A new case control study suggested that patients with chronic rhinosinusitis may have changes in the functional connection of the brain, which could lead to cognitive dysfunction.
The study was led by Aria Jafari, MD, Department of Otolaryngology – Head and Neck Surgery, University of Washington, Seattle. The team used open-access data to compare individuals with sinonasal inflammation with age- and sex-matched control groups.
“Several modern studies of chronic inflammatory and immune conditions, including Sjögren’s syndrome and inflammatory bowel disease, have identified changes in functional connectivity within networks associated with cognitive control and stimulus detection,” the researchers wrote.
However, they noted, there remains a need to further understand and clarify the cognitive dysfunction observed in chronic rhinosinusitis.
Assessment of functional connectivity
To examine the functional association of affected patients, the researchers used functional magnetic resonance imaging (fMRI) data at rest extracted from the Human Connectome project.
They evaluated data from 22 patients with chronic rhinosinusitis. Patients with a history of psychiatric disorders, neurological diseases, and genetic diseases were excluded. The team also excluded those with a history of diabetes or cardiovascular disease.
Among the investigative and control controls, 2 were aged 22-25 years, 26 aged 26-30 years and 16 aged 31-35 years. The majority (68%) were men.
As for those in the inflammatory group, 13 were categorized with moderate inflammation (Lund-Mackey score [LMS] <14) and 9 were categorized with severe inflammation (LMS ≥ 14)
“The primary outcome was a difference in the functional association of the state of rest within and between a given mode of operation, frontoparietal, prominent, and dorsal cerebral network,” they wrote. “Secondary outcomes include assessments of cognitive function using the cognitive battery of the National Institutes of Health.”
The investigators reported that those with sinonasal inflammation had reduced functional connectivity within the frontoparietal lobe. More specifically, this was observed in a region that included bilateral frontal medial cortexes.
They further noted that the region showed increased functional connectivity at 2 nodes within the network in the default mode and decreased functional connectivity at 1 node in the prominent network.
The level of severity of inflammation is associated with a larger magnitude in this functional association deviation.
Despite these findings, the team did not notice differences in cognitive assessment between the groups.
“Similarly, the analysis did not indicate any differences in odor, taste, and pain between groups, as measured by the NIH Toolbox Sensation Measures testing component,” they wrote.
And finally, there was no difference in the quality of sleep and its subdomains – latency, duration, usual efficiency, disorders, use of sleeping pills and daily dysfunction, etc. – which were assessed using the Pittsburgh Sleep Quality Index (PSQI).
“In this concept evidence study, we found that compared to controls, participants with sinonasal inflammation showed reduced functional connectivity within the frontoparietal network, a major network that plays a central role in modulating cognition through extensive connections to other brain areas,” the team wrote. .
On the other hand, the connections between the functional node that modulates cognition and the areas activated during introspective and self-referential processing are increased.
Although their data were limited by significant gaps, such as the lack of clinical information specific to rhinosinusitis, the researchers pointed to the importance of initial evidence showing that functional association may serve as a basis for cognitive impairment in this patient population.
What’s more, these findings can provide a basis and a guide to future, deeper research.
The study, “Association of Sinonasal Inflammation with a Functional Connection of the Brain,” was published online in JAMA Otolaryngology – head and neck surgery.