Hemicrania continua (HC) is a rare type of headache disorder characterized by a continuous, moderate, one-sided headache. This headache type was given its name because “hemicrania” refers to “half the head,” and “continua” refers to the continuous nature of the headache. Although HC is considered a rare type of headache, it is probably more common than originally believed. Many cases remain undiagnosed. It seems to be more common in women than in men.
Patients with HC often complain of more severe flare-ups in addition to the continuous headache. During these flare-ups, “autonomic” features (related to dysfunction of the autonomic nervous system) are usually present, which include: a droopy eyelid, redness or tearing of the eye, forehead sweating, and runny or stuffy nose, all on the side of the headache. Eye discomfort is another common feature. Often a feeling of “sand” in the eye is described. Many people with HC report occasional stabbing pains in addition to the continuous headache. These intermittent jabs and jolts usually last less than 1 minute.
Since HC is a relatively rare type of headache, not much is known about its cause. There does not seem to be a genetic component, and no specific causal factors have been identified. However, there may be an association with head trauma.
One of the important features of hemicrania continua is its dramatic response to a medication called indomethacin. Indomethacin is a non-steroidal anti-inflammatory drug that is taken three times daily. Often a significant improvement in the headache is seen after just a few doses. Sometimes indomethacin is not tolerated because it can cause upset stomach like many drugs in the family of NSAIDs. Other NSAIDs can be tried, but usually they are not as effective.
Anecdotal reports suggest that Botox injections can be very effective for HC.