Headaches are divided into two large families: primary and secondary; primary headaches are the most common, while secondary headaches are a symptom of another disease they are associated with.

Migraine, tension headache and cluster headache are the three primary headaches. Together with Dr. Vincenzo Tullo, Neurologist and head of the migraine outpatient clinic at Humanitas LAB, we are better acquainted with cluster headaches, a rare but complex and disabling disease.

Cluster headache is not a very common disease, and depending on the country it has an incidence of between 0.2 and 0.3% of the general population. It mainly concerns men, with a typical age of onset between twenty and thirty years.


Active and remission periods


“This headache sees the alternation of active periods (called clusters), with attacks of very violent headaches, and periods of remission. Active periods typically last a couple of months and are characterized by attacks lasting from 15 minutes to three hours; attacks can be daily or even reoccur 7-8 times in the same day. The periods of remission for some patients are very short (in this case the disease has a chronic course and is treated as such), in other cases they vary from a few months to several years.

The pain is unilateral and localized to the orbital region and therefore to the eye. Then there may be redness of the eye, lachrymation, rhinorrhea (runny nose), palpebral ptosis, facial and frontal sweating. In addition to pain, the attack is characterized by a sense of agitation and restlessness that affects the patient, precisely because of the aggressiveness of the pain. Faced with the attack, the patient has no choice but to take specific painkillers to deal with the pain or improve the situation; there is no point in taking the remedies that relieve migraines, such as lying in the dark with the eyes closed, in a silent place,” says Dr. Tullo.


The role of the seasonal change


“Active periods are affected by the change in season due to the fluctuation in the number of hours of light and darkness. The explanation is related to a pathophysiological hypothesis of cluster headache. This pathology would involve the hypothalamus, which among its many functions also presides over the regulation of biological rhythms and could therefore be affected by changes in light and dark. Patients with cluster headache have a structural alteration of the posterior hypothalamus, which may lead to a decrease in melatonin production. There is also an alteration of the hormone cortisol, with an increase in circadian production during the clusters.

The involvement of the hypothalamus could also be confirmed by the fact that lithium is used to contain crises, which accumulates in the hypothalamus”, explains the specialist.


Pharmacological therapy for cluster headache


“The management of this disease is rather complex and for patients with chronic disease we do not have definitive treatment.

In general, patients are treated with targeted pain relievers, such as sumatriptan (which is injected subcutaneously and can control pain in 10-15 minutes), indomethacin and oxygen. Then there is preventive therapy, which involves taking specific drugs (lithium, verapamil, cortisone, antiepileptic) at the onset of the clusters to reduce the number of crises.

An antibody therapy to block Calcitonin gene-related peptide (CGRP), a substance involved in the disease, is being tested globally and at an advanced stage.


Surgical options


“Depending on the case, it is also possible to undergo surgical treatments. Deep brain stimulation affects the posterior hypothalamus. It is an invasive solution, reserved for critical and drug-resistant patients. Other options include stimulation of the large occipital nerve and injection of anesthetics and cortisone into both the large occipital nerve and the sphenopalatin ganglion, a nervous ganglion that belongs to the trigeminal and it is found in nasal pits.

Finally, it is worth remembering that the cluster sufferers have an obligation to support each other and therefore pay attention to their quality of life: avoiding smoking and alcohol, maintaining a regular sleep-wake rhythm, following a balanced eating behavior and containing the levels of psycho-physical stress within the norm”, concludes Dr. Tullo.