Cluster headaches attacks commonly occur overnight, waking people from sleep. People living with cluster headache are diagnosed as episodic when the attacks occur in periods lasting between 7 days and 1 year and are separated by pain-free periods lasting 1 month or longer. In chronic cluster headache, attacks occur for more than 1 year without remission or with remissions lasting less than 1 month.
During attacks, some people develop a smaller pupil or a drooping eyelid on the headache side. Most cluster headache patients are restless or agitated during attacks; unlike patients with migraine, they find it hard to stay still and rarely lie down. Cluster headache consists of severe headaches on one side of the head. It is associated with cluster headaches symptoms that occur on the same side of the head that the pain is taking place on, and which can include red or teary eye, runny or stuffy nostril, and flushing or sweating of the face.
Treatments
There is no cure for cluster headaches, but drugs, such as sumatriptan, and other treatments, including oxygen therapy, can help reduce the incidence and severity of attacks.
Treatment aims to relieve some of the symptoms, shorten the periods of headaches, and reduce their frequency.
Over-the-counter (OTC) painkillers, such as aspirin or ibuprofen, are not effective, because the pain starts and finishes so rapidly that by the time the medication starts to work, the headache has probably gone.
Medications and treatments for cluster headaches aim either to prevent them or to act quickly.
Fast-acting treatments
Treatments that can provide rapid relief include:
Inhaling 100-percent oxygen: Breathing in oxygen through a mask at 7 to 10 liters per minute may bring significant relief within 15 minutes. It is not always practical to have an oxygen cylinder and regulator close at hand, but some small units are available. Oxygen therapy may only postpone symptoms, rather than alleviating them.
Injectable sumatriptan : Triptans are a class of drug that can treat migraines. Sumatriptan acts as an agonist for 5-hydroxytryptamine (5-HT) receptors. It can treat migraines, and it can bring rapid relief from cluster headaches. Zolmitriptan (Zomig) is a nasal spray, but it only works for some patients. The adult dose is a 6-milligram (mg) injection. Two injections can be taken in one 24-hour period, at least one hour apart. People with uncontrolled hypertension (high blood pressure) or ischemic heart disease should not take this drug.
Dihydroergotamine: This is an effective pain reliever for some people. It can be taken intravenously or inhaled. A medical professional will need to give an intravenous dose. The inhaler form is effective but less fast-acting.
Octreotide : These are synthetic versions of somatostatin, a brain hormone. It is injected. It is an effective treatment for cluster headaches and considered safe for those with hypertension or ischemic heart disease.
Local anesthetic nasal drops: Lidocaine (Xylocaine) is an effective treatment for cluster headaches.
Surgery: This may be an option if drug treatments do not work, or if the person cannot tolerate the medications. However, this is rare. It can only be performed once, and it is only suitable for those with pain on just one side of the head.
Surgical procedures include:
Conventional surgery: The surgeon cut part of the trigeminal nerve, which serves the area behind and around the eye. There are risks of damage to the eye.
Glycerol injection: Glycerol is injected into the facial nerves. This effective treatment is safer than other surgical procedures.
Possible future treatments
Some new treatment options are being investigated.
Occipital nerve stimulation: A small device is implanted over the occipital nerve. It sends impulses via electrodes. It appears to be well tolerated and safe to use.
Deep brain stimulation: This would involve implanting a stimulator in the hypothalamus, which appears to be linked to the timing of cluster headaches. This would change the electrical impulses in the brain.
Treatments that target the hypothalamus are considered by some researchers to be the most likely to succeed, and deep brain stimulation has been described as at present the most attractive option for patients who do not respond to other treatments. However, further studies are needed to confirm its safety and effectiveness.
The term cluster headache should be used carefully, as people will sometimes use it to refer to headaches that occur in clusters. The term cluster headache is defined by diagnostic criteria outlined by the International Headache Society.
However, Brewer says misdiagnosis is a real problem, and instead of too many people being wrongly diagnosed with cluster headache, it’s actually a matter of people not being correctly diagnosed with the disease—sometimes being misdiagnosed with a migraine disorder instead. Brewer says this issue means people sometimes wait between 5-7 years to get a proper cluster headache diagnosis.
People suspected of having cluster headache should be carefully assessed by their doctor for an underlying cause, and imaging of the brain and vessels in the head should occur. They should also be evaluated to make sure they do not have a different primary headache disorder that can mimic cluster headache.
Examples of other primary headache disorders that mimic cluster headache include:
migraine with prominent autonomic features
paroxysmal hemicrania
short-lasting unilateral neuralgiform headache with red eye and tearing
hemicrania continua
