Predictors for acute respiratory failure in AQP4-IgG-positive neuromyelitis optica spectrum disorders patients with medullary lesions

•The involvement of middle medulla (characterized by a nodular lateral surface due to the inferior olivary nucleus, MON) on MRI is the main cause and a predictor for acute respiratory failure (ARF) in AQP4-IgG-positive neuromyelitis optica spectrum disorders (NMOSD) patients with medulla oblongata lesions. •Practical clinical symptoms such as dysphagia and quadriplegia can predict ARF even earlier before MRI scan in AQP4-IgG-positive NMOSD patients. •Area postrema syndrome was irrelevant with ARF in AQP4-IgG-positive NMOSD patients.