Paroxysmal hemicrania (PH) is a rare form of headache. Paroxysmal hemicrania usually begins in adulthood, and affected persons experience severe throbbing, claw-like, or boring pain. The pain is usually on one side of the face, near or in the eye, temple, and occasionally reaching to the back of the neck. Red and tearing eyes, a drooping or swollen eyelid on the affected side of the face, and nasal congestion may accompany this pain. Persons experiencing the headache pain of paroxysmal hemicrania may also feel dull pain, soreness, or tenderness between attacks.
Paroxysmal hemicrania syndromes have two forms: chronic, in which persons experience attacks on a daily basis for a year or more, and episodic, in which the headaches do not occur for months or years. Episodic paroxysmal hemicrania is four times more common than the chronic form.
Chronic paroxysmal hemicrania (CPH), also known as Sjaastad syndrome, is a primary headache disorder first described by the Norwegian neurologist Ottar Sjaastad in 1974. In 1976, Sjaastad proposed the term chronic paroxysmal hemicrania after observing two patients, who had daily, solitary, severe headache pain that remained on one side of the head. The main feature of chronic paroxysmal hemicrania is frequent attacks of strictly one-sided severe pain localized in or around the eye or temple regions, lasting from 2–45 minutes in duration, and occurring 2–40 times per day.
Attacks of chronic paroxysmal hemicrania do not occur in recognizable time patterns. Episodic paroxysmal hemicrania (EPH), a more rare form of the disorder, is characterized by bouts of frequent, daily attacks with the same clinical features of CPH, but separated by relatively long periods without headache. Most episodic headaches in paroxysmal hemicrania occur at night or other recognizable time patterns.
In the United States, CPH is a rare syndrome, but the number of diagnosed cases is increasing. The prevalence of CPH is not known, but it occurs more often than cluster headaches, a disorder of that can sometimes be confused with CPH. Internationally, many cases of CPH have been described throughout the world, in different races and different countries.
Chronic paroxysmal hemicrania affects more women than men. In the past, because of female preponderance, CPH was considered a disease exclusive to women. However, CPH has been reported in increasing numbers of men. A study conducted in 1979 reported a female-to-male ratio of 7:1, but a review of 84 patients in 1989 reported a female-to-male ratio of 2.3:1. Chronic paroxysmal hemicrania can occur at any age, and the mean age of onset is 34 years.
Episodic paroxysmal hemicrania occurs in both sexes, with a slight female preponderance (1.3:1). The age of onset is variable; studies show EPH onset is 12–51 years.
Causes and symptoms
No definite cause of paroxysmal hemicrania is known. Persons who experience these headaches usually do not have additional neurological disorders, with the exception of trigeminal neuralgia, which has been observed in a small number of persons also having paroxysmal hemicrania. History of head or neck trauma is reported in about 20% of persons with paroxysmal hemicrania, but
Headache is the main symptom of both types of paroxysmal hemicrania. Chronic PH involves headaches that are one-sided, severe, affecting the eye or temple area, and lasting two to 45 minutes, occurring more than five times per day. Episodic paroxysmal hemicrania involves attacks of severe pain in the eye or temple area that last about one to 30 minutes, with a frequency of three or more events per day, and clear intervals between bouts of attacks that may last from months to years.
Both chronic and episodic paroxysmal hemicrania involve symptoms such as nasal congestion on the affected side, rhinorrhea (runny nose), and swelling of the eyelid on the affected side with tearing. Sweating, both on the forehead and generalized over the body, is also common.
The diagnosis of paroxysmal hemicrania is based on a person's history and clinical symptoms. There are conditions involving underlying lesions in the brain (such as tumors or arteriovenous malformation) that can lead to symptoms similar to the headaches of paroxysmal hemicrania. Because of this, various tests of the brain are recommended to exclude structural abnormalities.
Laboratory studies such as routine blood tests can help identify metabolic and other causes of headache and facial pain. Imaging studies including computed tomography (CT) scan, or preferably magnetic resonance imaging (MRI) of the brain may be needed to rule out structural disorders of the eye, ear, nose, neck, skull, and brain.
Testing the effectiveness of the drug indomethiacin may also be a useful tool in the assessment of one-sided headaches. The response to indomethacin is part of the criteria for a diagnosis of paroxysmal hemicrania. During two different periods, the drug is administered intramuscularly, and patterns of headache pain are evaluated. In paroxysmal hemicranias, indomethiacin relieves pain, prevents recurring pain, and/or decreases the frequency of pain. As the effects of indomethacin clear the body, the pain returns in its usual form and pattern.
The nonsteroidal anti-inflammatory drug (NSAID) indomethacin often provides complete relief from symptoms. Other less effective NSAIDs, calcium-channel blocking drugs (such as verapamil), and corticosteroids may be used to treat the disorder. Patients with both PH and trigeminal neuralgia (a condition of the fifth cranial nerve that causes sudden, severe pain typically felt on one side of the jaw or cheek) should receive separate treatment for each disorder.
Recovery and rehabilitation
When headaches are severe enough or frequent enough to interfere with a person's daily activities such as work, family life, and home responsibilities, a specially trained physical therapist can provide a variety of treatment and education services to manage or reduce headaches, including:
- exercises (stretching, strengthening, and aerobic conditioning)
- safe sleep, standing, and sitting postures
- performing daily activities safely
As of mid-2004, there were no ongoing clinical trials specific to the study or treatment of paroxysmal hemicrania. The National Institute for Neurological Disorders and Stroke (NINDS), however, carries out multifaceted research on headaches and their causes.
Many patients experience complete relief or near-complete relief of symptoms following medical treatment for paroxysmal hemicrania. PH headaches may occur throughout life, but have also been known to go into remission or stop spontaneously.
Chronic paroxysmal hemicrania headaches have been reported to improve during pregnancy; however, they often recur after delivery. In some persons, menstruation lessens the headaches, while in others, headaches are worse during menstruation. Birth control pills do not seem to influence the frequency of attacks, and the effects of menopause on paroxysmal hemicrania are unknown.
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"NINDS Paroxysmal Hemicrania Information Page." National Institute of Neurological Disorders and Stroke. May 8, 2004 (June 2, 2004). <http://www.ninds.nih.gov/health_and_medical/disorders/paroxysmal_hemicrania.htm>.
American Council for Headache Education. 19 Mantua Road, Mt. Royal, NJ 08061. (856)423-0258 or (800) 255-ACHE (255-2243); Fax: (856) 423-0082. firstname.lastname@example.org. <http://www.achenet.org>.
National Headache Foundation. 820 N. Orleans, Suite 217, Chicago, IL 60610-3132. (773) 388-6399 or (888) NHF-5552 (643-5552); Fax: (773) 525-7357. info@ headaches.org. <http://www.headaches.org>.
Greiciane Gaburro Paneto
Iuri Drumond Louro, MD, PhD