Chronic Stuffy Nose Linked to Changes in Brain Activity, Study Finds

Your always-congested sinuses might be a harbinger of more trouble down the road, new research out Friday suggests. The small study found evidence of a link between chronic sinus inflammation and altered, possibly harmful brain activity. The findings don’t necessarily prove that the two things are directly connected, but they do highlight the need for more study.

The sinuses are the hollow spaces around our nasal cavity and are thought to mainly keep the nose moist and protected by providing mucus. They can become occasionally inflamed for brief periods of time through infections, but some people are unlucky enough to develop chronic sinus inflammation, or chronic rhinosinusitis.

Of course, no one is feeling their best with a blocked nose, and there have been hints in recent years of a link between chronic sinus inflammation and decreased cognition. Studies have found, for instance, that patients perform worse on tests of their cognitive function than similarly matched control subjects and that their performance improves after they start receiving treatment for their condition. And patients themselves have described feeling a sense of “brain fog” in addition to their other physical symptoms, which can include nasal congestion, reduced taste and smell, and facial pain or discomfort.

This new study, published Friday in JAMA Otolaryngology–Head and Neck Surgery, seems to be one of the first to try looking for the physical underpinnings of this link. The researchers examined data from the Human Connectome Project, a U.S. government-sponsored study of the human brain. The project is an attempt to map and understand the circuitry of the brain and how these connections actually help the body function. It’s largely based on neuroimaging data collected from over 1,000 healthy and young adult volunteers, who also underwent a battery of cognitive tests.

Out of this project, the researchers looked at a group of 22 people who appeared to have chronic sinus inflammation and compared them to a similar group of people without inflammation. Compared to the control group, the people with sinus inflammation appeared to have decreased functional connectivity in areas of the brain key to cognition: the frontoparietal network, which helps us stay focused and problem-solve, and the salience network, which helps us distinguish important stimuli and plays a role in our ability to communicate and other social behaviors. They also found increased connectivity in the default-mode network, which is most active when we’re at rest and not focused on any particular task, like while daydreaming.

Importantly, the people with chronic sinus inflammation didn’t actually perform any worse on average on their cognitive tests than the control group did. But the findings do suggest that something may be going on in their brains that’s noticeably different from those without inflammation, and in ways that could explain the symptoms of brain fog that patients can experience. Because the people in this study were young, it’s also possible that more noticeable changes in their cognition linked to inflammation simply haven’t shown up yet—changes that could arise if their inflammation were to go untreated.

Still, the authors are careful to frame their research as a proof-of-concept, an attempt to show that this link needs to be studied more closely. This further research might not only confirm that sinus inflammation can harm our brains, but also provide opportunities for more treatments for the common condition to be found. Chronic sinus inflammation is thought to affect as many as one in every 10 Americans. Though there are treatments such as antibiotics or surgery, it often reoccurs and can take years before patients find lasting relief.

“The next step would be to study people who have been clinically diagnosed with chronic sinusitis. It might involve scanning patients’ brains, then providing typical treatment for sinus disease with medication or surgery, and then scanning again afterward to see if their brain activity had changed. Or we could look for inflammatory molecules or markers in patients’ bloodstreams,” said lead author Arie Jafari, a surgeon and assistant professor of Otolaryngology-Head & Neck Surgery at the University of Washington School of Medicine, in a statement from the university.

For now, the team hopes their findings will at least make doctors more aware that this chronic condition may be affecting their patients in deeper ways.

“Our care should not be limited to relieving the most overt physical symptoms, but the whole burden of patients’ disease,” Jafari said.