Beriberi is a disease caused by insufficient inclusion of thiamine (vitamin B1) in metabolic processes. Most often occurs when there is a deficiency in the intake of B1 with food, a violation of absorption in the gastrointestinal tract. Clinically, beriberi is manifested by bilateral polyneuropathy, cachexia, and cardiovascular disorders. It is possible to develop acute encephalopathy with a twilight state of consciousness. The basis of beriberi diagnostics is a blood test for B1 content. Treatment is carried out with increased doses of thiamine, relief of cardiac and digestive disorders is carried out, general restorative therapy is prescribed.
Beriberi translates from Sinhala as “great weakness”. The disease became widespread at the end of the XIX century in countries where rice was the main food. The incidence was epidemic in nature, the cause was unknown. In 1897 , the Dutch doctor H. Eikman, who observed similar symptoms in domestic birds, found that the pathology develops when feeding birds with purified rice and regresses when black unrefined grain is introduced into the diet. The researcher made an assumption about the presence of a substance vital for the body in rice bran. In 1911, the Polish scientist K. Funk managed to isolate vitamin B1 in crystalline form. Since the chemical composition of the vitamin includes an amino group, K. Funk called it thiamine. In the modern world, vitamin deficiency B1 is rare, mainly in developing countries of South America, Africa, and Southeast Asia.
The daily requirement for thiamine is 1.3-2.5 mg in adults, 0.5-1.7 mg in children, depending on age. The need for vitamin decreases in old age, increases with increased physical exertion, in cold climates, with psychoemotional stress, in pregnant and lactating women. Vitamin deficiency B1 is observed with insufficient intake of B1 into the body. The main etiofactors are:
- The absence of B1 in the diet. Monotonous nutrition with thiamine-free products (white rice, white wheat flour bread) leads to chronic vitamin deficiency. The metabolic processes occurring with his participation are disrupted. As a result, beriberi develops.
- Increased spending B1. It is noted with prolonged fever, thyrotoxicosis, excessive physical exertion, chronic stress, in women during pregnancy and lactation. Vitamin deficiency occurs when increased vitamin requirements are not compensated by its increased intake with food.
- Maldigestion syndrome. Chronic pancreatitis, enzyme insufficiency of the pancreas, decreased secretion of bile acids in hepatic insufficiency cause a deficiency of enzymes necessary for the breakdown of food. With gastroduodenitis, gastric ulcer and duodenal ulcer, there is a decrease in the activity of digestive enzymes. Insufficient cleavage of products in the gastrointestinal tract leads to a reduced intake of B1.
- Malabsorption syndrome. Prolonged enteritis, Whipple’s disease, chronic enterocolitis, Crohn’s disease, enteropathy, dysbiosis are accompanied by a violation of adequate absorption of nutrients in the intestine. The result is insufficient assimilation, excretion of most of the thiamine and other nutrients with feces.
- Metabolic disorders. There may be a lack of transport proteins, a violation of the release of B1 after transportation, its improper interaction with cellular receptors. These deviations make it difficult to transfer vitamin to tissues, its inclusion in biochemical reactions. Vitamin deficiency develops against the background of sufficient B1 content in the diet.
- Alcoholism. Alcohol dependence is characterized by irregular diet, anorexia during binge drinking, intestinal absorption disorder, liver damage. These factors lead to a critical decrease in the intake of B1. Beriberi manifests in the third stage of alcoholism.
Thiamine plays an important role in carbohydrate and fat metabolism. Its insufficiency provokes biochemical shifts with the accumulation of pyruvic acid in tissues. Excess pyruvate causes damage and demyelination of nerve fibers. In the gastrointestinal tract, the production of gastric juice decreases, which leads to loss of appetite, digestive disorders. Thiamine is necessary for the synthesis of thiamine diphosphate involved in energetic biochemical reactions. Insufficient energy supply of the myocardium causes a decrease in the strength of heart contractions, pronounced weakness of skeletal muscles. In the central nervous system, thiamine phosphate is involved in ensuring the full functioning of the mechanism of synaptic transmission of nerve impulses.
Macroscopically, there is an increase and swelling of internal organs. The heart expands mainly in the right parts, myocardial dystrophy occurs. The adrenal glands, thyroid gland, and pituitary gland are enlarged. The breakdown of the myelin sheath of nerve trunks, the destruction of axons is observed in the nervous tissue.
The occurrence of beriberi can be caused by external factors (low vitamin content in the diet, increased need) and internal disorders that lead to insufficient participation of thiamine in the necessary biochemical reactions. Taking into account the etiology , two main forms of the disease are distinguished:
- Primary. It is directly related to the insufficient intake of B1 with food. Occurs at any age with a change in the nature of nutrition, an increase in the level of stress (physical, mental). Seasonal nature of symptoms, long-term latent course is possible.
- Secondary. Caused by various diseases. It develops as a result of dysfunction of the digestive system, disruption of the transport of B1 into the tissues of the body, metabolic changes. Secondary vitamin deficiency is possible with intestinal pathology, severe liver damage, alcoholism, diabetes mellitus, hyperthyroidism.
The clinical classification of beriberi is based on the variability of the symptoms of the disease. In accordance with the predominance of lesions of the central nervous system, cardiovascular system, peripheral nerve trunks, the following forms are distinguished:
- Cerebral (Gaye-Wernicke syndrome) — occurs with a predominant lesion of brain tissues by the type of acute encephalopathy. Usually manifests on the basis of alcoholism.
- Cardiovascular (“wet” form) — myocardial damage with the development of myocardiodystrophy comes to the fore. Edema of the extremities is characteristic. Possible heart failure.
- Peripheral (“dry” form) — accompanied by multiple lesions of peripheral nerves. Polyneuropathy is characterized by symmetry, more pronounced in the lower extremities. With beriberi of this form, pronounced cachexia is observed.
In the phase of moderate hypovitaminosis, general malaise, headaches, decreased appetite, sleep disorders (difficulty falling asleep, insomnia, night awakenings) are noted. There are cardiovascular changes: patients complain of palpitations, interruptions of cardiac activity. Shortness of breath when walking is characteristic. As vitamin deficiency progresses, weakness in the legs and soreness of the calf muscles appear. The further course depends on the clinical form.
The peripheral form proceeds with pronounced polyneuritis. Initially, paresthesia and weakness develop in the distal parts of the lower extremities, there is a compaction of the calf muscles. Patients describe their sensations in the legs as “wadding”, a constant feeling of wearing stockings. Subsequently, paresis joins sensitive disorders. The first to be affected are the extensor muscles of the foot. A typical “sheep” gait is formed with support on the toes and the lateral edge of the foot without load on the heel.
Similar motor and sensory disturbances may occur in the upper extremities. In such cases, the patient experiences difficulties when performing small work with his hands (lacing shoes, buttoning buttons), in severe cases he cannot hold objects, including cutlery. A distinctive feature of the “dry” beriberi variant is pronounced cachexia. The body weight of patients is so reduced that the skin literally wraps around the bones.
Vitamin deficiency of the “wet” form is characterized by increasing edema, arterial hypertension, tachycardia. The right parts of the heart expand, shortness of breath appears, accompanying any movements of the patient. Cerebral beriberi is characterized by acute manifestation of symptoms. Confusion of consciousness, disorientation in the environment, agnosia, apraxia are revealed. The patient does not understand what is happening, cannot concentrate attention, thinking is incoherent. There is a mixed ataxia, including vestibular, sensitive and cerebellar components. Nystagmus, ptosis, oculomotor disorders are determined: strabismus, complete ophthalmoplegia.
In infants who feed on the milk of sick beriberi mothers, beriberi debuts gastrointestinal symptoms. There is anorexia (rejection of the breast), bloating, intestinal colic. Due to abdominal pain, the child assumes a bent antalgic position. Cardiac and vascular disorders are added. Aphonia is characteristic — absence of voice, loss of tendon reflexes, the appearance of meningeal symptoms. Symptoms progress within 1-2 days with the outcome in sopor and coma.
Progressive polyneuropathy with an increase in muscle weakness leads to the loss of the ability to move independently, self-service. Cachexia is accompanied by a decrease in immunity, which is a favorable background for the occurrence of intercurrent infectious diseases, the spread of pathogens throughout the body with the development of sepsis. Cardiovascular disorders with progressive right ventricular dysfunction, myocardiodystrophy cause the progression of heart failure. Death in beriberi occurs due to severe infections, cachexia, decompensated heart failure.
It is necessary to carefully collect anamnesis with an inquiry about the nature of nutrition, concomitant diseases, previous operations on the gastrointestinal tract. To verify the diagnosis of beriberi, a study of the level of thiamine in the blood is carried out. In order to find the cause of vitamin deficiency, assess the degree of damage to the heart, nervous system, the following diagnostic measures are recommended:
- Gastroenterological examination: coprogram, gastroduodenoscopy, gastric juice examination, contrast radiography of the intestine. The methods allow us to identify disorders of digestive, suction function, morphological abnormalities that caused beriberi.
- Neurological examination. Determines the peripheral nature of paresis, inhibition of tendon reflexes of the extremities, distal hyperesthesia, mixed ataxia. In the cerebral form, oculomotor disorders, disorders of consciousness are detected.
- Cardiological examination. It is carried out using ECG, echocardiography. Confirms rhythm disturbances, tachycardia, dilation of the right atrium and ventricle. Makes it possible to assess the degree of heart failure.
Vitamin deficiency B1 with polyneuritis should be differentiated from diabetic polyneuropathy, autoimmune lesions, cardiovascular form – from heart diseases (myocarditis, toxic myocardiodystrophy, infectious endocarditis). The cerebral form requires differentiation with psychiatric pathology, tick-borne encephalitis, brain tumor.
Therapy is aimed at the earliest possible compensation of the deficiency of B1. In parallel, correction of causal pathology, relief of cardiovascular disorders, restorative measures are carried out. If necessary, a neurologist, cardiologist, gastroenterologist are involved in the treatment. The main components are:
- Thiamine therapy. Treatment starts with parenteral administration of solution B1. After achieving a marked improvement in the condition, they switch to taking the drug orally for 2-3 months. A diet with a high content of vitamins and proteins is recommended.
- Treatment of gastrointestinal pathology. Performed by a gastroenterologist. According to the indications, antibacterial, enzyme, hepatoprotective therapy, correction of gastric secretion, normalization of intestinal microflora is carried out.
- Symptomatic therapy. With polyneuritis, intramuscular administration of vitamin B6, nicotinic acid, riboflavin gives a good effect. Neostigmine is used to restore neuromuscular transmission. With “wet” beriberi, it is necessary to prescribe diuretic pharmaceuticals, cardiac glycosides.
- Restorative treatment. Promotes the speedy recovery of the body, increases immunity. Massage sessions, physical therapy, general ultraviolet irradiation are used. Coniferous baths have a beneficial effect. Comprehensive rehabilitation under the guidance of a narcologist is recommended for alcohol-dependent patients.
Prognosis and prevention
Timely treatment is the key to a favorable outcome of beriberi. In advanced cases with the development of severe cachexia, heart failure, and the addition of intercurrent infections, a fatal outcome is possible. Vitamin B1-rich nutrition allows you to prevent vitamin deficiency. Vegetable products are saturated with this vitamin: cabbage, asparagus, carrots, nuts, legumes, coarse bread, unpeeled rice, raisins, oatmeal. With increased need, additional intake of multivitamin complexes with thiamine is possible. Timely therapy of gastroenterological diseases, treatment of alcoholism is of preventive importance.