What are Cluster Headaches?
A cluster headache is a head pain on one side of the head, typically occurring above or behind the eye. It is classified as one of the Trigeminal Autonomic Cephalalgias, and associated with “autonomic” symptoms such as nasal congestion, profuse sweating, swelling or drooping of the eyelids, and/or the excessive secretion of tears. Sometimes referred to as a “suicide headache”, cluster headache brings an immense amount of pain. In fact, according to Brian M. Grosberg, neurologist and director of Montefiore Headache Center, a cluster headache represents “one of the most painful conditions a person can experience.”
A cluster headache can recur over time. One headache typically lasts anywhere from thirty minutes up to three hours. From some, these headaches and pain will occur for as many as twelve weeks out of each year (which are classified as chronic cluster headaches). Cluster headaches typically awaken a patient from sleep at night, and are thought to be REM related headaches.
Cluster headaches are the least common type of headache, affecting less than one in one thousand people. They affect men considerably more often than they do women — at a ratio of 4:1 and are found more often in smokers than nonsmokers.
Causes of Cluster Headaches
The definite cause of cluster headaches is unknown. Initially, they were thought to be related to histamine, the chemical released by mast cells when they’re challenged with allergens. Based on this, they were treated with histamine desensitization injections.
The possible causes of Cluster Headaches have further developed over time. The most recent research shows increased activity in the hypothalamus during a cluster headache. The hypothalamus is a structure deep in the brain that controls sleep, hormones, eating, and many of the autonomic functions of the body. It also is where our body’s biological clock lives. Researchers believe that the abnormalities of the hypothalamus during a cluster headache could explain the routine timing of their onset.
Several triggers of cluster headaches are very similar to those of a migraine. Alcohol consumption, strong odors, and heat have all been linked to cluster headaches. Because of their overlap with migraine symptoms and triggers (so-called cluster-migraine variant), I’ve come to think of these headaches as merely being the way some brains, usually male, are wired to respond to sleep, sleep position, and neck triggers, just as many brains (usually female) are wired to respond with classic or common migraine to sleep, sleep position, and neck triggers.
Cluster Headaches and The Seasons
A period of cluster headaches tends to occur seasonally. Why would that be? The biological rhythm of the human body is inextricably linked to seasonal change, as are allergens in our environment. Thus, it’s the early summer days and the allergens that come with them that trigger cluster headaches.
How so? It’s very much a trickle effect. Our upper airways are surrounded by lymphoid tissue. (Examples of large aggregations of lymphoid tissue are the tonsils and the adenoids.) When the surrounding lymphoid tissue of the upper airway swells up in response to these allergens, resistance to breathing during sleep, and particularly REM sleep, increases. This leads to neck hyperextension to breathe. The hyperextension and poor sleep trigger a period of cluster headaches.
Is It a Cluster Headache?
Cluster headaches are at times misdiagnosed as other conditions. Because cluster headaches are so closely associated with seasonal change, they are often misdiagnosed as sinus headaches. Why? Sometimes so-called “occult ethmoid sinusitis” — sinusitis affecting one of the sinus cells beside and behind the eye — can mimic the pain of cluster headache. Likewise, problems with the arteries supplying the face, and those behind the eye and in the neck, can mimic the pain of cluster headache, as can inflammation behind the eye.
It’s always important to rule out these other conditions before trying more typical treatments for cluster headaches. As with any headache syndrome, we recommend that you keep a detailed log of headache occurrences in order to help your headache specialist identify any links between head pain and potential triggers (such as alcohol consumption, strong odors, and heat) as well as the time of year.
Some Common Treatments
Over-the-counter pain relievers are typically not sufficient to address cluster headache-induced pain.
Fortunately, medical professionals have identified several ways of mitigating and relieving the pain caused by cluster headaches.
- Avoid both smoking cigarettes and drinking alcohol during a cluster period. In fact, just smelling smoke triggers their headaches in some patients.
- Breathe pure oxygen for 10-15 minutes as soon as headache symptoms begin to arise. This is only advised for patients who do not suffer from chronic obstructive pulmonary disease.
- Drug Therapies. A number of drug therapies have also been developed to address cluster headaches. These include calcium-channel blockers, lithium, and prednisone taken every day during a cluster period to try to prevent them from occurring. To treat the acute phase, immediate-release calcium channel blockers, subcutaneously injectable sumatriptan, tran-scutaneously injected sumatriptan, and iontophoretically absorbed sumatriptan, as well as nasally delivered triptans, can be used.
- Since cluster headaches are commonly associated with REM sleep, melatonin, which is a manmade form of a hormone produced in the pineal gland that helps regulate your sleep and wake cycle, is also a commonly deployed treatment option.
- If cluster headaches are the body’s way of responding to sleep, sleep position, and neck triggers in certain people — as I’ve found them to be many times over the years— then they can be treated with strategies that correct sleep breathing disorders and physical therapy directed to the cervical spine, while the “fire is being put out” by the more traditional cluster headache treatments. Other treatments are on the horizon for this devastating disorder.
Whatever the case, cluster headaches are severe headaches, sometimes difficult to differentiate among the other Trigeminal Autonomic Cephalalgias, and should be treated by headache specialists in a dedicated headache center.