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

To assess clinical and/or imaging features useful to distinguish between Susac syndrome (SuS) and primary angiitis of central nervous system (PACNS).

Multicenter retrospective analysis of two cohorts of Argentine patients diagnosed with SuS and PACNS.

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).

Specific clinical and/or MRI findings may help distinguish SuS from PACNS with potential therapeutic implications.