patterns, fumes or strong scents such as perfumes and cigarette smoke, and exercise.

Migraine therapy consists of treatment for the acute symptoms as well as prophylactic management. For treatment of acute symptoms, various drugs can be used, including serotonin 5- HT1B/1D-receptor agonists (triptans), nonsteroidal anti-inflammatory drugs (NSAIDs), dihydroergotamine, and other combination drugs that include caffeine. (Long-term caffeine intake, however, worsens headaches.) An antiemetic drug may also be necessary. The triptans (eg, sumatriptan, rizatriptan, zolmitriptan, frovatriptan, and almotriptan) are useful for symptomatic relief of migraine but may be contraindicated for patients with basilar-type migraine. Though a rare effect, these drugs can cause myocardial infarction and are typically not used for patients with suspected or known coronary artery disease.

Analgesic medications should be prescribed with caution. The use of pain medications on more than 15 days a month can lead to analgesic rebound headache, characterized by a constant headache that is relieved only with the continuous use of pain medications. Therefore, a thorough medication history from patients with headache is important. Analgesic rebound headaches require the withdrawal of analgesics, and hospitalization may be needed. Prophylactic treatment is warranted if headaches disrupt activities of daily living beyond what the patient is willing to tolerate. Topiramate, an antiepileptic γ-aminobutyrate (gamma-aminobutyric acid, or GABA) agonist, has been increasingly prescribed for patients with migraine. In some patients using topiramate, however, a syndrome characterized by acute myopic shift (>6 D) and acute bilateral angle-closure glaucoma can occur (see BCSC Section 10, Glaucoma). Alternatively, beta-blockers, calcium channel blockers, tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), sodium valproate, and gabapentin may be used as prophylactic drugs, as may NSAIDs if their potential for causing analgesic rebound headaches is kept in mind. Oral administration of magnesium and riboflavin can be effective for some patients, as well as pericranial botulinum toxin injections. Tension-type headaches are more likely to respond to treatment with tricyclic antidepressants, topiramate, gabapentin, muscle relaxants, and NSAIDs, although the overall rate of success with such drugs is not as high as for migraine. Various forms of biofeedback may be helpful.

Couch JR. Update on chronic daily headache. Curr Treat Options Neurol. 2011;13(1):41–55.

El-Dairi MA, Bhatti MT. Headaches and facial pain for the ophthalmologist. Focal Points: Clinical Modules for Ophthalmologists. San Francisco: American Academy of Ophthalmology; September 2011, module 1.

Monteith TS, Goadsby PJ. Acute migraine therapy: new drugs and new approaches. Curr Treat Options Neurol. 2011;13(1):1– 14.

Trigeminal Autonomic Cephalgias and Hemicrania Continua

The trigeminal autonomic cephalgias (TACs) include cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). The TACs are primary headache disorders characterized by short-lasting unilateral head pain that occurs with ipsilateral cranial autonomic findings. They can be difficult to treat and are best managed by neurologists.

Cluster headache is about twice as common in men as in women. Although the typical age of onset is in the 20s and 30s, it can occur at any age and is typically precipitated by alcohol use. Cluster headache is characterized by excruciating bouts of pain lasting 15 minutes to 180 minutes and localized behind one eye in the distribution of the ophthalmic division of cranial nerve (CN) V. Associated features include ipsilateral tearing, conjunctival injection, rhinorrhea, and transient

(although it can become permanent) postganglionic Horner syndrome. The pain may wake the patient from sleep and cause restlessness. Headaches occur in clusters of episodes over days or weeks, typically beginning like clockwork at the same time of day, then remit for months or years, suggesting that the hypothalamus may play a role in the pathogenesis. Cluster headaches can be difficult to treat. Abortive drugs include subcutaneous sumatriptan, inhaled oxygen, dihydroergotamine, and intranasal lidocaine. Verapamil, lithium, methysergide, corticosteroids, topiramate, and gabapentin can be useful for prophylaxis.

Paroxysmal hemicrania is characterized by short, severe attacks of pain with cranial autonomic features that occur several times daily. The headache typically lasts between 2 minutes and 30 minutes but may persist for hours. A dramatic resolution of the headache occurs with indomethacin administration.

SUNCT is characterized by unilateral orbital or temporal pain that is severe and throbbing or stabbing. The headache typically occurs more than 20 times per day, lasts 5 seconds to 240 seconds, and is often associated with conjunctival injection and tearing.

Unlike the other TACs, hemicrania continua is characterized by a continuous unilateral headache of variable intensity that waxes and wanes without disappearing completely. The forehead, temple, orbit, and occiput are common sites of pain. Autonomic symptoms are present in most patients. This primary headache disorder is also responsive to treatment with indomethacin.

Idiopathic Stabbing Headache

Also known as “ice pick headache” and “jabs and jolts syndrome,” idiopathic stabbing headache manifests as episodic, momentary, sharp, jabbing pains and occurs more commonly in patients with migraine than in those with other types of headaches. Patients with cluster headaches also have a high incidence of idiopathic stabbing headache, typically occurring in the same area as the cluster pain. The most common location for such headaches is in the distribution of the ophthalmic division of CN V, particularly the orbit, and less commonly the parietal, temporal, facial, occipital, and retroauricular regions. The pain lasts less than a second or may occur as a series of stabbing sensations. Idiopathic stabbing headache often responds to indomethacin administration, and many patients improve with standard prophylactic headache drugs.

Inherited Encephalopathies Resembling Migraine

Mitochondrial myopathy and encephalopathy, lactic acidosis, and strokelike episodes (MELAS) is a hereditary mitochondrial disorder of children and young adults. Its symptoms (headache, nausea, vomiting, transient hemianopia, and hemiparesis) suggest migraine, but permanent neurologic disturbance occurs with spongiform cortical degeneration. Serum and cerebrospinal fluid (CSF) lactate levels are elevated, and hyperintense lesions may be observed on T2-weighted magnetic resonance imaging (MRI) of the temporal, parietal, and occipital lobes.

Headache resembling migraine may occur as the initial symptom of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), an autosomal dominant angiopathy that is associated with a mutation in the NOTCH3 gene on chromosome 19. Headaches occur in 30%–40% of patients with CADASIL and often arise later in life than typical migraine. Recurrent lacunar strokes with neurologic deficits and cognitive decline eventually occur. Widespread leukoencephalopathy, particularly within the temporal and frontal lobes, is apparent on