CLUSTER HEADACHE Cluster headaches are characterized by repetitive headaches that occur for weeks to months at a time, followed by periods of remission. Men are affected more commonly than women, with a peak age of onset of 25 to 50 years. The pain of cluster headache begins quickly without any warning and reaches a crescendo within a few minutes. The headache is usually deep, excruciating, continuous, and explosive in quality, although occasionally it may be pulsatile and throbbing. The pain usually begins in or around the eye or temple; less commonly it may start in the face, neck, ear, or hemicranium. The pain is always unilateral; it remains on the same side of the head during a single cluster, but can switch sides during the next cluster in a small percentage of patients. Some patients report superimposed paroxysms of stabbing ice pick-like pain in the periorbital region which last for a few seconds and occur once or several times in rapid succession. Most patients with cluster headache prefer to stay active when an attack is in progress, in contrast to migraine sufferers who tend to rest in a dark, quiet room. Cluster headaches are associated with ipsilateral lacrimation and redness of the eye, stuffy nose, rhinorrhea, sweating, pallor, and Horner's syndrome. Focal neurologic symptoms are rare. Over 50 percent of sufferers report a sensitivity to alcohol during a cluster bout which ceases when the cluster ends. A typical cluster headache lasts from 30 minutes to 3 hours with a mean of 45 to 60 minutes. The frequency of attacks depends upon the type of cluster: Episodic cluster headaches are most common, occurring in more than 90 percent of patients suffering from this disorder. They are characterized by one to three attacks of periorbital pain per day over a four to eight week period, followed by an average pain free interval of six months to one year. The remission may last for years. Chronic cluster headaches are characterized by the absence of sustained periods of remission. Either form of cluster headache can transform into the other. Attacks of pain tend to recur at the same hour each day for the duration of a single cluster; attacks occur between 9 pm and 9 am in up to 80 percent. Most patients experience one cluster per year, but this is not predictable. Pathophysiology The pathophysiology of cluster headache remains unclear. Vasodilatation occurs and may be responsible for the pain and autonomic features of cluster headaches; it likely is purely extracerebral (in contrast to migraine). Factors which may be important include cigarette smoking and alcohol use. Treatment Treatment of cluster headaches can be divided into abortive and prophylactic therapy. In contrast to migraine, most patients with cluster headaches will require both prophylactic and abortive treatment for the duration of the cluster. Abortive therapy Abortive therapy of cluster headaches can be difficult because of the short duration of each episode. Nevertheless, a number of medications have proven effective. Acute cluster headaches can be aborted by inhalation of 100 percent oxygen in the majority of patients. Sumatriptan appears to be helpful in aborting an acute cluster attack. Cafergot and DHE 45 also have been shown to relieve the pain of acute cluster attack. Indomethacin and other nonsteroidal antiinflammatory drugs may also be effective. Prophylaxis Prophylactic therapy should be started as soon as possible at the onset of a cluster episode. A number of drugs may be useful. Verapamil is effective for prophylaxis, although there is a four to six week delay before the headaches remit. Prednisone is highly effective for prophylaxis, but should not be used chronically due to side effects. Lithium appears to be particularly effective for the chronic form of cluster headaches. Ergotamine, methysergide, cyproheptadine, and indomethacin have also been shown to be effective. Prophylactic medications can be tapered after the expected duration of the cluster has passed. The drugs can be restarted if symptoms recur at the lowest effective dose. Tension-type headache Tension-type headache is the most common headache syndrome. Patients are given a diagnosis of episodic tension-type headache if the number of headache days is <180 per year and <15 per month; headache frequency in excess of these numbers is termed chronic tension-type headache. Tension-type headaches feel like pressure or tightness all around the head and have a tendency to wax and wane in intensity. An easy clinical rule is that tension-type headaches are characterized as head pain devoid of typical migrainous features (eg, nausea, vomiting, photophonia, photophobia, and aura.) Some individuals may have overlapping features of both migraine and tension-type headache. Those individuals are hard to satisfactorily label with a single diagnosis, but should be treated as tension-type headache sufferers. Many patients report daily headache symptoms for years and do not seek specialist consultation until very late in their course. There is a high correlation between analgesic abuse of over the counter analgesics, muscle relaxants, acetaminophen, aspirin, opioids, barbiturates, and benzodiazepines in these chronic headache sufferers. As a general rule, psychological factors play a more important role in these individuals compared to patients with either migraine or cluster headache. Pathophysiology Controversy exists regarding the pathophysiology of tension-type headache. Recent evidence supports the hypothesis that the basic pathophysiology of tension-type headache is qualitatively similar to but quantitatively different from migraine. The trigeminal neurovascular system and unstable serotonergic neurotransmission may play an important role in the pathogenesis of this disorder . Treatment General principles of tension-type headache treatment are similar to the prophylactic and abortive therapy of migraine. Simple analgesics such as acetaminophen, aspirin, and other nonsteroidal antiinflammatory drugs (NSAIDs) are the drugs of choice for abortive therapy. Combination drugs containing ergotamine, caffeine, butalbital and codeine should be avoided due to the potential for drug dependency and rebound headaches. Prophylactic therapy is indicated for patients with chronic headaches requiring daily analgesics. Tricyclic antidepressants have been used most commonly. Patients who have some features of migraine may benefit from beta blockers or calcium channel blockers, either alone or in combination with an antidepressant. Newer antidepressants may be useful in the prophylactic treatment of tension-type headache. Patients with daily intractable and severe tension-type headaches who exhibit a clear pattern of analgesic abuse may need to be treated on an inpatient basis with parenteral dihydroergotamine (DHE-45) while they are being detoxed from the analgesics of abuse and while building therapeutic levels of prophylactic medications. Biobehavioral techniques are very important in managing chronic tension-type headaches. Psychotherapy, relaxation therapy, and biofeedback all may be useful. Physical therapy also may reduce the frequency of headaches in some cases. Posttraumatic headache There are many variants of posttraumatic headache. A number of syndromes describe the same disease, including postconcussion syndrome, posttraumatic migraine, and head injury headache. This type of headache is relatively common and is surpassed in clinical practice only by migraine, tension-type headache, and temporomandibular joint dysfunction. Headache is the dominant symptom of the posttraumatic headache syndrome. The headache usually appears within one to two days of the head injury; it worsens initially before gradually improving. Most patients report a generalized dull, aching, constant discomfort with intermittent exacerbations. Other common accompanying symptoms include vertigo, light-headedness, inability to concentrate, emotional lability, problems with memory, easy fatiguability, and irritability. Some patients report these symptoms in the absence of headache or vertigo. Posttraumatic headaches should resolve within a few weeks to a couple of months, although occasionally they can linger for months, or rarely years. Treatment is usually symptomatic, but should be individualized according to the same guidelines for the abortive and prophylactic treatment of migraine and tension-type headaches. Temporomandibular joint dysfunction syndrome Temporomandibular joint dysfunction syndrome (TMJ) is characterized by chronic or acute musculoskeletal pain with dysfunction of the masticatory system. Many patients complain of headache; in some cases, the disorder presents only as a headache without the patient being aware of a TMJ disturbance. The typical headache associated with TMJ presents as unilateral ear or preauricular pain that radiates to the jaw, temple, or neck. The pain is deep, dull, continuous, and usually worse in the morning. It typically is associated with a limitation of jaw motion and deviation of the jaw upon opening. Physical examination may reveal tenderness of the muscles of mastication and, less commonly, clicking of the joint. Many cases are difficult to distinguish from tension-type headaches. The treatment of headache due to TMJ primarily involves therapy of the joint disorder itself. Most cases can be treated with local heat, physical therapy, dental hygiene, NSAIDs, and dietary measures. Occasional patients may require surgery. Brain tumors Headaches occur in approximately 50 percent of patients with brain tumors. The headaches are similar to tension-type in 77 percent, migraine in 9 percent, and other types in 14 percent. The typical headache is bifrontal but worse ipsilaterally; it is the worst symptom in only 45 percent of patients. The "classic" early morning brain tumor headache is uncommon. Nausea, vomiting, an abnormal neurologic examination, or a significant change in prior headache pattern suggest that the headache is caused by a tumor. Ruptured intracranial aneurysm A ruptured intracranial aneurysm causes a severe headache of sudden onset that patients often characterize as "the worst headache of their life." A decreased level of consciousness and stiff neck are common accompanying features. Some patients experience a minor leak prior to rupture. This leak may be manifested clinically as a "sentinel headache," which typically presents as a severe headache lasting for only a few minutes without associated neurologic abnormalities. The work-up of patients with a suspected subarachnoid hemorrhage begins with a noncontrast head CT scan. If that is negative, a lumbar puncture must be performed; a minor leak may not be evident on CT in up to 55 percent of patients.