Varicella-zoster virus encephalitis in a patient undergoing unrelated cord blood transplantation for myelodysplastic syndrome—overt leukemia

Varicella-zoster virus (VZV) infection of the central nervous system (CNS) is rare after hematopoietic stem cell transplantation (SCT). Here, we describe the first patient who developed VZV encephalitis after cord blood transplantation (CBT). A 35-year-old man with myelodysplastic syndrome-overt leukemia underwent CBT. On day +23, a neutrophil count consistently greater than 0.5 X 10 9 /L was achieved. On day +42,1 mg/kg per day of prednisolone therapy was initiated for grade III acute graft-versus-host disease (GVHD). Then, the dose of prednisolone was slowly reduced. For exacerbation of chronic GVHD, the dose of prednisolone was again increased to 1 mg/kg per day on day +231. On day +265, localized cutaneous zoster in the left thoracic region occurred, but soon resolved after acyclovir therapy. On day +309, he suddenly developed diplopia. Subsequently, right facial palsy and hearing impairment occurred. No skin rash was observed. Magnetic resonance imaging (MRI) scans revealed multifocal abnormal high-signal intensity in the CNS. A high level of VZV DNA was detected in a cerebrospinal fluid specimen. He was diagnosed with VZV encephalitis. Acyclovir was given intravenously for 40 days. Four months after the onset, the neurologic symptoms had incompletely resolved. MRI scans showed substantial resolution but with mild residual lesions. The present report indicates that VZV should be considered as a possible causative agent in patients who develop multifocal neurologic symptoms of the CNS after SCT.