Headache

September 13, 2011

Headache disorders can be divided into primary and secondary types. A secondary headache is one caused by an underlying disease or physiologic condition. Primary headaches are not symptomatic of another condition. They are among the commonest human afflictions. Tension-type headache has a lifetime prevalence of 78%, and migraine, 16%. Secondary headaches are much less common: posttraumatic headache has a lifetime prevalence of 4%, and headache caused by brain tumor, less than 0.5%.

The term tension headache is an old one that reflects two outdated, discredited ideas of pathophysiology: that the headache is due to emotional “tension” or to excessive “tension” (contraction) of pericranial muscles. Current thinking holds that abnormal sensitivity of brain nerve cells is the cause, but the old name, with a slight change, to tension-type headache, has been retained. Tension-type headache is more common in women, with gender ratios ranging from 1.04 to 1.4. Prevalence peaks between 20 and 50 years of age and then declines. The pain is dull, achy, pressure-like, and tight. It is mild to moderate in severity. It is located bilaterally, in the forehead, temples, back or top of the head, or all over the head, and often in a band-like distribution around the head. Unlike migraine, tensiontype headache is not worsened by physical activity or associated with nausea, vomiting, photophobia (light sensitivity), or phonophobia (sensitivity to sound). Headaches typically last a few hours but can be as brief as 30 minutes or go on for years.

Tension-type headache sometimes responds to stress management, relaxation therapy, and exercise, but most patients require pharmacotherapy. The choice of an abortive medication, aimed at terminating a headache, depends on the severity and duration of the attack. Mild headaches often respond to over-thecounter (OTC) analgesic drugs, including acetaminophen, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, although four tablets rather than the traditional two may be required for effective treatment. A combination of simple OTC analgesics and caffeine may be more effective than a single drug. For more severe attacks, a similar combination including butalbital with or without codeine, available only by prescription, is more effective. Patients who use abortive medicines more than 2 days a week are at risk of developing medication-overuse headache. This takes the form of a chronic daily headache that responds to each dose of medicine for a short time but recurs soon afterward, creating a vicious cycle of rebound headaches. Avoiding this complication of treatment is the purpose of using medicines to reduce the frequency, severity, and duration of headache, that is, preventive therapy. Patients take a drug regularly, everyday, for months to years. Once their headaches have been under control for 3-6 months, the drug may be withdrawn. Amitriptyline, a tricyclic antidepressant, in a low dose, is the drug most often used, but other types of medication, including tizanidine, a muscle relaxer, and all the drugs used for migraine headache prevention are also effective.

Migraine is the second most common headache disorder; it is discussed elsewhere in this volume. Cluster headache is much less common, occurring in 15.6 men per 100,000 person-years and in 4 women per 100,000 person-years. It has a familial occurrence: The risk among first-degree relatives is 14 times higher than in the general population. The mean age of onset is 27-31 years. Its most characteristic feature is its temporal pattern. Episodes occur every other day to eight times a day for months, then they stop for months to years, then they start again; hence, the name “cluster headache.” Sometimes headaches occur at the same time each day, often in the middle of the night. They are relatively brief, lasting 30 minutes to 3 hours, but usually less than 2 hours. The pain is strictly unilateral, and the side is the same in each episode of a cluster. It centers in the eye but may be more widespread and is very severe. Patients typically pace the floor during the headache, in contrast to migraine patients, who lie down. Cluster headaches are often associated with autonomic signs on the painful side of the head, including ptosis of the eyelid and pupillary miosis (Horner syndrome), conjunctival injection, lacrimation, and nasal congestion or rhinorrhea. Effective abortive treatments include inhaled oxygen, subcutaneous or intranasal sumatriptan, and intranasal lidocaine and preventive treatments include prednisone, verapamil, lithium, and valproate.

Pregnancy and breast-feeding have an impact on the treatment of headache. The formation of the organs of the body of the fetus takes place mainly in the first trimester of pregnancy. Some medicines are known to cause fetal malformations, and others are known not to do so, but there is no certain knowledge about most drugs. Most physicians advise women to take only medicines known not to cause fetal malformations during that period of pregnancy.

Acetaminophen, caffeine, NSAIDs, codeine, and other narcotics and probably sumatriptan are safe abortive agents, but only prednisone is safe as a preventive drug, for the types of headache discussed above. Amitriptyline is probably safe in the second and third trimesters. Late in pregnancy NSAIDs should be avoided, because they can impair closure of the fetal ductus arteriosus. Medicines taken by lactating women appear in their breast milk. The dose received by the infant is usually 1-2% of the maternal dose, which is safe for most drugs but not tricyclic antidepressants, butalbital, sumatriptan, or aspirin.

Secondary headaches may be due to physiologic states such as fasting, pathophysiologic states such as caffeine withdrawal, minor illnesses such as sinusitis, and serious diseases such as stroke and head trauma. Certain historical features may be regarded as “red flags,” which indicate the possibility of serious underlying disease. A new severe headache of sudden onset may indicate subarachnoid bleeding, meningitis, or dissection of an artery in the neck or head. A headache that grows worse and worse over a period of days to weeks suggests the possibility of increased intracranial pressure or an intracranial mass lesion. Precipitation of a headache by exertion or sexual activity suggests subarachnoid hemorrhage or a malformation of the hindbrain. A headache disorder beginning late in life may be due to giant cell arteritis. A background of AIDS or cancer suggests that a new headache may be due to intracranial infection or tumor. A headache that remains localized to one part of the head for a long period of time suggests the possibility of a structural intracranial lesion there. Diseases that can present as a new headache and occur more commonly in pregnancy include subarachnoid hemorrhage, pituitary tumor and choriocarcinoma, preeclampsia, and intracranial dural venous sinus thrombosis.

SEE ALSO: Chronic pain, Giant cell arteritis, Neuropathy, Pain, Temporomandibular joint disorders

Suggested Reading

  • Dalessio, D. J., & Silberstein, S. D. (1993). Wolffs headache and other head pain (6th ed.). New York: Oxford University Press.
  • Lance, J. W. (1993). Mechanism and management of headache (5th ed.). Oxford: Butterworth-Heinemann.
  • Raskin, N. H. (1988). Headache (2nd ed.). New York: Churchill Livingstone.
  • Silberstein, S. D., Lipton, R. B., & Goadsby, P. J. (1998). Headache in clinical practice. Oxford: Isis Medical.
  • Silberstein, S. D., Stiles, A., Young, W. B., & Rozen, T. D. (2002). An atlas of headache. New York: Parthenon.

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