Neuro-Ophthalmic Features of Autoimmune Encephalitides: Letter to the Editor.

Abstract

I enjoyed reading the recent article regarding the neuroophthalmic features of autoimmune encephalitides (1). In 2018, I evaluated a 20-year-old woman referred for pseudotumor cerebri (PTC). The patient did not have signs nor symptoms of PTC, save for a headache, and she had a completely normal neuro-ophthalmologic examination without papilledema. Brain MRI showed no signs of elevated intracranial pressure, and the lumbar puncture revealed an opening pressure of 10 cm of water with a normal formula. The patient did, however, endorse progressive neurologic symptoms over the past year consisting of memory deficits, the aforementioned headaches, “seizurelike episodes,” and infrequent dystonic posturing. She had been treated with intravenous corticosteroids early in her disease course without benefit. Given the clinical picture and lack of a psychiatric or drug abuse history, I worked the patient up for encephalitis. N-methyl-D-aspartate receptor (NMDAR) antibodies, thyroid functions, vitamin deficiency screening, and blood glucose were obtained. The NMDAR antibodies returned “weakly positive,” and the rest of the studies returned normal. Further workup was undertaken including electroencephalography showing no seizure activity, a negative drug screen, and a computed tomography (CT) of the chest abdomen and pelvis, which was normal. NMDAR antibodies in the CSF were not detected. A repeat serum NMDAR antibody and paraneoplastic antibody panel were normal. Despite the negative workup, the high clinical suspicion for autoimmune encephalitis prompted me to treat the patient with periodic intravenous immunoglobulin (IVIg) treatments every 4–12 weeks, with relief of her symptoms; however, there was no complete resolution. During this time, several pelvic ultrasounds were undertaken, all of which were negative. Finally, after 2 years of symptoms, one of the pelvic ultrasounds detected a right ovarian mass, and its subsequent removal revealed an ovarian teratoma. The patient currently is weaning off the IVIg and clinically is much improved. I write this correspondence to illustrate 4 points (A–D) I have learned from this case. (A) Many of these patients present with only psychiatric symptoms early in the course of the disease (2) and eventually come to the attention of the neurologist or neuro-ophthalmologist only after the disease has progressed to a more advanced stage (3). (B) When detected and treated early, permanent disability and death may be avoided (4). (C) The NMDAR antibody test can be negative in the disorder or initially positive and then negative, as in my patient. (D) Neuroimaging for an ovarian mass may initially be normal but one must continue to survey for a tumor with serial pelvic ultrasounds (5).