Working Up Relapsing Optic Neuritis: A Patient with Undiagnosed Chronic Relapsing Optic Neuritis

Abstract

Chronic relapsing inflammatory optic neuropathy (CRION) presents itself as a challenging clinical diagnosis, due to its rarity, mimicking clinical entities and workup required to obtain a well-substantiated diagnosis, deliver adequate treatment, and exclude potentially life-threatening differential diagnoses. A male patient presented with various episodes of optic neuritis. A full work-up was performed, including magnetic resonance imaging, lumbar puncture, and serologies for infectious and autoimmune diseases. Temporarily elevated levels of angiotensin-converting enzyme hampered the correct diagnosis, as repeat blood work was normal. After excluding multiple sclerosis, neuromyelitis optica, infectious and other autoimmune etiologies, the most likely diagnosis remained CRION. CRION should be kept as a differential diagnosis early during the disease course and repeat exams should be done whenever they do not match the clinical picture. CRION should be thought of whenever presented with a steroid dependent optic neuritis with decreased ganglion cell layer thickness and negative anti-myelin oligodendrocyte glycoprotein antibodies.