About pathognomonic images: an infrequent case of acute encephalopathy

BACKGROUND The occurrence of acute encephalopathy is a dramatic clinical dilemma when usual diagnostic techniques (blood tests, cerebral CT and cerebrospinal fluid analysis) show no abnormalities.
CLINICAL CASE We describe a case of a 73 years old man admitted in our Internal Medicine Unit for acute diarrhoea with vomiting and fever who developed a prolonged gastrointestinal dysmotility syndrome with poor nutritional intake. Although a parenteral support was provided, he developed acute encephalopathy followed by hypotension and lactic acidosis without evidence of renal and hepatic disease or glycemic alterations. Likewise, no cerebral CT and cerebrospinal fluid alterations were found. Conversely, cerebral MRI showed marked and diffuse DP-2 and FLAIR hyperintensity of the mesencephalic tectal plate, of the periaqueductal area, and of the periventricular region of the third ventricle including the median thalamic area. These MRI descriptions were considered pathognomonic of Wernicke encephalopathy. Thus, the immediate use of ev thiamine was followed by a prompt and complete recovery of neurological, hemodinamic and metabolic conditions.
CONCLUSIONS Non-alcoholic Wernicke encephalopathy is a rare and dramatic clinical event with high mortality. In this context, brain MRI is the best diagnostic tool providing a typical picture.