USEFULNESS OF CT AND MR-IMAGING IN THE DIAGNOSIS OF ACUTE WERNICKES ENCEPHALOPATHY

OBJECTIVE. In this study, we analyzed the sensitivity and specificity of CT and MR imaging in the diagnosis of acute Wernicke's's encephalop athy. SUBJECTS AND METHODS. Three groups of subjects were studied: 15 patients with acute Wernicke's encephalopathy; 15 asymptomatic alcohol ics; and 15 control subjects. Studies included clinical and laboratory examinations as well as CT and MR imaging of the brain. RESULTS. On C T scans, two patients with Wernicke's encephalopathy (13%) and no asym ptomatic alcoholics showed low-density abnormalities in the paraventri cular regions of the thalamus (p =.2414). On MR imaging, increased T2 signal of paraventricular regions of the thalamus was observed in seve n patients (46%) with Wernicke's encephalopathy and one asymptomatic a lcoholic (6%) (p <.01), and increased T2 signal of periaqueductal regi ons of the midbrain in six patients (40%) with Wernicke's encephalopat hy and one asymptomatic alcoholic (6%) (p <.05). However, no significa nt differences were observed in the prevalence of mamillary body shrin kage between alcoholics with Wernicke's encephalopathy (six [40%]) and asymptomatic chronic alcoholics (four [27%]). The sensitivity of MR i maging in revealing evidence of this disease was 53% and the specifici ty, 93%. CONCLUSION. MR imaging is useful in confirming the diagnosis of acute Wernicke's encephalopathy. However, the absence of abnormalit ies on MR imaging does not exclude this diagnosis. CT proved not usefu l in the diagnosis of Wernicke's encephalopathy.