Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune, inflammatory disorder of the CNS characterized by longitudinally extensive myelitis (LETM) in the spinal cord and optic nerves in most cases. NMOSD typically occurs in females (80%) between the ages 30-40.  However, late-onset NMOSD has been reported in octogenarians (80-82) and one case report of a 90-year-old women.  Herein, we report another case of elderly-onset NMOSD presenting with LETM, initially thought to be due to spinal cord infarct, but further workup revealing a late manifestation of the disease.   

A 93-year-old African American woman presented with left leg weakness progressing over 3 days to bilateral involvement and sensory deficits.  MRI of the thoracic spine showed abnormal T2/STIR intramedullary hyperintensity from C7-T6.  On the sagittal thoracic diffusion sequences, there was restriction observed. CT Angio (CTA) revealed a severely calcified thoracic aorta without any evidence of dissection.  The small branch vessels supplying the spinal cord were not conclusively identified and intercostal vessels to the upper thoracic spine levels demonstrated diminished to absent opacification. Based on CTA findings, spinal cord ischemia was initially suspected, however, the progressive course over several days and CSF pleocytosis suggested an inflammatory process.  Serum anti-AQP4 anybody titers were high at 1: 100,000. The patient received 5 days of intravenous methylprednisolone and plasma exchange, but of little benefit. Given the age and co-morbidities, she was treated conservatively without any disease modifying therapy. Patient died due to the complications of NMOSD.  

The case highlights the importance of testing for NMOSD antibody in the elderly regardless of age and vascular comorbidities. Acute treatment in late-onset NMOSD is less efficacious. Aging is associated with immune dysfunction in Th17 cells (increased number), increased permeability of BBB, accumulation of atypical B cells, and complement dysfunction, which could increase the risk of NMOSD relapses into senectitude.