Characteristics of headache in relation to the manifestation of Susac syndrome.

Susac syndrome is characterized by a clinical triad of encephalopathy, branch retinal artery occlusion, and hearing loss. Due to the absence of the whole complex of the triad in the majority of cases at disease presentation, the syndrome often remains underdiagnosed and untreated. Headache is estimated to affect up to 80% of Susac syndrome patients, but the relevance of headache characteristics and profile is not yet clear. The proposed diagnostic criteria of the European Susac Consortium acknowledge headache as a possible brain manifestation if it is new, described as migrainous or oppressive, and precedes the other symptoms by not more than 6 months. Herein, a case series of different migraine-like headache associations attributed to Susac syndrome is presented and discussed in relevance with previously published literature. Our patients experienced different presentations of migraine-like headache related with Susac syndrome: exacerbation and chronification of headache just before the manifestation of the first symptoms of Susac syndrome, the manifestation of headache during the first episode of the syndrome, and an increasing frequency of headache during the course of the disease. The diagnosis of Susac syndrome in all three cases was confirmed by typical clinical symptoms and findings in retinal fluorescein angiography, audiometry, and brain magnetic resonance imaging, based on the diagnostic criteria of the European Susac Consortium. Based on the analysis of our presented cases, we conclude that headache attributed to Susac's syndrome is of migraine-like type but could be of different presentations in relation to the onset of the syndrome.