By Paul Phelps, M.D., Chairman, Department of Anesthesia, Southwest Healthcare System, Murrieta, California

CASE
For over 20 years, Roger, aged 54, has had severe, intermittent headaches. These headaches are characterized by an intense burning pain on one side of his head, accompanied by tearing in his eye and a runny nose. When they strike, the attacks typically occur several times a day and usually last about an hour. Roger can be headache free for months at a time, but the attacks always return. He has seen several healthcare providers, including headache specialists, with little or no improvement.

DISCUSSION
Roger has cluster headache, which afflicts more men than women at a ratio of about 5 to 1. The condition can appear at any age, but the majority of cases start between the ages of 20 and 40. There seems to be no genetic or racial predisposition.

“Cluster” is a descriptive term that refers to the way the attacks occur in groups, bursts or clusters, which can last from days to months and then go into remission, often for years at a time. The clusters occur with some seasonal regularity, most often in the spring or fall. During a cluster period, a patient may have one or several headaches in a day. The attacks frequently occur at night, waking the patient from a sound sleep. The pain is of short duration, lasting from a few minutes to several hours, though most often for 30 to 45 minutes. The pain is rarely present longer than four hours.

The pain is excruciating and is described with such words as stabbing, boring, burning, stabbing, or a “hot poker in the eye.” It is always one-sided and usually located behind or around the eye. Patients may also experience flushing of the face, tearing of the eye, nasal congestion or a runny nose. The affected eyelid may become swollen or droop and the pupil may contract. The pain is so severe that patients feel better walking around, in contrast to migraine, in which patients usually prefer lying down.

TREATMENT
Patients with cluster headache must be instructed to avoid all factors that are known to trigger or precipitate attacks during a cluster series. These include ingestion of alcohol and exposure to vasodilating substances such as nitrates, gasoline fumes and various solvents. Foods that trigger migraine headaches may also trigger cluster headaches, including foods that contain tyramine (such as cheese) citrus fruits, chocolate, processed meats, MSG, nuts, seeds and peanut butter.

Patients with cluster headaches require both a preventive therapy and an abortive therapy to stop breakthrough attacks. The classic abortive therapy for cluster is inhalation of 100% oxygen at 7 liters per minute. Ergotamines can be taken a variety of ways including orally, sublingually, intramuscularly, or via nasal spray or suppository. The triptan drugs can also be used as abortive agents. However, while triptans have revolutionized the treatment of migraine, their role in the treatment of cluster headache is limited—most cluster headaches only last 30 to 45 minutes, which is about the time it takes for triptans to be absorbed and become effective. However, nasal sprays and subcutaneous forms of triptans can bring faster relief.

Preventive treatment is used to reduce the frequency, duration and severity of attacks, and to interrupt the cluster cycle. Daily treatment is begun at the onset of a new cycle. It does not, unfortunately, prevent future clusters, so treatment should be discontinued gradually two to four weeks after the last attack. Commonly used preventive therapies include calcium channel blockers (in particular, verapamil), lithium carbonate, valproic acid, ergotamine and different types of steroid therapy, such as prednisone. Some healthcare providers use triptans with long half-lives (naratriptan and frovatriptan) as a preventive treatment.

Roger’s most recent treatment regime had included lithium for prevention and a nasal spray of zolmitriptan for abortive therapy. Unfortunately, he reported little or no help from these therapies. We weaned him off the lithium and started him on Bellergal-S® (ergotamine, phenobarbital and Bellafoline®) for preventive therapy.

For abortive therapy, we decided to be creative and try a sphenopalatine ganglion (SPG) block. The SPG is a large collection of nerves located behind the nose, which acts as an important relay center for the autonomic nervous system. While the exact mechanism behind cluster headache is not known, it appears that the SPG plays an important role—when it is electrically stimulated, a syndrome much like that of cluster headache is produced. Because cluster headache occurs primarily in males who smoke heavily, several experts believe that the SPG is consistently irritated in heavy smokers and eventually becomes hyperactive, usually on one side. Blocking the SPG with a local anesthetic has been shown to be effective in the relief of a wide variety of pain conditions ranging from headache to low back pain.

There are several ways to block the SPG but the transnasal approach is the preferred technique. While the patient is lying down, two cotton applicators are soaked with 4% lidocaine solution and advanced into the nose (on the side of the head pain) and into the nasal passages. It takes affect in less than three minutes. If the block is successful and there are no side effects, patients can be taught to perform the block themselves.

The side effects of the SPG block are few. They include allergic reaction to lidocaine, which is rare, irritation to the nose, or nose bleed, which also rarely happens. It is a simple and safe treatment that is effective for some cluster sufferers.

It was certainly successful for Roger. Two months after learning the technique, Roger came back to the clinic for follow-up. He reported using the block several times with excellent relief of his headache pain. On one occasion, Roger felt the onset of a severe cluster headache while golfing. He proceeded to sit back in the golf cart and block his SPG. Roger finished his round of golf, headache-free.