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Acute encephalopathy with biphasic seizures and late reduced diffusion associated with hemophagocytic syndrome

Rieko Tadokoro1, Akihisa Okumura, Tomoyuki Nakazawa

  • 1Department of Pediatrics, Koshigaya Municipal Hospital, Saitama, Japan.

Brain & Development
|June 27, 2009
PubMed

Insights

Human herpesvirus 6 (HHV-6) infection can cause acute encephalopathy with biphasic seizures and hemophagocytic syndrome. This case highlights the link between HHV-6, severe neurological symptoms, and hypercytokinemia.

Area of Science:

  • Pediatric Neurology
  • Infectious Diseases
  • Neuroimmunology

Background:

  • Human herpesvirus 6 (HHV-6) is a common viral infection in children.
  • HHV-6 encephalitis can present with diverse neurological manifestations.
  • The association between HHV-6, acute encephalopathy, and hemophagocytic syndrome requires further elucidation.

Observation:

  • A pediatric patient presented with a febrile illness followed by biphasic seizures and altered consciousness.
  • Cerebrospinal fluid and initial brain imaging were unremarkable, but later diffusion-weighted MRI showed reduced diffusion in bilateral frontal areas.
  • The patient developed hematological abnormalities, including decreased white blood cells and platelets, and elevated liver enzymes and ferritin, consistent with hemophagocytic syndrome.

Findings:

  • Virological confirmation of HHV-6 infection was established via polymerase chain reaction.
  • Elevated serum and cerebrospinal fluid cytokine levels (IL-6, IL-8, IL-10, TNF-α) were observed during the late seizure phase.
  • Treatment with gamma-globulin, steroid pulse therapy, and brain hypothermia led to gradual recovery of hematological and clinical symptoms.

Implications:

  • This case suggests that HHV-6 infection can trigger a severe inflammatory response, leading to acute encephalopathy and hemophagocytic syndrome.
  • Hypercytokinemia may play a crucial role in the pathogenesis of HHV-6-associated acute encephalopathy.
  • Understanding this association can inform diagnostic and therapeutic strategies for severe HHV-6 infections in children.

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