AQP4 and transverse myelitis: AQP4-NMOSD may present with severe optic neuritis, longitudinally extensive transverse myelitis, and area postrema, brainstem, diencephalic, and cerebral syndromes.1,4 The prompt distinction between MOGAD, AQP4-NMOSD, and multiple sclerosis (MS) may be challenging for clinicians because the diseases share some clinical and magnetic resonance imaging (MRI) characteristics, which may hamper the treatment of patients.