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Cluster headache: an extraordinarily severe form of headache

How do you recognize cluster headaches, what are the causes and treatment possibilities? Read about it below.

About cluster headaches

Cluster headaches are a very severe form of headache characterized by attacks. In the Netherlands, approximately 17.000 patients suffer from cluster headaches (about 0,1% of the population). Because of the severity of this type of headache, it is nicknamed “suicidal headache”. In the medical world, cluster headaches are also called Horton’s neuralgia.

This type of headache occurs more in men than in women, and there are two different types: episodic cluster headaches and chronic cluster headaches. With the episodic type, the attacks happen in clusters of several weeks to months, after which they disappear. This is where the name cluster headache comes from. With the chronic type, there are no “resting periods”. Attacks can happen daily, the whole year.

Characteristics of cluster headaches

Cluster headaches take different forms. In the most typical form, the headache is characterized by:

  • Attacks which happen every other day, to 8 times a day
  • Attacks that last between 15 minutes and 3 hours
  • Severe, one-sided pain around the eye or temple
  • Side-effects, such as:
    • red, teary, or swollen eyes on the same side of the pain
    • stuffed or runny nose on the same side of the pain
    • sweaty forehead and/or face on the same side as the pain
    • feeling of restlessness or urge to move

Causes of cluster headaches

The cause of cluster headaches is, despite a lot of medical research, unknown. However, it is thought that times of attacks have to do with the biological clock. Recent research shows changes in different areas of the brain, the hypothalamus. This is the area in the brain which manages the biological clock.

It is thought that during attacks, there is too much of a pressure difference between the blood supplying and draining arteries in the head. Because of the pressure difference and widening of the blood veins, pressure is supposedly put on the nerves, which leads to pain and other side effects of cluster headaches.

An attack can only be “provoked” during an attack period. Alcoholic drinks and vein widening medicine can be important triggers of cluster headaches. It is not proved whether food can provoke cluster headaches. When you suspect that food can play a role, you can keep a diary of what you eat and drink, to see if there indeed is a relationship. However, it usually seems to be because of coincidence.


Because it is a rare condition, patients endure a long procedure of varying researches and treatments before cluster headaches are diagnosed. In general, cluster headaches as a diagnosis is based on typical symptoms which are paired with cluster headaches. The doctor will ask you about the type of pain, the pattern of attacks (length and frequency), the location of the headache, and accompanying symptoms. Besides that, there will be a neurological exam to judge whether there is a narrowing of the pupil, or a drooping eyelid, which can pertain between attacks.

Also, it has to be assessed whether there are no other causes that can cause a headache, which is why often a CT or MR scan has to be done.


Cluster headaches are treatable with treatments focused on relieving the attack (attack treatment), as well as with treatments focused on reducing the number of attacks (preventing treatments). As attack treatments, sumatriptan injections and inhaling of pure oxygen are the most effective possibilities. Possible preventative treatments are verapamil and lithium.

Participate in our research

Not only will the generations after you benefit from thorough drug research, but there are also advantages for you as a patient. During the research, you will receive optimal guidance, the medical signs and symptoms are properly monitored and you can benefit from the possible effect of the new medicine. At Brain Research Center, we are the expert in brain research. We have more than 10 years of experience in medicine research. We also research cluster headaches. Only by testing new medicine in practice, we can determine whether it works. For this, we are looking for participants with the diagnosis of cluster headache.

Frequently asked questions

I am already taking other medication, can I keep taking them?

Yes, you will continue to take your current medications. After your registration, we look closely at your current medication use. If you use a lot of (heavy) medicines, this may be a reason for not being admitted to an examination, but this varies per study. Under no circumstances should you give up your current medication use.

Will the regular treatment with my current specialist (neurologist / geriatrician) continue while participating in drug research? Or will Brain Research Center take over?

The regular treatment with your current specialist (neurologist/geriatrician) will in principle continue during the period of the examination. The Brain Research Center will inform your specialist and general practitioner about your participation. During the investigation, checks will be carried out at various times. In case of abnormal results, Brain Research Center will, with your permission, contact your general practitioner or treating specialist. In case of changes in your health, your general practitioner or specialist may also easily consult one of our research doctors.

Is Brain Research Center also looking for participants without symptoms or without diagnosis to participate in drug research?

Brain Research Center mainly conducts research on patients who have already had a diagnosis, but sometimes there are also studies that look for healthy volunteers. You can therefore also apply if no diagnosis has been made.

Can I stop the research prematurely or are there conditions attached?

Yes, you can stop at any time. There are no conditions attached to this.

Brain Research Center has several drug studies: can I indicate which research I am interested in?

Yes, you can read about current studies on our website. You can indicate your preference for a study: for example, would you prefer to participate in a short study (for example, a few months) or a long study (for example, several years). The Brain research center determines, among other things, on the basis of your medical history, age, and current medication use whether you are suitable for the research of your preference. Different criteria apply to each study and the options are examined together with the research doctor. Participation in a study is of course always in consultation.

What does participation in research mean in specific terms?

Step-by-step plan for participating in research:

  1. Sign up
    Sign up at the Brain Research Center.
  2. Telephone intake and request medical history
    You will be called for an intake by telephone, information about Brain Research Center will be sent and a form to be signed to request the medical history from the attending physician (this history is necessary to determine whether you are eligible for research). You will be asked whether you have a so-called study partner. This is often your partner, a brother or sister, son or daughter, or neighbor: someone who knows you well and who can answer questions about your daily functioning. This person must be available to travel occasionally to appointments at Brain Research Center.
  3. Introductory meeting and choosing a study
    If Brain Research Center does not discover any reasons in your medical history why you should not participate in a study, an introductory meeting of half an hour will be scheduled in the Brain Research Center with the pre-screening specialist and research doctor. In this conversation, you get to know more and your preferences and expectations are mutually expressed. You will then receive detailed information about a number of drug studies so that you can read it through at home and discuss it with family or friends if necessary. You then choose which study you want to participate in.
  4. Screening
    During the screening, all kinds of examinations are done to determine whether you can participate in the drug study. Sometimes the inspection only includes a series of questions, sometimes laboratory tests are necessary. These studies are of course always carried out in consultation with you and with your permission. This screening takes one and a half to three hours and differs per drug research. Based on the results, it is determined whether or not you can participate in the chosen drug study. If you are not eligible for one study because, for example, your memory is still too good or too weak, you may be eligible to participate in another study. Each study uses different criteria for participation.
  5. Randomization
    In drug research, some of the patients are administered the drug in question. The other part of the patients will receive a placebo. A placebo is a medicine without active substances. The patients are randomly placed in a group by a computer. Neither the patients nor the Brain Research Center knows who is assigned to which group. In this way, the research results can be compared well: does the group receiving the real drug perform the same, better or worse than the placebo group? Once the drug trial has been completed by all participants, you will be notified whether you were given the working drug or placebo.
  6. Follow-up appointments
    If the screening has been completed successfully, follow-up appointments will be scheduled. The number of appointments and the duration of the appointments differs per drug study. On average, patients come to Brain Research Center 1 to 2 times a month for a visit of half an hour to a few hours. During the introductory meeting, you will receive more information about this. The documentation that you will receive also states how often you visit the Brain Research Center during the research. When planning the appointments, we naturally take into account any working hours and vacation plans of you and your partner as much as possible, but we also ask for flexibility on your part.
  7. After the research
    When you have gone through the entire research, the results will be assessed: have you remained stable, have you progressed, or have you regressed? We can then decide together, for example, to go through another study or to end your time at Brain Research Center.

Can I participate in research multiple times?

Yes, that’s possible. When you have gone through the entire research process, the results will be assessed: have you remained stable, have you progressed, or have you regressed? We can then decide together to go through another study, for example, or to en your time at Brain Research Center.

Is there a financial compensation for patients?

All patients are of course reimbursed for travel and parking costs. Lunch is also provided for longer visits. There is no other financial compensation. You are participating in a clinical drug trial because the drugs offer you a chance for improvement and because you want to help future generations with a drug for brain diseases. Another advantage of participating in a study is that your clinical picture is properly monitored and you receive good guidance and support from professionals during the study.

What does randomization mean?

In clinical drug research, some of the patients are administered the drug in question. The other part of the patients will receive a placebo. A placebo is a medicine without active substances. The patients are randomly placed in a group by a computer. Neither the patients nor the doctors know who is assigned to which group.

What does blinding mean?

A computer randomly places the patients in a group. One group will receive the drug in question, the other group will receive a placebo. A placebo is a medicine without active substances. Nobody involved in the investigation knows which group you are in. We call that blinding.

What do the drugs look like?

The study medication consists mostly of tablets. You can take this daily at home. Depending on the drug study, the medication can also be administered every few weeks by injection or by IV. This is done in the Brain Research Center under the supervision of the doctor.

Do I always have a chance to get a placebo?

In most drug studies there is indeed an effective and ineffective (placebo) drug. The Brain Research Center has no say in the allocation of resources: this is done automatically and the Brain Research Center does not receive that information. The Brain Research Center can only request this information in acute emergencies. There are also a number of drug studies that only work with active substances. The research doctor can inform you about this during an introductory meeting.

Will the deductible of my health insurance be used if I participate in a study of the Brain research center?

No, the treatments at the Brain research center are not covered by health insurance. So you do not have to worry about any reduction of your deductible. For each drug trial, a separate insurance policy has been taken out for all participants. If you have any questions about this, ask them during the telephone intake or during the introductory meeting. Keep in mind that other things, such as check-ups with your own specialist (outside the Brain research center), go through your own health insurance.

Would you like to know more or participate?