What are Cluster Headaches?
Cluster headaches are severely painful headaches that occur in clusters, meaning that you experience cycles of headache attacks followed by headache-free periods.
The frequency of your headaches during those cycles may range from one headache every other day to several headaches per day. Cluster headaches can be so painful that they are sometimes called “suicide headaches.”
Cluster headaches are most common between adolescence and middle age, but they can occur at any age.
Older studies showed that cluster headaches were more commonly reported by men than women. A 1998 study published in Cephalagia, for example, showed that before 1960, men reported cluster headaches six times more often than men. Over time, however, that gap has shrunk, and by the 1990s, cluster headaches were found in only twice as many men than women (Manzoni, 1998).
Types of Cluster Headaches
There are two types of cluster headaches: episodic and chronic.
Episodic cluster headaches occur regularly between one week and one year, followed by a headache free period of one month or more.
Chronic cluster headaches occur regularly for longer than one year, followed by a headache free period that lasts for less than one month.
A person who has episodic cluster headaches may develop chronic cluster headaches and vice versa.
What Causes Cluster Headaches?
The pain from cluster headaches is caused by the dilation (widening) of the blood vessels that supply blood to your brain and face. The dilation of these vessels applies pressure to the trigeminal nerve, which transmits sensations from the face to the brain. Doctors do not know why this dilation occurs.
Researchers believe that abnormalities in a small area of the brain called the hypothalamus may be responsible for cluster headaches. The hypothalamus is the area of the brain that regulates body temperature, blood pressure, sleep, and the release of hormones.
Cluster headaches may also be caused by a sudden release of the chemicals histamine or serotonin, which fight allergens and regulate mood, respectively.
Distinguishing a Cluster Headache From Other Types of Headaches
Cluster headaches usually start suddenly. A small percentage of people experience aura-like visual disturbances, such as seeing flashes of light that are not there, before the headaches begin.
The headaches most commonly begin a few hours after you fall asleep, and are often painful enough to wake you. Cluster headaches may also begin when you are awake.
The headache pain becomes severe five to 10 minutes after the headache starts. Each headache usually lasts for several hours, with the most intense pain lasting between 30 minutes and two hours.
Cluster headache pain occurs on one side of the head, but the pain can switch sides in some patients. The headache pain is generally located behind or around the eye. It is a constant and deep burning or piercing pain. The pain may spread to the forehead, temples, teeth, nose, neck, or shoulders on the same side.
Other signs and symptoms may be evident on the painful side of the head, including:
- a droopy eyelid
- a constricted (small) pupil
- excessive tearing from your eye
- eye redness
- sensitivity to light
- swelling under or around one or both of your eyes
- a runny nose or stuffy nose
- facial redness or flushing
- agitation or restlessness
How Are Cluster Headaches Diagnosed?
Your doctor will ask you questions about your symptoms and give you a physical and neurological exam. This may include an MRI or CT scan of your brain to rule out other causes of the headaches, such as a brain tumor.
Treatment for Cluster Headaches
Treatment involves relieving and preventing your headache symptoms using medication. In rare cases, when pain relief and preventive treatment do not work, your doctor may recommend surgery.
The goal of pain medications is to relieve your headache pain once it has begun. Pain relieving treatments include:
- breathing 100 percent pure oxygen when the headache begins
- a nasal spray medication called sumatriptan (Imitrex) or other tripitan medications that constrict the blood vessels
- an injected medication called dihydroergotamine (DHE) which can relieve cluster headache pain within five minutes of use (DHE cannot be taken with sumatriptan)
- topical capsaicin cream can be applied to the painful area
Preventive medications stop the headaches before they start. These medications may not be 100 percent effective, but they can reduce the frequency of your headaches. Preventive medications include:
- blood pressure medications, such as propanol or verapamil, which relax your blood vessels
- steroid medications, such as prednisone, which reduce nerve inflammation
- a medication called ergotamine that keeps your blood vessels from dilating
- antidepressant medications, such as amitriptyline
- antiseizure medications, such as topiramate and valproic acid
- lithium carbonate
- muscle relaxants, such as baclofen
As a last resort, a surgical procedure can be used to destroy the trigeminal nerve. The surgery can cause permanent pain relief for some patients, but serious side effects, such as permanent facial numbness can result from this surgery
Tips to Prevent Cluster Headaches
You may be able to prevent cluster headaches by avoiding the following things, which can trigger the onset of the headaches in some patients:
- high altitudes
- strenuous activities
- hot weather
- hot baths
- foods that contain large amounts of nitrates, such as bacon, hot dogs, and preserved meats
Cluster headaches are not life threatening, but there is no cure for them. Your headaches may become more or less frequent and more or less painful over time, or they may eventually disappear completely.