Cluster Headache

What a cluster headache feels like

Cluster headache pain is among the most severe pains known, far beyond a typical tension headache. People describe a hot poker, drilling or stabbing behind or around one eye, sometimes spreading to the temple, forehead, cheek, teeth or jaw. It builds to peak within minutes.

During an attack, on the same side as the pain:

• red, watering eye
• drooping eyelid and small pupil (partial Horner syndrome)
• runny or blocked nostril
• sweating or flushing of the forehead and face
• swelling of the eyelid

Most people pace, rock, or press on the eye, unable to lie still. This restlessness contrasts with migraine, where people lie still in a dark room.

Pattern of attacks

• Attacks last 15 minutes to 3 hours if untreated.
• They occur from once every other day to 8 times a day.
• They often strike at the same time each day, commonly 1 to 2 hours after falling asleep.
• Bouts last weeks to a few months, often recurring at the same time of year.

Cluster headache vs migraine

Trigeminal neuralgia causes seconds-long electric shocks, and paroxysmal hemicrania causes shorter, more frequent attacks that respond completely to indomethacin.

Causes and triggers

The cause is not fully understood. The hypothalamus, which controls the body clock, is involved, explaining the clockwork timing and seasonal pattern. Activation of the trigeminal nerve and the autonomic nerves around the eye produces the pain and eye and nose symptoms.

Risk factors:

• male sex, though the gap is narrowing as diagnosis in women improves
• onset usually between ages 20 and 40
• smoking, current or past, in most people with cluster headache
• family history in a small minority

Triggers during a bout:

• alcohol, even a small amount, often within an hour
• strong smells such as solvents, perfume or gasoline
• naps and changes in sleep pattern
• heat and high altitude
• nitroglycerin

Triggers usually have no effect between bouts.

Diagnosis

Cluster headache is diagnosed from the history using International Headache Society criteria: at least 5 attacks of severe one-sided orbital or temporal pain lasting 15 to 180 minutes with eye and nose symptoms or restlessness. A headache diary helps. An MRI of the brain is usually done once to rule out other causes, such as a pituitary tumor or blood vessel problem, especially with atypical features or a persistent drooping eyelid.

Treatment for attacks

• High-flow oxygen: 100% oxygen through a non-rebreather mask at 12 to 15 liters per minute for 15 to 20 minutes. It is safe and works within 15 minutes for most people. Home oxygen can be prescribed.
• Sumatriptan injection under the skin: the fastest-acting medicine, often working within 10 to 15 minutes.
• Zolmitriptan or sumatriptan nasal spray: an alternative to injection.
• Non-invasive vagus nerve stimulation: a handheld device for some patients.

Tablets, including triptan tablets and over-the-counter painkillers, work too slowly for most attacks. Triptans are not suitable for people with heart disease or uncontrolled high blood pressure.

Preventive treatment

Started at the beginning of a bout and stopped after it ends:

• Verapamil: the main preventive medicine. It needs ECG monitoring because it can affect heart rhythm.
• Corticosteroids: a short course to break a bout while verapamil takes effect.
• Occipital nerve block: a steroid and anesthetic injection at the back of the head on the affected side.
• Galcanezumab: a monthly injection approved for episodic cluster headache.
• Lithium and topiramate: alternatives, especially for chronic cluster headache.
• Neuromodulation and surgery for severe chronic cases that do not respond.

Living with cluster headaches

• Avoid alcohol during bouts.
• Keep a regular sleep schedule and avoid naps during bouts.
• Stop smoking. It may not stop attacks but improves overall health and may help.
• Keep oxygen and medicines easy to reach, especially at night.
• Tell family and employers about the condition and what to do during attacks.
• Cluster headaches carry a high burden, including depression and suicidal thoughts during bouts. Mental health support and patient groups help.
• Sleep apnea is more common in people with cluster headaches and should be treated if present.

Frequently asked questions

What does a cluster headache feel like?

It feels like a severe, burning, drilling or stabbing pain in or around one eye, building within minutes and lasting 15 minutes to 3 hours. The eye on that side waters and reddens, the eyelid may droop and the nostril runs. Most people feel agitated and cannot lie still.

What triggers cluster headaches?

During a bout, alcohol is the most common trigger, often bringing on an attack within an hour. Strong smells, naps, changes in sleep, heat and high altitude can also trigger attacks. Between bouts, these usually have no effect. The underlying cause involves the hypothalamus.

How do you stop a cluster headache fast?

The fastest treatments are 100% oxygen through a face mask at high flow for 15 to 20 minutes, or a sumatriptan injection. Triptan nasal sprays also work. Tablets and over-the-counter painkillers usually act too slowly to help.

How long do cluster headache bouts last?

In episodic cluster headache, bouts typically last 6 to 12 weeks, with attacks every day, followed by months or years without attacks. About 10% to 15% of people have chronic cluster headache, with attacks most of the year and short or no remissions.

Is cluster headache the same as migraine?

No. Cluster headache attacks are shorter (15 to 180 minutes), occur several times a day in bouts, always affect one side around the eye, and cause restlessness and eye and nose symptoms. Migraine lasts hours to days, often causes nausea and light sensitivity, and people prefer to lie still.