Neuropsychological follow-up and audiometry in Susac syndrome — a case report

Abstract

Susac syndrome is an extremely rare autoimmune disease which is characterized by encephalopathy, cochleo-vestibular damage resulting in sensorineural hearing loss, and branch retinal artery occlusion (BRAO) leading to visual disturbances. The number of reported cases worldwide since Susac’s first report in 1979 on two patients is about 500. Long-term data on cognitive and audiometric course in Susac syndrome are scarce. We present a case of a 20-year-old male diagnosed with Susac syndrome in 2017, with cognitive and audiometric assessments conducted over spans of 50 and 71 months after initial diagnosis, in conjunction with functional MRI analysis of expressive speech lateralization. At the initial examination, the patient exhibited significant impairments in attention, processing speed, executive function, memory, and visuoconstructional abilities, together with left–right discrimination difficulties. Following monthly cyclophosphamide treatment, rehabilitation, and time, cognitive performance improved substantially across domains, and high-frequency sensorineural hearing loss in the left ear improved toward normal limits. On fMRI, sentence generation showed a leftward bias in the posterior perisylvian cortex whereas word generation was essentially bilateral, indicating that speech-production related lateralization was preserved but not uniformly left-dominant despite extensive callosal lesions. This longitudinal, multimodal case underscores the potential benefits of early diagnosis and treatment and the apparent preservation of speech-production lateralization despite callosal injury.