Paroxysmal Hemicrania - The Basics
In the simplest of terms, paroxysmal hemicrania (PH) is a rare form of headache that usually begins in adulthood.
Characteristics of the pain of PH
claw-like, or boring
usually on one side of the face; in, around, or behind the eye
occasionally reaching to the back of the neck
The pain of PH may be accompanied by:
red and tearing eyes (lacrimation)
a drooping or swollen eyelid on the affected side of the face
dull pain, soreness, or tenderness between attacks
Episodes of paroxysmal hemicrania typically occur from 5 to 40 times per day and last 2 to 45 minutes. The disorder has two forms:
Chronic PH: patients experience attacks on a daily basis for a year or more
Episodic PH: the headaches may remit for months or years
Certain movements of the head or neck or external pressure to the neck may trigger these headaches in some patients. The disorder is more common in women than in men.
Is there any treatment?
The nonsteroidal anti-inflammatory drug (NSAID) indomethacin often provides complete relief from symptoms. Other less effective NSAIDs including celecoxib (Celebrex), calcium-channel blocking drugs (such as verapamil), and corticosteroids may be used to treat the disorder. Patients with both paroxysmal hemicrania and trigeminal neuralgia (a condition of the 5th cranial nerve that causes sudden, severe pain typically felt on one side of the jaw or cheek) should receive treatment for each disorder.
What is the prognosis?
Many patients experience complete to near-complete relief of symptoms following physician-supervised medical treatment. Paroxysmal hemicrania may last indefinitely but has been known to go into remission or stop spontaneously.
Information from the International Headache Society's International Classification of Headache Disorders, 2nd Edition, is the best description of CP available:
3.2 Paroxysmal hemicrania
Description: Attacks with similar characteristics of pain and associated symptoms and signs to those of cluster headache, but they are shorter-lasting, more frequent, occur more commonly in females and respond absolutely to indomethacin.
At least 20 attacks fulfilling criteria B-D
Attacks of severe unilateral orbital, supraorbital or temporal pain lasting 2-30 minutes
Headache is accompanied by at least one of the following:
ipsilateral (on the same side as the headache) conjunctival injection (The forcing of a fluid into the conjuctiva, the mucous membrane that lines the eyelids.) and/or lacrimation (tearing)
ipsilateral nasal congestion and/or rhinorrhoea (runny nose)
ipsilateral eyelid oedema (swelling)
ipsilateral forehead and facial sweating
ipsilateral miosis (abnormal contraction of the pupils) and/or ptosis (drooping of the eyelid)
Attacks have a frequency above 5 per day for more than half of the time, although periods with lower frequency may occur
Attacks are prevented completely by therapeutic doses of indomethacin (Note 1)
Not attributed to another disorder (Note 2)
In order to rule out incomplete response, indomethacin should be used in a dose of 150mg or more daily orally or rectally, or 100 mg or by injection, but for maintenance smaller doses are often sufficient.
History and physical and neurological examinations do not suggest any of the disorders listed in groups 5-12, or history and/or physical and/or neurological examinations do suggest such disorder but it is ruled out by appropriate investigations, or such disorder is present but attacks do not occur for the first time in close temporal relation to the disorder.
Comments: There is no male predominance. Onset is usually in adulthood, although childhood cases are reported. In the first edition all paroxysmal hemicranias were referred to as chronic paroxysmal hemicrania. Sufficient clinical evidence for the episodic subtype has accumulated to separate it in a manner analogous to cluster headache.
Paroxysmal hemicrania with coexistent trigeminal neuralgia (CPH-tic syndrome): Patients who fulfill criteria for both 3.2 Paroxysmal hemicrania and 13.1 Trigeminal neuralgia should receive both diagnoses. The importance of this observation is that both conditions require treatment. The pathophysiological significance of the association is not yet clear.
Summary and comments:
Paroxysmal Hemicrania (PH) is rare and difficult to treat. In most cases, patients with PH should seek care from a headache and Migraine specialist. Some of the symptoms, to an untrained practitioner could be mistaken for cluster headache. The response to indomethacin is one confirmation of a PH diagnosis. However, indomethacin is not well tolerated by some patients. If that occurs, other less effective NSAIDs including celecoxib (Celebrex), calcium-channel blocking drugs (such as verapamil), and corticosteroids may be used.
The International Headache Society. "International Classification of Headache Disorders, 2nd Edition." Cephalalgia, Volume 24 Issue s1. May, 2004. doi:10.1111/j.1468-2982.2003.00823.x
Silberstein, Stephen D.; Lipton, Richard B.; Goadsby, Peter J.; Smith, Robert T. "Headache in Primary Care." Isis Medical Media. 1999.
Young, William B.; Silberstein, Stephen D. "Migraine and Other Headaches." AAN Press. 2004.
Goadsby, Peter J.; Silberstein, Stephen D.; Dodick, David W. "Chronic Daily Headache for Clinicians." BC Decker Inc. 2005.