Received: 23 January 2002 Revised: 19 June 2002 Accepted: 24 June 2002 Published online: 20 September 2002 © Springer-Verlag 2002 Abstract Wernicke encephalopathy (WE) is a severe neurological disor- der caused by vitamin B1 deficiency. The aim of the study was to analyse MRI findings typical for this disease and to evaluate the significance of their correlations with clinical symp- toms. Magnetic resonance images and clinical features of 12 patients with WE were analysed. The patients underwent MR imaging within 3–14 days after onset of clinical symptoms. In 7 of 12 patients MR imaging showed symmetrical dience- phalic and midbrain lesions. Postcon- trast T1-weighted images from 5 of 9 patients examined during the initial 6 days of acute WE showed a subtle enhancement of the mamillary bodies, the tectal plate, the periaque- ductal area and the periventricular region of the third ventricle including the paramedian thalamic nuclei. In addition, T2-weighted and fluid- attenuated inversion recovery (FLAIR) images revealed hyperin- tense signals in these regions (except for 2 patients where the mamillary bodies were normal). Hyperintense lesions on T2-weighted images with- out any enhancement on postcontrast T1-weighted images were detected in 2 patients by MR imaging performed 11 or 14 days after onset of WE. Patients with hyperintensities on T2-weighted images of the periven- tricular region of the third ventricle and the paramedian thalamic nuclei had poor recovery from their mental dysfunction. The MR examination in case of WE shows a typical pattern of lesions in 58% of cases. Enhance- ment of the mamillary bodies, the periventricular region of the third ventricle including the paramedian thalamic nuclei, and the periaqueduc- tal area on postcontrast T1-weighted images can be observed in the initial period after clinical onset of symp- toms and are characteristic signs of the acute stage of WE. Hyperintense lesions in the periventricular region and the paramedian thalamic nuclei on T2-weighted and FLAIR images in the subacute stage of WE and enhancement on postcontrast T1-weighted images of the mamillary bodies and the paramedian thalamic nuclei are indicators of poor progno- sis despite vitamin B1 substitution. Keywords Wernicke encephalopathy · MR imaging · Contrast enhancement · Prognosis Eur Radiol (2003) 13:1001–1009 DOI 10.1007/s00330-002-1624-7 NEURO Stefan Weidauer Michael Nichtweiss Heinrich Lanfermann Friedhelm E. Zanella Wernicke encephalopathy: MR findings and clinical presentation Introduction Wernicke encephalopathy is a serious neurological disorder caused by thiamine (vitamin B1) deficiency [1, 2]. The typ- ical clinical presentation is characterized by ophthalmople- gia, ataxia, nystagmus, bilateral abducens palsies and dis- turbances of consciousness [1, 3, 4]. In many cases, how- ever, clinical presentation is incomplete and only changes in consciousness are present. If untreated, WE may be fol- lowed by an amnestic syndrome or Korsakoff psychosis [1]. S. Weidauer ( ✉ ) · H. Lanfermann F.E. Zanella Institute of Neuroradiology, University of Frankfurt, Frankfurt, Germany e-mail: Weidauer@em.uni-frankfurt.de Tel.: +49-69-63015462 Fax: +49-69-63017176 M. Nichtweiss Department of Neurology, Municipal Hospital of Wismar, Wismar, Germany