Long-term cognitive outcomes in Susac syndrome

Background: Susac syndrome (SuS) is a rare autoimmune disorder mediated by the occlusion of micro-blood vessels in the brain, retina, and inner ear. Approximately 15% of cases present with the classic triad of CNS dysfunction, visual disturbances, and sensorineural hearing loss. While the literature is abundant about the severe, acute encephalopathy of SuS, not much is known about the extent of cognitive sequela in the post-era of efficient immunomodulatory treatment. Methods We report global cognitive function using a battery of cognitive tests in ten recovering SuS patients with an average of 2.9 (SD = 1.41) years post-disease onset. Results Patients showed intact delayed memory (both verbal and non-verbal) but below-average scores on tests of executive functions, and deficits in attention and copying. Results are discussed in light of the initial severity and extent of corpus callosum involvement on brain MRI. Conclusions study results suggest that the main cognitive sequela of SuS involves deficits in visual attention and executive functions possibly due to Corpus Callosum involvement. Additionally, this report supports a favorable prognosis for patients with SuS who receive a fast and efficacious immunomodulatory treatment protocol suggested in 2018.