Beriberi: Overview, Symptoms, Causes, Diagnosis and Management

Beriberi is a vitamin deficiency disorder which occurs due to deficiency of thiamine or vitamin B1. Vitamins are essential micronutrient, though they are required in the small amounts but still we must obtain it from our diet because our body cannot synthesize it. The term beriberi literally means ‘extreme weakness’.  A long-term deficiency of this vitamin can cause irreversible damage to nervous system and heart. Therefore, beriberi can be a serious life-threatening condition if left unmanaged.

Types

Thiamine is essential for the functioning of muscle and nervous system. It helps in breaking down carbohydrates, creating glucose, helping in muscle contraction and nerve conduction. A severe thiamine deficiency leads to disruption of these functions. On the basis of whether muscle or nervous system is affected, there are main two forms of beriberi but overlap can be present in the patient

Wet beriberi: as the name tells it is related to the fluids. It mainly affects the muscle of the heart causing poor functioning of cardiovascular system. It leads to poor circulation of blood in the body

Dry beriberi: it mainly affects the nervous system of the body leading to the degeneration of the nerves.

Symptoms

Depending upon the type symptoms can vary and there can be overlap between the symptoms of two different types beriberi

Symptoms pertaining to wet beriberi are those of heart failure

• Shortness of breath which may cause night awakening
• Increased heart rate
• Fatigue and tiredness
• Edema or swelling in the legs and feet.
• Cyanosis or bluishness of the hands and feet

Symptoms of dry beriberi are related to those of nervous system

• Numbness in the extremities
• Body aches and general pain
• Paralysis

Long term deficiency of thiamine can cause irreversible damage to brain neurons leading to a disorder known as Wernicke – Korsakoff syndrome and can have following symptoms

• General confusion
• Vomiting
• Loss of memory or inability to form new memories
• Psychosis like feature such as hallucinations
• Involuntary or rapid eye movements
• Decreased muscle coordination

Causes

For the body to be deficient in thiamine there can be three reasons.

First, the diet is low in thiamine. It is the most common reason of beriberi in overall world but in the developed countries where the food items are fortified with vitamins it rarely occurs. It cab occur due to intake of these foods

• Food containing high amount of thiamine destroying substance like raw fish, raw shellfish, milled rice.
• Food which are high in anti-thiamine factor like tea, coffee

The second reason is that the body is not able to absorb or process the thiamine present in the diet.

• Alcoholic state: It prevails in the developed countries where increasing alcohol use disorder makes it more difficult to absorb and process thiamine.
• It can be genetic too, like in genetic beriberi where the body is not able to absorb the thiamine present in the food.
• Starvation state

Third reason is that the body becomes deficient in thiamine due to its excessive use which occurs in

• Pregnancy
• Overactive thyroid gland
• Lactating mother
• Fever
• Diets high in carbohydrates

Diagnosis

Most of the times patient presents with the feature of heart failure or abnormalities with the nervous system. Your doctor will use your medical history, perform a medical examination and order some tests to find out the cause

• Medical history: you will be asked various questions related to your symptoms. It will help your physician to suspect how severe the condition is and what might be the cause.
• Physical examination: the physician will perform a neurological or cardiovascular exam to look for the specific signs and symptoms. It will help to assess the severity and to rule out other causes.
• Laboratory test: the most practical and rapid way to test would be to give thiamine to the patient. If the condition of the patient improves that means most of the disease cause can be attributed to the thiamine deficiency. To confirm the deficiency, blood levels of thiamine and other metabolites can be measured.

Management

Both the symptoms of heart failure and neurological disturbances are reversible. It can be easily treated with the help of thiamine supplements. Supplements can be in the form of an injection shot or pills. The goal of the treatment is to replace the lacking levels of thiamine. Adequate and proper follow-up would be required to assess the improvement.

Prognosis

There is quick recovery after the beginning of the treatment. Heart and nerve damage are both usually reversible if the treatment is started at the earlier stages of the disease. Long term deficiency without management can progress to Wernicke-Korsakoff syndrome in which permanent damage to brain occurs

Prevention

Since, it is a disease which can be easily prevented by having a balanced diet. These are some of the foods, rich in thiamine:

• Meat, fish, poultry, eggs
• Green and leafy vegetables
• Legumes, whole grains and beans
• Milk and milk products
• Limiting the usage of alcohol can improve the thiamine stores in the body.

References

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5. Vasan S, Dulebohn SC. Wernicke Encephalopathy. 2018 Jan 
6. Indraccolo U, Gentile G, Pomili G, et al. Thiamine deficiency and beriberi features in a patient with hyperemesis gravidarum. Nutrition. 2005 Sep. 21(9):967-8. 
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8. Sica DA. Loop diuretic therapy, thiamine balance, and heart failure. Congest Heart Fail. 2007 Jul-Aug. 13(4):244-7.