Air Line Pilot, November/December
2000, page 22
By Dr. Quay Snyder, ALPA Associate Aeromedical Advisor
Nearly everyone suffers from headaches of some type during their lifetime. Most of these headaches are very transient and do not significantly affect a persons ability to function or concentrate. Many headaches are associated with stress or illness and go away when the underlying condition is corrected. Over-the-counter medications will usually eliminate the symptoms of these inconvenient headaches.
Some headaches are much more significantthey can be temporarily incapacitating and adversely affect the sufferers ability to safely operate an aircraft. The most common headache of this nature is the "migraine" type. As noted in this article, a variety of symptom complexes are all categorized as "migraine" headaches. Rarely, a headache may be the symptom of a much more serious, and potentially life-threatening, condition. Immediate evaluation and treatment may be required to prevent permanent neurologic damage or death. The negative aeromedical implications of these conditions are obviously, though not necessarily permanently, disqualifying.
Severe or frequent headaches and their medical treatment must be reported on FAA Form 8500-8, Application for Airman Medical Certificate, in question 18a. Pilots should be careful not to characterize an isolated "bad" headache as a migraine headache. The Federal Air Surgeons Medical Bulletin, Winter 1999, warns about the risks of self-diagnosing various medical conditions. An incorrect diagnosis on Form 8500-8 may lead to loss of certification and to a lengthy, expensive evaluation process to regain a medical certificate.
Nearly everyone has experienced several episodes of tension-type headaches, as they are the most common type of headache. Almost 90 percent of headaches not related to disease are the tension type. Sometimes called "extracranial" because the source of the discomfort is outside of the skull, these headaches are thought to be the result of the muscles of the face, scalp, and neck contracting.
Soreness or aching that is not specific in location characterizes tension headaches. The discomfort is usually bilateral i.e., on both sides of the head and neck. Sufferers often describe neck soreness, a band-like pressure around the head, or an aching in the temples. Frequently, these people will gain some relief by massaging the sore muscles. Although muscle contraction headaches may be very severe, they must not be confused with, or described as, "migraine headaches."
Muscle-contraction/tension headaches have numerous causes. Illnesses that cause muscle soreness, such as the flu or other viral conditions, frequently cause contraction headaches that over-the-counter medications such as aspirin, Tylenol, or ibuprofen may relieve. Other causes may include personal stress, anger, fatigue, eyestrain, or dehydration. Although medications often relieve these headaches, the key to preventing them is avoiding the cause. Often, rest, fluids, and relaxation will eliminate the pain.
Acute sinus infections may cause pain behind an eye, over the eyebrows, or in the upper cheek and teeth. These symptoms may become much more intense when the sufferer is descending rapidly from altitude. Some people have described this sensation as being like having an ice pick driven through the face. These obviously incapacitating sinus headaches are relieved over time with decongestants and antibiotics, as well as pain medication. Chronic sinus headaches are not as intense, but require the same treatment.
FAR 61.53 requires pilots to ground themselves if they have a known medical defect that would compromise their ability to safely operate an aircraft. Acute conditions should be considered grounding, but pilots may legally fly while using nonsedating over-the-counter pain relievers such as aspirin, acetaminophen, naproxen, or ibuprofen.
|Aeromedical Certification Assistance
For a more specific personal discussion of your questions or those concerning aeromedical certification, contact the ALPA Aeromedical Office for advice from our aviation medicine physicians. The office is open from 8:30 a.m. to 4:00 p.m. Mountain time on weekdays.
A complete version of this articlecopyright 2000 Virtual Flight Surgeons, Inc., all rights reserved, and reprinted here with permissionwith active hyperlinks, numerous additional references, and sources of public information, may be found on the Internet at www.aviationmedicine.com/headaches.htm n
In the United States, 4 percent of women and 1 percent of men suffer true migraine headaches each year. Nationwide, 1216 million people suffer from migraine headaches each year. Lay persons often mistakenly use the term "migraine headache" to describe a rather severe headache from any cause. Pilots should be particularly careful in using this term, as it may adversely affect their medical certification. True "migraines" may occur without any head pain whatsoever.
Migraine headaches are defined as recurrent, benign headaches with or without neurologic symptoms. Certain foods, alcohol, flashing lights, lack of sleep, and many other specific stimuli are frequent triggers. A key element in the definition is "recurrent." A single typical headache is not characterized as a migraine unless it recurs. The inclusion of the term "benign" in the definition is not meant to imply that migraines are not severe or incapacitating, but indicates that no associated medical condition will progress if the headache is left untreated.
"Migraine" headaches are also termed "vascular" headaches because the symptoms are believed to be caused by spasm and dilation of the blood vessels to the brain and its surface. The muscles of the scalp and neck are not directly involved as they are with tension headaches. Treatments to both relieve and prevent migraine/vascular headaches are designed to alleviate the vascular spasm.
The several types of migraines are classified by the character of their symptoms. Depending on the symptoms and the frequency, migraine headaches may or may not be disqualifying for flying. The type of treatment and its success is also a major determinant in whether a pilot will be authorized to fly with this condition. Some of the various types of migraines follow:
* Classic migraine, or migraine with auraA sensory premonition or "aura" before the actual headache heralds about 10 percent of migraine headaches. The aura may be an unusual smell or taste, flickering lights in an eye, tingling of the face, or other warning, and may last seconds to minutes. This is usually followed by an intense headache that may last minutes to days. The headache is often one-sided (unilateral), pounding or throbbing, and very distracting, if not incapacitating.
Nausea and vomiting, sensitivity to light (photophobia) or to noise (hyperacusis) may accompany the migraine. Other symptoms may include loss of vision or speech, confusion, flashing lights, temporary partial paralysis, or loss of sensation/feeling. Classic migraines that cannot be prevented are usually disqualifying for medical certification because their intensity and associated symptoms could distract a pilot from full attention to flying. At times, an avoidable provoking cause may be discovered, such as a food (MSG in Chinese food is common), flashing lights, medications, or even intercourse. See the section "FAA Policy Treatment for Headaches," page 25, for treatment options available to pilots.
* Common migrainesmigraines without aurawhich are nearly identical to classic migraines but are not accompanied by a warning aura make up about 75 percent of migraine headaches. The headache symptoms are similar in nature, severity, and duration to those of the "classic" migraine.
Some sufferers may have both common and classic migraines, although most tend to have predominantly one or the other. Common migraines are treated the same as classic migraines, although eliminating a common migraine before the onset of pain is difficult without the aura.
* Acephalgic migraine means "without head pain"; thus, it is a complex of neurologic symptoms without a headache. About 5 percent of migraine headaches fall into this category. These episodes may easily be confused with strokes or transient ischemic attacks (TIAs). The symptoms may include partial loss of vision, loss of strength, loss of sensation, and/or difficulty with speech and memory or any other neurologic function. The cause of the symptoms is thought to be spasm of arteries in the brain, thus interrupting blood flow to segments of the brain. The same treatments used for other types of migraines may eliminate the symptoms.
* Basilar migraines are very similar to acephalgic migraines, but are associated with headaches that may initially cause total blindness, confusion, inability to speak, double vision, or vertigo. The confusional states may last from several hours to several days, although most symptoms are over in half an hour.
* Cluster headaches are a variant of migraines that have a seasonal or periodic nature. Unlike other types of migraines, men are more commonly afflicted than women (8:1 ratio). Cluster headaches make up about 5 percent of all migraine-type headaches. A person may be free of any headache symptoms for months or years, and then for a period of time (usually several weeks) be afflicted by as many as several headaches per day. The headaches are often very intense, associated with eye pain and involuntary tearing. The pain is confined to only one half of the head, usually behind the eye and in the temple. Rather than throbbing and building over time, they are usually explosive at onset, then deep and continuous. Cluster headaches last 1 to 2 hours and may occur several times a day, every day for several weeks. Frequently, they may occur at the same time every day.
The treatment of cluster headaches varies from that of other migraines. The usual medications to prevent migraines, such as beta blockers, do not help. Lithium, a medication usually used for manic-depressive syndromes, seems to be most effective. Sansert is also used for cluster headaches. Alcohol may set off the first of most cluster headaches, but usually not the recurrences.
* Jab and jolt is another variant of vascular headaches. The prime characteristic is a sudden sharp pain followed by a brief (usually less than 1 minute) neurologic deficit (disturbed vision or speech, etc.). Because of the brief duration of the symptoms, treatment is usually focused on preventing rather than eliminating symptoms after onset. Prevention is similar to the techniques used for other migraine-type headaches.
Headaches due to neurologic infections
Infections of the central nervous system (CNS) are extremely serious, many resulting in lifetime reductions in cognitive abilities or neurologic functions. Most demand immediate treatment to minimize the risk of permanent consequences or death. Infections of the brain itself are called "encephalitis," and infections of the protective covering of the brain and spinal cord are called "meningitis."
In general, bacterial infections progress more rapidly, are more often fatal, and have more long-term complications than viral infections. Bacterial meningitis is treated with antibiotics given intravenously, or even into the fluid-filled space around the brain. Viral meningitis often does not require treatment directly against the virus, but only medication to relieve the symptoms. Two exceptions, which are treated with antiviral agents, are encephalitis caused by herpes and HIV.
The major symptoms of a CNS-infection headache are an increasingly intense global headache and a stiffness of the neck with forward flexion. Fever, confusion, and possibly loss of consciousness often accompany CNS infections.
Because these headaches tend to be isolated events, the FAAs primary concern about them is not the risk of a sudden recurrence causing in-flight incapacitation, but whether they have caused any long-term mental or neurologic deficits that could impair judgment or the safe operation of an aircraft. Required evaluations before returning to flight duties include a comprehensive examination by a neurologist and possibly detailed neuropsychological testing of mental function.
Headaches may occur for a prolonged period following head trauma. The trauma may seem very minor and not be associated with loss of consciousness. The headaches may even begin several days after the head trauma. Associated symptoms include fatigue, decreased concentration or mental ability, sleep disturbances, nausea, and many other nonspecific complaints. This complex is often called a "postconcussive syndrome." Symptoms may last days, weeks, or even months after a relatively minor trauma.
Nonpenetrating head trauma
Three basic types of nonpenetrating head trauma follow:
* Concussion is any brain injury that causes symptoms or disturbances of mental function. Usually, no findings are discovered on CT or MRI scans of the brain. A classic example is an athlete "getting his bell rung." The U.S. military requires pilots who have suffered these injuries to wait from a month to several years before returning to flying status, depending on the seriousness and duration of their symptoms. The FAA does not have a fixed schedule of observation before returning pilots to flight status after a concussion. The FAAs certification decisions depend on the individual factors surrounding the injury, the resolution of symptoms, and sometimes neurocognitive testing.
* Cerebral contusions are similar to concussions, but bleeding or bruising occurs within the brain tissue. Symptoms are very similar to those of concussions. An additional concern to the aeromedical community is that blood in the brain is an irritant that places the pilot at increased risk for seizures. The risk decreases over time and after the bleeding or bruising in the brain clears up. After this type of injury, the required observation period before the FAA clears the pilot to return to flight duties will vary, but generally exceeds 12 years. Electroencephalograms (EEGs) are used to monitor for abnormal electrical brain activity that may lead to seizures.
* Intracranial bleeding, the third type of nonpenetrating brain injury, involves bleeding into the fluid-filled spaces between the brain and the skull. Depending on where the blood is found, the injury is called a subdural, epidural, or subarachnoid hematoma. The subdural is the most common and least serious, though it can be life-threatening. Subdural hematomas may not have any symptoms associated with them, though a headache, usually dull and diffuse, is the most common symptom. The other two forms of bleeding are immediately life-threatening. Symptoms usually include the sudden onset of a severe headache and loss of consciousness. With intracranial bleeding, immediate concerns are the preservation of life, usually with emergency neurosurgical intervention. The FAA will consider waiver requests after these injuries when the pilot has recovered completely and if the pilot has no increased risk for recurrence. Observation periods of variable lengths are required following intracranial injuries before the risk of seizure is low enough for the FAA to consider granting the applicant a medical certificate.
Penetrating head injuries
Any injury that fractures the skull, displacing skull fragments inward, is called "penetrating head trauma." The penetration may be limited to skull fragments, such as in a blow to the head by a blunt object (ball, bat, etc.) or by striking the head against a fixed object (dashboard, cement, etc.). Penetration by a heavy, sharp object (ax, knife, hammer) or high-speed projectile (bullet, arrow, shrapnel) will bring hair, scalp, and bone fragments into the wound and is associated with significant brain injuries. In both blunt and foreign-object penetrating trauma, surgery is often needed as a life-saving measure.
For a harrowing perspective involving penetrating head trauma in flight, see Hijacked : The True Story of the Heroes of Flight 705, by Dave Hirschman, the dramatic story of a life-and-death struggle in the cockpit of a Federal Express airplane during a hijacking attempt by another pilot.
The long-term consequences of penetrating head trauma are significant from both a medical and an aeromedical perspective. The person who recovers is at increased risk for seizures for many years. Most individuals who have had penetrating head trauma have neurologic problems, and many will have psychological consequences from their injury.
Increased intracranial pressure
A relatively rare cause of headaches is increased pressure within the skull, which may arise from fluid collections within the brain that do not properly drain. Both benign and malignant tumors may cause pressure within the skull. The approach to any of these conditions is nearly always surgical.
The FAA policy for reinstating medical certificates after surgery for benign tumors (dermoids, meningiomas, adenomas, etc.) requires a minimum 1-year observation period after surgery. All neurologic functions must return to normal, and the pilot must have no increased risk for seizures. Malignant tumors require significantly longer observation periods before the FAA will consider issuing any waiver. The current FAA policy requires a minimum of a 5-year observation period after removal of any malignant CNS tumor.
FAA policytreatments for headaches
Numerous treatments for headaches exist. Correcting the underlying cause of the headache, if possible, is paramount in the treatment and in the FAA consideration of whether the applicant is eligible for a medical certificate. Neurologic function and mental abilities should be normal for the safe operation of an aircraft.
* Nonmigraine headache treatmentAs mentioned above, tension headaches are usually resolved with time and lifestyle changes. Under the self-assessment of fitness for flight provisions of FAR 61.53, a pilot should control these issues sufficiently before performing flight duties. The FAA permits use of mild, over-the-counter analgesics (ibuprofen, Tylenol, aspirin, naproxen) during flight duties if the pilot experiences no side effects. Pilots should not use products containing antihistamines and sleep-inducing components ("night-time formulas"). Active hydration during long flights and during mild illnesses may minimize headaches.
* Migraine headache treatmentMedications used to treat vascular-type headaches fall into two categories: "abortant," which includes medications used to eliminate the symptoms once they occur, and "prophylactic," which includes medications that prevent headaches from occurring and decrease the frequency and intensity of those that do.
The FAA policy regarding the use of each category of medication is driven by the agencys overriding concern to ensure the continuous, safe operation of an aircraft. For this reason, the FAA usually does not waive abortant-type medications if they are the sole treatment for serious vascular headaches.
Abortant medications, such as those containing ergotamines, barbiturates, narcotics, caffeine, and analgesics, as well as the newer oral, injectable, and nasal-inhaled medications, take 10 minutes to 2 hours to take effect. They may require a second dose to eliminate symptoms. Sometimes the nausea and vomiting accompanying migraines preclude taking oral medications effectively. Narcotics are sometimes required to relieve severe migraine symptoms. Often nausea is so severe with migraines that intravenous, intranasal, or rectal suppository medications are given.
If the abortant-type medication is effective, the pilot may still have a period of not being able to fully concentrate on safe flying while waiting for the medication to take effect. Causes include neurologic symptoms (visual disturbances, impaired speech, temporary weakness), pain that distracts from mental function, or nausea and vomiting. The search for the medication, and its administration, particularly oral and injectable forms, could significantly distract a pilot while flying. Occasionally, a "drug rebound" headache will occur after the abortant medication loses effectiveness or is suddenly stopped.
For these reasons, the FAA does not generally certify pilots relying on abortant medications to treat migraine headaches. The FAA does, however, allow pilots who are otherwise well controlled on prophylactic medications to carry abortant medications for use in emergency situations in flight. This is similar to the frequent practice of pilots carrying Afrin nasal spray as an "emergency-get-me-down" drug in case they suffer a sinus block or ear block. Emergency use of these medications dictates a minimum 72-hour grounding period for a single episode. Recurrent episodes should trigger a reevaluation of the effectiveness of the prevention program.
Prophylactic medications, or preventive medications, may control vascular headaches. The FAA will certify a pilot to fly who uses such medication to prevent migraines, if the pilot tolerates them without experiencing significant side effects. The two major classes of medications used, beta blockers and calcium-channel blockers, are both used also to control blood pressure and irregular heart rates. Beta blockers include propranolol (Inderal), metoprolol (Lopressor), and others. Calcium-channel blockers include diltiazem (Cardizem), verapamil (Calan, Verelan), and others. They must be taken daily to be continuously effective.
Cluster headaches are also treated with Sansert, which the FAA will authorize for use when flying. Unfortunately, Sansert cannot be used for more than 6 months continuously.
The challenge in certifying pilots on prophylactic medication is determining if the treatment is effective. No set observation period will determine effectiveness. For pilots who have headaches weekly, several weeks free of headaches after starting medication is probably adequate. Pilots who experience headaches only several times per year may have to wait considerably longer to determine that the medication is effective. If a specific stimulus (flashing lights, MSG, foods, etc.) is known to provoke migraines, exposing the pilot to the stimulus and observing how the pilot reacts may be adequate to demonstrate control of the condition. Sometimes prophylactic medications do not completely eliminate migraines, but decrease the symptoms to tolerable levels or make them controllable with allowable medications such as Tylenol or ibuprofen.
After documenting control of vascular headaches with prophylactic medications tolerated without significant side effects, that documentation can be forwarded to the FAAs Aeromedical Certification Division for an eligibility letter. Airmen should obtain full evaluations and appropriate treatment of all medical conditions to enhance their health and to be fully capable of operating an aircraft safely.