WHAT IS A HEADACHE ?

What is a headache

A Headache is defined as a pain in the head or upper neck. It is one of the most common locations of pain in the body and has many causes.

How are headaches classified?

Headaches have numerous causes, and in 2007 the International Headache Society agreed upon an updated classification system for headache. Because so many people suffer from headaches and because treatment sometimes is difficult, it is hoped that the new classification system will allow health care practitioners come to a specific diagnosis as to the type of headache and to provide better and more effective treatment.

There are three major categories of headaches:

1. primary headaches,
2. secondary headaches, and
3. cranial neuralgias, facial pain, and other headaches

What are primary headaches?

Primary headaches include migraine, tension, and cluster headaches, as well as a variety of other less common types of headache.

• Tension headaches are the most common type of primary headache. Up to 90% of adults have had or will have tension headaches. Tension headaches occur more commonly among women than men.
• Migraine headaches are the second most common type of primary headache. An estimated 28 million people in the United States (about 12% of the population) will experience a migraine headache. Migraine headaches affect children as well as adults. Before puberty, boys and girls are affected equally by migraine headaches, but after puberty, more women than men are affected. It is estimated that 6% of men and up to 18% of women will experience a migraine headache in their lifetime.
• Cluster headaches are a rare type of primary headache affecting 0.1% of the population (1 in a 1,000 people). It more commonly affects men in their late 20s though women and children can also suffer these types of headache.

Primary headaches can affect the quality of life. Some people have occasional headaches that resolve quickly while others are debilitated. While these headaches are not life-threatening, they may be associated with symptoms that can mimic strokes or intracerebral bleeding.

What causes cluster headaches?

The cause of cluster headaches is uncertain. It may be that certain parts of the brain begin to malfunction for an unknown reason. The hypothalamus, an area located at the base of the brain is responsible for the body's biologic clock and may be the part of the brain that is the source for the headaches. When brain scans are performed on patients who are in the midst of a cluster headache, there is abnormal activity in the hypothalamus.

Cluster headaches also:

• tend to run in families and this suggests that there may be a genetic role;
• may be triggered by changes in sleeppatterns;
• may be triggered by medications (for example, nitroglycerin, used for heart disease).

If an individual is in a susceptible period for cluster headache, cigarette smoking, alcohol, and some foods (for example, chocolate) also can be potential causes for headache.

What are the symptoms of cluster headaches?

Cluster headaches are headaches that come in groups (clusters) lasting weeks or months, separated by pain-free periods of months or years.

• During the period in which the cluster headaches occur, pain typically occurs once or twice daily, but some patients may experience pain more than twice daily.
• Each episode of pain lasts from 30 to 90 minutes.
• Attacks tend to occur at about the same time every day and often awaken the patient at night from a sound sleep.
• The pain typically is excruciating and located around or behind one eye.
• Some patients describe the pain as feeling like a hot poker in the eye. The affected eye may become red, inflamed, and watery.
• The nose on the affected side may become congested and runny.

Unlike patients with migraine headaches, patients with cluster headaches tend to be restless. They often pace the floor, bang their heads against a wall, and can be driven to desperate measures. Cluster headaches are much more common in men than women.

How are cluster headaches diagnosed?

The diagnosis of cluster headache is made by taking the patient's history. The description of the pain and it's clock-like recurrence is usually enough to make the diagnosis.

If examined in the midst of an attack, the patient usually is in a painful crisis and may have the eye and nose watering as described previously. If the patient is seen when the pain is not present, the physical examination is normal and the diagnosis again depends upon the history.

How are cluster headaches treated?

Cluster headaches may be very difficult to treat, and it make take trial and error to find the specific treatment regimen that will work for each patient. Since the headache recurs daily, there are two treatment needs. The pain of the first episode needs to be controlled , and additional headaches need to be prevented.

Initial treatment options may include the following:

• inhalation of high concentrations of oxygen (though this will not work if the headache is well established);
• injection of tryptan medications, for example, sumatriptan (Imitrex),zolmitriptan (Zomig), and rizatriptan(Maxalt) which are commonly used for migraine treatments as well;
• injection of lidocaine, a local anesthetic, into the nostril;
• dihydroergotamine (DHE, Migranal), a medication that causes blood vessels to constrict;
• caffeine

Prevention of the next cluster headache may include the following:

• calcium channel blockers [for example,verapamil (Calan, Verelan, Verelan PM, Isoptin, Covera-HS), diltiazem(Cardizem, Dilacor, Tiazac)]
• prednisone (Deltasone, Liquid Pred)
• antidepressant medications
• lithium (Eskalith, Lithobid)
• valproic acid, divalproex (Depakote, Depakote ER, Depakene, Depacon), and topiramate (Topamax) (often used for seizure control)

When should I seek medical care for a headache?

A patient should seek medical care if their headache is:

• The "worst headache of your life." This is the wording often used in textbooks as a cue for medical practitioners to consider the diagnosis of a subarachnoid hemorrhage due to aruptured cerebral aneurysm. The amount of pain will often be taken in context with the appearance of the patient and other associated signs and symptoms.
• Different than your usual headaches
• Starts suddenly or is aggravated by exertion, coughing, bending over, or sexual activity
• Associated with persistent nausea and vomiting
• Associated with fever or stiff neck
• Associated with seizures
• Associated with recent head trauma or a fall
• Associated with changes in vision, speech, or behavior
• Associated with weakness or change in sensation
• Not responding to treatment and is getting worse
• Requires more than the recommended dose of over-the-counter medications for pain
• Disabling and interfering with work and quality of life

Headache At A Glance

• The head is one of the most common sites of pain in the body.
• The most common types of headache can be classified as 1) primary, 2) secondary, and 3) cranial neuralgias, facial pain, and other headaches.
• The most common types of primary headaches are 1) tension, 2) migraine, and 3) cluster.
• Tension headaches are the most common type of primary headache and usually are treated with over-the-counter medications for pain
• Secondary headaches are a symptom of an injury or an underlying illness.
• Patients should seek medical care for new onset headaches, fever, stiff neck, change in behavior, vomiting, weakness or change in sensation.

References: International Headache Society. The Classification.
<http://ihs-classification.org/en/02_klassifikation/>

Previous contributing author and editor: Dennis Lee, MD and Harley I. Kornblum, MD, PhD