Migraine-like Visual Aura Rriggered by a Large Aneurysm in the Left Extracranial Internal Carotid Artery with Successful Prevention of Recurrence by the new Anticoagulant Dabigatran: First Case Report.

PURPOSE We present a rare case of late-onset migraine-like visual aura triggered by a large aneurysm in the left extracranial internal carotid artery. To the best of our knowledge, this is the first case of migraine-like visual aura triggered by an extracranial internal carotid artery (ICA) aneurysm. This is also the first case of migraine-like visual aura with probable thromboembolic trigger being successfully treated with a new anticoagulant, dabigatran. CASE REPORT A 61-year-old woman complained about stereotypical episodes of a short-lasting flickering light in the right visual field for about half a year. Magnetic resonance imaging (MRI) of the head revealed a large aneurysm arising from the mid-cervical portion of the left internal carotid artery (ICA). After anticoagulant therapy with 110 mg of dabigatran twice a day, she became free from the visual symptom. CONCLUSION Late-onset migraine with aura, especially typical aura without headache should be diagnosed carefully since it can be a challenge to distinguish it from signaling something serious. Micro-thromboembolism, commonly cardiogenic, but rarely arising from a carotid aneurysm, can trigger cerebral ischemic injury, causing transient neuronal hyperexcitability and cortical spreading depression (CSD)-like ''spontaneous'' waves propagating through the penumbra of the injured region into normally perfused tissue. The resultant symptoms may semiologically mimic visual aura. Migraine-like visual aura in this patient was successfully treated with dabigatran. It may not only imply that the patient's migraine-like visual aura was a thromboembolic event, but may also suggest the potential efficacy of the new anticoagulant, dabigatran, as the optimal alternative of warfarin in treating a thromboembolic event arising from a carotid aneurysm.