In the US and western countries, thiamin deficiency is observed most commonly in chronic alcohol users and patients with GI diseases. Thiamin is contained in the outer coat of rice, and polishing destroys it. In Indonesia, beriberi is still endemic. Mortality and morbidity of beriberi depend on the degree of heart failure and the proper institution of thiamin replacement. Beriberi can affect both genders, though alcoholism is more prevalent in males.
Aphonic beriberi presents with hoarseness and aphonic cry due to paralysis of the laryngeal nerve.
For cardiac failure, differential diagnosis varies depending on the age group. High index of suspicion is needed for patients with chronic alcohol abuse, special diets, and malnutrition. The best diagnostic test is assessing clinical response to administration of thiamin. One of the most reliable laboratory tests is measurement of whole blood or erythrocyte transketolase activity. Nonspecific changes are observed on MRI or CT scan of the brain.