Vol. 18 •Issue 23 • Page 19
Asthma on the Brain
Recent Studies Find Close Bond Between Brain Activity, Asthma Attacks
Remember learning the basics of anatomy from the lyrics of an old children’s song? You might recall lines like, “the hip bone’s connected to the thigh bone.” Researchers should slightly revise the tune to include this line: “The lung function is connected to the central nervous system.”
That may sound like an improbable musical biology lesson, but according to recent discoveries of asthma investigators worldwide, the brain and lungs have a closer tie than initially thought.
For years, immunologists and psychiatrists have known that psychological distress can exacerbate asthma attacks. Now, however, they are discovering more of a physical connection between neurological activity and the lung function of asthmatics.
For instance, a team at the University of Wisconsin discovered that emotions can cause asthma flare-ups. Studying a small group of six asthmatics, investigators found when subjects said words associated with the disease like “wheeze,” two regions of the brain would activate and subsequently cause lung inflammation. The brain regions in question–the anterior cingulate cortex and the insula–already are known to be directly tied to emotional responses.
While participants read words from three categories (“wheeze” from the asthma list, “loneliness” from negative words and “curtains” from neutral terms), they inhaled asthma triggers like ragweed and dust mites. Simultaneously, investigators tested their lung function and measured their brain activity using functional magnetic resonance imaging. Only when asthma words were read did emotional sectors of the brain activate and lung inflammation occur.
The investigators said more research in this area may influence new therapies that tackle the brain’s emotional responses to ease lung inflammation.
Stress in Kids
As previously mentioned, the asthma community is well aware that when stress weighs on asthmatics, they are more likely to have an asthma attack. But a study completed at University College London in the United Kingdom discovered this is especially true in children. They published their study last year in the British Medical Journal Thorax.
Events like moving to a new house or a different school or a change in the family structure, including the birth of a sibling or hospitalization or death of a family member, raises a child’s risk of having an asthma attack four-fold. During the 18-month study period, 60 participants ages 6 to 13 experienced 124 stressful life events and recorded 361 episodes of rapidly worsening asthma symptoms.
Interestingly, stressful life events affected the kids not only immediately after but also weeks later. Bouts of acute asthma occurred on average within two days of the stressful event then again six weeks later. Immediate and delayed stress-related effects on asthma symptoms possibly are due to different physiological and immune processes of the autonomic nervous system and regulations of hormones and brain chemicals, according to the report.
Asthma, Psychiatric Disorders
Not only do all asthmatics of all ages report generally more stress and a lower quality of life than non-asthmatics, but also they are more likely to be afflicted with a psychological disorder.
While 11 percent of non-asthmatics fall into the category of having been diagnosed with a psychiatric disease, 55 percent of asthmatics have such a diagnosis, according to a University of Iowa College of Medicine study presented at the 2003 American Thoracic Society meeting in Seattle.
Investigators from the National Institute of Mental Health made a similar conclusion when they found asthma attacks were more strongly associated with panic disorder than with actual panic-attack symptoms like heart palpitations, sweating, trembling and an all-consuming fear.
Investigators found the prevalence for asthma and panic disorders separately were about the same: 7.3 percent and 7.8 percent respectively. But when the participants were asked whether they had experienced “any panic,” more than 20 percent said they had.
What’s the connection? The NIH report concluded that some asthma medications have anxiety-causing properties, and anxiety may enhance the use of asthma meds.
Brain Tumors and Asthma
On a slightly different note, having allergies and asthma may actually be beneficial for the brain. Specific genes prevalent in people who suffer from asthma or allergy protect against glioblastoma multiforme, the most common type of brain tumor.
Ohio State University researchers and a neurological team in England discovered that four variants on two different genes responsible for increased susceptibility to asthma and other allergic conditions decrease the risk of brain tumor.
For the study, published in July’s Cancer Research, DNA samples from 111 Swedes diagnosed with glioblastoma were examined to see whether participants had two genes—IL-4RA and IL-13—known to be associated with asthma and allergies.
“We found that one genetic variant that causes a two-fold risk in asthma susceptibility reduces the risk of glioblastoma multiforme by 40 percent,” lead author Judith Schwartzbaum, PhD, associate professor of Public Health at Ohio State, stated in a release.
Exactly why asthmatics rarely form brain tumors is unclear. The authors speculated that gene modifications hinder inflammation in the brain, even though those same genes cause inflammation in the lungs. It’s just another case of asthma on the brain that future scientists will investigate.
You can reach Stacey Miller at [email protected]