A patient with clear consciousness even with a glucose level of 5 mg/dL (0.2 mmol/L).

A 74-year-old man noted dysarthria and right hemiparesis. His history included a gastric ulcer 2 years previously, and he had gradually lost 10 kg over a 2-year period due to appetite loss. He daily consumed 120 mg of alcohol. Upon arrival, he had clear consciousness and stable vital signs. He was malnourished. Neurologic findings included a positive finding of Barre sign in the right hand and dysarthria. A venous blood gas analysis demonstrated the following: pH 7.059; PCO2, 21.5 mm Hg; PO2, 59.1 mm Hg; HCO(3-), 5.8 mmol/L; base excess, -22.7 mmol/L; lactate,17 mmol/L; and glucose, 4 mg/dL. After the administration of an infusion of thiamine and glucose, his abnormal neurologic findings subsided completely. Head magnetic resonance image (MRI; diffusion weighted image) disclosed 3 spotty, high-intensity signals in the brain. The main results of biochemical analyses of the blood collected on arrival were as follows: hemoglobin, 5.5 g/dL; glucose, 5 mg/dL; aspartate aminotransferase, 89 IU/L. He was admitted for further examination and was diagnosed as having alcoholic ketoacidosis with hypoglycemic encephalopathy and anemia due to colon cancer.