Real-time fMRI applied to pain management

Abstract

Current views recognize the brain as playing a pivotal role in the arising and maintenance of pain experience. Real-time fMRI (rtfMRI) feedback is a potential tool for pain modulation that directly targets the brain with the goal of restoring regulatory function. Though still relatively new, rtfMRI is a rapidly developing technology that has evolved in the last 15 years from simple proof of concept experiments to demonstrations of learned control of single and multiple brain areas. Numerous studies indicate rtfMRI feedback assisted control over specific brain areas may have applications including mood regulation, language processing, neurorehabilitation in stroke, enhancement of perception and learning, and pain management. We discuss in detail earlier work from our lab in which rtfMRI feedback was used to train both healthy controls and chronic pain patients to modulate anterior cingulate cortex (ACC) activation for the purposes of altering pain experience. Both groups improved in their ability to control ACC activation and modulate their pain with rtfMRI feedback training. Furthermore, the degree to which participants were able to modulate their pain correlated with the degree of control over ACC activation. We additionally review current advances in rtfMRI feedback, such as real-time pattern classification, that bring the technology closer to more comprehensive control over neural function. Finally, remaining methodological questions concerning the further development of rtfMRI feedback and its implications for the future of pain research are also discussed.

Figure

rtfMRI assisted control over anterior cingulate cortex (ACC). (A) Change in group mean activation comparing the last training session to the first training session showing activation in the ACC (located at cross hairs), (B) Change in group mean activation comparing the posttest session (after the last rtfMRI training session) to the initial training session, showing similar results. Seven total clusters were observed at this threshold level (t >12.80, top of scale t =18.00). Data are presented as thresholded, Bonferroni-corrected t-maps superimposed on high-resolution T1 data. Color designates the t value, using a general linear model comparing different time periods convolved with a canonical hemodynamic response function. All data are experimental group averages after normalization to Talairach–Tournoux coordinates. Figure used with permission from [31].