Introduction:
Paroxysmal hemicrania belongs to the trigeminal autonomic cephalalgias category of primary headache disorders. There are three categories of primary headache disorders: migraine, tension-type headache, and trigeminal autonomic cephalalgias (TAC). The characteristic features of trigeminal autonomic cephalalgias are unilateral trigeminal distribution pain in league with ipsilateral (same side) cranial autonomic features. The attacks of paroxysmal hemicrania are shorter and more frequent when compared with cluster headaches.
How Does Paroxysmal Hemicrania Differ From Hemicrania Continua?
The term ‘paroxysmal’ refers to a sudden attack or relapse, while ‘hemicrania’ refers to unilateral or one side of the head. Both paroxysmal hemicrania and hemicrania continua involve one side of the face and head. The headaches in hemicrania continua are continuous that rarely or never resolve. Paroxysmal hemicrania involves sudden, repeated headaches.
What Are the Two Forms of Paroxysmal Hemicrania?
The two forms are:
-
Chronic: The attacks happen daily and can last for a year or more.
-
Episodic: The headaches can decrease or fade off for months to years.
External pressure or specific movements of the head or neck can set off these headaches in some individuals. The disorder has a female predilection.
What Are the Reasons for Paroxysmal Hemicrania?
The exact cause or reason behind the occurrence of paroxysmal hemicrania is unknown. This condition is believed to be associated with the trigeminal nerve, which is a cranial nerve responsible for providing sensation to the face. Paroxysmal hemicrania can be triggered due to the following:
-
Trauma in the head.
-
Arteriovenous malformations (intertwining or tangling of blood vessels).
-
A tumor in the hormone-producing gland (pituitary) situated at the base of the skull.
Other external triggering factors include:
-
Cheese.
-
Chocolate.
-
Coffee.
-
Alcohol.
-
Exercise.
-
Stress or relaxation after a period of stress.
-
Changes in temperature.
-
Exerting pressure on the neck or moving the head in a particular manner.
What Are the Signs and Symptoms of Paroxysmal Hemicrania?
The pain caused by paroxysmal hemicrania can be so intense that the pain can be described as sharp, stabbing, claw-like, burning, or throbbing. The pain is strictly localized to one side and is usually experienced around or behind the eye in the temple region. Occasionally, the pain can manifest in the forehead or the back of the head.
One can also experience cranial autonomic symptoms that are linked with this headache disorder. Autonomic symptoms occur due to the firing of the pain-detecting nerves that surround the brain. These nerves send signals to the autonomic nervous system (the part of the nervous system that exerts influence on those parts that cannot be consciously controlled, like the tear and sweat glands). The cranial autonomic symptoms are as follows:
-
Runny nose or nasal congestion.
-
Drooping or swelling eyelids.
-
Sweating or flushing of the face.
-
Sweating in the head or face.
-
Redness or tearing of the eye.
-
Ear fullness.
Other symptoms of paroxysmal hemicrania include restlessness, agitation, photophobia (sensitivity to light), and nausea. Photophobia accompanying paroxysmal hemicrania is usually one-sided, unlike migraine, wherein the photophobia is common on both sides of the head. Similarly, sensitivity to sound (phonophobia) and vomiting are not experienced in paroxysmal hemicrania, unlike migraine.
How to Diagnose Paroxysmal Hemicrania?
Paroxysmal hemicrania is a disorder that occurs on its own accord and is not a consequence of another medical condition. It is a rare disorder; its symptoms can be similar to other primary headache disorders like cluster headaches. Hence, the history and nature of the symptoms need to be thoroughly assessed.
One or more of the International Classification of Headache Disorders criteria must be met to arrive at a diagnosis of paroxysmal hemicrania. These criteria include:
-
An individual must have experienced a minimum of 20 attacks.
-
The pain must be intense, around or behind the eye or temple region. The duration of the pain must be between 2 to 30 minutes.
-
At least one autonomic symptom mentioned above should be present.
-
Occurrence of more than five attacks a day for more than half the time.
-
Attacks respond to appropriate doses of Indomethacin.
Magnetic resonance imaging (MRI) can be useful to identify any issues within the brain that can imitate the symptoms of paroxysmal hemicrania, like a problem in the blood vessel or a pituitary brain tumor.
How Can Paroxysmal Hemicrania Be Treated?
The disorder can be treated as follows:
-
The most preferred drug of choice in treating paroxysmal hemicrania is Indomethacin, a non-steroidal anti-inflammatory drug (NSAID). Corticosteroids and other NSAIDs are inefficient in treating this disorder.
-
One can avoid getting exposed to the triggering factors.
-
Indomethacin can offer relief from the symptoms within one to two days of taking the drug. The starting dose of Indomethacin in adults is usually 25 mg (milligrams), which must be taken thrice daily.
-
One should not stop taking the drug as soon as the symptoms disappear because the headache can relapse within 12 hours of stopping the drug. It should be taken as prescribed by the physician and should not be skipped.
-
It is mandatory to consult a physician and gradually decrease the dosage of Indomethacin to prevent withdrawal symptoms.
What Are the Other Treatment Options for Paroxysmal Hemicrania Apart From Indomethacin?
In individuals who are allergic to NSAIDs or have a history of ulcer or stomach disease, the following medications can be given:
-
Verapamil.
-
Tegretol.
-
Amitriptyline.
-
Topamax.
If the headaches do not resolve even with medications, then a procedure called the peripheral nerve blockade may be done, but there is minimal scientific data regarding its benefits.
What Are the Side Effects of Indomethacin?
The side effects are as follows:
-
Gastrointestinal issues.
-
Abdominal discomfort.
-
Heartburn.
-
Diarrhea.
-
Constipation.
-
Dizziness.
-
Feeling tired or sleepy.
-
Allergy.
Serious side effects include high blood pressure, bleeding, heart and kidney problems.
Conclusion:
Headaches can cause discomfort and can affect daily activities. Paroxysmal hemicrania is one of the primary headache disorders that causes intense, throbbing, claw-like headaches on one side of the face and head. The duration of the pain can range from a few minutes to around 30 minutes. The day-to-day activities may be affected in those with paroxysmal hemicrania due to the intensity of the headache. A majority of the people grade their pain as 10 on a scale of 0-10. This shows the severity of the pain in these individuals. However, one can easily eliminate the headache with the wonder medication called Indomethacin. Further research needs to be done to find suitable treatment options for those where Indomethacin is contraindicated or in individuals who cannot tolerate the medication.
