Evaluating cluster headaches

Cluster headaches are the most common of the trigeminal autonomic cephalalgias as defined by the International Headache Society in the International Classification of Headache Disorders (ICHD), 3rd edition.

Cluster headache pain is severe and disabling, so these headaches can result in significant morbidity. On the other hand, they are quite manageable, once recognised.

Characteristics of cluster headaches

Cluster headaches are cyclical, episodic headaches which are associated with autonomic nervous system phenomena of the cranium. They have very distinct characteristics including their pain character and pattern, associated autonomic features, and timing.

Pain characteristics of cluster headaches

The pain is severe, often described as boring, searing, or burning, sometimes like a hot poker in the eye.

It is unilateral, orbital / periorbital (including supraorbital), and may or may not include temporal pain. While the pain is centered around the eye, it can radiate, thus causing confusion with secondary conditions such as dental disease, cranial neuralgias, or sinus disease.

characteristics of cluster headache pain
Characteristics of cluster headache pain

The intensity of tension headaches can vary, but it is rarely severe, and generally, they are not aggravated by activity.

Autonomic features associated with cluster headaches

Cluster headaches always include at least one of the following autonomic symptoms or signs, ipsilateral to the headache:

  • Conjunctival injection and / or lacrimation
  • Eyelid oedema
  • Nasal congestion and /or rhinorrhoea
  • Forehead and facial sweating
  • Miosis and / or ptosis
  • A sense of restlessness or agitation
Autonomic symptoms associated with cluster headaches
Autonomic symptoms associated with cluster headaches

The temporal pattern of cluster headaches

Cluster headaches must have produced at least five attacks to be properly diagnosed. Attacks occur from 15 minutes to three hours at a time, with a frequency of one headache every other day, up to eight headaches per day.

As the name implies, the attacks occur in clusters. The series of attacks may last weeks to months. Clusters are separated by periods of remission which can last months to years. Often, bouts occur seasonally, and the cluster may last six to 12 weeks.

Most patients report the cycles of recurrent cluster bouts occurring on the same side. However, the side might change with each new cluster cycle.

Cluster headaches can be easily misdiagnosed and overlooked. They are often confused with migraine headaches. Be sure to use the International Headache Society criteria to differentiate.

Subtypes of cluster headaches

Cluster headaches are divided into episodic and chronic forms based on the frequency of bouts.

  • Episodic cluster headaches occur periodically, with bouts recurrent over seven days to a year, punctuated by pain-free periods lasting at least three months.
  • Chronic cluster headaches occur for periods of a year or more with no pain-free periods, or pain-free periods of less than three months

Which type of patients tend to get cluster headaches?

Cluster headaches occur four times more frequently in men than in women. Age of onset can be variable, but typically cluster headaches appear in early adulthood. There is also a familial subtype of cluster headache.

Treatment of cluster headaches

Episodes of cluster headache can be treated with subcutaneous injections of Sumatriptan or inhalation of 100% oxygen. Dihydroergotamine nasal spray and intravenous therapy (IV) can be used as well. Intranasal Sumatriptan, Zolmitriptan, or Lidocaine have been used with less efficacy.

Clusters can also be treated with tapered oral steroids over ten or more days. Prevention is possible using Verapamil, Lithium, Topiramate, or Valproate

This is an edited excerpt from the Medmastery course Headache Masterclass by Robert Coni, DO, EdS, FAAN. Acknowledgement and attribution to Medmastery for providing course transcripts.


Neurology Library: The primary headache disorders

Neurology Library

Robert Coni, DO, EdS, FAAN. Vascular neurologist and neurohospitalist and Neurology Subspecialty Coordinator at the Grand Strand Medical Center in South Carolina. Former neuroscience curriculum coordinator at St. Luke’s / Temple Medical School and fellow of the American Academy of Neurology. In my spare time, I like to play guitar and go fly fishing. | Medmastery | Linkedin |

BMBS (The University of Nottingham) BMedSci (The University of Nottingham). Emergency Medicine RMO at Sir Charles Gairdner Hospital Perth, WA. Interested in Medical Education and Emergency Medicine. Swimmer and frequent concert attendee.

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