Magnetic Resonance Imaging (MRI)

Evaluation of pain-induced changes in functional connectivity was performed in pediatric complex regional pain syndrome (CRPS) patients. High field functional magnetic resonance imaging was done in the symptomatic painful state and at follow up in the asymptomatic pain free/recovered state. Two types of connectivity alterations were defined: (1) Transient increases in functional connectivity that identified regions with increased cold-induced functional connectivity in the affected limb vs.

Pharmacological magnetic resonance imaging (phMRI) is one method by which a drug's pharmacodynamic effects in the brain can be assessed. Although phMRI has been frequently used in preclinical and clinical settings, the extent to which a phMRI signature for a compound translates between rodents and humans has not been systematically examined. In the current investigation, we aimed to build on recent clinical work in which the functional response to 0.1 and 0.2 mg/70 kg i.v. buprenorphine (partial µ-opioid receptor agonist) was measured in healthy humans.

Migraine is twice as common in females as in males, but the mechanisms behind this difference are still poorly understood. We used high-field magnetic resonance imaging in male and female age-matched interictal (migraine free) migraineurs and matched healthy controls to determine alterations in brain structure. Female migraineurs had thicker posterior insula and precuneus cortices compared with male migraineurs and healthy controls of both sexes.

Peripheral inflammation or nerve damage result in changes in nervous system function, and may be a source of chronic pain. A number of animal studies have indicated that central neural plasticity, including sensitization of neurons within the spinal cord and brain, is part of the response to nervous system insult, and can result in the appearance of altered sensation, including pain. It cannot be assumed, however, that data obtained from animal models unambiguously reflects CNS changes that occur in humans.

Imaging pain pathways in rats offers a tool to investigate CNS systems in acute and chronic rodent models of pain, neural plasticity associated with the latter, and the opportunity to evaluate pharmacological effects of analgesics on these systems. Furthermore, the evaluation of CNS circuits (e.g., sensory, emotional, endogenous analgesic) offers the potential for defining the complexity of circuit-based behaviors that are difficult to evaluate in current preclinical behavioral models of pain.

The cerebellum is reliably activated during both acute and chronic pain conditions, but it is unclear whether the response to aversive painful stimuli can be generalized to other aversive stimuli. We hypothesized that cerebellar activation during pain reflects higher-level encoding of aversive stimuli. We used functional magnetic resonance imaging (fMRI) to compare cerebellar responses in 11 healthy volunteers to noxious heat (46 °C) applied to the hand and to the passive viewing of images selected from the International Affective Picture System.

An understanding of how the brain changes in chronic pain or responds to pharmacological or other therapeutic interventions has been significantly changed as a result of developments in neuroimaging of the CNS. These developments have occurred in 3 domains : (1) Anatomical Imaging which has demonstrated changes in brain volume in chronic pain; (2) Functional Imaging (fMRI) that has demonstrated an altered state in the brain in chronic pain conditions including back pain, neuropathic pain, and complex regional pain syndromes.

AIM: Various animal and human studies have contributed to the idea of cortical structural-functional alterations in migraine. Defining concurrent cortical alterations may provide specific insights into the unfolding adaptive or maladaptive changes taking place in cortex in migraine.

This review summarizes functional magnetic resonance imaging (fMRI) findings that have informed our current understanding of pain, analgesia and related phenomena, and discusses the potential role of fMRI in improved therapeutic approaches to pain. It is divided into 3 main sections: (1) fMRI studies of acute and chronic pain.

The majority of functional MRI studies of pain processing in the brain use the blood oxygenation level-dependent (BOLD) imaging approach. However, the BOLD signal is complex as it depends on simultaneous changes in blood flow, vascular volume and oxygen metabolism. Arterial spin labeling (ASL) perfusion imaging is another imaging approach in which the magnetically labeled arterial water is used as an endogenous tracer that allows for direct measurement of cerebral blood flow.