Optic neuritis in demyelinating diseases: study of 38 cases.

Background:  Optic neuritis is an inflammation of the optic nerve caused by genetic factors, external influences, and the activation of cross-reactive immune responses to infections.

Objective:  To describe the clinical and epidemiological characteristics of patients presenting optic neuritis as the initial symptom of some demyelinating diseases, divided among multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated disorders (MOGADs).

Methods:  Thirty-eight patients who had optic neuritis as their first symptom and later developed MS, NMOSD, or MOGADs were analyzed.

Results:  There were thirty-four female patients (90%) and 4 male patients (10%); 23 (60%) were white and 15 (40%) were black. The most frequent definitive diagnosis was MS, with 24 (63%) cases, followed by NMOSD with 12 (32%) cases, and MOGADs with 2 (5%) cases. Regarding age, 9 (24%) were under 20 years old, 19 (50%) were between 20 and 30 years old, 6 (21%) were between 31 and 40 years old, and 2 (5%) were over 41 years old. As for the time to diagnosis, MS required 54 months in the public sector and 12 months in the private sector. Neuromyelitis optica spectrum disorder took 108 months in the private sector and 14.5 months in the public sector, while MOGADs averaged 2 months in the private sector.

Conclusion:  Patients with optic neuritis as the initial symptom were predominantly female, aged between 21 and 40 years, and of predominantly white ethnicity, with a higher prevalence of MS. Additionally, a direct relationship between the healthcare sector and the time to diagnosis became evident.