This patient should receive rizatriptan to treat migraine, which is no longer adequately controlled by NSAIDs. Other than increased intensity, the headache pattern has been stable for 25 years. Her history, physical examination findings, and MRI provide no evidence of a secondary headache disorder. The white matter signal abnormalities evident on the MRI are typical of those seen with migraine, specifically in the posterior circulation and particularly in women, as documented in several population-based studies. Data suggest that these lesions are benign and have no correlation with migraine frequency or the appearance of neurologic or cognitive anomalies or deficits. Initiation of a triptan is appropriate in patients with acute migraine who have not responded to treatment with one or more NSAIDs.

Aspirin is unlikely to relieve acute migraine pain that has not responded to two NSAIDs and would be unnecessary for secondary stroke prevention in this patient.

The patient has not reported any clinical events suggestive of stroke or a demyelinating disease, and her normal neurologic examination findings and the absence of any larger or periventricular white matter lesions on MRI would be unusual in multiple sclerosis. Lumbar puncture is thus not warranted in this patient.

Magnetic resonance angiography is also unnecessary. Although migraine is a contributor to stroke risk in women, this patient has no features suggestive of cerebral ischemia and has no aura or other risk factors for cerebrovascular disease.

Timolol is a migraine prophylactic drug that is effective in reducing the frequency of migraine attacks. Pharmacologic prophylaxis of migraine is indicated for headache frequency greater than 2 days per week (or 8 days per month) or use of acute medications, successfully or unsuccessfully, more than 2 days per week. Migraine frequency in this patient is too low to warrant introduction of daily migraine preventive medication.