High viral load VZV encephalitis complicated by super refractory status epilepticus in a vaccinated child with in Acute Lymphocytic Leukemia: Case report and review of the literature

Varicella is a benign, self-limiting disease, but both primary VZV infection and VZV reactivation can be life-threatening in immunocompromised children, due to CNS and systemic dissemination of the virus. Reactivation of the vaccine-type VZV (vOka) has been reported sporadically, although SARS COV2 infection may have recently played a role in facilitating VZV reactivation. Here we report on the case of a young boy with Acute Lymphocytic Leukemia, in remission after induction chemotherapy, and recent SARS COV 2 infection. He developed VZV encephalitis due to massive reactivation of VZV virus, complicated by PRES, diagnosed with brain MRI, and Super Refractory Status Epilepticus, lasting until substantial suppression of VZV replication in the CNS. We also report and discuss the role of the remarkably augmented renal clearance persistently observed in our patient, complicating CNS involvement and making both antiviral and antiepileptic treatments more difficult to manage. Effective neuroprotection was completed by physical hypothermia and infusion of IVIG and steroids. The patient obtained complete functional recovery, with reversion of MRI signs of occipital involvement at presentation, at 6-month follow-up. Intense and daily interplay of intensivists, neurologists, hematologists and infectious disease experts likely made his uneventful recovery possible, combining all skills necessary to manage his unusual and complex clinical picture.