title: Atypical brainstem encephalitis caused by herpes simplex virus 2.
abstract: BACKGROUND
  Herpes simplex encephalitis is one of the most common and serious sporadic encephalitides of immunocompetent adults. Herpes simplex virus 2 (HSV-2) infections of the central nervous system usually manifest as subacute encephalitis, recurrent meningitis, myelitis, and forms resembling psychiatric syndromes.
  
  
  OBJECTIVE
  To report and discuss magnetic resonance imaging (MRI) findings and clinical features in atypical brainstem encephalitis and facial palsy associated with HSV-2.
  
  
  METHODS
  Neurology department of a tertiary referral center.
  
  
  METHODS
  A 37-year-old woman was admitted to the hospital with fever, diplopia, left hemiparesis, sensory change in the face and limbs, personality changes, frontal dysexecutive syndrome, and a stiff neck. Brain MRI showed multifocal high-signal intensities in the pons, midbrain, and frontal lobe white matter on T2-weighted and fluid-attenuated inversion recovery images. Cerebrospinal fluid (CSF) polymerase chain reaction (PCR) amplification analysis was positive for HSV-2. Acyclovir therapy was started, and the encephalitic symptoms disappeared with a negative conversion of HSV-2 PCR in the CSF. However, after the discontinuation of acyclovir therapy, peripheral facial palsy occurred on the left side. A possible relapse or delayed manifestation of the HSV-2 infection was suspected, and the acyclovir therapy was restarted. A complete remission was achieved 3 days after the treatment. She was discharged without any neurologic sequelae.
  
  
  CONCLUSIONS
  We describe a patient who developed atypical encephalitis due to HSV-2 and peripheral facial palsy, which could also be related to the HSV-2. This case suggests that HSV-2 should be considered among the possible causes of atypical or brainstem encephalitis and that the PCR amplification method of the CSF can help reveal the possible cause of HSV-2.
authors.affiliation: Department of Neurology, Seoul National University Hospital, 28, Yongon-Dong, Chongno-Gu, Seoul 110-744, South Korea.
authors.forename: Kon
authors.initials: K
authors.lastname: Chu
authors.forename: Dong-Wha
authors.initials: DW
authors.lastname: Kang
authors.forename: Jung-Ju
authors.initials: JJ
authors.lastname: Lee
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Yoon
mesh_terms: D000212:Acyclovir / Q000627:therapeutic use; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D020330:Bell Palsy / Q000821:virology*; D001933:Brain Stem / Q000473:pathology / Q000821:virology*; D002555:Cerebrospinal Fluid / Q000821:virology; D018792:Encephalitis, Viral / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006566:Herpesviridae Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology / Q000523:psychology; D018258:Herpesvirus 2, Human / Q000302:isolation & purification; D006801:Humans; D008279:Magnetic Resonance Imaging; D016133:Polymerase Chain Reaction; D012008:Recurrence
chemical_list: D000998:Antiviral Agents; D000212:Acyclovir