Hemicrania continua is a persistent headache on one side of the head or face that continues for at least three months and is accompanied by other symptoms on the same side such as a stuffy nose and eye swelling, tearing or redness.
There is no known cause for hemicrania continua, nor any way to prevent it.
What sets hemicrania continua apart from other similar headache disorders is its treatment. Hemicrania continua is completely responsive to a medication called indomethacin, so much so that a response to indomethacin is a factor in diagnosing hemicrania.
This article can help you understand the symptoms and treatment of hemicrania continua. Click the headings below to jump to a specific section.
This headache type is a primary headache disorder, meaning nothing else causes it. It belongs to a category of primary headache disorders called ‘trigeminal autonomic cephalalgias’ (TACs). Other TACs include cluster headache, paroxysmal hemicrania and short-lasting unilateral neuralgiform headache attacks.
Usually, hemicrania continua first presents in adulthood, though it has been reported in children. It is more common in women than men.
When it was first described in the early 1980s, hemicrania continua was considered a rare disorder (1). However greater awareness of the disorder has increased diagnosis and, while still unusual, it is no longer considered rare (2).
Causes
There is no known cause for hemicrania continua, which is what makes it a primary headache disorder.
Without known causes, there is also no known way to prevent hemicrania continua, although some research has shown that symptoms may worsen with alcohol consumption or physical exertion. There are also claims that stress, fatigue, sleep changes, bright lights and neck movement or pressure can worsen symptoms (3).
Symptoms
Diagnostic symptoms
As for migraine and many other headache disorders, there is no definitive diagnostic test for hemicrania continua. Instead it is diagnosed when:
- headache is constantly present for at least three months
- the headache is unilateral, daily, continuous and moderate with exacerbations of severe pain or fluctuating pain levels (usually three to five times in a 24-hour cycle)
- headache is accompanied by at least one other involuntary symptom – either redness and tearing of the eye, drooping or swollen eyelids, miosis (constricted pupil), stuffy nose, or a combination of these on the same side as the pain, and
- symptoms respond to treatment with a non-steroidal, anti-inflammatory medication (NSAID) called indomethacin (Tivorbex, Indocid, Arthrexin) (4).
Many of these symptoms are typical of migraine and other TACs, however what sets hemicrania continua apart is its complete response to treatment with indomethacin. When a patient with hemicrania continua takes indomethacin correctly, it will always have an effect to lessen or resolve the headache, and if it does not, then the patient does not have hemicrania continua.
Other symptoms
Some people with hemicrania continua have symptoms other than the diagnostic symptoms described above.
For example, despite hemicrania continua being characterised by pain on one side of the head, some people with hemicrania continua have pain on both sides of the head. For a small number of people, the pain may switch sides (3). While pain is typically mild to moderate, some people may have severe exacerbations of pain (such as a stabbing pain) on top of the mild to moderate continuous pain.
Some people also have other involuntary symptoms that are additional to the diagnostic involuntary symptoms. These other involuntary symptoms may include nose bleeds and migraine symptoms such as throbbing pain, nausea, vomiting, sensitivity to light and sound, forehead sweating, and restlessness or agitation (3).
While responding to indomethacin is diagnostic, there have also been rare cases where hemicrania continua has not resolved with therapeutic doses of indomethacin (5).
Hemicrania continua symptoms
| Diagnostic symptoms | Other symptoms | ||
|---|---|---|---|
| Headache characteristics | Autonomic symptoms | Treatment response | |
| Headache constantly present for 3 months – no pain free time Unilateral Daily Continuous Exacerbations of severe pain or fluctuating pain levels (usually three to five times in a 24-hour cycle | At least one of the following on the same side as the headache pain: - eye redness - eye tearing - nasal congestion - runny nose - ptosis (drooping eyelid) - miosis (constricted pupils) | Symptoms respond to treatment with indomethacin (a non-steroidal, anti-inflammatory medication) | - forehead sweating - restlessness - agitation - vomiting - nausea - light sensitivity - sound sensitivity - nose bleeds - migraine-like symptoms eg throbbing pain |
When to see your doctor
If you have headache symptoms, it is important to see your doctor as different headache types require different treatments.
The circumstances in which you should see your doctor are the same whether your headache turns out to be hemicrania continua or another primary headache disorder or secondary to another medical condition.
You should see your doctor if you have headache that lasts for more than three days, or occurs weekly or more frequently than weekly. Other symptoms that should prompt an immediate visit to the doctor are:
- sudden severe headache
- worsening headache
- headache that prevents you from functioning normally
- headache accompanied by confusion, stiff neck, fever, seizure, double vision, numbness or speech difficulties
- headache following head injury, and
- headache that doesn’t respond to the recommended dosage over-the-counter pain relief, and or that persists so that over-the-counter pain relief is required daily.
Headache diaries
The duration and nature of headache is relevant to the diagnosis of hemicrania continua, as well as other headache types. Therefore a headache diary can be useful for discussing your symptoms with your doctor, and can assist your doctor to make the correct diagnosis and to monitor the effectiveness of your treatment.
If you keep a headache diary, you should take this with you when you see your doctor. Alternatively, you can begin a headache diary once you’ve seen your doctor.
Useful information for your headache diary includes:
- the location of the pain
- when and how often the pain worsens
- the duration of the pain or any breaks in the pain, and
- the presence of other symptoms additional to the pain, such as eye watering or redness, nasal congestion, nausea and vomiting, and any sensitivities (eg. light, sound, smell, movement).
Here are some resources to help you create and use a headache diary – Headache & migraine diaries.
Treatment
There is no cure for hemicrania continua. Instead, treatment reduces symptoms to minimise the disruption to the lives of people with the disorder.
Your doctor may also arrange other diagnostic tests to rule out other causes for the headache, including medical imaging.
Indomethacin
Hemicrania continua is first treated with indomethacin. Indomethacin is used as an acute and preventive strategy uniquely in hemicrania continua. If there is a positive response to this medication, it is often used to confirm the diagnosis of the disorder.
Even if your headache responds to indomethacin and has all the diagnostic criteria for hemicrania continua, your doctor may arrange other tests to check if the headache has another cause.
Initially your doctor will prescribe a low dose of indomethacin (eg. 25 milligrams) three times daily with meals, and increase the dose gradually (commonly up to 300 milligrams total daily dose) until you no longer feel head pain.
Once your head pain subsides, your doctor will decrease the dose to ensure you are taking the lowest effective dose to keep your pain at bay. That lower dose will be continued long term.
Most people can take sufficient doses of indomethacin to keep their headache at bay without side effects, but the medication is associated with side effects for some people.
The main side effect of indomethacin is irritation of the stomach and digestive tract, which can cause gastrointestinal side effects such as stomach upsets, nausea, and over time can lead to stomach ulcers. This is why indomethacin should be taken with food. In addition, you may need to take acid-suppression medication, which protects your stomach lining by helping your stomach make less acid.
Other less common side effects while take indomethacin can include tiredness and feeling depressed.
Over time, indomethacin may become ineffective for some people. When indomethacin is not tolerated or becomes ineffective, your doctor will try other treatments.
Other treatments
The most common other acute treatment used when indomethacin cannot be used is another NSAID, celecoxib (“Celebrex”). It is less effective than indomethacin, but may still help and is associated with fewer gastro-intestinal side effects.
Other preventive treatments include:
- tablets such as gabapentin, topiramate, melatonin, verapamil, amitriptyline
- injections such as nerve blocks, onabotulinumtoxin-A
- occipital nerve stimulation
Tricyclic antidepressants (eg. amitriptyline) are also used as a preventative treatment for symptoms of hemicrania continua (6).
Variants and similar diagnoses
There are two forms of hemicrania continua (4):
- unremitting subtype, when headaches are daily, and
- remitting subtype, when headaches are not continuous, but interrupted, without treatment, by remission periods of 24 hours or more.
Other variants include pain swapping sides, or pain on both sides of the head.
Hemicrania continua can also look like other headache disorders, such as chronic cluster headache (especially the additional symptoms of sweating, and eye and nose irritation), chronic migraine, and other secondary headache disorders. Similar pain can also be caused by conditions affecting blood vessels and pituitary glands.
Paroxysmal hemicrania is a similar but separate disorder that causes pain on one side of the head. Paroxysmal hemicrania can be differentiated from hemicrania continua by the duration of pain. While people with hemicrania continua experience continuous pain, those with paroxysmal hemicrania experience at least five attacks of severe head pain on one side of the head over the course of a day, with each attack lasting 2 to 30 minutes and no pain between the attacks (4).
Outlook
The duration of hemicrania continua is unpredictable. Some people only ever experience one episode, while others deal with recurring pain throughout their lives.
While hemicrania continua pain may return on and off throughout a person’s life, most people are able to live with very little hemicrania continua pain and can do their usual activities without restriction so long as they maintain regular medical care and are treated with indomethacin and other preventatives.
Further information & resources
If you would like to learn more about headache disorders related to hemicrania continua, you can check out our articles on other trigeminal autonomic cephalalgias (TACs):
References
- O Sjaastad & EL Spierings, 1984, “Hemicrania continua”: another headache absolutely responsive to indomethacin. DOI: 10.1046/j.1468-2982.1984.0401065.x
- MF Peres et al, 2001, Hemicrania continua is not that rare. DOI: 10.1212/WNL.57.6.948
- E Cittadini & PJ Goadsby, 2010, Hemicrania continua: a clinical study of 39 patients with diagnostic implications. DOI: 10.1093/brain/awq137
- International Headache Society, 2018, 3.4. Hemicrania Continua. Retrieved from: https://ichd-3.org/3-trigeminal-autonomic-cephalalgias/3-4-hemicrania-continua/
- S Prakash, ND Shah & RJ Bhanvadia, 2009, Hemicrania continua unresponsive or partially responsive to indomethacin: does it exist? A diagnostic and therapeutic dilemma. DOI: 10.1007/s10194-008-0088-9
- S Hameed & T Sharman, 2022, Hemicrania Continua [eBook]. StatPearls. Bookshelf ID: NBK557568
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