Migraine is not the only debilitating headache-related condition. One of its close cousins is cluster headache. Cluster headache has some things in common with migraine, including some overlap in treatment, but it’s usually a distinct and separate diagnosis.
What is cluster headache?
Cluster headache is a type of headache that occurs on one side of the face, causing severe pain, typically in or around the eye or temple, and symptoms of eye and nose watering, eye and face redness, eyelid drooping or swelling and sweating of the face. During an attack, which can be relatively short (15 minutes) or last for several hours, the person usually feels agitated and may pace the room or want to bang their head on the wall.
These symptoms occur because of activation of both the trigeminal nerve, the large nerve that supplies sensation to the face, and the autonomic nervous system, which controls all those bodily functions we don’t have conscious control over, like sweating and constricting our pupils.
Like migraine, cluster headache is defined as episodic or chronic. In episodic cluster headache, attacks occur in a 'cluster’, a period of time usually lasting for a few weeks but often longer if not treated, with remission for at least three months. During the cluster, attacks can occur from every other day to eight times a day. Attacks often occur at the same time of day (peaking between 9pm and 3am and often waking people from sleep) and clusters often happen at the same time in the year (often spring and autumn).¹ About 20% of people with cluster headache have chronic cluster headache, when attacks occur without remission.
How is cluster headache different from migraine?
Cluster headache is rare, affecting only 0.1% of the population. Migraine affects around 16% of the population.²
People with migraine headache pain usually want to keep still and exercise can aggravate symptoms. People with a cluster headache often want to move around and can’t lie still.
People with a cluster headache have pronounced autonomic symptoms – tearing, nasal congestion, sweating, and red, swollen eye. These can occur in migraine, but are usually less prominent and occur on both sides of the face (they only occur on the affected side in cluster headache).
Cluster attacks occur more often at night than migraine attacks.
Cluster headache is almost always only on one side of the head; the pain of migraine headache can switch sides or occur on both sides of the head.
Cluster attacks are typically much shorter than migraine attacks, that last for at least four hours if not treated.
Cluster headaches often have a more rapid onset of pain, peaking within minutes and also quickly subsiding, whereas the onset and cessation of migraine headache pain can be more gradual.
Cluster headache is more common in men; migraine is more common in women.
The pain of cluster headache is described as excruciating, to the point that suicidal thoughts are common. Migraine pain can be on a spectrum of mild to severe.³
What are the similarities between cluster headache and migraine?
Triggers for both can include alcohol, strong smells, changes in sleep and weather.
Both can be inherited but most people with cluster headache don’t have a family history of it.
Both involve the trigeminal nerve in the face and the neuropeptide calcitonin gene-related peptide (CGRP).
Classic features of migraine such as aura symptoms, sensitivity to light and sound (on the side of the cluster headache) and nausea and vomiting can also occur in cluster headache. This can lead to cluster headache being misdiagnosed as migraine.⁴
Can you have both cluster headache and migraine?
Unfortunately, some people have both conditions. Migraine occurs in 10–17% of those with cluster headache.³
Sometimes migraine attacks can ‘cluster’ together in time, but this isn’t the same as cluster headache. To avoid confusion, clinicians tend to talk about cyclical migraine attacks, when a person has a bout of frequent attacks, followed by a period of remission. These cycles can occur in response to changes in hormone levels, such as for menstrual migraine. Sometimes they occur for no apparent reason. An increasing frequency of migraine attacks could also indicate the development of chronic migraine.
There are cases reported in the literature where it can be difficult to distinguish between migraine and cluster headache, even for experts.⁵ In such cases, clinicians try to find a treatment that will work for both conditions, but it can be a trial and error process.
How is cluster headache treated?
One reason to differentiate between migraine and cluster headache is that the optimal treatment can vary.
Acute therapy for cluster headache
To treat a cluster headache attack, the primary options are subcutaneous sumatriptan (the oral route doesn’t work quickly enough), intranasal zolmitriptan (not available in New Zealand), high flow oxygen (quite difficult to get hold of in NZ) and vagus nerve stimulation using a hand-held device (not available in NZ).
Non-steroidal anti-inflammatories, paracetamol and opioids are not effective.
Preventive therapy for cluster headache
Verapamil is first line therapy for prevention of cluster headache, then galcanezumab (Emgality – available in NZ but not funded). Other options include lithium, melatonin, topiramate and gabapentin. Oral steroids and occipital nerve blocks can help dampen down attacks while preventive therapy is starting to work. The treatment of chronic cluster headache can be more difficult – surgery is a last resort.
Common issues with cluster headache and migraine
Accurate and timely diagnosis, access to funded treatment and access to specialists to support best-practice diagnosis and treatment are all issues for both people with cluster headache and people with migraine.
Migraine Foundation Aotearoa New Zealand is advocating for improvements in all of these areas. Our cousins with cluster headache are more than welcome to join us.
References
Benkli, B. et al. Circadian Features of Cluster Headache and Migraine: A Systematic Review, Meta-analysis, and Genetic Analysis. Neurology 100, e2224–e2236 (2023).
Matharu, M. S. & Goadsby, P. J. Trigeminal autonomic cephalgias. J Neurol Neurosurg Psychiatry 72, ii9–ii26 (2002).
Al-Mahdi Al-Karagholi, M. et al. Are cluster headache and migraine distinct headache disorders? The Journal of Headache and Pain 23, 151 (2022).
VanderPlyum, J., Starling, A. & Anderson, C. Cluster headache. BMJ Best Practice (2023).
Chwolka, M., Goadsby, P. J. & Gantenbein, A. R. Comorbidity or combination – more evidence for cluster-migraine? Cephalalgia 0, 1–6 (2023).