Cluster Headache

A type of vascular headache, cluster headache suggests clustering of headaches in the head. It behaves peculiarly in the sense, that it may occur for a period of few weeks or months and then may disappear completely, sometimes, even for years altogether. Considered to be quite rare, the reasons behind cluster headaches are still unclear.

Just as a vascular headache, it is thought to be caused by the swelling of blood vessels in the head with chemically active proteins found in nerve endings around blood vessels of the trigeminal nerve. It is also believed that there is some abnormality in the autonomic nervous system that leads to this disorder. A disturbance in the neurotransmitter serotonin is also being held responsible for the disease.

Cluster headache starts suddenly without giving any warning except a slight discomfort or a mild burning sensation in one side of the head. This warning may last for a period of 30 - 45 minutes but the actual headache may last for a few hours usually occurring at around the same period almost every day. Generally, the sufferers complain of it during the night or early morning hours. The patients may even be awakened by it. It is because of this quality that these are called ‘alarm clock headaches’. Other names attributed to cluster headaches are histamine headache, red migraine and Hortony's headache.

The pain in cluster headaches is described as intense, severe and of a piercing kind. It may either be throbbing or constant. In fact, cluster pains are so intense that the scalp becomes tender, the arteries can be seen pulsating and the patient can not sit still.

With some patients, these headaches may occur seasonally. But, with others, it may be a regular feature of the calendar.

Types of cluster headaches:

Cluster headaches are commonly divided into two types: episodic and chronic cluster headache.

Episodic cluster headache attacks, quite true to their name, occur in episodes of one or more daily, usually at a particular time. They last for a few weeks or months. Then there is a pain-free interval which may last for a few months or if the patient is lucky, a few years as well.

Chronic cluster headache may last for a period of even a few years with these headaches occurring almost on a daily basis. If one experiences episodic cluster headache with not even a month of pain-free remission, then these headaches can be labeled as chronic cluster headaches. Almost 10 – 15 % of the sufferers experience the chronic variety of headache. Hence, the control of these headaches is more difficult because the patient does not respond quite well to the conventional forms of cluster therapy.

The episodic cluster may change to a chronic form and vice versa. And remission of even decades has been reported between their attacks.

Symptoms of cluster headache:
Considered to be an excruciatingly bad pain, the symptoms of a cluster headache are varied. These are as follows:

•Like a migraine attack, the pain in this case is also on one side of the head. But it may change direction and occur on the other side of the head when a new series of attacks starts.
•The pain is localized behind the eye and the region around it.
•It can radiate to the gum, forehead, nose, temple, cheek or chin on the affected side.
•It is often seen that the eyelid of the affected side swells and becomes droopy.
•The nostril on the affected side may become congested. Nasal discharge is also seen often.
•All this is accompanied by sweating as well as a flushing of the face on the affected side.
•There can also be conjunctival infection leading to red, watery eyes. Constriction of pupil, either stiffness or tenderness in neck, and jaw and teeth pain are also reported.

A person may start getting cluster headaches when he is in his adolescence or early 20s. The individual attack lasts for less than two hours. And when the pain ends, there are additional stabs of pain. Whereas a migraine patient needs rest during the attack, a cluster headache patient gets restless, active and violent. Lying down further aggravates the already bad condition of the patient suffering from cluster headaches.
What Triggers Off A Cluster Headache

Just like no one cause can be pinpointed as the cause of many diseases, similarly there is not one single factor that can lead to a cluster headache. A multitude of factors may be responsible for the same.

Any vasodilator, that is, a substance leading to swelling of the blood vessels can lead to an acute attack of cluster headache. Nitroglycerin and histamine have been labeled as the possible culprits. So is alcohol which is a well-known vasodilator. Even minimal amounts of it can be harmful as it leads to a rapid change in the blood vessels. Smoking is another factor that can contribute to cluster headaches. But during the headache-free period, alcohol and smoking do not appear to be a factor. It is only during one of the attacks that these substances lead to aggravation of the Hormonal changes in women either during periods or menopause do not seem to be the cause of cluster headaches. Also, it is seen that the sufferer gets affected during the spring or autumn. But then this headache is not seasonal and not even associated with business stress. In fact, these seasons vary from patient to patient. Somebody may get affected in the winters while another may suffer during the summers.

Some studies point out that glare or even ingestion of specific types of food can lead to a cluster headache, just as in the case of migraine.

Even exposure to hydrocarbons as found in petroleum solvents and petrol has been recognized as a trigger. If the patient has low tolerance to heat, then heat may also act as an aggravating factor. Surprisingly, even innocent things like napping might trigger the headache in certain susceptible people.

All this clearly shows that though there are specific triggers, in the form of vasodilators, that cause cluster headaches, the triggers for aggravating the problem are highly individualized owing to your vulnerability and susceptibility to certain things.

Prevalence of cluster headaches:

It is often seen that it is the older population which is more at risk of developing cluster headaches. Also, men are more prone to it than women.

But, over the past few decades, it has been found that the gap between the sexes, as far as cluster headaches are concerned, is decreasing. This can probably be because now more and more women are being afflicted and diagnosed with it.

The statistics for the rest of the world are not available, but it is estimated that approximately 1 to 4 in every thousand people in the United States and Western Europe suffer from this condition. It is more common as you move away from the equator towards the poles.

Although no single gene has been identified which can result in this condition, if any one in your immediate family has this disease, then you are also likely to be a candidate for the same.

Diagnosis of cluster headaches:

The symptoms of cluster headaches are so distinctive that it is relatively easy for the physician to pinpoint the condition. However, some tests may be recommended to confirm the presence of cluster headaches. This is because there are some other conditions which may mimic the symptoms of cluster headaches. An aneurysm of the carotid artery in the head, a tumor, sinusitis and glaucoma - all of these conditions can exhibit similar symptoms.

Also, if the pain occurs at regular intervals throughout the day and gets worse with lying down, it is a sure shot sign of a cluster headache. Sometimes, even some doctors are unfamiliar about this disease and they may misconstrue it as drug-seeking behavior. But actually the victim is under a lot of pain and needs to be promptly attended to.