Generality
Cluster headache is a condition characterized by intense one-sided pain of the head, that is, localized on only one side of the head. The painful attacks associated with this form of primary headache occur regularly, with a periodic character: the active phases last from weeks to months and alternate with long periods of spontaneous remission, free of pain.
Forms of cluster headache
There are two forms of cluster headache:
- The episodic form occurs when the cluster lasts from seven days to a few months, with disease-free intervals of more than two weeks.
- The chronic form occurs when the attacks occur every day for more than a year consecutively, without significant pain-free intervals. About 10% of cluster headache cases are chronic.
Causes
The intense pain arises as a result of the excessive dilation of the cranial blood vessels, which exert pressure on the trigeminal nerve.
The causes of cluster headache have not yet been fully clarified, but there are some hypotheses:
- Research has shown that during a cluster headache attack, there is much more activity at the level of the hypothalamus. The painful stimulus could originate from this area, and then involve the nerve pathways that, from the base of the brain, extend up to the face (trigeminal-autonomic reflex path). The trigeminal nerve is the main cranial nerve responsible for conveying sensory information from the face, such as the perception of pressure (touch), heat or pain. When activated by the hypothalamus, the sensory endings of the trigeminal nerve cause the characteristic ocular pain associated with cluster headache, and in turn also involve another group of nerve fibers, which induce nasal congestion, tearing and redness of the "eye.
- Furthermore, the "hypothalamus is responsible for our" internal biological clock ", as it regulates sleep-wake cycles. It is therefore believed that there may be an imbalance in the management of circadian rhythms by the hypothalamus; it is probably for this reason that cluster headache attacks and the cycles themselves tend to occur with a precise cadence.
- Finally, some think that the responsibility lies with a malfunction of the terminations of the spheno-palatine ganglion, a nerve structure connected to the trigeminal nerve and the nerve pathways that conduct stimuli to the lacrimal glands and nasal mucosa. This would explain some of the symptoms that accompany the painful crisis, such as intense tearing and nasal congestion.
Note. Cluster headache is not caused by an underlying brain condition, such as a tumor or aneurysm.
Triggering factors
The main triggers of cluster headache are:
- The consumption of alcoholic beverages (they would favor a possible chemical imbalance action of the hypothalamus);
- Cigarette smoke;
- Stress and intense emotions;
- The alteration of sleep-wake rhythms;
- The effects of jet lag;
- Some drugs (example: nitroglycerin, an antianginal drug used in patients with ischemic heart disease).
It seems that these factors act in the active phase of the disease, that is, during the period of painful crises (the cluster), and not in the remission phase (between one cluster and the other). Furthermore, it should be noted that cluster headache tends to appear with greater frequency during the period of climate change, especially in spring and autumn.However, attacks occur with extremely variable frequency, duration and intensity from person to person.
Who is most at risk
Anyone can be affected, but this type of headache mainly affects men. The most affected age group is that between 20 and 50 years. Apparently the most affected economic classes are the medium-high and most of the patients are smokers. Cluster headache seems to begin earlier when it occurs in women .
Symptoms
Cluster headache causes pain of extreme intensity. Attacks cannot be predicted and generally reach their full force within five to ten minutes after starting.
- Kind of pain. Cluster headache pain is almost always one-sided (it always affects only one side of the head) and remains strictly on the same side during an attack. When a new cluster headache episode occurs, it rarely occurs on the opposite side of the head.
- Pain intensity. The pain of a cluster headache is usually very intense and severe and is often described as stabbing and stabbing. It can be episodic or constant. During an intense attack, most people feel restless and frustrated: to seek relief, they are prone to move, pacing back and forth, and pressing the aching side of the head with their hands or objects. The lying position worsens the pain and, at times, prolongs the attack.
- Localization of pain. The pain is localized around the eye and cheekbone, with possible radiation to the temple, jaw, nose, dental arch or chin. In some cases the whole side of the skull is affected by pain, even involving the scalp.
- Duration of pain. The "Cluster headache attack starts without warning and quickly reaches maximum intensity within 5-10 minutes. A single episode can last from 15 minutes to three hours (but often less than an" hour), then abruptly subside, such as it began, with a rapid decrease in intensity, until it disappeared completely. After the attacks, most patients are completely free of pain, but exhausted.
- Headache frequency. Headache occurs periodically: usually 1 to 3 attacks per day (up to eight attacks per day). These outbreaks occur every day for several weeks or months and are followed by a headache-free period, which lasts for months or years (the average is one year). In many cases, cluster headache occurs at the same time of day, especially between nine in the evening and 10 in the morning, mainly during the REM (Rapid Eyes Movement) sleep phase.
