BackgroundWe present a case of a patient diagnosed with optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM) following Mycoplasma pneumoniae (M.pneumoniae) pneumonia.MethodsA 60-year-old male, 16 days post-M.pneumoniae pneumonia, was evaluated for vision loss-no light perception in the right eye and perceiving only finger movements at a distance of 20 cm in the left. He also exhibited paraparesis, absent tendon reflexes in the lower limbs, urinary incontinence, and sensory deficits below the left L1 and right T10 dermatomes. Clinical data were collected, followed by a literature review of case reports from the 1990s to the present.ResultsSerum testing showed positive IgG antibodies against GM1 and GD1b, while cerebrospinal fluid (CSF) was negative for these antibodies. CSF analysis indicated mild pleocytosis and slight protein elevation, with negative PCR for M.pneumoniae. Cranial MRI identified contrast-enhanced lesions in the left occipital lobe, the optic nerve, optic chiasm, and adjacent tracts, while spinal MRI revealed multiple intramedullary lesions at C2-C4, T4-T7, and T10-T11 levels. Nerve conduction studies were normal. The patient received treatment with intravenous immunoglobulin, corticosteroids, and moxifloxacin, leading to a significant improvement in myelitic symptoms and partial recovery of visual function. The literature review indicated ten cases of isolated ON, nineteen with isolated acute myelitis, and five with concomitant ON and myelitis.ConclusionMOG-like ON, either occurring in isolation or in conjunction with LETM (i.e.NMOSD-like), is a rare complication following M.pneumoniae infection. Immune-mediated mechanisms may significantly contribute to its pathogenesis.