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Antique numbers

Evaluating traumatic brain bleeding and CT scans

So, you are playing goalie for your 16-year-old soccer player when he puts one right in your face. Your nose is bleeding and to the ER you go, worried your snozola is permanently deformed.

The emergency physician does a detailed examination including a detailed neurological exam (both exams are rarities in today’s ERs) and determines you do not have a concussion, or a post-concussion syndrome based on both exams being normal.

However, the ER doctor sees that you have good insurance and says, “We should get a CT scan of your head just to be sure.” Pay attention, that CT scan could ground you for five years—five long years! Statistically, with no headache, no loss of consciousness, no amnesia, and a normal exam, you do not need a scan anyway.

The concern is that modern CTs will show bleeding in the brain as small as 0.5 mm or 1/54th of an inch. Bleeds this small are inconsequential when given the above circumstances, but not to the FAA. Using a study published in 1998—ancient history in the world of medicine—the FAA alleges an increased risk of seizures in people who have traumatic brain injuries with bleeding inside the skull. The study covers patients from 1935 to 1984. That means that only patients from about 1974 to 1984 had CT scans and that equipment had resolution that would not pick up small bleeding like today’s scanners. In addition, the study classified the brain injury as severe if there is an “intracranial hematoma” but no mention of size nor how many patients had just a hematoma and no other symptoms.

Obviously, CT scans are not seizure protective, but findings in a 1998 study like these should give the FAA reason to reevaluate absolute antique numbers they rely on a lot.Using some interesting statistical analysis that would make horse race handicappers blush, the authors state the risk of post-traumatic brain injury patients who had an intracranial bleed is greater than the FAA’s adopted 1 percent rule. If the risk is greater than 1 percent, you cannot fly. The study basically rates the risk at 1.5 percent for five years and actually states “increased risk of seizures in patients with these factors persisted for at least 20 years.” Well, why just five years of grounding?

Here is a kicker for these findings. The authors mention that “none of the 34 patients with mild or moderate traumatic brain injuries and abnormalities on CT had seizures,” which means none of the patients in the past 10 years of the study, when CT scans were available, and had abnormalities had seizures—zero percent incidence. Obviously, CT scans are not seizure protective but findings in a 1998 study like these should give the FAA reason to reevaluate absolute antique numbers they rely on a lot.

Going back to our goalie who cannot protect his face, if he refuses the CT scan in the ER, which is perfectly reasonable, he will need to report on his next FAA exam “hit in the face with a soccer ball, broken nose, full recovery.” He will be issued his medical by the AME.

If he gets the CT scan and it shows a 1 mm (1/27th of inch) inconsequential bleed inside his skull, he will have to report that finding. The AME will have to defer the medical and ask the pilot to submit all the records including a disk with the scan on it to the FAA. The minimum wait time to ask for a special issuance is 12 months. (For a specific type of bleed, called parafalcine sub dural hematoma, the pilot can apply after six months but only if he has a negative MRI.)

For other bleeds, the FAA’s process cannot be started for five years. After five years, there are 12 requirements to follow including repeat imaging and an electroencephalogram. Since this follow-up is not medically indicated and only being done for the FAA, the cost will not be covered by insurance and can add up to thousands of dollars. Once this new data is submitted, it will take a few months for the FAA to make a decision, which is not guaranteed to be the one the pilot is hoping to receive.

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Dr. Brent Blue

Senior Aviation Medical Examiner
Dr. Brent Blue is an FAA senior aviation medical examiner and airline transport pilot with more than 9,000 hours of flight time. Through his company, Aeromedix.com, he introduced pulse oximetry and digital carbon monoxide detection to general aviation in 1995.

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