Nervous system thiamin deficiency affecting

Thiamin Deficiency Affects the Nervous System Heart... 

Historically, thiamin deficiency affecting the peripheral nervous system (beriberi) was a major public health problem in South-East Asia following the introduction of the steam-powered mill that made highly polished (thiamin-depleted) rice widely available. There are still sporadic outbreaks of deficiency among people whose diet is rich in carbohydrate and poor in thiamin. More commonly, thiamin deficiency affecting the heart and central nervous system is a problem in people with an excessive consumption of alcohol - to the extent that there was it was seriously suggested in Australia at one time that thiamin should be added to beer. 

Although now largely eradicated, beriberi remains a problem in some parts of the world among people whose diet is especially high in carbohydrates. A different condition, affecting the central rather than peripheral nervous system, the Wemicke-Korsakoff syndrome, is also due to thiamin deficiency. It occurs in developed countries, especially among alcoholics and narcotic addicts. 

Thiamin-Responsive Pyruvate Dehydrogenase Deficiency Genetic deficiency of pyruvate dehydrogenase Ela (which is on the X chromosome) leads to potentially fatal lactic acidosis, with psychomotor retardation, central nervous system damage, atrophy of muscle fibers and ataxia, and developmental delay. At least some cases respond to the administration of high doses (20 to 3,000 mg per day) of thiamin. In those cases where the enzyme has been studied, there is a considerable increase in the of the enzyme for thiamin diphosphate. Female carriers of this X-linked disease are affected to a variable extent, depending on the X-chromosome inactivation pattern in different tissues (Robinson et al., 1996). 

Severe thiamine deficiency is called beriberi. The major organs affected are the nervous system (in dry beriberi), the cardiova.scuIar system (in wet beriberi), and the gastrointestinal tract. Thiamine administration reverses the gasUointesli-nal and cardiovascular symptoms. The neurological danugc may be permanent, however, if the deficiency has been severe or of long duration. Thiamine hydrochloride is indicated... 

Early signs of thiamin deficiency in most species include loss of appetite, emaciation, muscular weakness and a progressive dysfunction of the nervous system. In pigs, appetite and growth are adversely affected and the animals may vomit and have respiratory troubles. 

Wernicke-Korsakoff syndrome results from alcohol-induced thiamin deficiency. It affects the central nervous system. The patients suffer from irreversible memory loss as a result of severe mesencephalic lesions. 

Beriberi is a nervous system disorder caused by a thiamine deficiency. Wet beriberi primarily affects the cardiovascular system, while dry beriberi affects the nervous system. Wet beriberi can also be characterized by vasodilation, peripheral oedema, shortness of breath and swelling of the lower legs. Dry beriberi causes partial paralysis resulting from damaged peripheral nerves and can be characterized by difficulty walking, loss of muscle function, mental confusion and involuntary eye movements. 

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