A CASE REPORT OF AQUAPORIN-4 ANTIBODY NEGATIVE OLIGOCLONAL BAND TYPE 2 POSITIVE NEUROMYELITIS OPTICA SPECTRUM DISORDER

Abstract

Introduction. Neuromyelitis optica spectrum disorder is a rare anticor-mediated demyelinating disease of the central nervous system. Long segment myelitis, persistent vomiting and hiccups, or optic neuritis are classic symptoms of the disease. Although CSF OCD negativity is detected in most of the NMO patients, being positive does not rule out the diagnosis. Here, we aimed to present a case of NMO with AQP-4 negative and type-2 OCD positivity. Case presentation. A 28-years old female patient was admitted showing symptoms of numbness starting in the right hand and spreading to extremities, weakness and urinary incontinence. Tetraplegia was present during her neurological examination. Cranial and Cervical MRI revealed an expanded, hyperintense, edematous lesion with peripheral enhancement extending from the bulbus to the c7 vertebra level. In her story, there was persistent vomiting and hiccups that started two months ago and lasted for about a month. CSF biochemistry was within normal limits, Anti-AQP4 negative, OCD Type-2 positive, igg index was 1.24. After 10 days of IV methylprednisolone treatment, the patient was administered 1 mg/kg oral prednisolone, 10 sessions of plasmapheresis. At 1 month, she was tracheostomized and muscle strength was 2/5 in all four extremities. It was regarded that the patient had Area Postrema syndrome and tetraplegia clinic due to persistent vomiting and hiccups, and acute myelitis involvement, hence she was deemed as seronegative NMO and 2.5 mg/kg/day azathioprine was started. In 3rd month, she could be mobilized short distance without support in spontaneous respiration and muscle strength was proximal 4/5 distal frust paresis in all four extremities. Control examination at 6 months, 1 year and 2 years was normal, cranial MRI was within normal limits, and a regressive pale T2 hyperintense lesion at C3-C7 level was observed in cervical MRI. Discussion. Neuromyelitis optica is an immune-mediated, inflammatory, demyelinating disease that affects the optic nerves and spinal cord, with less persistent vomiting, hiccups, and symptomatic narcolepsy. It differs from multiple sclerosis in pathogenesis, biomarkers, imaging features, and response to treatment. Compared to MS, it consists of longitudinally extending spinal cord lesions that spans three or more segments. Although CSF OCD’s are a diagnostic mainstay in MS, AQP4-IgG is mainly produced outside of CSF, is not found in most patients with NMO, but it is known that positive OCDs do not exclude the diagnosis. The diagnosis of NMO of our patient was made based on the clinical findings of area postrema syndrome and the formation of transverse myelitis involving multiple segments of the spinal cord (from bulbus to c7) on MRI. Conclusion. We wanted to emphasize that AQP4-IgG negative and OCD Type-2 positivity, which meets the clinical and MRI criteria for neuromyelitis optica, can be observed together, and persistent vomiting and hiccup attacks can be linked to area postrema syndrome and NMO.