Brain histopathology in three cases of Susac's syndrome: implications for lesion pathogenesis and treatment: Figure 1

Susac's syndrome (SS) is the triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. While rare, it has become increasingly recognised since characteristic ‘snowball’ corpus callosum lesions were appreciated on MRI.1 We present clinical and histopathological findings on three patients with SS. Our findings demonstrate a T-cell-mediated inflammatory contribution to lesion pathogenesis. Treatment with the tumour necrosis factor (TNF) inhibitor, infliximab was beneficial in two patients, including in one previously reported,2 and in another who failed rituximab. This report provides a histological rationale for the observed benefit of infliximab, and suggests that infliximab should be considered as an adjunct therapy in patients with refractory SS. Three patients with SS most recently diagnosed among the authors’ practices who had undergone brain biopsy as part of their diagnostic clinical workup were identified. The clinical features, radiology, treatment and outcomes for the three patients are presented as online supplementary data (tables S1–S5 and figures S1 and S2). Extensive serum autoantibody screening was negative. Headache was present in all patients, highlighting the fact that it is a common manifestation of encephalopathy in SS. All three cases reported relatively non-specific auditory and visual symptoms, emphasising that fluorescein angiography±audiology testing should be considered in the diagnostic workup of patients with unexplained encephalopathy. Two patients underwent cerebellar biopsies and one a frontal lobe biopsy. One biopsy was from a treatment-naive patient (case 1). All contained variable numbers of wedge-shaped microinfarcts surrounded by microglia. In cerebellar biopsies (cases 1 and 3), …