Case report: Unilateral optic atrophy and intracranial hypertension in anti-NF155 nodopathy: a case managed with sequential efgartigimod and rituximab.

Background: Autoimmune nodopathy (AN) associated with anti-neurofascin-155 (NF155) antibodies is a distinct disorder characterized by treatment-resistant peripheral neuropathy. Although central nervous system (CNS) involvement is theorized due to the presence of NF155 in oligodendrocytes, definitive clinical reports remain limited. Case presentation: A 31-year-old male presented with a seven-year history of relapsing-remitting progressive sensorimotor neuropathy, tremor, and sensory ataxia. He was initially diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) and demonstrated a partial response to intravenous immunoglobulin (IVIG) and steroids. Three years after being diagnosed, he developed unilateral visual loss that progressed to no light perception accompanied by an episode of acutely elevated intraocular pressure without typical symptoms of acute glaucoma. Neurological examination revealed anisocoria, left optic atrophy, pseudoathetosis, and distal sensory deficits. Investigations confirmed markedly elevated cerebrospinal fluid (CSF) protein levels (>3 g/L) and opening pressure (335 mmH Management and outcomes: Efgartigimod, an FcRn antagonist, was initiated as an induction therapy. After receiving four weekly doses, there was noticeable improvement in his neurological function with his inflammatory neuropathy cause and treatment (INCAT) score decreasing from 4 to 3. Maintenance therapy was changed to rituximab. His INCAT score further improved to 1 at the one-year follow-up, indicating significant neurological recovery; however, the vision in his left eye did not improve. Conclusion: This case underscores that anti-NF155 nodopathy may be associated with severe CNS complications, such as optic atrophy and intracranial hypertension, possibly because of a combination of direct antibody-mediated damage and CSF dynamic dysfunction. Additionally, in this patient, an episode of acute intraocular hypertension may have served as a further independent insult, contributing to irreversible visual loss. These findings highlight the importance of specific antibody testing in atypical CIDP cases. Moreover, the potential of a sequential treatment strategy is demonstrated, using efgartigimod for rapid induction and rituximab for maintenance as a viable and effective therapeutic approach for this complex condition.