Wernicke’s Encephalopathy Diagnosis and Treatment
Metabolic / Endocrine
Wernicke’s encephalopathy is a life-threatening neurological condition caused by a deficiency of thiamine (vitamin B1).
- Substantial morbidity and mortality yet remain underdiagnosed.
- Left untreated, there’s mortality in ~20% of patients with acute Wernicke’s encephalopathy and ~80% develop irreversible memory loss consistent with Korsakoff syndrome with only ~16% making full recovery.
- Alcoholics and chronically malnourished individuals.
- Compromised absorption (ex. hyperemesis gravidarum, intestinal obstruction, chemotherapy), with increased metabolism (ex. sepsis, malignancy), with increased carbohydrate intake (iatrogenic), secondary to liver disease or post-bariatric surgery.
Consider in any patient presenting with at least two of the following:
- Dietary/nutritional deficiency.
- Ocular abnormalities.
- Cerebellar dysfunction.
- Altered mental status or mild memory impairment.
- This diagnosis is made clinically.
- CN III or VI palsies, upbeat nystagmus, sluggish pupillary response, anisocoria, ataxia or gait instability, and peripheral neuropathy.
- MRI may show hyperintense signals in the dorsomedial thalamic nuclei, periaqueductal grey matter, third or fourth ventricles, and the cerebral aqueduct. This is due to variable degrees of acidosis in the brain, wherein the absence of thiamine, glucose is metabolized anaerobically to lactic acid and induces tissue injury.
- Failure to recognize that alcohol consumption is not required for the diagnosis of Wernicke’s encephalopathy.
- Mistake Wernicke’s encephalopathy for cerebellar infarction because both conditions tend to present with the classic triad of ophthalmoplegia, gait ataxia, and changes in mental status.
- Failure to check for hypomagnesemia in the context of thiamine deficiency which may cause resistance to any administration of thiamine.
- Failure to keep a high index of suspicion for Wernicke’s encephalopathy in vulnerable populations.
Goal of treatment is rapid correction of thiamine deficiency, particularly in the brain.
- The traditional recommendation is immediate replacement with 100mg IV thiamine followed by additional doses as needed, until symptoms improve; however, this is not based on randomized control trials.
- The European Federation of Neurological Societies guideline recommends an IV infusion of 200mg thiamine diluted in 100mL normal saline or 5% dextrose, given over 30 min and 3x daily until symptoms resolve
Magnesium levels should be checked and treated if low.
Quality Of Evidence?
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Low – Although thiamine replacement therapy is the recommended treatment for Wernicke’s encephalopathy, randomized control trials have not provided sufficient evidence to suggest an optimal dose, frequency, route or duration of treatment.
Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed.
Walls R., Hockerberger R., & Gausche-Hill M. (eds)
Philadelphia, PA: Elsevier; 2018.
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by Emergency Care BC (formerly the BC Emergency Medicine Network) and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. Emergency Care BC is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. Emergency Care BC also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Jun 05, 2021
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