Synonasal inflammation is associated with changes in the brain network that may precede cognitive symptoms in young people, according to a small study of a proven concept.
Compared with healthy controls, people with chronic rhinosinusitis showed reduced functional connectivity within the frontoparietal network, the major functional center central to cognition modulation, on MRI at rest.
In addition, these individuals had a greater connection of this region to the given-mode network (areas activated during introspective and self-referential processing) and a reduced connection to the isolated network (areas involved in detection and response to stimuli) on brain imaging, they reported . Dr. Aria Jafari of the University of Washington in Seattle and colleagues.
People with more severe rhinosinusitis had greater differences in functional association compared to control, they reported in JAMA Otolaryngology – head and neck surgery. The results were first reported at a virtual meeting of the American Rhinological Society 2020.
“Although final conclusions are not possible given the limitations inherent in the data set, including the lack of clinical information specific to rhinosinusitis, our results provide initial evidence of changes in functional association as a potential basis for cognitive impairment seen in patients with chronic rhinosinusitis and may help guide future research “, said Jafari and colleagues.
However, the observed changes in functional association were not accompanied by cognitive deficits in the study.
People with chronic rhinosinusitis and their matching controls shared similar cognitive status (both on the mental state exam and on the composite cognitive function tool) and reported similar sleep quality on the Pittsburgh Sleep Quality Index. There were no differences between the groups in smell, taste and pain.
“Therefore, given the brain’s ability to adapt and compensate, especially in young and cognitively healthy individuals, our findings may represent early and subclinical functional brain changes that may precede or be more sensitive than predicted behavioral responses,” the researchers suggest.
“It is possible that clinical chronic rhinosinusitis with a broader age distribution and more significant symptoms may have even greater changes in brain functional connectivity in the regions identified in this study,” they added.
“Overall, I think this study provides credibility to a large body of evidence that patients with chronic rhinosinusitis, or in this case sinonasal inflammation, have problems with cognition,” commented Nicholas Rowan, Ph.D. Med., From Johns Hopkins University School of Medicine in Baltimore, which was not part of the study.
It is well documented that sinonasal inflammation and chronic rhinosinusitis have significant impacts on quality of life, psychosocial functions (e.g., depression), productivity, and general well-being, according to Rowan. Other studies have found that cognitive dysfunction responds to medical or surgical intervention for chronic rhinosinusitis.
“Although unfortunately the data found here are not clinically effective, they provide new information for further prospective studies of patients with chronic rhinosinusitis, as well as laboratory studies aimed at better understanding the mechanism why patients with CRS have such significant implications for quality of life.” says Rowan.
Comorbid psychiatric illness and sleep dysfunction are among the proposed mechanisms of cognitive dysfunction.
Jafari and colleagues said their data instead supported a direct link between immune molecules, including cytokines and antibodies, to brain function.
The case control study, which used the Human Connectome project, included 22 individuals with radiological sinonasal inflammation who were age- and sex-related associated with healthy 1: 1 controls. Synonasal inflammation was classified as moderate in 13 individuals and severe in nine individuals.
They were all young adults between the ages of 22 and 35. Men made up 68% of the cohort.
Jafari’s group acknowledged that the study of proving the concept was retrospective and that their sample was small. The results of the study may have limited generalization as these were cognitively normal participants radiographically identified from a large database, the authors added.
“Future future studies are needed to determine the applicability of these findings to the clinical population of chronic rhinosinusitis,” they said.
Jafari did not disclose relevant relationships with the industry. The co-author revealed relevant relationships with Olympus, Medtronic, Karl Storz, Sinopsys, Baxter, 3-D matrix, frequency therapy, and Thieme, as well as possessing relevant patents.