Neurosarcoidosis, Coccidioidomycosis, or Both!

Purpose: To report a case of neurosarcoidosis (NS) who was initially diagnosed as Coccidioidomycosis immitis (CI) infection. Observations: A 57-year-old diabetic man presented with sudden painless diminution of vision, metamorphopsia, and color vision deficits in the left eye (OS) for one month. His vision was 20/20 in the right eye (OD) and 20/40 OS. Ophthalmic examination revealed left relative afferent pupillary defect, blurred optic nerve margin, creamy chorioretinal infiltration around the optic disc, and mild macular edema. OD examination was non-revealing. Chest CT scan with contrast showed calcified mediastinal lymph nodes, but biopsy of the lymph nodes was normal. Brain and orbit MRI demonstrated soft tissue abnormality with enhancement in left orbital apex with involvement of the extraocular muscles. CSF culture was negative, but complement fixation had positive titer of 1:2 for CI. The patient was diagnosed with CI meningitis, and antifungal therapy was initiated. Slight visual and symptomatic improvement was observed, which was not completely satisfactory. Biopsy of extraocular orbital muscle five months later revealed non-caseating granulomatous inflammation, leading to initiation of prednisone trial therapy. Nine months later, the patient was referred to a tertiary center owing to persistence of optic disc edema OS. PET CT was consistent with a diagnosis of sarcoidosis. Antifungal treatment was discontinued, and oral prednisone with methotrexate was initiated. Subsequently, methotrexate was replaced by infliximab to further manage ocular inflammation and neurologic symptoms which was effective. Vision was 20/20 OD and 20/30 OS at the most recent visit.Conclusion and Importance: Signs and symptoms of neurosarcoidosis and coccidioidomycosis can be similar and deceiving. The index case underscores importance of considering appropriate differential diagnoses in patients with similar symptoms and signs who may respond to preliminary designated treatment but not to the optimal extent. Considering such possibility could assist clinicians in managing the patients timely and efficiently.