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Intractable vomiting as an initial presentation of lupus-related neuromyelitis optica.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare neurological condition known to occur in association with systemic autoimmune disorders. We describe here a patient with intractable nausea and vomiting as the first presentation of NMOSD, in which systemic lupus erythematosus was diagnosed subsequently. A previously healthy 41-year-old Chinese woman presented with a 1-week history of severe nausea and vomiting, which was occurring 8 to 10 times daily and was unresponsive to oral antiemetics. She also reported mild paresthesias of the face and extremities. She did not report any other symptoms, such as headaches, visual changes, abdominal pain, or diarrhea. An evaluation by a gastroenterologist included esophagogastroduodenoscopy, gastric emptying scan, and computed tomography of the abdomen; all did not show abnormalities. A magnetic resonance imaging (MRI) of the brain and spine showed a small region of abnormally increased signal intensity within the area postrema and no abnormalities of the cervical spine (Figure). Four days later, the nausea and vomiting resolved spontaneously. She was discharged to home and instructed to schedule a follow-up appointment with neurology. Two months later, the patient presented with increased paresthesias of the left upper and lower extremities and the evolution of weakness in bilateral lower extremities over 1 week. A lumbar puncture revealed 58 white blood cells (reference range, 0Y5) with 97% lymphocytes, normal protein and glucose, no oligoclonal bands, and normal immunoglobulin G (IgG) index. An MRI showed progression of signal abnormalities at the craniocervical junction involving the medulla and upper cervical cord down to the level of C3Y4 with associated mild upper cord expansion with no evidence of optic neuritis (Figure). Complete blood count demonstrated low white blood cell count at 2700/HL (reference, 4000Y11,000/HL) with low absolute lymphocyte count at 550 (reference, 91500) and normal hemoglobin and platelet count. Her serologies were remarkable for a positive antinuclear antibody of 1:640 dilution (reference, G1:80), anti-SSA greater than 8 (reference, G1), anti-SSB greater than 8 (reference, G1), C3 27 mg/dL (reference range, 86Y184 mg/dL), and C4 6 mg/dL (reference range, 20Y59 mg/dL). Anti-Smith, anti-RNP, antiYdouble-stranded DNA antibodies, lupus anticoagulant, anticardiolipin, and anti-A2 glycoprotein I antibodies were negative. Urinalysis was within reference range, and serum creatinine was within reference range. The serum NMO-IgG autoantibody test was positive at 1/1600 U performed by immunofluorescence assay. The patient denied any sicca symptoms, fatigue, joint pain, swelling, or skin rash. Based on her clinical symptoms, positive serology, and MRI findings, coexistence of NMOSD and a systemic autoimmune disorder was highly suspected. The patient received pulse methylprednisolone at a dose of 1000 mg/d for 3 days, which was followed by intravenous cyclophosphamide at a dose of 750 mg/m monthly for 6 cycles. After completion of her cyclophosphamide course, she was switched to maintenance therapy with azathioprine at a dose of 1.5 mg/kg per day. Her prednisone dose was started at 60 mg/d and tapered to 10 mg/d over 6 months. She recovered well in response to treatments and has no residual paresthesias or weakness. A cervical MRI done by the end of her cyclophosphamide course showed near-complete resolution of the previously noted signal abnormalities. After 6 months from her initial presentation, she began to note pain in joints of the hands and feet, which is consistent with a diagnosis of systemic lupus erythematosus. Neuromyelitis optica (also known as Devic disease) is a central nervous system demyelinating autoimmune disease characterized by severe recurrent attacks that target the optic nerves and spinal cord. The prognosis is often unfavorable, with either monocular blindness or loss of ambulatory capacity in more than 50% of patients within 5 years. Its pathophysiology is not entirely understood; however, aquaporin 4, the predominant central nervous system water channel, is believed to be the target antigen for the NMO-IgG autoantibody. According to the first report, NMO-IgG antibody test performed by an indirect immunofluorescence assay had a sensitivity of 73% and a specificity of 91% for NMO. The area postrema, where the vomiting center is located, is an aquaporin 4Yenriched region and is thought to be an important first point of attack in NMO. This finding is compatible with clinical reports of nausea and vomiting preceding episodes of optic neuritis or myelitis in NMO. The initial MRI findings in our case demonstrated isolated involvement of the area postrema during the vomiting episode, supporting the diagnosis of NMO. Intractable nausea and vomiting in association with an abnormal signal in the area postrema on MRI should be regarded as a heralding symptom of NMO. The most widely accepted diagnostic criteria for NMO require the presence of optic neuritis, acute myelitis, and at least 2 out of (i) contiguous spinal cord MRI lesion extending over 3 or more vertebral segments; (ii) brain MRI not meeting diagnostic criteria for multiple sclerosis; and (iii) NMO-IgG seropositive status. Patients with isolated optic neuritis or myelitis and a positive NMO-IgG antibody are described as having NMOSD. It has been recognized that the association of optic neuritis or longitudinally extensive myelitis with systemic autoimmune disorders, as well as with brain MRI lesions such as brainstem lesions, is now considered typical of NMOSD. Our patient fulfills the criteria for NMOSD but not the diagnostic criteria for definite NMO, as she has no evidence of optic neuritis on MRI. CONCISE REPORT