Serum and cerebrospinal fluid AQP4-MOG double-positive longitudinally extensive transverse myelitis: a rare case report and literature review

The following case report details a patient with serum and cerebrospinal fluid AQP4-MOG double-positive longitudinally extensive transverse myelitis, whose condition was found to be progressively exacerbated and which resulted in severe disability. A 51-year-old female patient initially presented with pain and discomfort in the left upper limb and posterior occipital region for a period of 10 days. Unfortunately, she then developed hypoesthesia and flaccid paralysis, in addition to urinary retention within a few days. Concurrently, she exhibited symptoms consistent with area postrema syndrome (nausea, vomiting, and hiccups) and brain-stem syndrome (hoarseness and dysphagia). Concomitantly, AQP4 and MOG antibodies were identified as positive in both the serum and cerebrospinal fluid (CSF). MRI findings were consistent with longitudinally extensive transverse myelitis (LETM), spanning cervical through thoracic spinal cord levels. Despite presenting with meningismus, the patient's gadolinium-enhanced brain MRI revealed no abnormal leptomeningeal enhancement. Following treatment with pulse intravenous methylprednisolone and plasmapheresis, a stabilisation of symptoms was observed. Patients presenting with longitudinally extensive transverse myelitis may exhibit a positive double-immunofluorescence test result for aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) in both serum and CSF. The administration of early, more potent immunotherapy has the potential to enhance outcomes.