NEUROIMAGING DIAGNOSIS OF SUSAC SYNDROME WITH OPHTALMIC PRESENTATION – CASE REPORT
Introduction: Susac syndrome is a rare disease, typically affecting young adult women. It is an autoimmune microendotheliopathy affecting retina, cochlea and brain arterioles, giving the classic triad: vision abnormalities (caused by branch retinal arterial occlusions), sensorineural hearing loss, and subacute encephalopathy. In 50% of cases, migraine-like headache is a heralding symptom. Presence of multiple hyperintense lesions in the corpus callosum on T2WI may be a clue to the diagnosis. Treatment includes corticosteroids and immunotherapy. The syndrome is self-limiting and may go on for years, with fluctuations in its course.
Case Report: Female, 38 years old, migraine without aura history. Two hospital admissions in two weeks. The first with ophthalmic presentation (brief sudden blurred vision, without headache or imbalance; photopsias in external visual fields associated with nausea) and left leg paresthesias; normal on neurological and ophthalmic examination; normal complementary study, except brain MRI. The second with encephalopathic presentation (malaise, nausea and vomiting, disorientation, tongue paresthesias and urinary retention); slowed speech, disoriented in time and slight imbalance on neurological examination; normal audiogram, but EEG with generalized delta wave surges (anterior dominant), and retinal angiography with vasculitis phenomena and bilaterally multifocal occlusion of retinal arterioles. Brain MRI: multiple rounded focal lesions hyperintense in T2/FLAIR (“snowballs”) dispersed by the white matter of the cerebral hemispheres, centrum semiovale bilaterally, subcortical white matter (sparing U-fibers), corona radiata bilaterally, corpus callosum (preferentially middle layers, but some lesions in the callososeptal interface), right lenticular nucleus, diencephalic-mesencephalic transition bilaterally, and posterior fossa (middle cerebellar peduncles); DWI/ADC: most of these lesions exhibit restricted diffusion of water molecules; T1 C+ (Gd): lesions without enhancement.
Conclusion: The distribution and signal characteristics of the lesions suggest recent ischemic vascular lesions in the context of small vessel vasculitis, most likely Susac Syndrome, considering the involvement of the corpus callosum middle layers.