Migraine: Expanding our Tx arsenal

How is migraine defined? Simply, migraine is classically defined as a unilateral, pulsating headache of moderate to severe intensity lasting 4 to 72 hours, associated with photophobia and phonophobia or nausea and vomiting, or both.¹¹ Often visual in nature, aura is a set of neurologic symptoms that lasts for minutes and precedes the onset of the headache. The visual aura is often described as a scintillating scotoma that begins near the point of visual fixation and then spreads left or right. Other aura symptoms include tingling or numbness (second most common), speech disturbance (aphasia), motor changes and, in rare cases, a combination of these in succession. By definition, all of these symptoms fully resolve between attacks.¹¹

Validated valuable questionnaires. To help with accurate and timely diagnosis, researchers have developed and validated simplified questionnaires that can be completed independently by patients presenting to primary care (TABLE 1^12,13):

• ID Migraine is a set of 3 questions that scores positive when a patient endorses at least 2 of the 3 symptoms. ¹²
• MS-Q is similar to the ID Migraine but includes 5 items. A score of ≥4 is a positive screen. ¹³

The sensitivity and specificity of MS-Q (0.93 and 0.81, respectively) are slightly higher than those of ID Migraine (0.81 and 0.75).¹³

Remember POUND. This mnemonic device can also be used during history-taking to aid in diagnostic accuracy. Migraine is highly likely (92%) in patients who endorse 4 of the following 5 symptoms and unlikely (17%) in those who endorse ≤2 symptoms¹⁴: Pulsatile quality of headache 4 to 72 hOurs in duration, Unilateral location, Nausea or vomiting, and Disabling intensity.

Differential Dx. Although the differential diagnosis of headache is broad (TABLE 2^14,15), the history alone can often guide clinicians towards the correct assessment. After taking the initial history (headache onset, location, duration, and associated symptoms), focus your attention on assessing the risk of intracranial pathology. This is best accomplished by assessing specific details of the history (TABLE 3¹⁴) and findings on physical examination¹⁵:

• blood pressure measurement (seated, legs uncrossed, feet flat on the floor; having rested for 5 minutes; arm well supported)
• cranial nerve exam
• extremity strength testing
• eye exam (vision, extra-ocular muscles, visual fields, pupillary reactivity, and funduscopic exam)
• gait (tandem walk)
• reflexes.

Continue to: Further testing needed?