Functional magnetic resonance imaging tomography in assessing the functional state of the brain in patients with opioid addiction

Abstract

The possibilities of functional magnetic resonance imaging in the diagnosis of opioid dependence syndrome are considered. It is known that opioid addiction is one of the leading problems of modern narcology. Despite the fact that the number of researches of the neurobiological effects of opioids is increasing every year, the pathogenetic effects of dependence on this narcotic substance are still not fully understood. Functional magnetic resonance imaging rest allows one to assess the functional connectivity of the remote from each other parts of the brain and makes a great contribution to understanding the mechanisms of development of addictive disorders in general. In patients with opioid dependence, an analysis was made of the neural network of the passive mode of the brain (default mode network). This resting network is associated with the processes of control and thinking, including emotional and cognitive components, and consists of medial frontal regions, posterior cingulate sections, precuneus, lower parietal and temporal divisions. It was found that, in comparison with the control group, in all patients suffering from opioid dependence, weakened functional connections of all structures of the cerebro-spinal cord system (p0,05). In this case, changes in the medial prefrontal cortex and precuneus are more pronounced in patients who are in the state of opioid intoxication, and in the parietal-temporal regions in patients who are in a state of remission up to 1 month. The correlation of cortical structures responsible for the «behavior control» system (orbitofrontal cortex, prefrontal cortex) with subcortical structures responsible for emotions in the limbic system was also evaluated. In comparison with the control group, in patients with early remission, weakened functional connections between cortical structures and left contiguous nucleus, almond-shaped body from two sides. In patients in a state of intoxication in addition to these changes, the functional relationship between the orbital frontal cortex and the shell on the left has been weakened. The weakening of functional links in the network of the passive mode of the brain in the groups of drug addicts suggests that they have violated the processes of control, thinking and making the right decision. The resulting functional changes can form the basis for creating biomarker maps for patients suffering from opioid dependence, which can be used to guide and evaluate the treatment of this pathology.