Pharmacological Dissociation in Hemicrania Continua With Persistent Visual Aura Evolved From Episodic Migraine: A Case Report.

Objective: To report a case of hemicrania continua (HC) and persistent visual aura without infarction in a patient with previous episodic migraine with visual aura, whose persistent aura symptoms improved only after treatment with divalproex sodium.

Background: Once regarded as highly specific for migraine, visual aura has been associated with trigeminal autonomic cephalalgias, including HC. In previous descriptions of HC and episodes of typical visual aura, the aura occurred exclusively with severe headache exacerbations and, like the pain, resolved with indomethacin.

Methods: Case report and literature review.

Results: A 54-year-old man with a history of episodic migraine with visual aura reported a gradual onset of HC with persistent visual aura of 15 months duration. General medical and neurological examinations were normal, including imaging studies. HC's headache responded to indomethacin, while the visual aura was recalcitrant, only improving with oral divalproex sodium treatment.

Conclusion: As our patient experienced HC, which evolved from episodic migraine, we hypothesize that migraine and HC may share a common pathophysiology. However, the persistence of the visual aura, despite the abolition of pain and autonomic features with a therapeutic dose of indomethacin, and the subsequent successful treatment of the aura with divalproex sodium, suggest that aura and HC headache arise from distinct and dissociable mechanisms.