Hemicrania continua

Hemicrania continua
Synonyms
Pronounce	N/A
Specialty	N/A
Symptoms	Unilateral headache, autonomic symptoms
Complications	N/A
Onset
Duration
Types
Causes	Unknown
Risks
Diagnosis	Clinical evaluation, response to indomethacin
Differential diagnosis	Migraine, cluster headache, tension-type headache
Prevention	N/A
Treatment	Indomethacin
Medication
Prognosis	N/A
Frequency
Deaths

Hemicrania continua is a rare primary headache disorder characterized by continuous, unilateral headache that varies in intensity but does not resolve completely. It is classified under the group of trigeminal autonomic cephalalgias and is known for its responsiveness to indomethacin, a nonsteroidal anti-inflammatory drug.

Clinical Features

Hemicrania continua is defined by its persistent nature, with patients experiencing a continuous headache on one side of the head. The pain can fluctuate in intensity, with periods of exacerbation that may include additional symptoms such as:

• Nausea
• Photophobia (sensitivity to light)
• Phonophobia (sensitivity to sound)
• Autonomic symptoms such as tearing, nasal congestion, or ptosis on the affected side

The condition is unique in its absolute response to indomethacin, which is a key diagnostic criterion.

Diagnosis

The diagnosis of hemicrania continua is primarily clinical, based on the characteristic symptoms and the patient's response to indomethacin. The International Classification of Headache Disorders (ICHD) provides criteria that include:

• Unilateral headache for more than three months
• Complete resolution of headache with indomethacin
• Presence of at least one autonomic symptom during exacerbations

Pathophysiology

The exact pathophysiology of hemicrania continua is not well understood. It is believed to involve dysfunction in the trigeminal nerve pathways and possibly the hypothalamus, similar to other trigeminal autonomic cephalalgias. The role of indomethacin suggests an inflammatory component, although the precise mechanisms remain unclear.

Treatment

The hallmark of hemicrania continua treatment is the use of indomethacin, which typically provides complete relief of symptoms. The dosage of indomethacin may vary, and it is often started at a low dose and gradually increased until the headache is controlled. Long-term use of indomethacin can have side effects, so patients are monitored closely. In cases where indomethacin is not tolerated, alternative treatments may include other nonsteroidal anti-inflammatory drugs, gabapentin, or topiramate, although these are generally less effective.

Prognosis

With appropriate treatment, the prognosis for individuals with hemicrania continua is generally good. Most patients experience significant relief from symptoms with indomethacin. However, the condition is chronic and may require long-term management.

Related Pages

• Trigeminal autonomic cephalalgias
• Indomethacin
• Chronic daily headache
• Cluster headache