Since her encephalopathy, ataxia, and nystagmus persisted, magnetic resonance imaging (MRI) of the brain was performed on Day 3 of hospitalization (FIGURE). A lumbar puncture and an electroencephalogram were also considered but were not performed because the MRI results revealed bilateral enhancement of the mammillary bodies and mild signal hyperintensity, thus confirming a diagnosis of Wernicke-Korsakoff syndrome (WKS).
WKS is the concurrence of Wernicke’s encephalopathy (an acute, life-threatening condition marked by ataxia, confusion, and ocular signs) and Korsakoff’s psychosis (a long-term, debilitating amnestic syndrome). WKS is a neuropsychiatric disorder in which patients experience profound short-term amnesia; it is precipitated by thiamine deficiency (defined as a whole blood thiamine level <0.7 ng/ml1).The link to thiamine was confirmed during World War II, when thiamine treatment resolved symptoms in starving prisoners. If recognized early, treatment of thiamine deficiency can prevent long-term morbidity from WKS.
Etiology of thiamine deficiency
Our patient’s alcohol abuse placed her at risk for WKS, and her olfactory aversion to certain foods was a diagnostic clue. In this case, we inadvertently administered dextrose with antibiotics for the UTI prior to administering thiamine; this exacerbated the thiamine deficiency because glucose and thiamine compete for the same substrate.
Is alcohol abuse always to blame for WKS?
The quantity and type of alcohol that results in the development of WKS has not been well studied, but the Caine diagnostic criteria defines chronic alcoholism as the consumption of 80 g/d of ethanol (8 drinks/d).2 While WKS is commonly associated with alcoholism, other causative conditions may be overlooked. Other associated illnesses include acquired immune deficiency syndrome (AIDS), cancer, hyperemesis gravidarum, prolonged total parenteral nutrition, and psychiatric illnesses such as eating disorders and schizophrenia. Procedures such as gastric bypass and dialysis can also precipitate WKS.3
Men and women are both at risk of developing WKS. A lack of consumption of thiamine-rich sources such as cereals, rice, and legumes puts patients at risk for WKS. The recommended dietary allowance of thiamine increases with age and may be higher for obese patients.4
Continue to: Suspect thiamine deficiency and obstain a thorough history