S AKSHAYA

WHY GLUCOSE CAN DESTROY AN ALCOHOLIC’S BRAIN ?

Here’s the biochemistry behind it,

Thiamine (Vitamin B1) is the essential cofactor for pyruvate dehydrogenase, the enzyme that shuttles glucose into the Krebs cycle to generate ATP. Chronic alcoholics are almost always thiamine-deficient because alcohol destroys gut absorption, depletes liver stores, and increases utilization. Their pyruvate dehydrogenase is barely functioning.

 When we flood these patients with IV dextrose for hypoglycemia, we suddenly spike the brain’s glucose metabolism five-fold. But without thiamine,  pyruvate dehydrogenase  cannot convert pyruvate to Acetyl CoA. The metabolic pathway gets shunted and all the pyruvate  gets converted to lactate instead.

WERNICKE’S TRAP

The accumulation of lactate causes lactic acidosis which combined with ATP depletion, destroys neurons in thalamus and mammillary bodies. This neuronal death is the pathological basis of Wernicke’s Encephalopathy.

TREATMENT

Thiamine

Initial dose: 500mg IV Q-8-Hr for 3 days.

Followed by 250mg IV once daily for further 3-5 days.

Then shift to oral thiamine 50-100mg daily.

The condition can be reversible on immediate administration of Thiamine. If not, it’ll progress to Korsakoff Syndrome, a permanent type of anterograde amnesia which leads to an irreversible brain damage.

 PREVENTION

Always administer the thiamine prior to glucose or with glucose to the malnourished or alcoholics to prevent the brain damage.