[Characteristics of neuromyelitis optica spectrum disorder associated with the area postrema]

Objective: To evaluate the clinical characteristics and the corresponding MRI and laboratory findings in patients with neuromyelitis optica spectrum disorder (NMOSD) associated with area postrema (AP). Methods: The study was a retrospective analysis of data from 120 NMOSD patients, and 18 cases were with AP out of these patients, The clinical presentation, MRI changes, serological markers and treatment outcome were reported. Results: AP occurred in 18 patients (15%, 18/120). AP was the onset symptom in 14 (14/18) patients and 3 days to 7 months (median 40 days) later, optic neuritis or myelitis was involved. One patient presented AP after optic neuritis. Three patients (3/18) had AP and myelitis or optic neuritis simultaneously. AP symptom presented as intractable nausea and vomiting, hiccups. Compared to the patients without AP (n=102), the patients with AP (n=18) had shorter duration and fewer numbers of optic neuritis(P<0.05). There was no statistical difference in sex, onset age, course of disease (relapsing or monophasic) and EDSS scores (P>0.05). The MRI revealed flake or linear lesions in medulla. Twelve patients had cervical cord lesions extending to medulla lesions (12/18). Eleven patients had long cord lesions extending more than 3 spinal cords. The AQP4-antibody did not differ in patients with or without AP (14/18 vs 75/102). The symptom of AP was successfully relieved with methylprednisolone. Conclusion: AP symptoms/signs are common in patients with NMOSD. Vomiting and hiccups can be the first symptoms. The medulla lesions and the lesions extending to upper cervical cord are unique to NMOSD. Awareness of AP presentations is helpful for early diagnosis and proper treatment to prevent further disability.