People with sinonasal inflammation show decreased functional brain connectivity, according to a small proof-of-concept study. "We have known for a long time that patients with chronic rhinosinusitis suffer cognitive changes as a part of their condition," Dr. Aria Jafari of the University of Washington, Seattle, told Reuters Health by email. "This study is the first to demonstrate measurable changes in brain activity associated with sinus inflammation and represents an important step forward in our understanding of the brain-sinus connection." In a paper in JAMA Otolaryngology-Head and Neck Surgery, Dr. Jafari and colleagues note that researchers have also reported that patients with chronic rhinosinusitis "exhibit worse performance on tests of reaction time, processing speed and selective attention." Collectively, these and other data, they say, "indicate that there may be a relatively unexplored putative link between the underlying inflammatory disease and higher order neural processing." To investigate further, the researchers examined resting-state functional magnetic resonance imaging data from the Human Connectome Project. This was used to examine the functional brain connectivity profile of brain networks involved in cognitive processing in participants with sinonasal inflammation compared with healthy controls. The comparison comprised 22 patients with chronic rhinosinusitis and 22 healthy controls ranging in age from 22 to 35 years. Those with sinonasal inflammation showed decreased brain connectivity within the frontoparietal network, a major functional hub. This network, say the researchers, "is of particular significance for its critical role in cognitive performance and control." The effects were dose dependent in that the magnitude of these differences increased with inflammation severity. However, overall cognitive status, as assessed by standard tests was similar between groups. Self-reported sleep quality also did not differ. In addition, analysis of a variety of National Institutes of Health Toolbox Cognition Battery results did not suggest any differences in cognitive assessment. The researchers concede that "the results are based on a cohort of young, cognitively normal participants identified radiographically from a large database, rather than by clinical examination and history." Still, they conclude, "This study provides several important insights into potential neural correlates of cognitive dysfunction seen in sinonasal inflammation." "Future work," Dr. Aria added, "will focus on understanding this relationship on a more molecular level and ultimately help direct treatments to address all aspects of this complex condition." —David Douglas Source
