Cluster Headache: Providing Relief for a Debilitating Disorder
to stem severity and frequency of attacks.
Headache continues to be the most common pain complaint of patients presenting to general practitioners, internal medicine specialists, and neurologists. Although the various primary headache types (vascular: migraine and cluster; nonvascular: tension-type headache) may appear alone or in various combinations in the headache patient, cluster headache (CH) is felt by many experts to be the most debilitating. CH sufferers frequently are misdiagnosed and subject to inappropriate treatment. Because this disorder often is associated with self-directed violence, even suicide, it is imperative to diagnose and treat the problem quickly and efficiently. This article will review the incidence, diagnosis, and treatment of CH from a pain management viewpoint.
Prevalence of CH
CH is considered the most common type of trigemino-autonomic headache, with estimates ranging from as low as 5 to 69 patients per 100,000 people to as high as 240 to 900 patients per 100,000 people—or between 0.5 and 2 million Americans.1 Despite its prevalence, patients with CH face difficulty in receiving a correct diagnosis. In one study, the average delay from the onset of the CH to diagnosis was 6.6 years, with patients seeing an average of 4.3 physicians and receiving 3.9 incorrect diagnoses prior to receiving the correct diagnosis.2
CH primarily has been a disorder of males, with various studies showing a predominance in males of between 84% and 88%, but change in the gender ratio of CH has been noted over the last several decades.3 When the incidence was analyzed in association with significant lifestyle changes, including employment rate, level of school education, smoking, and coffee and alcohol intake, the male to female ratio fell from 6.2:1 for patients with CH onset prior to 1960, to 3.0:1 for those with onset in the 1990s.
The onset of CH most commonly occurs between 20 and 40 years of age, with a sharp rise between 25 and 30 years of age. Less than 20% of CH patients have their first attack before the age of 20, and rarely is it found in children between 7 and 14 years of age, and then only in boys. Although CH is rare in children, Arruda et al studied 3 pediatric cases over a 10-year period and found, in their small sample, that sustained, long-term medical or spontaneous remissions do occur in children with early onset of CH.4 On the other hand, Manzoni studied a group of 73 late-onset patients—with onset of CH after age 50—and found chronic CH was more common in the older patients and the cluster period lasted longer.5 There also was a male to female ratio of 1.4:1 in this group, showing that development of late-onset CH was higher in older women and there was a higher number of women with chronic CH.
CH has been found to occur in families as well as in twins. Although the current perception is that 80% or more of patients with migraine have a positive family history of migraine, only 3% to 7% of CH patients have a positive family history of CH.6 It also has been postulated that CH may be an autosomal dominant inherited disorder in some families.
Migraine-like features are common in patients with CH. Approximately 25% of CH patients experience migraine features during an attack, a percentage that is higher than that found for migraine in the general population.7,8 It has been reported that these patients experience significantly more allodynia (P=0.022) than CH patients without migraine.7
Studies have also reported that CH patients have a greater incidence of smoking, drinking, and illicit drug use than non-CH patients or controls.9,10 Key facts about CH from the United States Cluster Headache Survey are outlined in Table 1.11
Romberg first described CH in 1840.12 The term CH was taken from Kunkle’s work, which noted its clustering pattern.13 In 1939, Horton et al conducted a great deal of work on the subject, and proposed the nosological entity known as Horton’s histaminic cephalalgia because of the apparent, at that time, relationship to histamine.14
The major clinical features of CH are listed in Table 2. The CH may be preceded by an emotional prodrome, such as hypomania or euphoria. These premonitory signs may precede the CH episode by days or weeks. The headache itself may begin with unilateral or bilateral cervical pressure. Patients may report a feeling of warmth over the ipsilateral (same side) temporal region for several minutes before the headache begins. Mild pain may occur around the ipsilateral eye or temple, and it may be associated with nasal stuffiness. As the pain settles behind the eye, the patient may experience throbbing pain of increasing intensity that may “stab” the patient in the temple, the teeth, or the face. The “stuffed nostril,” ipsilateral to the pain, may now begin to exhibit a clear discharge.
The patient typically develops autonomic nervous system signs, including ipsilateral lacrimation (tearing), redness of the conjunctiva, ptosis, and miosis. The partial Horner’s syndrome of ptosis and miosis does not include anhidrosis. Interestingly, numerous patients, when asked for a description of the pain, state that “it feels like there is someone in my head, behind my eye, trying to push my eye out with a hot poker.”
The physical appearance of the cluster patient has been described as “leonine.”9 Patients are felt to have a particularly masculine physiognomy and physique. The noted facial characteristics include thick, coarse skin, with a peau d’orange appearance, and extreme wrinkling of the forehead and face with deep furrows, which may be secondary to heavy tobacco use, CH, or both. Facial telangiectasias are frequently seen. Freitag noted that these “tall rugged male types frequently may be seen with a diminutive wife who, between she and her husband, has the dominant personality, frequently answering questions for the patient.”15 Female CH patients also tend to have a “masculine” appearance, with very creased, or furrowed, square faces.16
Pattern of Headaches
Typical patients experience between 1 and 10 headaches per day, with most averaging 1 to 3 per day. The average duration of the attack is 45 minutes, but it may be shorter or last as long as 3 hours. The greater duration of headache may indicate that the diagnosis must be reviewed (ie, longer time may indicate unrecognized migraine). The peak pain intensity may occur within 1 minute, while the pain may last from 10 to 60 minutes or longer before gradually decreasing.
The attacks most often occur after working hours, most commonly 90 to 120 minutes after the patient falls asleep, during the first assumed rapid eye movement (REM) stage of sleep.17 The pain of CH most often is seen over the oculofrontal or oculotemporal regions, unilaterally. It does not switch sides. Some reports indicate an association with CH and obstructive sleep apnea.18 If the sleep apnea is addressed, in some cases, the CH improves.19 (See below for more regarding hypoxia and CH.)