Mark W. Green, M.D. Frederick R. Taylor, M.D., Park Nicollet Headache Clinic and Research Center and Adjunct Professor of Neurology, University of Minnesota, Minneapolis, MN
A 45-year-old woman has had occasional headaches for twenty years, which she attributes to drinking beer. For the past two years, she has also been getting headaches during extremely hot weather about 45 minutes into mowing her lawn with a push mower. The frontal headache, which lasts about three hours, responds partially to acetaminophen, but no off-the-shelf medication has worked to her satisfaction. Similar headaches have occurred inconsistently with her workouts. She exercises indoors and finds that a fan reduces the likelihood of a headache. She has never had a headache with coughing or sexual activity, a suddenly explosive headache, or a headache relieved by lying flat or in any other position. She doesn't recall one-sided headache, throbbing or vomiting but from time to time has had stomach queasiness she attributed to medicines. The patient is of good health and her general and neurological examinations are normal.
This woman likely has two benign headache types, although the second one creates concerns about an unusual and life-threatening form of headache. The beer-provoked headaches meet migraine criteria (aggravation of moderate headache by activity and queasy stomach misattributed to medication) while the headaches induced by mowing are exertional headaches. These are due in all likelihood to the level of exertion performed in excessive heat. There may be a component of overheating and dehydration, but neither is a necessary condition for the headaches to occur.
The patient's exertional headache is not worrisome as it has occurred many times, is not associated with abnormal neurological symptoms or examination signs, and has not had an onset as if hit by a 'lightening bolt or frying pan.'
Benign exertional headache is typically due to sustained physical exertion that is often uncharacteristically strenuous for the particular individual's conditioning. Push mowing probably fits such a description! Exercising in unusually hot weather or high altitude also increases the risk. Benign exertional headache is four times more frequent in men than women, while secondary exertional headache types (those caused by other disorders) are experienced equally. Secondary exertional headaches are most often due to structural problems such as displacement of part of the cerebellum from the base of the skull into the upper neck (known as a Chiari malformation), a space-filling lesion in the back of the brain (called posterior fossa lesion), blood from a hemorrhage near the brain , or cranioverteral (skull-neck) junction abnormalities.
Cardiac cephalalgia is a type of exertional secondary headache that is not to be missed as it is of great portent for heart attack. It occurs in individuals with heart disease, typically those with multiple heart disease-related risk factors but not necessarily with known coronary disease. This headache can be triggered with as slight a task as stair climbing. It typically improves with rest. Diagnosis can be difficult and for some individuals may only be accomplished through stress exercise testing.
There are three main types of exertional headaches: headache associated with sustained physical activity as discussed here; headache precipitated by sudden, short bursts of activity known as cough or valsalva (holding one's breath) headache; and sexual headache, which has been associated with either of the aforementioned. A recent case series that studied all three types of headache reported a secondary cause in slightly greater than four out of every ten individuals. Nearly 57 percent of all cough headaches have an association with an acquired lesion, most often the Chiari malformation.
The first step in treatment for the sustained activity type of exertional headache should be, if possible, to avoid the triggering activity. Stop exercising until serious secondary causes have been excluded. A prolonged warm-up period, increased consistency of exercise and moderation in exertion may be helpful. Yoga accompanied by breathing exercises or other relaxation or biofeedback techniques can be useful. Indomethacin is often effective as a preventive but can be a difficult medication to take, due to various gastrointestinal complaints including bleeding. Propranolol and verapamil have also been suggested.
Acute therapy of exertional headaches is based on trial and error with migraine-specific drugs (triptans or dihydroergotamine) indicated after cardiac concerns have been eliminated. For occasional headaches, patients can consider indomethacin one hour before activity. Other nonsteroidal anti-inflammatories may also be tried.