Carotid Cavernous Fistula Mimicking Hemicrania Continua: A Case Report.

Hemicrania continua is a primary headache disorder characterized by a continuous, unilateral headache associated with ipsilateral cranial autonomic features that responds to indomethacin. By definition, the symptoms are not referable to an underlying structural pathology. However, several cases of secondary hemicrania continua related to underlying structural lesions have been reported.We present a case of a 53-year-old male with a prolonged, right-sided headache associated with intermittent right-sided ptosis, conjunctival injection, tearing, and nasal congestion, suggestive of hemicrania continua, who was found to have an indirect carotid-cavernous fistula, and who, after endovascular treatment of the fistula, had resolution of his symptoms.Alternative, and perhaps less common, causes of headache should be considered when the clinical presentation is atypical or does not clearly fulfill diagnostic criteria for primary headache disorders. Carotid cavernous fistulas should be included within this differential, and represent a potentially treatable and reversible cause of otherwise refractory headache.