A 60-year-old man with chronic alcohol abuse presents with altered mental status and ataxia. Nystagmus is noted. Vitals are normal. What is the most likely diagnosis?

A. Subdural Hemorrhage

B. Acute Alcohol Intoxication

C. Wernicke's Encephalopathy

D. Wet Beriberi

E. Dry Beriberi

F. Korsakoff's Syndrome

Answer: C

-An acute neuropsychiatric syndrome secondary to thiamine deficiency; thiamine is a key cofactor in energy metabolism and without leads to decreased ATP.

-Etiologies: i. Alcoholism ii. Malnutrition states like anorexia or diets iii. Gastric bypass iv. Hyperemesis Gravidarum v. High metabolic states like cancer, sepsis, pregnancy, thyrotoxicosis. vi. AIDS, Liver Disease vii. CHF patients, especially on Lasix.

-Clinical triad of Ophthalmoplegia (nystagmus, lateral rectus palsy, diplopia) + ataxia/ incoordination + altered mental status (confusion, disorientation).

-Other Clinical Syndromes of Thiamine Deficiency: i. Wet Beriberi (high output heart failure) ii. Dry Beriberi (polyneuropathy) iii. Korsakoff's (anterograde and retrograde amnesia, personality changes, confabulations). iv. GI Beriberi (abdominal pain, vomiting, lactic acidosis)

-Diagnosis is clinical but easy to miss given symptoms of acute alcoholism (ataxia, confusion) can overlap with Wernicke's Encephalopathy.

-Management:

i. Thiamine 500 mg IV and admission

ii. Classic teaching is thiamine before glucose but do not withhold urgent administration of glucose as no documented single glucose load has precipitated Wernicke's.

iii. Give Magnesium if hypomagnesemia.

iv. 100 mg PO Thiamine is given for the chronic alcoholic to prevent Wernicke's but does not treat active Wernicke's Encephalopathy.

References

Sechi GP, Serra A: Wernicke’s encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol 2007; 6: 442–455.