What is Beriberi?
Beriberi is a vitamin deficiency disease caused by inadequate bodily stores of thiamine (vitamin B-1). It can damage the heart and nervous system.
Thiamine deficiency; Vitamin B1 deficiency
Causes, incidence, and risk factors:
There are two major manifestations of thiamine deficiency: cardiovascular disease (wet beriberi) and nervous system disease ("dry beriberi" and Wernicke-Korsakoff syndrome). Dry beriberi is somewhat of a misnomer because both types are most often caused by excessive alcohol consumption.
Symptoms of dry beriberi include pain, tingling, or loss of sensation in hands and feet (peripheral neuropathy), muscle wasting with loss of function or paralysis of the lower extremities, and potentially brain damage and death.
Wet beriberi is characterized by swelling (edema), increased heart rate (tachycardia), lung congestion, and enlarged heart related to congestive heart failure.
Beriberi has become very rare in the United States because most foods are now vitamin-enriched, which means that a normal diet contains adequate amounts of thiamine.
As a result, beriberi now occurs primarily in patients who abuse alcohol, because drinking heavily can lead to malnutrition and poor absorption and storage of thiamine. This is the cause of Wernicke-Korsakoff syndrome, which is alcohol-related brain damage affecting language and thinking.
Beriberi can also occur in breast-fed infants when the mother has an inadequate intake of thiamine. It can also affect infants fed unusual formulas with inadequate thiamine supplements.
Others at risk for beriberi include patients undergoing dialysis, patients receiving high doses of diuretics, and people in developing countries with limited diets who consume milled rice.
Nervous system symptoms are caused by degeneration of the nerve fibers and their insulation (myelin sheath). Heart failure is the most common cause of death in people with beriberi.
Early Neurological Symptoms:
Complaints of symmetric tingling or burning pain in the extremities
Numbness in the extremities
Strange eye movements (nystagmus)
Later Neurologic Symptoms (Wernicke's encephalopathy):
Mental confusion/speech difficulties
Difficulty walking (ataxia)
If a patient with Wernicke's encephalopathy receives thiamine replacement, language problems, unusual eye movements, and walking difficulties may subside, but may be replaced by Korsakoff's syndrome, which includes retrograde amnesia (memory loss), impaired ability to learn, and confabulation (making up stories to explain behavior that have little relation to reality).
Heart Failure Symptoms:
Shortness of breath with exertion (dyspnea)
Symmetric swelling of the lower legs
Awakening at night short of breath (paroxysmal nocturnal dyspnea).
Administration of thiamine can reverse the deficiency, and symptoms should improve rapidly. However, with severe deficiency, some symptoms may be irreversible. Patients should also receive therapeutic doses of other water-soluble vitamins.
Cardiac damage is usually reversible and is not permanent. Full recovery is expected after treatment. Untreated, beriberi is often fatal.
If acute heart failure has already occurred, the outlook is poor.
Nervous system damage is also reversible, if caught early. If not, some symptoms (such as memory loss) may not be completely recovered with treatment.
Congestive heart failure
Adequate intake of thiamine will prevent beriberi. Nursing mothers should insure that their diet is adequate in all vitamins and be sure that infant formulas contain thiamine. People who drink heavily should try to cut down or quit and supplement their diets with B-vitamins to ensure appropriate intake of thiamine.