or somatic pain, mood and affect, and their responsiveness to centrally targeted treatments, an important role of central nervous system in their pathophysiology is likely. A growing number of brain imaging studies in irritable bowel syndrome, functional dyspepsia and bladder pain syndrome/interstitial cystitis has identified abnormalities in evoked brain responses, resting state activity and connectivity, as well as in grey and white matter properties. Structural and functional alterations in brain regions of the salience, emotional arousal, and sensorimotor networks, as well as in prefrontal regions, are the most consistently reported findings. Some of these changes show moderate correlations with behavioral and clinical measures. Most recently, data driven machine-learning approaches to larger data sets have been able to classify visceral pain syndromes from healthy control subjects. Future studies need to identify the mechanisms underlying the altered brain signatures of chronic visceral pain and identify targets for therapeutic interventions.

Topological Alterations of the Intrinsic Brain Network in Patients with Functional Dyspepsia

“…To our knowledge, the symptom severity (subjective experience) is determined by multiple factors involving emotion, cognition, past experience, further prediction, and so on. 3 Therefore, we suspected that the ACG may be closely linked to FD-related experiences through its relationship with the multifactorial integration in the brain network. This is to some extent in concordance with our previous finding that the ACG was related to the symptom severity of FD patients.…”

“…Currently, the central nervous system is widely accepted to be important in symptom generation of FD. There is an increasing consensus that multiple factors encompassing emotion, cognition, reward, past memories of discomfort experiences, and salience appraisal are integrated with sensory information in the human brain, and the integrated information ultimately determines the subjective experience of patients with chronic pain, [3][4][5] such as FD and irritable bowel syndrome (IBS). However, it remains unclear how the information is integrated in the brain architecture in FD patients.…”

Functional dyspepsia

“…gastrointestinal disorders 145,148 . In patients with functional dyspepsia, altered neural activation in response to gastric distension or sham distension has been documented 149 , which supports altered processing not only during noxious visceral stimulation but also during anticipation.…”

Brain imaging tests for chronic pain: medical, legal and ethical issues and recommendations

“…1), including areas that are associated with coding information about noxious stimuli and reactions to noxious stimuli, the modulation of such information, the production of affective interpretations, attentional and emotional responses, and decisionmaking 19,27,[32][33][34] . These brain areas include somatosensory, insular, cingulate and prefrontal cortices, and subcortical areas, including the amygdala, hippo campus, hypothalamus, ventral striatum, thalamus, periaqueductal grey, rostroventral medulla, numerous other brainstem areas and the cerebellum 19,27,31,32,[35][36][37] . Neuronal oscillations in these areas differ from each other in frequency 38 , and dynamic and flexibly accessible brain networks are formed between these regions that subserve multiple functions.…”