The patient should undergo brain MRI. Although she has a long-standing history of migraine with aura, the recent escalation in headache frequency and intensity is concerning. The pattern of her headaches has fundamentally changed, and she exhibits several other red flags, such as the development of a new headache condition after age 50 years and neurologic symptoms lasting more than 1 hour, that are compatible with the presence of a secondary headache. Diplopia, when present in migraine aura, should be accompanied by other features seen in migraine with brainstem aura (basilar migraine), such as vertigo, ataxia, dysarthria, diplopia, tinnitus, hyperacusis, or alteration in consciousness; this patient has none of these features. Additionally, the maximum duration of aura in basilar migraine is 60 minutes or less, not the 2 hours she experienced. MRI is the preferred study to confirm the diagnosis of a secondary headache.

Discontinuation of ibuprofen would be helpful in the setting of medication overuse headache. Excessive analgesic intake can result in worsening of the underlying headache or the appearance of a milder, nonspecific headache. However, this medication would not cause new neurologic symptoms, such as diplopia.

In this patient with a probable secondary headache, neuroimaging is necessary before consideration of lumbar puncture to exclude any space-occupying lesion that could affect intracranial pressure.

Switching from naratriptan to sumatriptan may have been a consideration if the diagnosis were only worsening migraine. However, this patient most likely has a secondary headache disorder, so changing triptans in unlikely to be helpful.

Substituting topiramate for amitriptyline may be an appropriate treatment in patients with escalating migraine frequency, but not in those suspected to have a secondary headache disorder.