title: Enterovirus 71-related encephalomyelitis: usual and unusual magnetic resonance imaging findings.
abstract: BACKGROUND
  Most enterovirus (EV) 71 infections manifest as mild cases of hand-foot-mouth disease (HFMD)/herpangina with seasonal variations, having peak incidence during the summer. Meanwhile, EV 71 may involve the central nervous system (CNS), causing severe neurologic disease. In many cases, enteroviral encephalomyelitis involves the central midbrain, posterior portion of the medulla oblongata and pons, bilateral dentate nuclei of the cerebellum, and the ventral roots of the cervical spinal cord, and the lesions show hyperintensity on T2-weighted and fluid-attenuation inversion recovery (FLAIR) images. Our goal was to review usual and unusual magnetic resonance (MR) findings in CNS involvement of enteroviral infection.
  
  
  METHODS
  Among consecutive patients who had HFMD and clinically suspected encephalitis or myelitis and who underwent brain or spinal MR imaging, five patients revealed abnormal MR findings. Diffusion-weighted and conventional MR and follow-up MR images were obtained. From cerebrospinal fluid, stool, or nasopharyngeal swabs, EV 71 was confirmed in all patients.
  
  
  RESULTS
  MR imaging studies of two patients showed hyperintensity in the posterior portion of the brainstem on T2-weighted and FLAIR images, which is the well-known MR finding of EV 71 encephalitis. The remaining three cases revealed unusual manifestations: leptomeningeal enhancement, abnormal enhancement along the ventral roots at the conus medullaris level without brain involvement, and hyperintensity in the left hippocampus on T2/FLAIR images.
  
  
  CONCLUSIONS
  EV 71 encephalomyelitis shows relatively characteristic MR findings; therefore, imaging can be helpful in radiologic diagnosis. However, physicians should also be aware of unusual radiologic manifestations of EV 71.
authors.affiliation: Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, 97 Gurodong, Guro-gu, Seoul, 152-703, South Korea.
authors.forename: Seonah
authors.initials: S
authors.lastname: Jang
authors.forename: Sang-il
authors.initials: SI
authors.lastname: Suh
authors.forename: Su Min
authors.initials: SM
authors.lastname: Ha
authors.forename: Jung Hye
authors.initials: JH
authors.lastname: Byeon
authors.forename: Baik-Lin
authors.initials: BL
authors.lastname: Eun
authors.forename: Young Hen
authors.initials: YH
authors.lastname: Lee
authors.forename: Hyung Suk
authors.initials: HS
authors.lastname: Seo
authors.forename: So-Hee
authors.initials: SH
authors.lastname: Eun
authors.forename: Hae-Young
authors.initials: HY
authors.lastname: Seol
mesh_terms: D002675:Child, Preschool; D003287:Contrast Media; D003937:Diagnosis, Differential; D004679:Encephalomyelitis / Q000175:diagnosis* / Q000821:virology*; D029821:Enterovirus A, Human / Q000302:isolation & purification*; D005260:Female; D006232:Hand, Foot and Mouth Disease / Q000175:diagnosis* / Q000821:virology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D009942:Organometallic Compounds; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine