Malignancy-associated primary thiamine deficiency has been documented in several experimental tumors, clinical case reports, and in patients with fast growing malignancies. We report a terminally ill cancer patient who developed delirium. Close examination of the patient demonstrated that delirium was caused by thiamine deficiency, although she had been consuming an average of 990 cal/day for the past 3 weeks. Malabsorption or consumption by the tumor was considered the mechanism of thiamine deficiency. Early recognition and subsequent treatment resulted in successful palliation of delirium. In terminally ill cancer patients, clinicians must remain aware of the possibility of Wernicke's encephalopathy, when the patients develop unexplained delirium, even if the patient has been consuming adequate amounts of food. Early intervention may correct the symptoms and prevent irreversible brain damage, and the quality of life for the patient may improve.

Objective: Although Wernicke encephalopathy has been reported in the oncological literature, it has not previously been reported in postoperative cancer patients.

Methods: In this communication, we report a patient of hepatocellular carcinoma with liver cirrhosis who developed Wernicke encephalopathy in the form of postoperative delirium. Preoperatively, the patient had a very good appetite and had eaten all the food of an 1800 cal/day diet until 1 day before operation. The operation was done without any complications. The patient developed delirium 2 days after the lobectomy of the liver. The level of delirium remained unchanged until administration of thiamine starting on day 7 postoperatively, which resulted in palliation of delirium without brain damage. Laboratory data demonstrated that the serum thiamine level at day 6 postoperatively was below the lower limit of normal. As the mechanism of Wernicke encephalopathy, we thought that decreased ability to store thiamine due to liver cirrhosis led to depletion of thiamine faster than had been expected.

Results and significance of the research: In cancer patients, clinicians must always remain aware of the possibility of Wernicke encephalopathy, especially in patients with liver dysfunction, which decreases the ability to store thiamine in the liver. Early detection and intervention may alleviate the symptoms of delirium and prevent irreversible brain damage.