Not so fast, Gradenigo: a diagnostic twist in orbital apex syndrome

A 62-year-old man with a history of herpes zoster and tuberculosis presented with 2 months of bilateral otalgia, hearing loss, and sinusitis, later progressing to ophthalmoplegia, diplopia, retroorbital pain, and dyschromatopsia. Initial findings suggested Gradenigo syndrome based on involvement of cranial nerves V and VI. Magnetic resonance imaging demonstrated bilateral mastoid effusions, diffuse pachymeningeal enhancement, and asymmetric left orbital apex involvement. Cerebrospinal fluid studies and polymerase chain reaction testing were unremarkable, and symptoms progressed to cranial nerve II dysfunction despite antimicrobial therapy. Rheumatologic evaluation revealed positive P-ANCA, elevated myeloperoxidase antibodies, and elevated IgG4, raising concern for ANCA-associated vasculitis. Computed tomography showed no petrous bone erosion, shifting suspicion toward orbital apex syndrome. Dural biopsy demonstrated chronic meningitis with T cell- and macrophage-predominant inflammation. This case illustrates the diagnostic complexity of orbital apex syndrome and emphasizes early multidisciplinary evaluation to distinguish infectious from autoimmune etiologies and prevent irreversible vision loss.