Cluster headache

Generality

The cluster headache is a condition characterized by an intense unilateral head pain, 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, without pain.

These active phases are called "clusters" (or "clusters" ), precisely because the attacks are frequent and close together (they occur at rather short intervals of time), and tend to occur at certain times of the day and year. The individual episodes of cluster headache can last from 15 minutes to three hours (in most patients they last less than an hour); the disorder can manifest itself with a crisis every two days or with more attacks within twenty-four hours. Although there are numerous hypotheses, the etiology is still unknown. Cluster headache is less widespread compared to tension-type headache and migraine, but still represents the third most common type of primary headache. Unlike the other two forms, however, it affects men more frequently and it is not clear whether genetic predisposition plays an important role in its appearance. Treatments can help make the active phases of the cluster headache shorter and less severe.

Forms of cluster headache

Two forms of cluster headache are distinguished:

The episodic form occurs when the bunch lasts from seven days to several months, with disease-free intervals of more than two weeks.
The chronic form occurs when attacks occur every day for more than a year consecutively, without significant pain-free intervals. About 10% of cluster headache cases are chronic.

Causes

Intense pain arises as a result of excessive dilation of the cranial blood vessels, which exert pressure on the trigeminal nerve.

The causes of cluster headaches have not yet been completely clarified, but there are some hypotheses:

Research has shown that during a cluster headache attack, there is much more activity at the hypothalamus. The painful stimulus could originate from this area, to then involve the nerve pathways that extend from the base of the brain to the face (trigeminal-autonomic reflex pathway). The trigeminus is the main cranial nerve responsible for conveying the sensory information of the face, such as the perception of pressure (touch), heat or pain. When they are activated by the hypothalamus, the sensitive terminations of the trigeminal nerve cause the characteristic ocular pain associated with cluster headaches, 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 the 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 the attacks of cluster headaches and the cycles themselves tend to manifest themselves with a precise cadence.
Finally, some think that the responsibility lies with a malfunction of the terminations of the spheno-palatine ganglion, a nervous structure connected to the trigeminal nerve and to the nerve pathways that lead the stimuli to the lacrimal glands and the nasal mucosa. This would explain some of the symptoms that accompany the painful crisis, such as intense watering and nasal congestion.

Note. Cluster headache is not caused by an underlying brain condition, such as a tumor or an aneurysm.

Triggering factors

The main factors triggering the cluster headache are:

The consumption of alcoholic beverages (would favor a possible action of chemical imbalance of the hypothalamus);
Cigarette smoke;
Stress and intense emotions;
The alteration of sleep-wake rhythms;
The effects of Jet lag;
Some drugs (example: nitroglycerin, anti-anginal drug used in patients suffering from ischemic heart disease).

It seems that these factors act in the active phase of the disease, ie during the period of painful crises (the cluster), and not in the remission phase (between one cluster and another). Furthermore, it should be noted that the cluster headache tends to appear more frequently during the period of climate change, especially in spring and autumn. The attacks are presented, however, with frequency, duration and intensity extremely variable 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 range is between 20 and 50 years. Apparently the most affected economic classes are the medium-high ones and most of the patients are smokers. The cluster headache seems to begin earlier when it is needed in the female sex.

Symptoms

Cluster headache causes extreme pain. The attacks cannot be foreseen and generally reach their full strength within five or ten minutes after the start.

Kind of pain. The pain of the cluster headache is almost always unilateral (it always affects only one side of the head) and during an attack it remains strictly on the same side. When a new episode of cluster headache occurs, it rarely occurs on the opposite side of the head.
Pain intensity. The pain of a cluster headache is generally 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 uneasy and frustrated: in order to find relief, they are led to move, to walk back and forth and to press the aching side of the head with their hands or objects. The lying position worsens the pain and sometimes prolongs the attack.
Pain localization. The pain is localized around the eye and the cheekbone, with possible irradiation to the temple, to the jaw, to the nose, to the dental arch or to the chin. In some cases the whole side of the skull is affected by pain, even involving the scalp.
Duration of pain. Grappoloinizia headache attack 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), and then suddenly decreases, as it began, with a rapid decrease in intensity, until it disappears completely. After the attacks, most patients are completely pain free but exhausted.
Headache frequency. Lacefalea occurs periodically: usually 1 to 3 attacks a day are required (up to eight attacks a day). These epidodes occur every day for several weeks or months and are followed by a period without headaches, which lasts for months or years (the average is one year). In many cases, cluster headaches occur 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.

Other symptoms of cluster headache

The characteristic head pain may be associated with other well-defined symptoms, such as:

Sense of agitation;
Tear and conjunctival congestion;
Blepharoptosis (lowering of the upper eyelid);
Miosis (contraction of the pupil);
Irritation of the conjunctiva;
Hyperemia (increased blood flow to the head);
Appearance of palpebral edema;
Rhinorrhea and nasal congestion;
Photophobia (light sensitivity) and phonophobia (noise aversion);
Redness of the face.

Unlike migraine, cluster headache almost never accompanies nausea or vomiting.

Diagnosis

The diagnosis of cluster headache is mainly based on the description of the symptomatology reported by the patient. The cluster headache shows a characteristic type of pain (by position and intensity) and with a precise attack pattern (frequency and duration): it is necessary to report this information to the doctor to define the extent of the disorder.

If the physical examination is performed during an episode of cluster headache, it is possible to highlight, sometimes, the Bernard-Horner oculopupillar syndrome (unilateral lowering of the eyelid, narrowing of the pupil, etc.). These symptoms are generally not present at other times.

No evidence is available that can provide diagnostic confirmation, but the patient is sometimes subjected to further investigations to rule out other causes that may be at the base of the headache or to search for more serious pathological conditions. For example:

Computed tomography ( CT ) and magnetic resonance allow the exclusion of benign or malignant expansive lesions, such as a pituitary adenoma or a brain neoplasm.
The lumbar puncture (rachicentesi, a technique that involves the extraction of the cerebrospinal fluid) is performed to obtain the differential diagnosis with respect to conditions such as an infection, a meningitis or another neurological condition.

Differential diagnosis

The doctor must exclude a series of other causes that cause manifestations similar to the cluster headache, such as:

Trigeminal neuralgia : occurs with often bilateral headaches (cluster headache tends to be unilateral);
Chronic paroxysmal migraine : a condition similar to a cluster headache, but the attacks are much shorter (often lasting a few seconds);
Sinusitis : occurs with pain in the face, located in the same areas as the cluster headache, but does not manifest as episodic.

The patient should consult a doctor as soon as episodes of cluster headaches begin to occur, to rule out other diseases and to find the most effective treatment. Headache, although severe, is usually not the result of an underlying disease, but may occasionally indicate a very serious medical condition, such as a brain tumor or rupture of a blood vessel (aneurysm). Furthermore, if you suffer from cluster headaches, you need to consult your doctor if the pattern of the disorder suddenly changes, if other symptoms occur if they tend to progressively worsen.

Some conditions may indicate a number of problems, including stroke, meningitis, encephalitis or brain tumor and should prompt the patient to seek immediate medical attention. These may include:

Sudden headache, very intense, with changes in perception (vision disorders, drowsiness, etc.) and in movement;
Headache associated with fever, nausea or vomiting, mental confusion, convulsions, numbness or difficulty in articulating words;
Headache after a head injury.

Treatment

The goal of treatment is to help reduce the severity of headaches, shorten their duration and prevent future attacks. The pain associated with the cluster headache can occur suddenly and may subside within a short time, so painkillers such as acetylsalicylic acid, paracetamol or ibuprofen are not effective, since the disorder may disappear before the drug exerts its therapeutic effect. .

For this reason, the cluster headache can be managed with a specific pharmacological therapy, which can be of two types:

Attack therapy, to relieve cluster headaches . The most successful treatments involve the administration of sumatriptan (Imigran ®) or other triptans, which manage to act on pain within 10-15 minutes. Even inhaling pure oxygen, through a mask for about 15 minutes, is a measure that has proven to be really effective in alleviating cluster headaches. Other options for rapid-acting symptomatic treatment include: intranasal lidocaine (with local anesthetic effect) and dihydroergotamine (effective pain reliever against acute attacks of cluster headache).
Prophylactic therapy, to prevent cluster headache attacks . Preventive medications can be prescribed to reduce the frequency and duration of attacks, as well as decrease the intensity of headaches. They are included in a therapeutic protocol that begins with the onset of the cluster headache and which must continue for the entire period in which this is needed. Preventive treatments should only be administered under the guidance and careful supervision of a specialist. Some drugs used in the prevention of cluster headaches include: verapamil (calcium antagonist, acts on blood pressure), lithium carbonate (adopted for the chronic form), sodium valproate (anticonvulsant) and prednisone (steroid anti-inflammatory, only for preventive treatments short term).

All drugs used to prevent or manage cluster headaches have potential side effects and may not be suitable for people with other pathological conditions. As with any medication, it is important to follow the directions given by your doctor carefully. Rarely, for patients with chronic form and refractory to drug treatment, surgery may be recommended, which involves the partial inhibition of conduction of pain mediated by the trigeminal nerve.