The Most Common Headache
By Robert G. Kaniecki, MD
Director of the University of Pittsburgh Headache Center
The most frequent of all the headache disorders is also the least distinct in its symptoms. Called episodic tension-type headaches by headache specialists (and tension or stress headaches by others), between 30% and 80% of people experience them, according to various studies. One Danish study found that 69% of men and 88% of women have tension-type headache over the course of their lives, while 63% of men and 86% of women have them over the course of a year. More recent estimates place the prevalence of episodic tension-type headache, as defined by the International Headache Society (IHS), at 40% of the adult population.
Despite this high prevalence, the diagnosis of tension-type headache by IHS criteria is based chiefly on what characteristics are not seen. Whereas migraine is characterized primarily by the presence of positive symptoms of light and sound sensitivity, nausea/vomiting, and pain that worsens with activity, the IHS classification characterizes tension-type headache by the absence of these features.
As opposed to the one-sided, throbbing, moderate-to-severe pain of migraine, tension-type headache is characterized by bilateral, steady, and mild-to-moderate pain qualities. There are no aura or premonitory symptoms such as those seen with migraine. The headache is generally associated with minimal disability, and physical activity generally has minimal impact on the intensity of the headache. Occasionally, patients will report slight light or sound sensitivity, scalp tenderness, or muscular tension or soreness in the cervical (neck) region. The most common precipitating factors are stress and sleep disruption.
Slightly more women than men experience them, with a ratio of 1.2: 1 to 1.6: 1 in studies performed in Denmark and the United States, respectively. There is also a correlation between increased prevalence of tension-type headache and increasing levels of education. The prevalence of tension-type headache peeks between the ages of 30 and 39, and subsequently declines with age for both sexes.
Tension-type headaches are divided into episodic and chronic subtypes, with the episodic subtype involving attacks fewer than 15 days per month or 180 days per year. They may last from 30 minutes to 7 days. Chronic tension-type headaches are daily or continuous headaches that are more difficultÃ”Ã¸Î©but more imperativeÃ”Ã¸Î©to treat. (See below for more information on chronic tension-type headache).
CRITERIA FOR EPISODIC TENSION-TYPE HEADACHE
At least 10 previous headache episodes fulfilling the criteria listed below:
Number of days with such headaches less than 180 per year (fewer than 15 each month)
Headache lasting from 30 minutes to 7 days
At least two of the following pain characteristics:
Pressing/tightening (nonpulsating) quality
Mild or moderate intensity (may inhibit, but does not prohibit activity)
No aggravation through climbing stairs or similar routine physical activity
Both of the following:
No nausea or vomiting
Absence of light or sound sensitivity, or one but not the other is present
Secondary causes are excluded
The IHS further subclassifies episodic tension-type headache into categories with and without muscular tenderness around the skull. Certain patients may have points or bands of muscular tension and soreness that can be detected by manual palpation of both the head and neck areas. Both between and during headache attacks, individuals with tension-type headache have more muscle tenderness than do non-headache controls.
Tension-Type Headache or Migraine?
Initially, it was believed that tension-type headache arose from excessive contraction of the head and neck muscles. This led to one of its original namesÃ”Ã¸Î©Ã”Ã¸Î©muscle contraction headache.Ã”Ã¸Î© Many people believe that a link exists between these headaches and emotional distress or tension. However, studies have been unable to establish any clear correlation between muscle contraction, soreness or tenderness, and the presence of headache.
It is now postulated that tension-type headache arises from abnormal sensitivity of brain nerves and the facilitation of pain transmission. This pathophysiology is similar to that behind migraine. In fact, while tension-type headache is defined by characteristics that are typically different from those seen in migraine and other headache disorders, it can often be difficult to distinguish episodic tension-type headache from migraine headache. Among respondents in the American Migraine Study II who met the IHS criteria for migraine, but who had not been diagnosed with migraine by a healthcare provider, 32% had been given a diagnosis of tension-type headache. In a recently reported analysis of data from The Spectrum Study, 37% of patients initially diagnosed with tension-type headache were later found, on the basis of a neurologistÃ”Ã¸Î©s evaluation of headache diaries and medical records, to have migraine or migrainous headache.
Healthcare providers are more likely to diagnosis tension-type headache when a patient experiences bilateral or non-throbbing head pain, if the patient reports that the headache is triggered by stress or muscle tension, or when neck pain is present. In fact, migraine is often associated with these features. In recent studies, 41% of migraineurs reported bilateral pain; more than 50% reported nonpulsating pain; and 84% identified stress or tension as a precipitant of headache.
Neck pain has also been demonstrated to be quite common in migraine. In a recent study of 144 patients meeting IHS criteria for migraine, 75% described neck pain in association with their migraine attacks. And although these patients meet the criteria for migraine, 82% had a previous diagnosis of tension-type headache. The triptan medications, which are used to treat migraine attacks, were found to be effective for the tension-headache-like symptom of neck pain when it occurred as a feature of migraine.
Many individuals reporting tension or stress headaches have been established as actually experiencing migraine. In one recent study of 423 patients describing severe stress or tension headaches, 88% met the criteria for migraine or probable migraine. Of those patients with migraine, 74% felt they suffered from tension-type headaches due to the presence of discomfort in the neck or shoulders.
The similarities between migraine and tension-type headache have led to a debate as to whether they are actually unique disorders or manifestations of the same disorder. Proponents of what is called the continuum-severity theory contend that tension-type headache and migraine constitute the same entity and can only be distinguished by severity. Proponents of an alternative hypothesis, known as the convergence theory, also believe that tension-type headache and migraine are the same disorder, but that they are distinguished by the duration or extent of activation of the central nervous system pain-transmission pathways. Other researchers continue to support the concept that tension-type headache and migraine are distinct entities with different pathophysiological processes that require different treatments. Healthcare providers who care for patients with headache should be aware of the diagnostic and therapeutic overlaps between these two disorders and of the implications for the management of patients with headache.
Managing Episodic Tension-Type Headache
Because there are few symptoms and a lack of severe pain or disability, patients rarely see a healthcare provider specifically for episodic tension-type headache. Common measures to relieve the pain include taking analgesic pain medications, rest or sleep, physical massage or manipulation, local application of heat or ice, and, sometimes, aerobic physical activity.
The best approach for managing episodic tension-type headache involves a combination of lifestyle, physical and pharmacologic measures. Recommendations to regulate sleep, meals and exercise are generally quite valuable. Stress management techniques and other steps towards avoiding headache triggers may be of great benefit. Passive physical manipulation and active cervical muscle stretching or exercise programs are often advised. Behavioral therapies are quite useful adjuncts in the management of episodic tension-type headache, with the most frequently advised techniques involving relaxation therapy and EMG-guided biofeedback. Cognitive behavioral therapy may provide additional benefit in cases of significant depression or anxiety.
In the majority of cases of tension-type headache, acute therapies are used to relieve the pain of individual headache attacks. Simple analgesics, non- steroidal anti-inflammatory agents, and combination agents are most commonly used. The over-the-counter drugs of choice are aspirin, acetaminophen, ibuprofen or naproxen sodium. The use of any of these medications should be strictly limited to an average of 2-3 days per week at most to avoid developing medication overuse headache (also known as analgesic rebound headache) and the potential of transforming episodic tension-type headache into chronic tension-type headache. Opioid analgesics are rarely if ever necessary to control this type of headache.
Preventive pharmacologic therapy is generally advised for those patients who experience at least 2-3 headache days each week. Although analgesics may continue to be beneficial when taken at such levels, again, patients need to consider the risk of developing analgesic rebound or transformation into more refractory cases of chronic tension-type headache. Progression in the frequency or severity of attacks, the development of side effects, and a decline in the effectiveness of medications may all be additional indications for using preventive therapy.
Most clinicians advise taking certain antidepressants and anticonvulsants to help prevent tension-type headaches, although there is little well-controlled scientific evidence to support their use in these headaches. Centrally-acting muscle relaxants, benzodiazepines and botulinum toxin (Botox®) injections have been helpful in individual cases. There is no evidence that standard muscle relaxant therapies are effective.
If episodic tension-type headaches bother a patient enough to cause a visit to a healthcare provider, it may be necessary to exclude the possibility of an underlying, secondary headache disorder. Headaches of similar characteristics are commonly seen in patients who have elevations in their intracranial pressure, such as that seen with brain tumor, pseudotumor cerebri, or hydrocephalus. There are specific Ã”Ã¸Î©red flagsÃ”Ã¸Î© for organic disease. Particularly worrisome features are new presentations of such headaches in individuals under the age of 5 or over the age of 50; those with a past history of cancer or immunosuppression; those describing exacerbation with physical activity; or those who describe a fundamental change in their headache pattern. In such instances neuroimaging studies and other investigations should be added to a detailed neurological examination.
When to See a Doctor
While tension-type headaches are more common and typically less painful than other forms of headache, there are still times when seeking the advice of a healthcare provider is appropriate. Consider making an appointment if:
You have a headache that is the Ã”Ã¸Î©worst headache of your life;
Your headaches increase in frequency or severity;
You are experiencing headaches four or more times a month;
You miss school, work or social activities because of headache;
You have such symptoms as changes in vision or hearing, numbness, tingling or weakness in the face or extremities, blurred speech, or dizziness.
CHRONIC TENSION-TYPE HEADACHE
A tension-type headache that occurs 15 or more days per month is referred to as chronic tension-type headache. It is often a daily or continuous headache, which may have some variability in the intensity of the pain during a 24-hour cycle. Unlike the episodic form, chronic tension-type headache does cause disability and is associated more often with anxiety and/or depression. Along with the typical tension-type headache symptom of a bilateral band-like headache, symptoms can include sleep disturbances and neck pain.
Behavioral medicine, such as biofeedback, and other nonpharmacological measures including physical therapy are often used. A number of different drugs are prescribed for chronic tension-type headache. The primary drug of choice is the antidepressant amitriptyline, or other tricylic antidepressant, taken daily.
It's important that the patient with chronic tension-type headaches avoid taking analgesics or other pain medications on a daily basis as doing so can lead to medication overuse headache (rebound headache). If medication-overuse is involved, it needs to be identified and addressed. If a sufferer is taking medication daily or almost daily and is receiving little or no relief from the pain, then a healthcare provider should be seen for diagnosis and treatment.
Chronic tension-type headache can also be the result of anxiety or depression. Changes in sleep patterns or insomnia, early morning or late day occurrence of headache, feelings of guilt, weight loss, dizziness, poor concentration, ongoing fatigue and nausea commonly occur. Seek professional diagnosis for proper treatment if these symptoms exist.
The Complete Guide to Headache
You can learn more about tension-type headache, migraine and other forms of headache with "The Complete Guide to Headache," an educational module found on the NHFÃ”Ã¸Î©s Web site at www.headaches.org. The readable format makes it easy to understand symptoms, learn about treatment options, and make good choices when it comes to selecting a doctor. You'll find "The Complete Guide to Headache" in the Educational Resources section, along with topic sheets on a variety of headache subjects, tools to measure the impact of your headaches on your life, and more.