title: Human herpesvirus 6 rhombencephalitis in immunocompetent children.
abstract: This article describes the clinical presentation, diagnostic workup, and neurologic outcome of 3 immunocompetent pediatric patients diagnosed with human herpesvirus 6 (HHV6) rhombencephalitis. Presentation of HHV6 rhombencephalitis included new onset seizures, ataxia, encephalopathy, and opsoclonus-myoclonus. Neurologic examination revealed cranial neuropathies, cerebellar dysfunction, and extremity weakness. Magnetic resonance imaging abnormalities located in the cerebellum, basal ganglia/thalamus, and cerebral hemispheres were detected in 2 patients. Diagnosis of HHV6 encephalitis was made by real-time and nested polymerase chain reaction of serum and cerebrospinal fluid. The HHV6 variant A was detected in 2 patients by sequence analysis, and HHV6 protein was detected by immunomicroscopy in a patient who underwent biopsy secondary to progressive clinical and neuroradiographic findings. Therapy with intravenous ganciclovir did not correlate with resolution of neurologic symptoms, despite eventual non-detectable HHV6. Human herpesvirus 6 should be considered in the differential diagnosis of unexplained cases of rhombencephalitis in immunocompetent children. Features may be rapidly progressive and include profound encephalopathy, seizures, ataxia, and opsoclonus-myoclonus.
authors.affiliation: Department of Neurology Children's National Medical Center, George Washington University, Washington District of Columbia, USA. jcrawfor@cnmc.org
authors.forename: John R
authors.initials: JR
authors.lastname: Crawford
authors.forename: Nadja
authors.initials: N
authors.lastname: Kadom
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Santi
authors.forename: Brian
authors.initials: B
authors.lastname: Mariani
authors.forename: Bennett L
authors.initials: BL
authors.lastname: Lavenstein
mesh_terms: D002675:Child, Preschool; D020803:Encephalitis, Herpes Simplex / Q000473:pathology* / Q000821:virology*; D005260:Female; D015654:Herpesvirus 6, Human / Q000302:isolation & purification / Q000472:pathogenicity*; D006801:Humans; D007121:Immunocompetence; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012249:Rhombencephalon / Q000821:virology*