Clinical and imaging features distinguishing Susac syndrome from primary angiitis of the central nervous system

Introduction: To assess clinical and/or imaging features useful to distinguish between Susac syndrome (SuS) and primary angiitis of central nervous system (PACNS). Methods: Multicenter retrospective analysis of two cohorts of Argentine patients diagnosed with SuS and PACNS. Results: 13 patients diagnosed with SuS (6 women and 7 men, mean age 35 ± 10 years) and 15 with PACNS (10 women and 5 men, mean age 44 ± 18 years) were analyzed. Cognitive impairment (11 out of 13 patients vs. 5 out of 15, p = .006), ataxia (7 out of 13 vs. 2 out of 15, p = .042) and auditory disturbances (7 out of 13 vs. 0 out of 15, p = .003) were more frequent in SuS patients; whereas seizures were more frequent in PACNS patients (8 out of 15 vs. 1 out of 13, p = .035). On MRI, corpus callosum (CC) involvement was observed more often in SuS, with abnormalities in CC genu, in 13 out of 13 SuS patients vs. only 2 out of 15 PACNS patients (p < .001); in CC body these were present in 13 out of 13 SuS patients vs. 1 out of 15 PACNS patients, (p < .001); and in CC splenium in 12 out of 13 Sus patients vs. 1 of 15 PACNS, p < .001). Cortical lesions were more frequent in PACNS patients (10 out of 15 vs. 3 out of 13 SuS patients, p = .02), as were hemorrhages (5 out of 15 vs. 0 out of 13 SuS, p = .04) and multiple basal ganglia infarcts (7 out of 15 vs. 1 out of 13 Sus, p = .037). Conclusion: Specific clinical and/or MRI findings may help distinguish SuS from PACNS with potential therapeutic implications.