pain neuromatrix

Why does the brain choose pain? Why does an organ that is able to mask pain, even when intense as in fractures or in fighting wounds, decide to let pain pass and begin conscious, such as that of migraine, when there is no noxa patogena and there is no threat to the integrity of the organism, failing in the main function of pain, that of protection? In this brief review, we retrace the journey that led to the identification of the first complex mechanism of regulation of painful input, the spinal gate control system, through the identification of the predominantly thalamocortical supraspinal centers of the neuromatrix, up to the recognition of a pain matrix extremely articulate and sophisticated that integrates elementary sensations with much more complex functions, related to memory, affectivity, emotion, autonomic self-regulation, and homeostasis systems and so on...

Chronic pain is described as a manifestation of real or potential tissue damage. It is identified as a perception influenced by the complex interactions of biological, psychological, and social factors. Different types of pain and their comorbidities dramatically affect patients' quality of life and their families. Due to diverse etiology and pathogenesis, pain management represents a controversial issue in clinical practice. In 1986, the WHO developed a three-step ladder model based on the use of analgesics for pain management according to pain intensity in a linear up or down movement...

Background: Recent findings have implicated supraspinal origins from the pain neuromatrix- central autonomic network (PNM-CAN) in the generation of neuropathic pain (NP) after spinal cord injury (SCI). The aim of this study was to further investigate the theorized PNM-CAN mechanisms in persons with SCI by using a centrally directed pain intervention, provided by breathing-controlled electrical stimulation (BreEStim), to measure resultant autonomic changes measured by time and frequency domain heart rate variability (HRV) analysis...

BACKGROUND: Somatoform disorders (SDs) are a heterogeneous group of psychiatric syndromes characterized by common symptoms, which may mimic a physical condition but they are not explained by a medical condition. Although the biologic nature of this disorder has been widely accepted, the neuroanatomical correlates characterizing SDs are still inconclusive. OBJECTIVE: This study aims to explore gray matter (GM) volume alterations in SD patients compared to healthy controls and their possible association with clinical and cognitive measures...

Background and aims In functional chest pain (FCP) of presumed esophageal origin central nervous system hyperexcitability is generally believed to play an important role in pain pathogenesis. However, this theory has recently been challenged. Using magnetic resonance diffusion tensor imaging, the aim was to characterize any microstructural reorganization of the pain neuromatrix in FCP patients. Methods 13 FCP patients and 20 matched healthy controls were studied in a 3T MR scanner. Inclusion criteria were relevant chest pain, normal coronary angiogram and normal upper gastrointestinal evaluation...

BACKGROUND: Chronic pain conditions are associated with neuroplasticity within the central nervous system. In most patients the maladaptive consequence of neuroplasticity supports prolonged course of chronic pain, despite the absence of a commensurate etiology. From a pain neuromatrix perspective it can involve three different circuits within the central nervous system; the classical sensory pathway, the limbic system pathway, and the associative pathways involving the parietal cortical connections...

The neuromatrix, or "pain matrix", is a network of cortical brain areas which is activated by noxious as well as salient somatosensory stimulation. This has been studied in mice and humans using blood oxygenation level-dependent (BOLD) fMRI. Here we demonstrate that BOLD effects observed in the murine neuromatrix in response to salient somatosensory stimuli are prone to reflect mean arterial blood pressure (MABP) changes, rather than neural activity. We show that a standard electrostimulus typically used in murine somatosensory fMRI can induce substantial elevations in MABP...

Background Cluster headache is a disorder characterized by intermittent, severe unilateral head pain accompanied by cranial autonomic symptoms. Most cases of CH are episodic, manifesting as "in-bout" periods of frequent headache separated by month-to-year-long "out-of-bout" periods of remission. Previous imaging studies have implicated the hypothalamus and pain matrix in the pathogenesis of episodic CH. However, the pathophysiology driving the transition between in- and out-of-bout periods remains unclear...

PURPOSE: Burning mouth syndrome (BMS) is a chronic intraoral pain syndrome featuring idiopathic oral pain and burning discomfort despite clinically normal oral mucosa. The etiology of chronic pain syndrome is unclear, but preliminary neuroimaging research has suggested the alteration of volume, metabolism, blood flow, and diffusion at multiple brain regions. According to the neuromatrix theory of Melzack, pain sense is generated in the brain by the network of multiple pain-related brain regions...

BACKGROUND: Rapid gastric balloon distension to discomfort threshold activates the "pain neuromatrix" and deactivates exteroceptive sensory and "default mode network" regions. However, little is known about brain mechanisms underlying tolerance of meal-induced gastric distension. We aimed to directly compare brain responses to gradual balloon distension and intragastric nutrient infusion and to explore the role of differential gut peptide release in these responses...

Hypnosis is a physiological mind activity characterized by focused attention, absorption, dissociation and plastic imagination. In the early 19th century, several hundred surgical interventions were described with hypnosis as the sole anesthetic, in an epoch when no anesthetic drugs were available; then hypnosis was prejudicially abandoned and forgotten after its introduction. In the past two decades, an increasing number of studies on hypnosis has shown its capacity to modify the activity of the prefrontal cortex, default mode network and pain neuromatrix (including the anterior cingulate cortex, amygdala, thalamus, insula and somatosensory cortex) and increase pain threshold up to the level of surgical anesthesia...

Pain is a complex and multidimensional perception, embodied in our daily experiences through interoceptive appraisal processes. The article reviews the recent literature about interoception along with predictive coding theories and tries to explain a missing link between the sense of the physiological condition of the entire body and the perception of pain in chronic conditions, which are characterized by interoceptive deficits. Understanding chronic pain from an interoceptive point of view allows us to better comprehend the multidimensional nature of this specific organic information, integrating the input of several sources from Gifford's Mature Organism Model to Melzack's neuromatrix...

In recent years there has been an increased interest in pain neuroscience in physical therapy.1,2 Emerging pain neuroscience research has challenged prevailing models used to understand and treat pain, including the Cartesian model of pain and the pain gate.2-4 Focus has shifted to the brain's processing of a pain experience, the pain neuromatrix and more recently, cortical reorganisation of body maps.2,3,5,6 In turn, these emerging theories have catapulted new treatments, such as therapeutic neuroscience education (TNE)7-10 and graded motor imagery (GMI),11,12 to the forefront of treating people suffering from persistent spinal pain...

The gate control theory of pain, introduced by Melzack and Wall in 1965, led the way in pain research during the second half of the 20th century. Eventually, the observation of pain-related phenomena which the theory could not satisfactorily explain propelled Melzack to develop a new concept, the neuromatrix, which considers as participants in the pain transmission and modulation system, certain brain areas not traditionally associated with the pain experience. This concept places equal importance on the sensory, affective and cognitive aspects of pain, helping the advancement of novel diagnostic and therapeutic approaches in different clinical pain conditions...

The primary aim of this study was to assess the effects of cathodal transcranial direct current stimulation (c-tDCS) over cortical regions of the pain neuromatrix, including the primary motor (M1), sensory (S1) and dorsolateral prefrontal (DLPFC) cortices on M1/S1 excitability, sensory (STh), and pain thresholds (PTh) in healthy adults. The secondary aim was to evaluate the placebo effects of c-tDCS on induced cortical and behavioural changes. Before, immediately after and 30 min after c-tDCS the amplitude of N20-P25 components of somatosensory evoked potentials (SEPs) and peak-to-peak amplitudes of motor evoked potentials (MEPs) were measured under four different experimental conditions...

Pain anticipation plays a critical role in pain chronification and results in disability due to pain avoidance. It is important to understand how different sensory modalities (auditory, visual or tactile) may influence pain anticipation as different strategies could be applied to mitigate anticipatory phenomena and chronification. In this study, using a countdown paradigm, we evaluated with magnetoencephalography the neural networks associated with pain anticipation elicited by different sensory modalities in normal volunteers...

Pain is a significant national burden in terms of patient suffering, expenditure and lost productivity. Understanding pain is fundamental to improving evaluation, treatment and innovation in the management of acute and persistent pain syndromes. Pain perception begins in the periphery, and then ascends in several tracts, relaying at different levels. Pain signals arrive in the thalamus and midbrain structures which form the pain neuromatrix, a constantly shifting set of networks and connections that determine conscious perception...

Functional imaging has comprehensively demonstrated that pain involves a number of cortical regions that are often collectively referred to as the pain neuromatrix. This neuromatrix is assumed to be necessary to process the sensory, affective, and cognitive components of pain. Patients who report pain in the apparent absence of injury or disease may experience their symptoms because of dysfunction in one or more components of the pain neuromatrix. Two articles in this edition of Psychosomatic Medicine explore that possibility and provide evidence of altered neural connectivity and activation within components of the pain neuromatrix in patients with low back pain and irritable bowel syndrome...

The experience of pain is affected by remarkable psychological factors. The concept of neuromatrix suggests that pain is an amalgam of affect, cognition, and sensation mediated through diverse brain regions. Moreover, the experience of pain appears to be reduced by environmental stimuli that drive attention away from the noxious events. Accordingly, immersion in a computer-generated, three-dimensional virtual environment has been used as an efficient distraction tool in a number of studies on pain management...

BACKGROUND: The "neuromatrix" theory of Melzack and the studies of Decety on motor imagery have opened the way to an alternative rehabilitation method in chronic pain. AIM: To evaluate the role of motor imagery in chronic shoulder pain rehabilitation. DESIGN: Case report. SETTING: University outpatient rehabilitation. POPULATION: A 49-year-old female with chronic shoulder pain. METHODS: Neurocognitive approach, which involves the use of a new tool called "naval battle" to achieve chronic pain relief as assessed by the Visual Analogic Scale (VAS) and McGill Pain Questionnaire (MPQ)...