In most patients who seek treatment for headache, the cause is benign (primary headache). More worrisome, however, both to the patient and the physician, is the secondary or organic headache, which may be associated with significant morbidity or even mortality.
Most patients who seek treatment for headache have the benign type--usually migraine, tension, or cluster headache. This review looks at what distinguishes benign-type headache from the more worrisome secondary organic-type headache.
In most patients who seek treatment for headache, the cause is benign (primary headache). More worrisome, however, both to the patient and the physician, is the secondary or organic headache, which may be associated with significant morbidity or even mortality. Headaches in this category include those of sudden onset in a person older than 50 years or younger than 5 years and those described as "the worst of my life." Other worrisome headache features are listed in Table 1.
TYPES OF BENIGN HEADACHE SEEN IN OFFICE PRACTICE
Benign headaches, such as migraines, are not caused by structural problems; however, they can interfere with the patient's lifestyle and functioning. Some headaches, such as tension-type headaches, are mild to moderate and are not exacerbated by routine physical activity. In fact, they usually respond to mild physical activity or "a break from the routine." If not--or if the symptoms are exacerbated by activity--the diagnosis is usually migraine. Benign headaches may occasionally be associated with nausea or vomiting; anorexia may occur. Photophobia or phonophobia may also be present, as in migraine. Generally, the headache pattern remains stable over time.
Although many more headache types are listed in the revised International Classification of Headache Disorders (ICHD II; Table 2 lists the ICHD II diagnostic criteria),1 these 9 are the most often encountered in general practice:
*Migraine without aura.
*Probable migraine without aura.
*Migraine with aura.
*Probable migraine with aura.
*Chronic migraine associated with analgesic overuse.
*Chronic daily headache.
Tension-type headache is by far the most common type, occurring in about 70% of patients. These headaches are seldom incapacitating and often improve with physical activity. Sufferers generally obtain relief from over-the-counter (OTC) analgesics. However, when symptoms become moderate to severe or increase with physical activity, or when they are not relieved by OTC medications or impair function, the patient typically consults a clinician, usually a primary care practitioner. That is, patients who present with headache do so because the pain has become so severe or debilitating that it impairs their ability to function in occupational or social settings.
Moderate to severe headaches that are incapacitating are generally considered migraine, although they often masquerade as sinus or tension-type headache in the sense that they may occur in the occipital portion of the head or neck or in the sinuses. However, these symptoms satisfy the criteria for probable or early migraine.
A key distinction between migraine and other types of headache is a family history; 70% to 90% of patients with migraine have family members who suffer with the condition as well. Moreover, migraine is often triggered by certain foods and agents--including caffeine, red wine, nitrites, nitrates, chocolate, monosodium glutamate, and aspartame and other artificial sweeteners. Some other factors include hormone fluctuations or changes in the weather.
Migraine affects 3 times as many women as men. About 15% of patients report an aura and 50% have a prodrome. The principal "benign" features of migraine are listed in Table 3.
Migraine without aura This is one of the most common types of migraine seen in primary care office practice; it affects about 85% of all migraine patients. As with other headaches, secondary headache must be ruled out. A principal criterion for a migraine diagnosis in an adult is a history of at least 5 migraine attacks with an average duration of 4 to 72 hours. In children, the duration is 1 to 48 hours. Two of the 4 following symptoms are also required to establish the diagnosis:
*Pain is unilateral.
*Pain is moderate to severe.
*Pain is throbbing or pulsating.
*Pain is exacerbated by routine physical activity.
Migraine without aura is generally described as unilateral and throbbing. It may also be the presumptive diagnosis in a patient who has moderate to severe headaches that intensify with routine physical activity and that are diffuse rather than unilateral and may not be throbbing. However, a diagnosis of migraine must include one or both of the following:
*Nausea and/or vomiting.
*Photo- and/or phonophobia.
Probable migraine without aura This type of headache meets all of the qualifications of migraine without aura, except that it involves 1 less symptom (see Table 2, A and B). In other words, although all 3 symptoms in the first subcategory must be included to establish the diagnosis, 1 symptom from either the second or third subcategory (but not both) is missing. For example, probable migraine without aura may consist of moderate to severe headaches that are aggravated by routine activity. The absence of corresponding symptoms such as nausea and/or vomiting, or photophobia and/or phonophobia, confirms the diagnosis of probable migraine without aura. Another example of probable migraine without aura is the presence of all 3 symptoms in the first subcategory, plus moderate to severe intensity and phonophobia or photophobia.
Migraine with aura This type of migraine is diagnosed when a patient has had at least 2 attacks of migraine preceded by an aura. Aura is not classified as a headache in the ICHD II guidelines, but it is usually followed by migraine and is not attributable to another disorder. It develops gradually over the course of 5 to 20 minutes and lasts for less than 60 minutes. Sensory symptoms, which are reversible, include flickering lights; spots or lines and/or alteration of sight or loss of vision; alteration of sound, smell, or sensation (such as pins and needles and/or numbness); paresthesias; ataxia; dysphasia; and other neurologic signs and symptoms. Any one of these sensory symptoms confirms the presence of aura.
Probable migraine with aura This follows the same pattern as probable migraine without aura, but includes the additional symptoms of aura.
Chronic migraine This is migraine that occurs on 15 or more days per month for more than 3 consecutive months in the absence of medication overuse.
Chronic migraine with analgesic overuse This migraine is one that occurs on 15 or more days per month for more than 3 consecutive months as a result of medication overuse (see Table 2, F).
Tension-type headache Tension-type headaches last from 30 minutes to about 7 days. At least 10 attacks are needed to establish the diagnosis, and secondary headache must be ruled out. Tension-type headaches are bilateral and have a pressing or tightening quality (see Table 2, G).
Cluster headache These occur 8 times more frequently in men than women. The duration of a cluster headache is 15 to 180 minutes. It is usually unilateral and occurs behind the eyes--orbital, supraorbital, or temporal--and has a piercing or boring quality. The pain is intense. The patient may exhibit evidence of conjunctival irritation or injection, lacrimation, nasal congestion, rhinorrhea, forehead or facial sweating, miosis, ptosis, or eyelid edema on the side of the ache. At least 1 of these symptoms must be present to establish the diagnosis (see Table 2, H).
Chronic daily headache Chronic daily headache occurs infrequently (in 2% to 3% of persons prone to headache); however, this condition is difficult to treat. Complex issues of diagnosis, medication overuse, and comorbid conditions such as anxiety and depression are frequently seen in patients who have chronic daily headache. The headaches often impair their ability to function in social and occupational settings.
Several patterns of chronic daily headache have been observed. Often the underlying pattern can be defined as transformation from an episodic migraine, tension-type, or cluster-type headache to a chronic daily headache that waxes and wanes (Table 4). These patients also experience a periodic disabling headache superimposed on the baseline pattern. This headache type may be associated with medication overuse, or it may contain features of transformed migraine and/or chronic tension-type headache.
A second type of chronic daily headache can be described as a persistent daily headache of new onset. Patients often can pinpoint exactly when the headaches started--for example, following a viral infection.
A third type of chronic daily headache emanates from such causes as head trauma or structural patterns, including degenerative joint disease of the cervical spine. Although these headaches are not initially associated with medication overuse, patients with this type of headache may become overusers of analgesics as they seek to control the pain. *
An earlier version of this article appeared in the September 2004 issue of Headache & Pain.
1. Headache Classification Subcommittee of the International Headache Society. International Classification of Headache Disorders. 2nd ed. Cephalalgia. 2004;24(suppl 1):9-160.