Migraine: Diagnosis and Treatment

Diagnosis

Migraine is a clinical diagnosis. Neuroimaging is only necessary if another possible etiology is suspected. Providers may consider a CT scan and lumbar puncture for patients with rapid onset of severe headache (to rule out subarachnoid hemorrhage), focal neurologic signs, gait instability, or other migraine–inconsistent findings.

Migraine without aura

A clinical diagnosis of migraine is indicated for patients who experience 5 or more episodes fulfilling the following criteria:

• Duration of 4 to 72 hours.
• Two or more of the following: unilateral location, pulsating quality, moderate or severe intensity, aggravation by routine physical activity.
• One or more of the following: nausea/vomiting, photo/phonophobia.
• Headache not attributed to another disorder.

Migraine with aura   

The following criteria establish the clinical diagnosis of migraine with aura:

• Aura consisting of one or more of the following, and without motor weakness: fully reversible visual symptoms, fully reversible sensory symptoms, or fully reversible speech disturbance.
• Two or more of the following: homonymous (same field defect in both eyes) visual symptoms or unilateral sensory symptoms, at least one aura developing gradually over 5 minutes or different auras developing in succession over at least 5 minutes, or each aura lasting between 5 to 60 minutes
• Two episodes fulfilling above criteria with migraine headaches beginning within 1 hour of the aura(s)
• Headache not attributed to any other disorder

Treatment

Prevention is the mainstay of migraine therapy. The patient will benefit from avoiding situations that trigger or exacerbate migraines–for example, by maintaining appropriate sleep patterns, avoiding fasting and trigger foods, and participating in stress management. It should be kept in mind that absorption of oral medicines may be decreased due to migraine–induced gastric stasis.

Abortive therapy

Abortive therapies are more effective when given early, and in larger appropriate doses, although frequent use (more than 10 times per month) can lead to medication–overuse headaches. All short–acting analgesic medications can result in these headaches (also called analgesic rebound headaches or transformed migraine). Non–oral drugs–suppository, intramuscular, or intravenous–may work better for the many patients who suffer from nausea and vomiting during episodes. The following agents are commonly used:

Analgesics. Aspirin, other NSAIDs including indomethacin, and acetaminophen. Chronic use can lead to overuse headaches.

Triptans (sumatriptan, rizatriptan, almotriptan, zolmitriptan). These serotonin receptor agonists are for moderate–to–severe migraine when vascular disease and uncontrolled hypertension are absent. Triptans inhibit vasoactive peptide release, cause vasoconstriction, and block pain pathways in the brainstem.¹³ Sensitization may decrease effect. They should be avoided in pregnancy and in hemiplegic migraine.

Dihydroergotamine (intranasal or injectable). This medicine is effective for moderate–to–severe attacks when vascular disease and hypertension are absent. Administration may require anti–emetic premedication. The medicine should not be used within 24 hours of triptans due to risk of myocardial infarction, and should be avoided during pregnancy.

Aspirin or acetaminophen with caffeine. Note: Caffeine withdrawal is a very common migraine trigger.

Isometheptene (a vasoconstrictor) and dichloralphenazone (a mild sedative), both components of the drug Midrin).

Intranasal lidocaine solution (4%).

Anti–emetics, prochlorperazine and metoclopramide. These can be administered intravenously, as monotherapy, or as an adjunct to above therapies.

Benzodiazepines, narcotics, and barbiturates should be used sparingly, due to their habit–forming qualities.

Prophylactic therapy

Daily prophylaxis is indicated if headaches are more frequent than 4 per month, or have associated severe disability or complications. It may be several weeks before benefits are evident. The following agents are commonly used:

Beta–Adrenergic blockers, such as propranolol or atenolol. Propranolol  increases rizatriptan levels, so doses of rizatriptan being used to abort migraine should be halved.

Anticonvulsants, such as topiramate, gabapentin, or valproic acid.

Calcium channel blockers, such as verapamil.

Nonsteroidal anti–inflammatory drugs (NSAIDs), such as naproxen,¹⁴ which are most useful when there is a short period of migraine susceptibility each month.

Tricyclic antidepressants, such as amitriptyline or nortriptyline.

Riboflavin (high dose, 200 mg twice daily).

Cognitive and behavioral therapy.

Angiotensin–converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs). The evidence supporting the use of these drugs for migraine is weak.

Two medicinal botanicals, feverfew¹⁵ and petasites,¹⁶ are under study for their efficacy in migraine treatment.

Butterbur (Petasites hybridusroot ). In double–blind, randomized clinical trials, butterbur reduced migraine frequency by roughly half, compared with placebo. Although this effect was achieved with 25 mg BID in one study,¹⁷ a second trial with a larger number of patients found that only a higher dose (75 mg BID) resulted in a statistically significant reduction in migraine frequency (~ 50% fewer attacks over a 4–month period), when compared with 50 mg BID.16 Similar results were obtained in a multicenter prospective open–label study with children and adolescents.¹⁸

The mechanisms by which this botanical may reduce migraine attacks have not been established, but may include spasmolytic and anti–leukotriene effects and an effect on calcium channels.¹⁷ So far, Petasites has a good safety record; belching is its most common side effect.¹⁹ Efficacy comparisons with commonly–prescribed medications for migraine have not yet been performed.

Feverfew is an herb with anti–inflammatory properties. Research studies have yielded mixed verdicts as to its efficacy for migraines. Some clinical trials have suggested efficacy of the native herb or its extracts in preventing or aborting migraines, while others have yielded inconclusive results, perhaps due to variations in preparations tested.²⁰ However, a recent randomized, double–blind, multicenter, parallel–group study found that a feverfew extract (6.25 mg TID) decreased migraine attacks by 40%, compared with a 27% reduction for placebo (P = .05).²¹