A Case of Neuromyelitis Optica Spectrum Disorder Aggravated after Varicella Zoster Infection

Abstract

Neuromyelitis optica (NMO) is a rare demyelinating disease of the central nervous system (CNS) that affects the optic nerves and spinal cord. Although aggressive immunosuppressive treatment is mandatory due to the poor prognosis of NMO, there is always a risk of life-threatening infections. A 4-year-old boy was admitted because of headache and weakness of both lower extremities. Brain and spinal magnetic resonance imaging (MRI) demonstrated diffuse ill-defined lesions with T2 hyperintensity in the lower medulla and whole cervical cord. He improved with intravenous immune-globulin (IVIG) and methylprednisolone pulse therapy. However, after 2 years, he developed recurrent vomiting and hyperesthesia on his neck and shoulder. Aquaporin-4 antibody (AQP-4 Ab) was positive in his serum and he was diagnosed with NMO spectrum disorder (NMOSD). After 1 year, he developed a generalized vesicular rash and was treated with acyclovir for chickenpox. However, after 2 weeks, he re-developed left ear vesicles with severe headache and hyperesthesia on his post scalp and upper shoulder without muscle weakness. His brain and spinal MRI revealed extensively increased T2 hyperintensity lesions down through the upper thoracic cord (T6). He again received IVIG and methylprednisolone pulse therapy, followed by oral prednisolone and azathioprine maintenance. We also treated zoster infection with IV acyclovir for 3weeks and chronic famciclovir prophylaxis and neurontin for trigeminal neuralgia. His headache and hyperesthesia showed some improvement, but not complete. Here, we present a case of NMOSD aggravated after varicella zoster infection during chronic steroid maintenance.