The pathological features of Wernicke encephalopathy

Abstract

Case reportA 47-year-old man with a history of alcoholic liver diseasewas found dead at his home address on the floor, lying facedown. He had been unwell for 2 months prior to death andhad complained of abdominal pain. He also had a diagnosisof prolonged QT interval.At autopsy there was no evidence of liver failurealthough the liver was fatty and fibrotic. There was acongenital anomaly of the coronary arteries with the cir-cumflex coronary artery arising from the right sinus ofValsalva with significant narrowing of the ostium. Therewas no evidence of trauma and toxicological screening ofblood was unremarkable. Biochemical analysis of vitreoushumor revealed elevated sodium (144 mmol/L) and creat-inine (217 lmol/L) levels in keeping with terminal dehy-dration and renal failure, with a normal b-hydroxy butyrate(thus excluding alcoholic ketoacidosis).Althoughthebrainappearedexternallyunremarkablewithnovermal atrophy of the cerebellum, sectioning of the mammillarybodiesdemonstratedsymmetricalhemorrhagehighlysuggestiveof Wernicke encephalopathy (Figs. 1, 2). Focal hemorrhagicareas were also noted within the walls of the third ventricle.Microscopically the mammillary bodies displayedrecent microhemorrhages and prominent microvascularproliferation with endothelial swelling typical of Wernickeencephalopathy (Fig. 3). The mammillothalamic tracts andthe walls of third ventricle also contained microhemor-rhages. There was patchy microvacuolation of the neuropilwith unremarkable neurons, fibrous astrocytes, and occa-sional perivascular macrophages containing hemosiderin,indicative of more chronic disease. Mild extravasation oferythrocytes and prominent congested vessels were notedwithin medullary dorsal motor vagal nuclei.Death was attributed to natural causes, most likelyinvolving a combination of cardiac and alcohol-relateddisease. The striking finding was of clinically unsuspectedWernicke encephalopathy.DiscussionWernicke encephalopathy is a neurological disorderresulting from thiamine (vitamin B-1) deficiency [1].Although in Western countries it occurs predominantly inalcoholics, related to poor dietary intake and impairedutilization, it can also be caused by a variety of otherconditions that interfere with normal thiamine metabolism.These include starvation, bariatric surgery, hyperemesisgravidarum, human immunodeficiency virus/acquiredimmunodeficiency syndrome (HIV/AIDS), and in infantsgiven thiamine-deficient formulas [1, 2].The clinical prevalence of Wernicke encephalopathy isuncertain as autopsy studies indicate that the condition islikely under-diagnosed during life [3]. Delay in diagnosismay result from nonspecific symptoms that resembleintoxication. The symptoms, severity, and the regions ofthe brain that are affected are also variable due to a