News | Neuro Imaging | February 05, 2016

Functional MRI May Help Identify More Effective Painkillers for Chronic Pain Sufferers

Imaging brain’s pain centers provides more accurate assessment of drug efficacy than traditional patient self-reporting

Functional MRI May Help Identify More Effective Painkillers for Chronic Pain Sufferers

February 5, 2016 — New research may allow more effective and safer pain medications to reach patients who suffer from chronic pain sooner. According to a recent study published in Anesthesiology, the official medical journal of the American Society of Anesthesiologists (ASA), using functional magnetic resonance imaging (fMRI) to measure the brain’s neural response to pain may be a viable tool for evaluating the effectiveness of new pain medications during the early stages of human drug development. This could provide the needed objective evidence to prevent the premature discarding of potentially beneficial therapies.

“Many potential pain-relieving drugs identified in preclinical research fail to reach the market because of a lack of early objective evidence that shows whether a drug is effectively reaching target pain receptors in the body and regulating chronic pain mechanisms,” said Vishvarani Wanigasekera, M.D., study lead author and clinical post-doctoral research fellow, Nuffield Division of Anaesthetics, University of Oxford, England. “We have used noninvasive fMRI to successfully obtain such evidence that we hope can help to prevent the premature discarding of potentially effective pain relievers, as well as avoid exposing patients to ineffective ones.”

Currently, patient-reported pain relief is the primary outcome measure used in human drug development studies to assess whether a pain-relieving medication is effective. However, due to their subjective and context-dependent nature, self-reported pain perception and relief is subject to many influences, in addition to the actual pain-relieving effectiveness of the drug. Early drug development studies typically involve a small sample size. When subjective pain reports are used as the sole outcome measure in these studies, researchers can easily miss effective compounds that might work well in the population at large.

In the double-blind, randomized study, researchers induced a phenomenon called central sensitization and some symptom-like features of neuropathic pain, a complex chronic pain condition, on three separate occasions in 24 healthy volunteers. These results were achieved by applying capsaicin cream, a topical irritant often used to produce similar characteristics of neuropathic pain in an experimental setting, on the subjects’ skin.

Prior to capsaicin cream application, subjects either received a single dose of gabapentin, which is considered effective and a first line treatment for neuropathic pain; ibuprofen, which is generally not considered an effective treatment for the condition; or a placebo. Researchers then assessed the effect the drugs or placebo had on the brain’s neural response to pain using fMRI in addition to patient-reported pain relief.

They found in the absence of behavioral measures distinguishing which drug was most effective at low subject numbers, the imaging responses were clear. Pain-relevant neural activity was significantly reduced in the subjects who received gabapentin, even with extremely low subject numbers, highlighting the potential for fMRI to make a drug’s effect clear in small cohorts.

The authors acknowledge the mechanisms and neural activity involved in the expression of pain in neuropathic patients is not exactly the same as in the healthy subjects with capsaicin cream-induced pain. However, similar studies in early human drug development can determine whether a drug has the ability to affect relevant neural activity in the brain.

“There is a clear need for more effective, safer pain relievers,” said Wanigasekera. “Chronic pain is a very common condition. Even the most effective pain medications currently available only provide adequate pain relief, defined as a 50 percent reduction in pain, in one out of four patients, while some drugs, such as opioids, have significant side effects, including dependence and overuse. We believe that neuroimaging techniques, such as fMRI, can provide objective evidence that can be used as outcome measures in early drug development to enhance the efficiency of the drug development process.”

For more information: www.anesthesiology.pubs.asahq.org

Related Content

RSNA Study Shows Real-Time Indicator Improves Mammographic Compression
News | Mammography | December 12, 2018
Sigmascreening recently announced that more than 100,000 women have had mammography exams with the Sensitive Sigma...
Canon Aquilion One CT Helps Gates Vascular Institute Adhere to New Stroke Guidelines
News | Computed Tomography (CT) | December 12, 2018
In stroke, time saved on imaging is time gained in the treatment window. The recently updated guidelines from the...
Youth Football Changes Nerve Fibers in Brain

Statistically significant clusters (red-colored) showing group differences (Control vs. Football) in white matter strain along the primary (F1) and secondary (F2) fibers. While body of corpus callosum (BBC) showed relative shrinkage in Football group, the other clusters showed relative stretching of fibers. PCR: Posterior Corona Radiata, PLIC: Posterior Limb of Internal Capsule, SCR: Superior Corona Radiata, SLF: Superior Longitudinal Fasciculus, SCC: Splenium of Corpus Callosum. Image courtesy of Kim et al.

News | Neuro Imaging | December 07, 2018
Magnetic resonance imaging (MRI) scans show repetitive blows to the head result in brain changes among youth football...
Siemens Healthineers Debuts Magnetom Altea 1.5T MRI Scanner
Technology | Magnetic Resonance Imaging (MRI) | December 06, 2018
During the 104th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA), Nov. 25-30...
GE Healthcare Unveils New Applications and Smart Devices Built on Edison Platform
Technology | Artificial Intelligence | December 05, 2018
GE Healthcare recently announced new applications and smart devices built on Edison – a platform that helps accelerate...
NeuroLogica and MaxQ AI Announce Distribution Agreement
News | Stroke | November 30, 2018
Clinical diagnostics intelligence platform company MaxQ AI and Samsung NeuroLogica announced a distribution agreement...
Snoring Poses Greater Cardiac Risk to Women
News | Women's Health | November 29, 2018
Obstructive sleep apnea (OSA) and snoring may lead to earlier impairment of cardiac function in women than in men,...
Vital Showcases Enterprise Imaging Advances at RSNA 2018

Global Illumination from Vital Images

News | Enterprise Imaging | November 28, 2018
Vital, a Canon Group company, will highlight the latest additions to its enterprise imaging portfolio at the 2018...
Artificial Intelligence May Help Reduce Gadolinium Dose in MRI

Example of full-dose, 10 percent low-dose and algorithm-enhanced low-dose. Image courtesy of Enhao Gong, Ph.D.

News | Contrast Media | November 27, 2018
Researchers are using artificial intelligence (AI) to reduce the dose of a contrast agent that may be left behind in...