Cortical damage in Wernicke's encephalopathy with good prognosis: a report of two cases and literature review.

Wernicke's encephalopathy (WE) is a thiamine deficiency-related condition, in which lesions are usually present in the periventricular and subcortical areas of the brain. However, lesions have also been found in atypical areas, such as the cerebral cortex. The present study summarizes the clinical outcomes and radiological features of WE with cortical impairment. We report two cases of cortical involvement in patients with WE, and review 22 similar cases from other reports. Among all 24 cases, 4 patients had a confirmed history of chronic daily alcohol abuse, and 19 of them had an identified causes of thiamine deficiency. 17 cases reported specific clinical information, among which 11 patients had symptoms of cortical impairment. 23 cases reported prognostic information at the end of treatment or at follow-up. The mortality rate was 26.1 % in our review. All patients had abnormal magnetic resonance imaging (MRI) signals or pathological findings in the bilateral cortex. Among patients with available MRI, 89.0 % had banding-like signs along the para-central sulcus. 13 cases underwent follow-up MRI examinations and 76.9 % displayed normal images. We suggest that WE with bilateral cortical involvement may have an acceptable prognosis, but that the mortality rate is higher than that among typical cases, especially if patients are not treated promptly and correctly. We identified the frontal and parietal lobes, especially around the central sulcus, to be the most susceptible areas, and suggest that the banding signs may be characteristic of WE. Persistent hyper-intensity on T2-weighted-fluid-attenuated inversion recovery, or gadolinium enhancement, may predict poor outcome.