2026 American Academy of Neurology Abstract Website

Tuncay Gunduz¹, Ahmed Serkan Emekli¹, Mehmet Barburoglu², Serkan Ozakbas³, Bilge Piri Cinar⁴, Ergi Kaya⁵, Serkan Demir⁶, ipek gungor dogan⁶, Damla Cetinkaya Tezer⁶, Belgin Kocer⁷, Merve Bahar Ercan⁷, Asli Tuncer⁸, Rana Karabudak⁹, Nazire Acar Ozen⁸, Ezgi Demirel⁸, Vedat Cilingir¹⁰, Meral Seferoglu¹¹, Ozlem Ethemoglu¹², Ali SIVACI¹¹, Sami Omerhoca¹³, Nilufer Kale¹³, Eda Derle ciftci¹⁴, Munire Kilinc Toprak¹⁴, Ugurcan Ugur¹⁴, Levent Ocek⁵, Irem Ciftci Gedik¹⁵, Cihat Uzunkopru¹⁶, Yesim Beckmann¹⁶, Haluk Gumus¹⁷, Sedat Sen¹⁸, Murat Kurtuncu¹
¹Department of Neurology, ²Department of Radiology, Istanbul Faculty of Medicine, Istanbul University, ³Department of Neurology, Izmir University of Economics Medical Point Hospital, ⁴Department of Neurology, Faculty of Medicine, Samsun University, ⁵Department of Neurology, University of Health Sciences Tepecik Training and Research Hospital, ⁶Department of Neurology, University of Health Sciences, Sancaktepe Sehit Prof Dr Ilhan Varank Training and Research Hospital, ⁷Department of Neurology, Faculty of Medicine Gazi University, ⁸Department of Neurology, School of Medicine, Hacettepe University, ⁹Academic Neurologist, ¹⁰Department of Neurology, Faculty of Medicine, Van Yuzuncu Yil University, ¹¹Department of Neurology, Bursa Yüksek İhtisas Education and Research Hospital, ¹²Department of Neurology, Faculty of Medicine, Harran University, ¹³Department of Neurology, University of Health Sciences Bagcilar Training and Research Hospital, ¹⁴Department of Neurology, Faculty of Medicine, Baskent University, ¹⁵Department of Neurology, Health Sciences University Haydarpasa Numune Training and Research Hospital, ¹⁶Department of Neurology, Katip Celebi University, Ataturk Training and Research Hospital, ¹⁷Department of Neurology, Faculty of Medicine, Selcuk University, ¹⁸Department of Neurology, Faculty of Medicine, Ondokuz Mayıs University

Objective:

To compare the diagnostic accuracy and predictive value of the 2023 radiologically isolated syndrome (RIS) and the 2024 McDonald multiple sclerosis (MS) criteria for the first symptomatic clinical event.

Background:

The 2024 McDonald criteria classify individuals with RIS who have dissemination in space or oligoclonal bands (OCB) to be diagnosed with MS. However, whether this revision improves the prediction of the first clinical event compared with the 2023 RIS definition has not been validated.

Design/Methods:

We analyzed a multicenter cohort of 216 individuals with incidental MRI findings suggestive of demyelination. Each individual was classified according to both the 2023 RIS and 2024 McDonald criteria. We calculated the time to first clinical event, sensitivity, specificity, accuracy, and predictive values for each criterion. Covariates included age at index MRI, OCB status, spinal cord and corpus callosum lesion counts, and new T2 lesions on follow-up imaging.

Results:

The 2023 RIS criteria were fulfilled by 63.4% of the cohort, whereas 57.9% fulfilled the 2024 McDonald criteria; 27.3% did not meet either. Overall, 50% of RIS (2023) had their first clinical event within a median of 5.8 years (95% CI 3.0–8.7), compared to 4.1 (95% CI 2.7–5.8) years for those meeting the 2024 criteria. In Cox regression analysis, hazard ratios were 3.6 (p = 0.002) for the 2023 RIS and 4.9 (p < 0.001) for the 2024 MS group. The 2024 criteria improved specificity (0.53 vs 0.45) and overall accuracy (0.62 vs 0.56) while maintaining sensitivity (0.89 vs 0.87).

Conclusions:

The 2024 McDonald criteria demonstrate a higher diagnostic precision and predictive accuracy for early clinical conversion compared to the 2023 RIS definition. Integrating OCB positivity with dissemination in space identifies a clinically meaningful subset of individuals with RIS who may benefit from early initiation of disease-modifying therapy.