LAUSR

N euromyelitis optica (NMO) and NMO spectrum disorder (NMOSD) are inflammatory disorders of the central nervous system characterized by severe, immunemediated demyelination and axonal damage targeting the optic nerve and spinal cord (1). The autoimmune pathogenesis of NMO involves immunoglobulin G (IgG) antibody against aquaporin-4 (AQP4). AQP4 is a waterchannel protein highly concentrated in the spinal cord gray matter, periaqueductal and periventricular regions, and the astrocytic foot processes (2). The hallmark presentation of NMO includes acute attacks of bilateral or rapidly sequential optic neuritis (ON, leading to severe visual loss) or transverse myelitis (TM, causing limb weakness, sensory loss, and bladder dysfunction) with a relapsing course (3). Relapse occurs within the first year after the initial event in 60 percent of patients and within 3 years in 90% (1). Other clinical presentations include brainstem symptoms, encephalopathy, fulminant demyelination, hypothalamic dysfunction, and posterior reversible leukoencephalopathy. In particular, the area postrema syndrome of nausea and vomiting or intractable hiccups occurs with an incidence of 16%–43% in NMOSD (4). We report a 57-year-old woman who presented with a serologically proven NMO exacerbation 25 years after her first unexplained episode of ON. This case documents an unusually long duration between episodes of recurrent ON in a patient with serologically confirmed NMO. Patients with unexplained ON, particularly those with lack of recovery, should be considered for testing for NMO antibody even decades after their initial ON event. A 57-year-old woman presented with acute painless visual loss in her right eye. This was associated with 3–4 episodes of a constant, dull headache localized to the left retrobulbar region. Family history was negative for multiple sclerosis (MS). The medical history was significant for anxiety, depression, and a remote history of recurrent ON in the left eye as her initial demyelinating episode in 1993. After this initial event, the patient experienced several similar episodes of visual loss in the left eye over the next 4 years. She had headache, left eye pain, and visual deterioration that progressively worsened with each episode. Each attack was treated with intravenous corticosteroids with some recovery until the last episode in 1996; this resulted in no light perception (NLP) vision in the left eye. The patient had no further episodes of ON or neurologic symptoms until the time of her current presentation (25 years after the initial episode). During the current episode of ON, serial cranial MRI scans, lumbar puncture, and laboratory testing for infectious and inflammatory etiologies were unrevealing. In retrospect, the patient had several unexplained bouts of nausea and hiccups before admission and was found asleep while sitting in a chair several times by her sister; she had not been diagnosed with narcolepsy. On neuro-ophthalmic examination, the visual acuities were 20/70 in the right eye and NLP in the left eye. Ocular motility was full. There was a left afferent pupillary defect (amaurotic pupil). Ophthalmoscopy demonstrated a normal optic disc on the right and optic atrophy in the left eye. MRI of the brain and orbits demonstrated contrast enhancement of the optic chiasm (Fig. 1). Lumbar puncture showed a normal opening pressure of 18-cm water and normal cerebrospinal fluid (CSF) cell counts, protein, glucose, and oligoclonal bands. CSF myelin basic protein was elevated and consistent with intrathecal production of immunoglobulin against myelin. The IgG albumin index, synthesis rate, and IgG were all elevated, consistent with breakdown of the blood–brain barrier. NMO AQP4-IgG serum antibody test was positive (1:10,000). The patient was started on methylprednisolone 1 g intravenously daily for 3 days before initiating intravenous immunoglobulin (IVIG). She received 4 days of IVIG before discharge. At the last follow-up at 1 month after presentation, the visual acuities had improved to 20/25 in the right eye but remained NLP in the left eye. Optical coherence tomography measurement of the peripapillary retinal nerve fiber Texas A&M College of Medicine (RW, AGL), Bryan, Texas; Department of Ophthalmology (AK, BA), Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas; The Houston Methodist Research Institute (AGL), Houston Methodist Hospital, Houston, Texas; Departments of Ophthalmology, Neurology, and Neurosurgery (AGL), Weill Cornell Medicine, New York, New York; Department of Ophthalmology (AGL), University of Texas Medical Branch, Galveston, Texas; Department of Ophthalmology (AGL), Baylor College of Medicine, Houston, Texas; University of Texas MD Anderson Cancer Center (AGL), Houston, Texas; and Department of Ophthalmology (AGL), The University of Iowa Hospitals and Clinics, Iowa City, Iowa.