Is there a role of MOG antibodies in idiopathic intracranial hypertension: A comparative analysis with optic neuritis-MOG antibody associated disease.

OBJECTIVE: Idiopathic intracranial hypertension (IIH) is defined by elevated intracranial pressure without identifiable structural, infectious, or neoplastic cause. While the underlying pathophysiology remains unclear, emerging evidence suggests a potential role for autoimmune mechanisms, including antibodies against myelin oligodendrocyte glycoprotein (MOG). This retrospective study aimed to investigate the presence and clinical relevance of MOG-IgG antibodies in patients with IIH.

METHODS: We included 58 consecutive patients diagnosed according to the current clinical criteria and divided them into three groups: MOG antibody-associated optic neuritis (MOG-ON, n = 19), MOG-positive IIH (MOG+ IIH, n = 10), and MOG-negative IIH (MOG-IIH, n = 29). MOG-IgG levels were measured using a live-cell-based assay. Clinical characteristics, cerebrospinal fluid (CSF) findings, visual assessments, cranial magnetic resonance imaging (MRI) results, and treatment responses were compared.

RESULTS: MOG antibodies were detected in 25.6 % of the patients with IIH. MOG+ IIH patients were exclusively female and had higher rates of diplopia and acute symptom onset than MOG- IIH patients. MOG-ON patients had significantly lower CSF opening pressure. Visual acuity, OCT, and VEP abnormalities were more severe in the MOG-ON group, whereas there were no significant differences between MOG+ IIH and MOG- IIH. Some MRI findings related to IIH (e.g., transverse sinus stenosis) were more common in MOG- IIH.

CONCLUSION: MOG-IgG antibodies may be detected in a subset of IIH patients who exhibit distinct clinical features, suggesting a potential inflammatory or autoimmune etiology. Although a direct causal relationship could not be established, these findings support the need for further investigation into the immunological spectrum of IIH.