AQP4 and transverse myelitis: Neither do our recommendations encompass high-risk syndromes suggestive of NMOSD, not fulfilling 2015 IPND diagnostic criteria,1which are seronegative for both AQP4-IgG and MOG-IgG, including isolated or recurrent optic neuritis, chronic relapsing idiopathic optic neuritis, isolated or recurrent transverse myelitis, and brainstem syndromes.