Thiamine def. and WE

Q: The best way to determine thiamine deficiency in Wernicke encephalopathy (WE) is via blood level? (select one)

A) True
B) False


Answer: B

There is no direct blood test available to document thiamine deficiency. The only test available is measuring erythrocyte thiamine transketolase (ETKA) before and after the addition of thiamine pyrophosphate (TPP). A low ETKA, along with a more than 25 percent stimulation, confirms thiamine deficiency. Also, serum thiamine or serum thiamine pyrophosphate level can be obtained by high-performance liquid chromatography. Both of these tests are special tests and are not easily available. Also, they do not correlate well with clinical signs. 

Thiamine deficiency gets establish by clinical signs and diagnostic criteria named Caine criteria. WE is diagnostic with two of the four Caine criteria positive: 

 ●Dietary deficiency 
 ●Oculomotor abnormalities 
 ●Cerebellar dysfunction 
 ●Either altered mental status or memory impairment


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References:

1. Galvin R, Bråthen G, Ivashynka A, et al. EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy. Eur J Neurol 2010; 17:1408. 

2. Caine D, Halliday GM, Kril JJ, Harper CG. Operational criteria for the classification of chronic alcoholics: identification of Wernicke's encephalopathy. J Neurol Neurosurg Psychiatry 1997; 62:51. 

3. Leigh, D. Erythrocyte transketolase activity in the Wernicke-Korsakoff syndrome. Br J Psychol 1981; 138:153.  

4. Lu J, Frank EL. Rapid HPLC measurement of thiamine and its phosphate esters in whole blood. Clin Chem 2008; 54:901.