Cluster or migraine headaches?

Cluster headaches are excruciating unilateral headaches of extreme intensity. The duration of the common attack ranges from as short as 15 minutes to three hours or more. The onset of an attack is rapid, and most often without the preliminary signs that are characteristic of a migraine. However, some sufferers report preliminary sensations of pain in the general area of attack, often referred to as "shadows", that may warn them an attack is lurking or imminent.

The pain may be very sharp and may cause pain around the eye area and may also be a pain within the back of the eye. The pain of cluster headaches is markedly greater than in other headache conditions, including severe migraines; experts have suggested that it may be the most painful condition known to medical science. Female patients have reported it as being more severe than childbirth. Dr. Peter Goadsby, Professor of Clinical Neurology at University College London (now University of California, San Francisco), a leading researcher on the condition has commented:

"Cluster headache is probably the worst pain that humans experience. I know that?s quite a strong remark to make, but if you ask a cluster headache patient if they?ve had a worse experience, they?ll universally say they haven't. Women with cluster headache will tell you that an attack is worse than giving birth. So you can imagine that these people give birth without anesthetic once or twice a day, for six, eight, or ten weeks at a time, and then have a break. It's just awful."

The pain is lancinating or boring/drilling in quality, and is located behind the eye (periorbital) or in the temple, sometimes radiating to the neck or shoulder. Analogies frequently used to describe the pain are a red-hot poker inserted into the eye, or a spike penetrating from the top of the head, behind one eye, radiating down to the neck, or sometimes having a leg amputated without any anaesthetic. The condition was originally named Horton's Cephalalgia after Dr. B.T Horton, who postulated the first theory as to their pathogenesis. His original paper describes the severity of the headaches as being able to take normal men and force them to attempt or complete suicide. From Horton's 1939 paper on cluster headache:

"Our patients were disabled by the disorder and suffered from bouts of pain from two to twenty times a week. They had found no relief from the usual methods of treatment. Their pain was so severe that several of them had to be constantly watched for fear of suicide. Most of them were willing to submit to any operation which might bring relief."

Thus, cluster headaches are also known by the nickname "suicide headaches".