Neuromyelitis Optica and Immune Thrombocytopenic Purpura Treated With Rituximab in a Patient With Combined Neurologic...

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory demyelinating disease of the central nervous system affecting the optic nerves and spinal cord. Immune thrombocytopenia (ITP), on the other hand, is an autoimmune disorder characterized by a platelet count of <100 in the absence of any known condition that could be associated with thrombocytopenia. This case report focuses on a 56-year-old female presenting with the unique coexistence of NMOSD and ITP. A 56-year-old woman of Russian descent had a sudden onset of right eye blindness at the age of 24 and was diagnosed with multiple sclerosis. She developed petechial rashes on both lower extremities two weeks before consultation with no associated findings. Cranial MRI revealed multiple nodular and patchy areas of hyperintense signals on T2-weighted/fluid-attenuated inversion recovery without restricted diffusion. A thoracolumbar MRI revealed long segment foci of intramedullary cord non-enhancing abnormal hyperintense signal from T2 to T11. Cerebrospinal fluid aquaporin 4 IgG was negative. A complete blood count revealed platelets of 4 × 10⁹/L, leading to the management of ITP. She was started on methylprednisolone 1 g/day for five days. Her platelet count improved eventually and rashes resolved. Rituximab treatment was initiated at a dose of 1 g on day 1 and day 15. On the 18th day of admission, the Expanded Disability Status Scale and functional score improved to 6.0 from 7.0 upon admission.