title: Wallenberg's lateral medullary syndrome: diffusion-weighted imaging findings.
abstract: OBJECTIVE
  To investigate the efficacy of diffusion-weighted imaging in patients with Wallenberg's lateral medullary syndrome.
  
  
  METHODS
  Thirteen patients with Wallenberg's lateral medullary syndrome were examined with conventional and echoplanar diffusion-weighted magnetic resonance (MR) imaging in a 1.5 T magnetic resonance unit. MR examinations were obtained in the acute or subacute stage of clinical syndrome, and diffusion-weighted imaging (DWI) was considered to be positive for infarction when an increase in signal was seen on b = 1000 s/mm2 images in the posterolateral medullary localization.
  
  
  RESULTS
  DWIs were positive in 12 patients in the acute or subacute stages of this clinical syndrome. A false-negative result was obtained in only one patient examined within the first day, 10 h after onset of the symptoms. In the visual evaluation of the DWI, the contrast between normal and infarcted brainstem area was better in the high b-value images than in the apparent diffusion coefficient map images.
  
  
  CONCLUSIONS
  DWI is a valuable technique for examining patients presenting with the signs and symptoms of Wallenberg's syndrome and high b-value images can provide complementary data to T2-weighted images. However, because most of our case group were in either the acute or subacute stage, true sensitivity of the method in the hyperacute stage of the syndrome remains unclear.
authors.affiliation: Ege University, Medical Faculty, Department of Radiology, Bornova, Izmir, Turkey. okitis@med.ege.edu.tr
authors.forename: O
authors.initials: O
authors.lastname: Kitis
authors.forename: C
authors.initials: C
authors.lastname: Calli
authors.forename: N
authors.initials: N
authors.lastname: Yunten
authors.forename: A
authors.initials: A
authors.lastname: Kocaman
authors.forename: H
authors.initials: H
authors.lastname: Sirin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D014854:Lateral Medullary Syndrome / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged