Estudio de las características clínicas, de laboratorio, radiológicas y oftalmológicas de pacientes afectos de neuritis óptica retrobulbar en contexto de procesos inflamatorios desmielinizantes primarios del sistema nervioso central

Retrobulbar optic neuritis (ON) is an inflammatory process that affects the optic nerve, and can occur in an isolated (monophasic) or recurrent course. The most frequent etiology is CNS demyelinating diseases, such as multiple sclerosis (MS) or Neuromyelitis optica spectrum disorders (NMOSD). 3-5% of cases of ON have a recurrent course (RON) in the absence of a neurological or systemic disease. Two forms of RON have been described, CRION for cases with early response to corticosteroid treatment, and RION is a non-progressive condition without steroid dependence. After a first episode of ON, it is difficult to establish its recurring nature. There are a series of factors (clinical and paraclinical) that allow establishing the diagnostic suspicion and / or the risk of conversion to MS, NMOSD or NOR. No biomarkers have been found in relation to NOR. Methods and objective: This work includes patients affected by these CNS demyelinating processes that present with ON as the first manifestation of their disease. The main objective has been to make a description and comparison of the demographic, clinical and paraclinical characteristics of these patients, divided into diagnostic groups and subgroups; with the intention of facilitating the early identification of any of the possible underlying processes, which is essential for the establishment of the correct treatment. Secondarily, it has also been tried to identify new biomarkers. Results: The results of this work indicate that the clinical profile of ON is comparable between the CRION and NMOSD subgroups and between the MS and RION subgroups. The greatest clinical severity has been observed in the NMOSD and CRION subgroups. These clinical findings have been consistent and correlate with findings on optical coherence tomography. However, for brain volumetric values, a different behavior has been observed. The MS group, group with the best visual prognosis, presented a higher degree of brain atrophy, followed closely by the CRION group. While a significantly lower degree of brain atrophy has been observed in the NMOSD group, which was the group with the worst prognosis, and in RION group. Seropositivity for anti-AQP4 and anti-MOG antibodies implies a worse prognosis in all the variables analyzed. Anti-MOG antibodies are frequently associated with the CRION phenotype, as has already been described in the literature. Conclusions: Brain atrophy in RON patients is related to MOG-Abs and is present in patients with the CRION phenotype, a new observation suggesting a more widespread effect of the disease not limited to the optic nerve. Brain atrophy, along with anti-MOG antibodies, could be used as a biomarker for CRION patients and should be further investigated in larger and prospective studies.