[A case of spinal cord infarction accompanied with neuromyelitis optica spectrum pathophysiology]

We report a 60-year-old woman who developed spinal cord infarction (SCI) with anti-aquaporin (AQP) 4 antibody seropositive. She was admitted to our hospital with acute onset of flaccid paraparesis and urinary disturbances that completed within a few minutes after acute pain in her lower back. Neurological examination revealed flaccid paraparesis, bladder and bowel dysfunction and dissociated sensory loss below the level of Th11 spinal cord segment. Diffusion weighted imaging (DWI) and T₂-wighted imaging (T₂WI) of thoracic spine MRI showed high signal intensity in the spinal cord between Th9 and Th12 vertebral levels with decreased apparent diffusion coefficient (ADC). We diagnosed her as having SCI. Thereafter the serum examination on admission was reported as positive for anti-aquaporin 4 (AQP4) antibody. Cerebrospinal fluid (CSF) analysis revealed pleocytosis, and the spinal cord lesions became enlarged in MRI on 12 days after the onset. We, therefore, suspected that the pathophysiology of neuromyelitis optica spectrum disorder (NMOSD) accompanied SCI. The patient underwent two courses of high dose intravenous methylprednisolone (IVMP) for three days (1 g/day). Her neurological symptoms did not improve significantly, but the size of T₂WI MRI high signal lesion improved to that of the initial MRI scan. Anti-AQP4 antibody seropositivity may have modified the SCI pathology in the present patient.