title: Diagnostic Clues to Human Herpesvirus 6 Encephalitis and Wernicke Encephalopathy After Pediatric Hematopoietic Cell Transplantation.
abstract: Human herpesvirus 6 (HHV6) encephalitis and Wernicke encephalopathy are treatable yet frequently undiagnosed causes of encephalopathy in pediatric recipients of allogeneic and autologous hematopoietic cell transplantation. Here we review representative cases of both conditions to highlight specific and relevant neurologic features that prompted effective diagnosis and treatment. Two patients with confusion accompanied by seizures, memory changes, or specific visual hallucinations and HHV6 detectable by polymerase chain reaction (PCR) in cerebrospinal fluid had improvement in viral load with ganciclovir or foscarnet treatment. Two patients had confusion, ataxia, or ocular changes and low serum thiamine levels, which resolved with parenteral thiamine. In all cases, definitive diagnosis and treatment were facilitated by a high index of suspicion and search for specific pathognomonic neurologic deficits accompanying the confusional state. It is critical to clinically differentiate these 2 conditions from other common neurologic syndromes occurring after transplant, allowing potentially improved patient outcomes by prompt diagnosis and effective treatment.
authors.affiliation: Department of Neurology, St Jude Children's Research Hospital, Memphis, TN, USA zsila.sadighi@stjude.org.
authors.forename: Zsila
authors.initials: Z
authors.lastname: Sadighi
authors.affiliation: St Jude Children's Research Hospital, Memphis, TN, USA.
authors.forename: Noah D
authors.initials: ND
authors.lastname: Sabin
authors.affiliation: St Jude Children's Research Hospital, Memphis, TN, USA.
authors.forename: Randall
authors.initials: R
authors.lastname: Hayden
authors.affiliation: St Jude Children's Research Hospital, Memphis, TN, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Stewart
authors.affiliation: Department of Bone Marrow Transplantation and Cellular Therapy, St Jude Children's Research Hospital, Memphis, TN, USA asha.pillai@stjude.org.
authors.forename: Asha
authors.initials: A
authors.lastname: Pillai
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D018792:Encephalitis, Viral / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D015654:Herpesvirus 6, Human; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019349:Roseolovirus Infections / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D014899:Wernicke Encephalopathy / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D055815:Young Adult
keywords: Wernicke encephalopathy; central nervous system; hematopoietic cell transplant; human herpesvirus 6 encephalitis; thiamine