Aeromedical Forum: September 2015

In July we talked about migraines. Last month, strokes. Now, brain tumors. I know this is starting to look like “The Grim Reaper Report” but these things are more common than you’d think and sure can affect your flying!

As a matter of fact, if you were to do a brain scan (MRI) on every healthy adult that walked in the FBO, you’d find one brain tumor in every 2,000 exams. So these things are by no means rare. How do you know if you have one? Symptoms can vary, but headache is common. The trouble with that is that headaches are common and the overwhelming majority of them are not associated with a tumor.

Seizures are also a frequent tip-off that something is wrong. If an adult with no prior history of seizures has a fit coming out of the blue, it’s a brain tumor until proven otherwise. Other problems that make you think of brain tumor include unexplained weakness of an arm or leg or changes in mental status. A lot of things can get a guy acting funny, but brain tumor is one thing you have to think of.

Brain tumors divide into two types: those that initially form in the brain (primary tumors) and those that have spread or are metastatic from another location. Obviously metastatic tumors are really bad news. They frequently come from a lung cancer, although other sources such as breast cancer or a lymphoma or leukemia may be the source.

Primary brain tumors are less common. They can be either benign or malignant. Fortunately, the majority of brain tumors in adults are benign. They can sit happily in the brain for some time before they get big enough to press on something and cause symptoms. Sometimes their location can make them difficult to remove without damaging brain tissue. The malignant kinds, while less common in adults, are more aggressive and treatment less effective. Treatment varies with the tumor type but can include surgery, radiation and/ or chemotherapy with drugs.

How the FAA handles brain tumors varies with the type and extent of its growth. First let’s assume we are not dealing with metastatic spread but rather with a tumor arising in the brain. The FAA is going to be looking for and potential neurologic problems such as weakness, loss of sensation, difficulty walking, seeing or thinking. Headaches, vertigo or seizures would have to be controlled before consideration for Special Issuance (SI). For sure they will ask for a complete neurological examination complete with brain scans and other laboratory studies. Chances for a fairly quick SI are best when the tumor is benign and arising from the coverings of the brain rather than being in the brain itself. Even then the FAA usually requires at least a one-year convalescence with the airman being free of any symptoms.

Obviously brain tumors are God-awful. However, are several exposures that might increase your risk that you can avoid.

• Cigarette smoking definitely increases the risk for several cancers which spread to the brain. Dump the cancer sticks!

• Radiation exposure especially at a young age seems to increase risk. If an X-ray is indicated get it. Higher radiation exposures occur with CT scans, however and you should be certain they are necessary before you get one. Therapeutic radiation to the head to treat some types of cancers can increase the chances of a subsequent brain tumor.

• Chemical exposure: Exposure to certain industrial chemicals or solvents has been linked to an increased risk of brain cancer. There is evidence to suggest that there is a higher incidence of certain types of brain tumors in people who work in oil refining, rubber manufacturing and drug manufacturing. A lot depends on what they are doing in the plant and what they are exposed to.

• Electromagnetic Field Exposure: The evidence for this one is shaky. There has been a lot of press about heavy cell-phone use predisposing to brain tumors but precious little hard evidence. I guess the most I would do is not buy a house directly under a high voltage transmission line and sleep with my cell phone strapped to my head.

• Age: In general, the chance of a brain cancer increases with age, especially in folks 65 and older. I’m not sure what you can do to prevent that!

Fly wisely. See you next month!

As always, comments, questions and suggestions are welcome: jdlakin@mnallergyclinic.com.