Brief overview
- Symptoms: Unilateral, severe headache, boring or cutting pain especially behind the eye, attack duration 15 to 180 minutes, restlessness and urge to move; watery, red eye, swollen or drooping eyelid, runny nose, sweating in the forehead area or face, constricted pupil, sunken eyeball
- Causes: Not clear, probably misregulated biological rhythms (such as diurnal rhythm); brain region that regulates sleep-wake rhythm (hypothalamus) possibly more active; possibly heredity; questionable triggers include alcohol, nicotine, flickering light, certain foods, high altitude, vasodilator medications
- Diagnosis: medical history, neurological examinations such as light reaction of the pupil, at the first occurrence or neurological deficits computer tomography (CT) or magnetic resonance imaging (MRI) of the head, sometimes examination of blood or cerebrospinal fluid (CSF)
- Therapy: Acute treatment with drugs such as triptans, inhalation of pure oxygen, insertion of local anesthetics (such as lidocaine) into the nostril, surgical procedures such as stimulation of the occipital nerve or stimulation of a specific brain region (hypothalamus)
- Preventive: Medicinal, usually by the active substance verapamil, sometimes in combination with glucocorticoids, more rarely lithium, topiramate or methysergide.
What are cluster headaches?
Cluster headache is probably the most severe unilateral headache there is. Untreated, the attacks last up to 180 minutes and sometimes occur several times a day. There are sometimes months between cluster pain episodes.
The term cluster means “accumulation” and refers to the characteristic that the form of headache occurs periodically clustered usually in certain phases.
In addition to the headache, other accompanying symptoms occur on the affected side of the head or face, such as a watery eye or runny nose. These accompanying symptoms are an automatic reaction to the severe pain and are controlled by the so-called autonomic (vegetative) nervous system.
In Germany, about 120,000 people are affected by cluster headache, three times more men than women. In principle, cluster headache can occur at any age. Men between 20 and 40 years of age are most frequently affected, especially around the age of 30.
In about two to seven percent of patients with cluster headache, the disease occurs more frequently in the family. A genetic component therefore appears to contribute to the development of the disease. However, exactly which genes are involved is still the subject of research.
What are the symptoms?
Cluster headaches occur either on the right or left side, but never at the same time on both sides of the head. They usually remain confined to one side of the head for the entire duration of the disorder, changing sides only in a few cases.
The individual attacks last between 15 and 180 minutes. The intervals between attacks vary widely. They sometimes occur every other day or as often as eight times a day. In some patients, there are weeks and months between episodes of cluster pain attacks, during which they are symptom-free.
In addition to the pain, there are the following accompanying symptoms in the affected side of the face:
- Watery eye
- Reddened conjunctiva of the eye
- Swelling of the eyelid
- Runny nose
- Sweating in the area of the forehead or face
- Horner’s syndrome
In cluster headache, Horner’s syndrome, characterized by three symptoms, is often observed on the side of the face affected by the pain. These include a constricted pupil, a drooping upper eyelid, and an eyeball that sinks somewhat into the orbit. Horner’s syndrome, however, is not unique to cluster headache. It is also possible in numerous other disorders.
Over 90 percent of patients during a cluster headache attack are extremely restless. This characteristic also distinguishes them from migraine patients. For example, they pace up and down the room or bob their upper body apathetically (so-called “pacing around”). Migraine patients, on the other hand, seek absolute rest and try to move as little as possible.
Some patients develop depression due to the severity of the pain and the impairment of quality of life.
What are the causes and risk factors?
Causes and mechanism of development of a cluster headache are not exactly known at present. Since the attacks occur in a certain daily and seasonal rhythm (especially after falling asleep, in the early morning hours, in spring and autumn), it is assumed that a malfunction of biological rhythms is the underlying cause.
The control of the sleep-wake rhythm is regulated, among other things, by the diencephalon, the hypothalamus. Experts suspect that the attacks originate in this brain region and are maintained by the autonomic nervous system and a specific cranial nerve, the trigeminal nerve. Studies have shown that the brain region around the hypothalamus is more active in cluster headache patients.
