What are the Cane criteria for diagnosing Wernicke's (Wernicke's encephalopathy) encephalopathy?

Caine Criteria for Wernicke's Encephalopathy

The Caine criteria for diagnosing Wernicke's encephalopathy require the presence of two or more of the following: nutritional deficiency, delirium or mild memory impairment, cerebellar dysfunction/ataxia, and oculomotor abnormalities. 1

Clinical Presentation and Diagnostic Criteria

• The classic triad of Wernicke's encephalopathy consists of confusion, ataxia, and ophthalmoplegia, but this complete triad is observed in less than 20% of patients with the condition 2
• The Caine criteria were developed to enhance diagnostic sensitivity by requiring a history of malnutrition along with two elements of the Wernicke's encephalopathy triad 3
• The four components of the Caine criteria are:
  1. Nutritional deficiency (evidence of malnutrition)
  2. Delirium or mild memory impairment (mental status changes)
  3. Cerebellar dysfunction/ataxia (gait incoordination)
  4. Oculomotor abnormalities (nystagmus, ophthalmoplegia, conjugate gaze palsy) 1
• Presence of two or more of these criteria is considered diagnostic for Wernicke's encephalopathy 1

Risk Factors for Wernicke's Encephalopathy

• Alcoholism is the most common risk factor for Wernicke's encephalopathy, but non-alcoholic causes are increasingly recognized 4
• Other important risk factors include:
  • Post-bariatric surgery status 4, 2
  • Prolonged vomiting or dysphagia 4
  • Hyperemesis gravidarum 4
  • Gastric carcinoma and pyloric obstruction 4
  • Prolonged intravenous feeding without thiamine supplementation 4, 5
  • Malnutrition from any cause 4
  • Hypermetabolic states such as hyperthyroidism 2

Clinical Manifestations Beyond the Classic Triad

• Mental status changes can range from mild cognitive impairment to coma 4
• Ocular findings may include nystagmus, ophthalmoplegia, and conjugate gaze palsy 4
• Cerebellar dysfunction presents as ataxia of gait and incoordination 4
• Additional manifestations may include:
  • Hearing loss that can improve with thiamine replacement 3
  • Vestibular dysfunction with decreased vestibulo-ocular reflex gain 3
  • Unexplained metabolic lactic acidosis 4
  • Cardiovascular involvement resembling beriberi heart disease 4

Diagnostic Approach Using Caine Criteria

• Diagnosis should be made clinically using the Caine criteria without waiting for laboratory confirmation 4
• Thiamine levels can be measured (thiamine diphosphate in whole blood or red blood cells), but treatment should not be delayed pending results 4
• Other biomarkers such as lactate, pyruvate, alpha-ketoglutarate, and glyoxylate concentrations can support the diagnosis 4
• Rapid improvement in symptoms with intravenous thiamine administration supports the diagnosis 3

Treatment Implications

• Patients meeting Caine criteria should receive immediate high-dose parenteral thiamine 4
• The American College of Physicians recommends 500 mg thiamine IV three times daily for 3-5 days, followed by 250 mg IV daily for at least 3-5 additional days 4
• Thiamine must always be administered before any glucose-containing solutions to prevent precipitation or worsening of Wernicke's encephalopathy 4, 6
• After parenteral treatment, patients should be transitioned to oral thiamine 50-100 mg daily 4

Clinical Significance of Caine Criteria

• In a study of psychiatric inpatients, 12% met Caine criteria for Wernicke-Korsakoff syndrome, with only half having alcohol use 1
• Patients treated with high-dose thiamine based on Caine criteria showed significant improvement in cognitive function and gait/coordination compared to untreated patients 1
• Early diagnosis and treatment using Caine criteria can prevent progression to Korsakoff syndrome, characterized by anterograde amnesia and decreased word memory 4

Common Pitfalls in Diagnosis

• Failing to consider Wernicke's encephalopathy in non-alcoholic patients 4
• Administering glucose-containing solutions before thiamine 4, 6
• Waiting for the complete classic triad to appear before diagnosis 3, 1
• Not recognizing Wernicke's encephalopathy in patients with concurrent conditions such as hepatic encephalopathy 4