A small proof-of-concept study found that sinonasal inflammation was associated with neural changes that could precede cognitive symptoms in young people.
In comparison to healthy controls, people with chronic rhinosinusitis showed decreased functional connectivity within the frontoparietal network, a major cognition modulating hub, in resting-state functional MRI imaging. The frontoparietal network allows individuals to coordinate behaviour in a rapid, accurate, and flexible goal-driven manner.
These individuals also had greater connectivity of this region to the default mode network (areas that are activated during introspective and self-referential processing) and decreased connectivity to the salience network (areas involved in detection and response to stimuli) on brain imaging, reported Aria Jafari, MD, of University of Washington in Seattle, and colleagues.
Compared to controls, individuals with more severe rhinosinusitis inflammation tended to have greater differences in functional connectivity, Dr Jafari and colleagues stated.
“Although definitive conclusions are not possible given the limitations inherent in the data set, including lack of rhinosinusitis-specific clinical information, our results present initial evidence for functional connectivity alterations as a potential basis for cognitive impairments seen in patients affected by chronic rhinosinusitis and may help direct future research,” Dr Jafari and colleagues said.
However, in this study, no cognitive deficits accompanied the functional connectivity changes. People with chronic rhinosinusitis and their matched controls shared similar cognitive status and similar sleep quality, with no between-group differences in olfaction, taste, and pain, either.
It was suggested by the researchers that, “given the brain’s ability to adapt and compensate, particularly in young and cognitively healthy individuals, our findings may represent early and subclinical functional brain alterations that may precede or be more sensitive than anticipated behavioral responses.”
“It is possible that a clinical chronic rhinosinusitis cohort with broader age distribution and more significant symptoms may have even greater changes in functional brain connectivity in the regions identified in this study,” they added.
“Overall, I do think that this study gives credence to the large body of evidence that patients with chronic rhinosinusitis, or in this case sinonasal inflammation, do have issues with cognition,” commented Nicholas Rowan, MD, of Johns Hopkins University School of Medicine in Baltimore, who was not part of the study.
Sinonasal inflammation and chronic rhinosinusitis have well established negative impacts on quality of life, according to Rowan. Previous research has found that medical or surgical intervention for chronic rhinosinusitis can alleviate cognitive dysfunction.
“Though unfortunately, the findings here are not actionable from a clinical standpoint, they do provide novel information for further prospective study of patients with chronic rhinosinusitis, as well as laboratory studies that are aimed to better understand the mechanism of why patients with CRS have such substantial quality of life implications,” according to Dr Rowan.
Although comorbid psychiatric disorders and sleep dysfunction are among the proposed mechanisms for cognitive dysfunction, the researchers said their data was supportive of a direct association of immune molecules with brain function.
Using data from The Human Connectome Project, the case-control study included 22 people with radiologic sinonasal inflammation who were matched 1:1 by age and sex to healthy controls. Sinonasal inflammation was classified as moderate in 13 people and severe in nine.
All were young adults age 22 to 35, and 68% were male.
Limitations included the retrospective nature of the study and the small sample size. Since cognitively normal participants identified radiographically from a large database, this limited the generalisability of the results, the authors added.
“Future prospective studies are warranted to determine the applicability of these findings to a clinical chronic rhinosinusitis population,” they said.
Source: MedPage Today
Journal information: Jafari A, et al “Association of sinonasal inflammation with functional brain connectivity” JAMA Otolaryngal Head Neck Surg 2021; DOI: 10.1001/jamaoto.2021.0204.
