(Vitamin B1; thiamine)
Thiamine deficiency, beriberi causes, most often occurs in people who, as is common in developing countries, feed on white rice or intensively processed carbohydrates. Also alcoholics are affected. Symptoms diffuse polyneuropathy, rhythmogene heart failure and the Wernicke-Korsakoff syndrome apply. Thiamine is administered for diagnosis and for the treatment of the defect.
Thiamine is abundant in the diet (see table: sources, functions and effects of vitamins). The vitamin plays a role in the metabolism of carbohydrates, fats, amino acids, glucose and alcohol. It is non-toxic.
(See also overview of vitamins.) Thiamine is abundant in the diet (see table: sources, functions and effects of vitamins). The vitamin plays a role in the metabolism of carbohydrates, fats, amino acids, glucose and alcohol. It is non-toxic. Thiamine deficiency causes a thiamine deficiency, beriberi, occurs most often in people who, as is common in developing countries, feed on white rice or intensively processed carbohydrates. Also alcoholics are affected. Symptoms diffuse polyneuropathy, rhythmogene heart failure and the Wernicke-Korsakoff syndrome apply. Thiamine is administered for diagnosis and for the treatment of the defect. A primary etiology thiamine deficiency caused by inadequate intake of thiamine. It is usually the result of a usual diet in developing countries with intensively processed carbohydrates (eg. As bleached rice, white flour, white sugar). In addition, a shortage develops when more nutrients are absorbed not sufficient, as is the case in young adults with severe anorexia. Thiamine deficiency often occurs along with deficiencies of other B vitamins. A secondary thiamine deficiency is caused by: elevated demand (. Eg with hyperthyroidism, pregnancy and lactation, in intense physical activity, or for fever), limited absorption (for example in persistent diarrhea.), Impaired metabolism (e.g. B. . in hepatic insufficiency). In alcoholics several mechanisms contribute to a thiamine deficiency: reduced feeding, reduced absorption and utilization, increased demand and possibly a Apoenzymdefekt.Pathophysiologie A thiamine deficiency results in the degeneration of peripheral nerves, thalamus, Mamillarkörpern and cerebellum. The cerebral blood flow decreases markedly, vascular resistance increases. Cardiac dilation can occur; Muscle fibers swell, and form fragments vakuolisieren, the interstitial spaces to be extended by fluid. Vasodilation leads to leg and Armödemen. Arteriovenous shunts are increasing. Finally, a rhythmogene heart failure entstehen.Symptome and complaints can The early symptoms are non-specific: fatigue, irritability, poor memory, sleep disturbances, precordial pain, anorexia, and abdominal discomfort. Various forms of beriberi cause different symptoms. Dry beriberi refers to thiamine deficiency caused by disorders of peripheral nervous system. These deficits are bilaterally symmetrical and about and occur in a stocking-glove distribution. The impairments relate primarily to the lower extremities and start with paresthesias of the toes and burning in the feet, which is especially pronounced at night to continue with leg cramps, pain in the legs and plantar dysesthesia. Weakness in the calf muscles, trouble getting up from a squatting position and decreased vibratory sensation in the toes are early symptoms. Muscles are broken down. For prolonged lack the polyneuropathy, that ultimately affects the arms worsens. The Wernicke-Korsakoff syndrome, a combination of pseudo encephalitis Wernicke and Korsakoff’s psychosis, occurs with some alcoholics who do not consume fortified with thiamine food. The pseudo encephalitis Wernicke shows up with psychomotor retardation or apathy, nystagmus, ataxia, ophthalmoplegia, and disturbances of consciousness and untreated, leads to coma and death. You probably caused by a severe acute deficiency, which superimposes a chronic shortage. From Korsakoff’s psychosis sufferers are mentally confused, suffering from dysphonia and confabulate in dim memory for current events. The disease results from a chronic shortage and develops after repeated episodes of encephalitis pseudo Wernicke. Humidity (cardiovascular) disease beriberi called a myocardial by thiamine deficiency. First signs are vasodilation, tachycardia, a high pulse pressure, sweating, warm skin, and lactic acidosis. Later of heart failure, which leads to orthopnea and pulmonary and peripheral edema developed. The vasodilation may progress and cause a shock. Infantile beriberi affects infants up to the third or fourth week of life who are breastfed by mothers with thiamine deficiency. Characteristic of this are sudden heart failure, loss of voice and lack of deep tendon reflexes. Since thiamine is required for glucose metabolism, which in Thiaminmangelsymptome affected are acutely or worsen when glucose infusions erhalten.Diagnose Positive response to thiamine The diagnosis of thiamine deficiency is based on a positive response in the treatment of deficiency symptoms with thiamine. Similar bilateral polyneuropathy of the lower extremities, as they arise in diabetes mellitus, alcoholism, vitamin B12Mangel or heavy metal poisoning, however, do not improve under a Thiamintherapie. Individual nerve neuropathies, z. As the sciatica, and multiple Mononeuropathies how the mononeuritis multiplex will not be triggered most likely by a thiamine deficiency. Electrolytes including magnesium should be measured to rule out other causes. To confirm a possible misdiagnosis, the activity of Erythrozytentransketolase and Thiaminausscheidung over 24 h are measured. The diagnosis of cardiovascular beriberi is difficult when additional illnesses with symptoms of heart failure are present. Remedy in this case achieves a therapeutic trial with Thiamin.Therapie Thiaminergänzung; the size of the dose depends on the clinical manifestations, regardless of the symptoms is to clarify whether thiamine is consumed in the diet is sufficient. Since the i.v. Administration of glucose exacerbated a thiamine deficiency, alcoholics and other patients at risk should thiamine 100 mg iv obtained before glucose is infused. Tips and risks alcoholics and other patients at risk should thiamine 100 mg iv obtained before glucose is infused. The dose of thiamine is in mild polyneuropathy: 10-20 mg / day orally for 2 weeks with little pronounced or advanced neuropathy: 20-30 mg / day; continue for several weeks after the symptoms disappear in edema and constipation due to cardiovascular beriberi: 100 mg / day i.v. for several days. Heart failure is also to treat. If a Wernicke-Korsakoff syndrome before, over several days 50-100 mg thiamine i.m. or iv 2 times given daily. It is followed by the application of 10 to 20 mg once a day until the therapy strikes. Anaphylactic reactions to a I.V. Thiamintherapie are rare. The symptoms of ophthalmoplegia may dissolve within a day; a Korsakoff’s psychosis improves within one to three months. Neurological deficits of Wernicke-Korsakoff syndrome and other diseases of thiamine deficiency often disappear not complete. Since thiamine deficiency often occurs with a simultaneous lack of other B vitamins, many water-soluble vitamins are prescribed for several weeks. Alcohol should not be opened. Patients should continue to eat nutritious and up to twice the amount of the reference values ??for nutrient intake aufnehmen.Wichtige points The risk of thiamine deficiency is increased in people who feed on intensively processed carbohydrates such as bleached rice and white flour (as in developing countries common), or alcoholics. The first results can be non-specific; peripheral neurological deficits, rhythmogene heart failure and Wernicke-Korsakoff syndrome (v. a. in alcoholics) may also occur. Diagnosis is based on clinical presentation, including a positive response to treatment with additional thiamine.