Human herpesvirus 6 is associated with status epilepticus and hyponatremia after umbilical cord blood transplantation

Human herpesvirus 6 (HHV-6) associated permanent hyponatremia in umbilical cord blood transplant recipient

Long-term neurocognitive deficits after human herpesvirus-6 (HHV-6) infection are common in stem-cell transplant recipients, but SIADH (Syndrome of inappropriate antidiuretic hormone secretion) with persistent hyponatremia is rare. A 51-year-old woman presented with somnolence, hyponatremia (121 mmol/L) and HHV-6 viremia (80,330 copies/ml) on day +22 post umbilical cord blood transplant (UCBT). With waterrestriction, tolvaptan and combination of foscarnet and ganciclovir, patient's hyponatremia and HHV-6 viremia improved. On day +94 UCBT, hyponatremia and HHV-6 viremia recurred. Foscarnet was restarted and continued until day +269 UCBT due to multiple HHV-6 recurrences with persistent hyponatremia. At day +712, patient remains on water-restriction, tolvaptan for continuous hyponatremia from SIADH.

Status epilepticus during correction of hyponatremia in a patient with Alzheimer's disease: A case report

An 83-year-old Japanese man with Alzheimer’s disease was admitted to our hospital for treatment of hyponatremia resulting from water intoxication. During hospitalization, the patient developed focal impaired awareness seizures, focal to bilateral tonic-clonic seizures, and subsequent status epilepticus. Electroencephalogram during focal impaired awareness seizures showed rhythmic 5–9 Hz theta activity in the right frontotemporal region. Electroencephalogram during focal to bilateral tonic-clonic seizures showed bilateral polyspikes. Electroencephalogram during an interseizure period revealed sharp waves in the right frontal region. Continuous intravenous administration of midazolam was the only effective treatment for status epilepticus. The patient died of aspiration pneumonia on day 58. Hyponatremia-associated status epilepticus is rare; in the present case, multifocal epileptogenicity resulting from Alzheimer’s disease and hyponatremia-associated elevation of glutamate levels in the synaptic cleft may have contributed to the onset of focal to bilateral tonic-clonic seizures with subsequent status epilepticus.

Clinical practice recommendations for the diagnosis and management of human herpesvirus-6B encephalitis after allogeneic hematopoietic stem cell transplantation: the Japan Society for Hematopoietic Cell Transplantation

Reactivation of human herpesvirus (HHV)-6B is relatively common after allogeneic hematopoietic stem cell transplantation (HSCT) and HHV-6B diseases may consequently develop. Among them, HHV-6B encephalitis is a serious and often fatal complication. The aim of these clinical practice recommendations is to provide diagnostic and therapeutic guidance for HHV-6B encephalitis after allogeneic HSCT. In this evidence-based review, we critically evaluated data from the published literature. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assist in generating recommendations. We have summarized the findings that contribute to decision-making and we have provided our recommendations. In cases where rigorous clinical data are unavailable, recommendations have been developed in discussions with physicians who have relevant expertize.