Relapsing Optic Neuropathy and Multiple Cranial Neuropathies
A 55-year-old white woman presented with 1 week of decreased visual acuity and ache on abduction in the right eye. She had decreased right-sided hearing and tinnitus, a moderate right-sided frontal headache, and an unsteady gait. She did not have diplopia, facial numbness, or paresthesias. She had a history of stage IV breast cancer treated with letrozole after a mastectomy 5 years prior. On an initial examination, her best-corrected visual acuity was 20/50 OD and 20/25 OS, with dyschromatopsia, relative afferent pupillary defect, and visual-field defects on the right side. Her extraocular movements were full.

A dilated fundus examination demonstrated a pale right optic nerve. Magnetic resonance imaging (MRI) of the brain was reported to have normal results, but on review, Author noted thickening and enhancement of both optic nerves (with the right eye larger than the left eye) (Figure 1A), cranial nerve III in the right eye, cranial nerve V bilaterally, the pituitary infundibulum, and the hypothalamus, as well as adjacent cavernous sinuses. Leptomeningeal thickening over the convexities of the anterior frontal lobes was also evident (Figure 1B). The patient’s cerebrospinal fluid contained a small population of polyclonal CD19+ B cells and CD4+ and CD8+ T cells.

Targeted immunomodulatory therapy was started after the establishment of the diagnosis. The patient reported feeling better overall. Her neuro-ophthalmic examination results have been stable since then, and she continued to have decreased visual acuity with dyschromatopsia (with greater intensity in the right eye than the left eye), with a relative afferent pupillary defect on the right eye and right-sided hearing loss. The patient has followed up with autoimmune neurology and neuro-ophthalmology.