• Inability to form new memories
• Loss of memory, can be severe
• Loss of muscle coordination (ataxia)
  • Unsteady, uncoordinated walking
• Making up stories (confabulation)
• Seeing or hearing things that aren't really there (hallucinations)
• Vision changes
  • Abnormal eye movements
  • Double vision
  • Eyelid drooping

Note: There may also be symptoms of alcohol withdrawal.

Examination of the nervous/muscular system may show damage to many nerve systems:

• Decreased or abnormal reflexes
• Problems with walk (gait) and coordination
• Muscle weakness and atrophy (loss of tissue mass)
• Abnormal eye movement
• Low blood pressure
• Low body temperature
• Fast pulse (heart rate)

The person may appear poorly nourished. The following tests are used to check a person's nutrition level:

• Pyruvate
• Serum B1 levels
• Transketolase activity

Blood or urine alcohol levels and liver enzymes may be high in people with a history of long-term alcohol abuse.

Other conditions that may cause thiamine deficiency include:

• AIDS
• Cancers that have spread throughout the body
• Extreme nausea and vomiting during pregnancy (hyperemesis gravidarum)
• Heart failure (when treated with long-term diuretic therapy)
• Long periods of intravenous (IV) therapy without receiving thiamine supplements
• Long-term dialysis
• Very high thyroid hormone levels (thyrotoxicosis)

A brain MRI in rare cases shows changes in the tissue of the brain.