At the first attack, cluster headache could be mistaken for a strong migraine or trigeminal neuralgia, so much so that the International Headache Society (IHS) international classification system of headaches places it in the group of trigeminal autonomic cephalalgias, or headaches characterized by very intense ipsilateral pain that are associated with a series of symptoms such as drooping of the eyelid, narrowing of the pupil etc. This group also includes paroxysmal migraine and continuous migraine.
To differentiate cluster headache from other forms of unilateral severe headache (ie localized mainly in one side of the head, in particular in the area around the eye, although the extreme intensity of the pain means that it can extend more nuanced to the whole skull) is above all the temporal distribution of attacks, followed by the finding of some peculiar secondary signs and symptoms and the reduction of pain in response to specific drugs and not to others.
What is it
Cluster headache is, by far, one of the most painful headaches that can be experienced, to the point of being highly disabling and even being called “suicide headache”. Its name derives from the fact that headache attacks are concentrated in limited periods of time (cluster or active period), interspersed with periods of complete remission in which crises are never present, cyclically following a “cluster” pattern.
In order to diagnose cluster headache, each cluster of head pain attacks must last from a few weeks to a few months and be separated from the next by a wellness phase lasting at least one month. To tell the truth, however, this rule applies only to the so-called “episodic” cluster headache, which can occur only once or a few times in life or on several occasions a year.
About 10-15% of people with this disease are, unfortunately, affected by a form of chronic headache, completely similar in intensity of pain and characteristics to the episodic one, but without a period of remission or with phases of well-being lasting less than a month. This constant torture may occur as a negative evolution of an episodic form of pre-existing cluster headache or present with a chronic course from the onset.
By way of reassurance, however, it must be said that in most cases cluster headache crises are repeated once or twice a year, according to a pattern that varies from person to person.
The incidence of cluster headache is higher among men, who suffer from it up to three times more frequently than women. Generally, the first attack occurs just before the age of thirty (the age range of maximum onset is from 20 to 40 years), but it is not excluded that this form of headache can make its appearance at any other time of life.
Causes of cluster headache
According to the IHS International Headache Classification, cluster headache can be either primary or, more often, secondary. Let’s see what the respective causes are.
| Cause | |
| Primary headache | “Spontaneous” onset |
| Secondary headache | Induced/triggered by another disorder or factor known to cause headaches (e.g. infections, such as influenza or meningitis) |
In both cases, the biological and neurological mechanisms leading to the development of cluster headaches have not yet been fully elucidated. On the basis of the outcome of brain imaging studies, it is believed that the hypothalamus may be involved in the onset and / or persistence of this type of headache, a very important area present in the center of the brain, also involved in the control of circadian rhythms (or the so-called biological clock), in the regulation of thermal homeostasis (thermoregulation, sweating, vasodilation, etc.), energetic (hunger, food intake, salivation etc.) and hydrosaline (introduction of liquids, pressure, diuresis, etc.), as well as in emotional response and sexual behavior.
In particular, it has been observed that during acute attacks of cluster headache the gray matter of the posterior part of the hypothalamus is activated: in consideration of the involvement of this brain structure in the regulation of the biological clock, this could explain the cyclical nature with which headache crises occur.
Among the other possible causes of triggering clusters of attacks, hormonal factors (especially melatonin and cortisol, involved respectively in the regulation of sleep-wake rhythm and stress) and imbalances in the levels of some neurotransmitters, such as serotonin (brain substance primarily involved in the development of mood disorders such as depression and anxiety) have been examined. , but with a role also in the regulation of sleep). Genetic predisposition also seems to play an important role in the development of cluster headache, as it can affect multiple members of the same family.
Unlike migraine and tension headache, cluster headache does not generally seem to be linked to food-type triggers (specific foods or additives), imbalances in sex hormone levels or situations of psychophysical stress.
Conversely, it has been observed that attacks of episodic cluster headache and, in some cases, even the chronic form, can be triggered or worsened by the intake of alcoholic beverages, histamine (substance secreted during allergic reactions and contained in significant quantities in some foods such as mackerel fish and seafood, aged cheeses, salami and speck, red wine and sparkling wine, tomatoes, eggplant, spinach, sauerkraut, ketchup and soy sauce) and nitroglycerin-based drugs (mainly used to appease acute episodes of angina pectoris).
Symptoms of cluster headache
The main symptom of cluster headache is stabbing, unilateral pain, localized mainly at eye level and in the surrounding orbital area (up to the temple), which tends to radiate to different parts of the face (for example the frontal area), head, neck and shoulders. Usually the pain appears suddenly, without any warning signs, and is often described as piercing or sharp or as a strong burning sensation that resembles a hot stab in the eye.
Each individual attack can last for a period between 15 minutes and three hours and to establish that it is cluster headache, during cluster periods, it must recur with a frequency varying from one to every other day up to 8 times a day (a real torment).
During the attack, the pain may be accompanied by contour symptoms that make the manifestations of cluster headache similar to those of migraine, such as: nausea (sometimes vomiting), hypersensitivity to light (photophobia) and noise (phonophobia), swelling of the eyelids, tearing and redness of the eye, nasal congestion and rhinorrhea, feeling of fullness in the ear, facial redness and sweating (at the level of the face and forehead), narrowing of the pupil (miosis).
In addition, during the crisis there is often psychomotor agitation (ie an extreme form of excitement, characterized by the increase in verbal and motor activity not aimed at any specific purpose) more or less intense that makes it impossible to lie down or sit in an armchair to rest. Moreover, it is common experience among cluster headache sufferers that, instead of alleviating suffering, lying down makes the pain even more acute.
In some cases, the attack of cluster headache can be anticipated by symptoms completely similar to those of migraine with aura, ie a set, subjectively variable in type and duration, of visual, auditory, sensory and language disorders. Typically, the aura develops in the 30-60 minutes before the onset of pain.
Complications of cluster headache
The main health risk associated with cluster headaches, as with any other form of headache of any importance, comes from inadequate treatment that can lead to an increase in the duration, intensity and frequency of attacks, resulting in a significant decline in quality of life.
To avoid seeing the disorder worsen, the first advice is not to abuse over-the-counter pain medications and anti-inflammatories when attacks tend to recur more than 2-3 times a month or persist for more than 3-4 days. Moreover, the common analgesics available in non-prescription drugs are unlikely to offer real relief from pain nor, even less, to prevent the latter from reoccurring after a few hours or the next day.
To obtain a real benefit without taking risks, it is important to contact the family doctor and, after obtaining a precise diagnosis, initiate targeted treatment of episodic acute attacks and / or undertake prophylactic therapy if the form of cluster headache from which you suffer is chronic.
Cluster headache therapies
As anticipated, in the case of cluster headache, over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) to be taken by mouth are not very effective, and the dosage should not be increased carelessly, because as the only result you could only get a greater risk of side effects.
The pharmacological treatment of this form of headache must always be prescribed by the doctor and is substantially comparable to that used against migraine. In particular, to alleviate pain during acute attacks, anti-migraine drugs of the triptan class are useful which, administered by subcutaneous injection, are effective in a few minutes in 95% of cases.
In case of mild-medium attacks, inhaled oxygen (with mask) and indomethacin (an NSAID with a strong analgesic power) administered through intramuscular injections or in suppositories can also help to soothe pain.
In view of the disabling severity of cluster headache crises and their recurrence, in addition to treatments for individual acute attacks, the doctor usually proposes therapy aimed at preventing new episodes.
The drugs that have proven useful for this purpose are some corticosteroids (also associated with the injection of a local anesthetic), verapamil (an active ingredient also used against hypertension), lithium (also used to treat psychiatric disorders such as major depression and bipolar disorder) and some anticonvulsants.
The choice of specific prophylactic treatment depends on the characteristics assumed by cluster headache in the individual patient, the age and general clinical picture of the latter, as well as his preferences or fears regarding possible side effects.
Finally, surgical techniques can also be used to extinguish attacks, such as stimulation of the large occipital nerve and deep brain stimulation (a stereotactic neurosurgery technique reserved for the most severe forms of cluster headache and resistant to drug therapies).
When to consult your doctor
When an intense headache appears, with the characteristics of cluster headache, migraine or inflammation of the trigeminal nerve, or in any case such as to prevent the performance of common daily activities, it is always advisable to go to the attending physician or a neurologist (the specialist in nervous system disorders), to exclude the presence of other pathologies and identify the most effective therapy as soon as possible.
To this end, in some cases, in relation to the characteristics of the headache complained of, age, personal and family clinical history and any specific individual risk factors, the doctor may request some laboratory and / or instrumental tests (CT, magnetic resonance imaging), able to better clarify the nature of the disorders and any underlying causes.
The doctor should also be consulted when a headache you have already suffered in the past suddenly changes characteristics in terms of pain intensity, mode of onset, frequency and duration of attacks.
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
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