Diagnostic MRI Score to Differentiate Susac Syndrome from Primary Angiitis of the Central Nervous System and Multiple Sclerosis

• Published in: Annals of neurology Vol. 96; no. 5; pp. 846 - 854
• Main Authors: Marrodan, Mariano, Calandri, Ismael L., Bocancea, Diana I., Ysrraelit, Maria C., Gomez Figueroa, Enrique, Massó Páez, Montserrat, Flores, José D.J., Rojas, Juan I., Ciampi, Ethel, Ioli, Pablo, Zanga, Gisela, Ardohain, Carolina, Fracaro, Maria E., Amaya, Mariela, Tkachuk, Verónica, Fernandez, Victoria C., José, Gustavo, Silva, Emanuel, Luetic, Geraldine, Carnero Contentti, Edgar, Köhler, Eduardo, Pagani Cassara, Fatima, Moran, Dolores, Seimandi, Carla, Paviolo, Juan P., D'elio, Brenda, Da Prat, Gustavo, Gatto, Emilia, Cristiano, Edgardo, Pujol Lereis, Virginia, Ameriso, Sebastian F., Fiol, Marcela P., Correale, Jorge
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-11-2024; Wiley Subscription Services, Inc
• Subjects: Central nervous system; Cerebellum; Corpus callosum; Gadolinium; Lesions; Magnetic resonance imaging; Multiple sclerosis; Nervous system; Performance prediction; Spokes; Vasculitis
• ISSN: 0364-5134; 1531-8249; 1531-8249
• DOI: 10.1002/ana.27043

Objective
Susac syndrome (SuS), multiple sclerosis (MS), and primary angiitis of the central nervous system (PACNS) present diagnostic challenges due to overlapping clinical features. We aimed to enhance diagnostic precision by developing the SPAMS (SuS, PACNS, MS) score, a practical radiological tool.
Methods
This multicenter study included 99 patients (43 SuS, 37 MS, 19 PACNS) from South American countries. Relevant MRI features were identified through an elastic‐net model determined key variables.
Results
The SPAMS score assigned 2 points for snowball lesions, 1 point for spokes‐like lesions, or if there are more than 4 lesions in the corpus callosum, corpus callosum involvement, or cerebellar involvement. It subtracted 1 point if gadolinium‐enhancing lesions or 4 points if Dawson's fingers are present. Bootstrapping validated the optimal cutoff at 2 points, exhibiting a diagnostic performance of area under the curve = 0.931, sensitivity = 88%, specificity = 89%, positive predictive value = 88%, negative predictive value = 89%, and accuracy = 88%.
Interpretation
When specific MRI findings coexisted, the SPAMS score differentiated SuS from MS and PACNS. Access to MRI and standard protocol sequences makes it a valuable tool for timely diagnosis and treatment, potentially preventing disability progression and severe clinical outcomes. ANN NEUROL 2024;96:846–854