Wernicke’s Encephalopathy – At A Glance

Wernicke’s encephalopathy is a neurological disorder caused by the deficiency of thiamine (Vitamin B1) which is characterized by the presence of….

  • Ophthalmoplegia
  • Cerebellar dysfunction /Ataxia
  • Impaired mental state 
 
Predominantly associated with alcohol abuse, but can occur due to other causes as well.

Incidence : 2% (Considered to be under diagnosed)
 
It is considered as a medical emergency

Without prompt management Wernicke’s encephalopathy will progress to Wernicke-Korsakoff syndrome / Wernicke-Korsakoff psychosis.

Wernicke’s encephalopathy is the acute reversible presentation of thiamine deficiency where as Wernicke-Korsakoff syndrome is considered to be the late neuropsychiatric manifestation which is irreversible.

 
Causes Of Wernicke’s Encephalopathy
  • Chronic alcoholism
    • Alcohol impairs the conversion of thiamine to its activated form (Thiamine pyrophosphate)
    • Impairs absorption from the duodenum 
    • If patient develops alcoholic cirrhosis – Impairs the storage of thamine
  • Prolong starvation / Malnutrition
  • Malabsorption syndrome 
  • Hyperemesis gravidarum
  • Bariatric surgery


Pathophysiology Of Wernicke’s Encephalopathy 
 
Deficiency of thiamine 
                ↓
Impairs glucose metabolism 
Glucose metabolizes through anaerobic pathway and produce lactic acid
                ↓
This acidotic state affects the periventricular structures
Cerebellum leading to ataxia
Oculomotor nuclei leading to ophthalmoplegia
Respiratory center and vasomotor center leading to changes in breathing and heart rate
Limbic system – Mammillary bodies leading to impaired memory and behaviour 
 
 
Clinical Presentation Of Wernicke’s Encephalopathy
 
Even though there is a classical triad, only 10% present with all three features.
  • Classical presentation 
    • Ophthalmoplegia
      • Commonly affect lateral rectus muscle presenting with a convergence squint 
    • Ataxia
    • Impaired mental state
      • Confusion 
      • Difficulty to concentrate
      • Apathy
  • History of alcohol abuse / malnutrition 
  • Later, disease progress to Wernicke-Korsakoff syndrome / Wernicke-Korsakoff psychosis
    • Affects the limbic system 
    • Irreversible 
    • Presents with….
      • Amnesia 
        • Anterograde amnesia – Inability to create new memories 
        • Retrograde amnesia – Inability to recall memories 
      • Confabulation 
        • Gaps in memory is filled up with made up stories


Diagnosis Of Wernicke’s Encephalopathy

It is a clinical diagnosis
 
Clinical Diagnostic Criteria
  • In alcoholics requires two of the following four signs
    • Evidence of dietary deficiencies
    • Ocular signs
    • Cerebellar dysfunction
    • Altered mental state / Memory impairment
 
Thiamine assay can be done 
Imaging – CT / MRI 
 
But investigations are performed to rule out other diseases
 
 
Treatment Of Wernicke’s Encephalopathy
  • Immediate infusion of thiamine
    • 2 – 3 times a day till clinical improvement
  • If hypoglycemia present – dextrose should be given along with thiamine 
  • Identify and correct other nutritional deficiencies 
 
* It is important to note that giving dextrose to a patient with thiamine deficiency will further worsen the thiamine deficiency, precipitating the neurological injury 
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