Chronic paroxysmal hemicrania


Chronic paroxysmal hemicrania is a severe debilitating unilateral headache usually affecting the area around the eye. It normally consists of multiple severe, yet short, headache attacks affecting only one side of the cranium. It is more commonly diagnosed in women than in men, but, unlike a migraine, has no neurological symptoms associated with it. CPH headaches are treated through the use of non-steroidal anti-inflammatory drugs, with indomethacin found to be usually effective in eliminating symptoms.
Paroxysmal hemicrania is classified by the frequency and duration of attacks experienced by patients. Episodic paroxysmal hemicrania attacks occur at least twice a year and last anywhere from seven days to a year with pain free periods of a month or longer separating them. Chronic paroxysmal hemicrania attacks occur over the course of more than a year without remission or with remissions lasting less than a month.

Signs and symptoms

Individuals with CPH suffer multiple short, severe headaches a day, often more than five, with most lasting between 5 and 30 minutes each. When compared to cluster headaches, CPH attacks are typically shorter. Each headache is centered around the eye, temple and forehead and is localized to one side of the head. While redness and watering of the eye are associated with CPH, patients typically do not experience nausea or vomiting.

Causes

Many secondary conditions have been reported to be possible causes of CPH, according to Mehta et al., most of which are arterial abrasions or tumors. These include aneurysms in the circle of Willis, middle cerebral artery infarction, parietal arteriovenous malformation, cavernous sinus and petrous ridge meningiomas, pituitary adenoma, Pancoast tumor, gangliocytoma of the sella turcica, and malignant frontal tumors. This accentuates the urgency for those diagnosed with CPH to receive an MRI head scan.

Diagnosis

CPH is a long-term disease with symptoms lasting for longer than a year, either without remission or with remissions that last less than a month. In order to be diagnosed with CPH, a patient needs to have had at least 20 attacks filling the following criteria:
In addition, diagnosis of CPH requires that neuropathy of the supraorbital area in the temporal branch of the facial nerve be ruled out.

Comparison to cluster headaches

Though outwardly similar to cluster headaches, chronic paroxysmal hemicrania is rather different, and the two headaches are not a subset of one or the other. Key differences include:
A ten-patient study conducted by Pareja et al. found that all patients diagnosed with CPH were responsive to indomethacin and were able to completely control their symptoms. Doses of the drug ranged from 25 mg per day to 150 mg per day with a median dose of 75 mg per 24-hour period.
Almost all cases of CPH respond positively and effectively to indometacin, but as much as 25 percent of patients discontinued use of the drug due to adverse side effects, namely complications in the gastrointestinal tract.
According to a case study by Milanlioglu et al., 100mg of lamotrigine, an antiepileptic drug, administered twice daily alleviated all painful symptoms. No side effects were noted after two months of treatment. Dosage of lamotrigine was decreased to 50mg a day after the first two months, and no symptoms or side-effects were recorded after a three-month followup.
Use of topiramate has also been found to be an effective treatment for CPH, but cluster headache medications have been found to have little effect.

Epidemiology

Although CPH is often compared to cluster headaches, it is much less prevalent, occurring in only 1–3% of those who experience cluster headaches. CPH occurs roughly in 1 in 50,000 people, while cluster headaches are comparatively more common and are found in 1 in 1000 people.
Cluster headaches occur primarily in men, while CPH is more commonly diagnosed in women. The female to male ratio of diagnosed patients can range anywhere from 1.6:1 to 2.36:1. Symptoms may begin to appear at any age, but onset usually occurs in adulthood with a mean starting age within the thirties.

History

CPH was discovered by Norwegians Ottar Sjaastad and Inge Dale in 1974. The term 'chronic paroxysmal hemicrania' was first used in 1976 by Sjaastad to describe a condition seen in two of their patients who were experiencing repeated solitary and limited daily headache attacks on only one side of the cranium.
It is possible that chronic paroxysmal hemicrania was first described by Johann Oppermann in 1747 under the term "hemicranias horologica". Oppermann's report included a 35-year-old woman who had hemicranial pain that lasted for 15 minutes and recurred regularly every hour.
CPH has been included in the International Headache Society's classification system since 1988.