Encephalopathy Wernicke-Korsakoff

Beri-beri or clinically manifest thiamin deficiency exists in several subforms infantile beri-beri and adult beri-beri. Infantile beri-beri occurs in exclusively breastfed infants of thiamin-deficient mothers. Adults can develop different forms of the disease, depending on their constitution, environmental conditions, the relative contribution of other nutrients to the diet as well as the duration and severity of deficiency. First of all, there is a so called dry or atrophic (paralytic or nervous) form, including peripheral degenerative polyneuropathy, muscle weakness and paralysis. Second, a wet or exudative (cardiac) form exists. In this form, typical symptoms are lung and peripheral oedema as well as ascites. Finally, there is a cerebral form, that can occur as Wernicke encephalopathy or Korsakoff psychosis. Tli is latter form mostly affects chronic alcoholics with severe thiamin deficiency. 

Thiamin has a very low toxicity (oral LD5o of thiaminchloride hydrochloride in mice 3-15 g/kg body weight). The vitamin is used therapeutically to cure polyneuropathy, beri-beii (clinically manifest thiamin deficiency), and Wernicke-Korsakoff Syndrome ( Wernicke encephalopathy and Korsakoff psychosis). In mild polyneuropathy, 10-20 mg/d water-soluble or 5-10 mg/d lipid-soluble thiamin are given orally. In more severe cases, 20-50 mg/d water-soluble or 10-20 mg/d lipid-soluble thiamin are administered orally. Patients suffering from beri-beri or from early stages of Wernicke-Korsakoff Syndrome receive 50-100 mg of thiamin two times a day for several days subcutaneously or intravenously until symptoms are alleviated. Afterwards, the vitamin is administered orally for several weeks. 

Thiamine deficiency results in early decreases in activity of the mitochondrial enzyme a-ketoglutarate dehydrogenase in brain. Wernicke s encephalopathy, also known as the Wernicke-Korsakoff syndrome is a neuropsychiatric disorder characterized by ophthalmoplegia, ataxia and memory loss. Wernicke s encephalopathy is encountered in chronic alcoholism, in patients with HIV-AIDS and in other disorders associated with grossly impaired nutritional status. The condition results from thiamine deficiency. 

A variety of pathological problems involving the CNS have been described in chronic alcoholics, the main ones being Wernicke s encephalopathy and Korsakoff s psychosis Brain damage from chronic ethanol consumption can be especially severe in the elderly and may accelerate aging. 

The spectrum of cognitive deficits associated with chronic alcohol use extends to the extreme of Wernicke s encephalopathy and Korsakoff s psychosis. Wernicke s encephalopathy is an acute neurologic syndrome caused by thiamine deficiency. Symptoms include mental confusion, ophthalmoplegia, and ataxia. Many of these symptoms reverse with administration of thiamine however about 50% of patients are left with some degree of ataxia. Left untreated, Wernicke s encephalopathy can progress to stupor, coma, and death. Approximately 80% to 90% of alcoholics treated for Wernicke s encephalopathy are left with Korsakoff s psychosis, a syndrome of impaired learning and recent memory produced by lesions of the medial dorsal nuclei of the thalamus. 

Thiamin deficiency can result in three distinct syndromes a chronic peripheral neuritis, beriberi, which may or may not be associated with heart failure and edema acute pernicious (fulminating) beriberi (shoshin beriberi), in which heart failure and metabolic abnormalities predominate, with little evidence of peripheral neuritis and Wernicke s encephalopathy with Korsakoff s psychosis, a thiamin-responsive condition associated especially with alcoholism and narcotic abuse. 

Thiamine is used to diminish Wernicke-Korsakoff encephalopathy, which is characterized by confusion, memory loss, and loss of cranial nerve function resulting from chronic alcohol abuse. 

Cirignotta, F., Manconi, M., Mondini, S., Buzzi, G., and Ambrosetto, P. (2000). Wernicke-Korsakoff encephalopathy and polyneuropathy after gastroplasty for morbid obesity. Arch. Neurol. 57 1356-1359. 

Nerve tissue is mainly dependent for ATP production on glucose metabolism via glycolysis to produce acetyl CoA by the PDH reaction for oxidation in Krebs cycle. Since thiamin is essential for PDH activity, thiamin deficiency, which can occur in malnourished alcoholics, results in PDH dysfunction and an energy deficit in nerve tissue. This causes hyperlactataemia and neuropathy, which can progress to Wernicke s encephalopathy and Korsakoff s psychosis (Chapter 53). 

Thiamine deficiency can result in beriberi, Wernicke s encephalopathy or Korsakoff syndrome. 

Thiamine deficiency is the established cause of Wernicke s encephalopathy (WE), an acute neurological disorder constituting one of two components of Wernicke-Korsakoff syndrome (WKS), a neuropsychiatric disorder characterized by ophthalmoplegia, gait ataxia and confusion/memory loss. Up to 80-90% of these patients with WE go on to develop the more debilitating chronic amnesic state, referred to as Korsakoff s psychosis. 

Wernicke s encephalopathy with KorsakofFs psychosis, a thiamin-responsive condition associated especially with alcohol and narcotic abuse. 

While peripheral neuritis and acute cardiac beriberi with lactic acidosis occur in thiamin deficiency associated with alcohol abuse, the more usual presentation is as the Wernicke—Korsakoff syndrome, due to central nervous system lesions. Initially there is a confused state, Korsakoff s psychosis, which is characterized by confabulation and loss of recent memory, although memory for past events may be unimpaired. Later, clear neurological signs develop — Wernicke s encephalopathy. This is characterized by nystagmus and extraocular palsy. Post-mortem examination shows characteristic brain lesions. 

Wernicke s encephalopathy A neurological condition characterised by visual disturbances, motor dysfunction and confusion which, like Korsakoff s syndrome, is commonly associated with long-term alcohol misuse. 

Inadequate nutrition and conditions which are complicated by malabsorption may lead to thiamine deficiency. Beriberi, a diet-deficiency disease, is especially prevalent in those parts of the East where the diet consists mainly of polished rice. The disease is characterized by neuritis but may also lead to serious heart failure. Recovery is prompt when adequate amounts of vitamin B1 are restored to the diet. Severe deficiency as can occur in alcoholics may lead to Wernicke s encephalopathy, often accompanied by Korsakoff s syndrome. Care should be taken with intravenous substitution with thiamine in these cases to prevent serious complications like vascular collapse with hypotension, respiratory distress or an-gioedema. 

It is indicated in wet beriberi, dry beriberi, Wernicke s encephalopathy, prophylaxis of thiamine deficiency, hyperemesis gravidarum, Korsakoff s syndrome, chronic alcoholics, multiple neuritis, toxic and confusional states, delirium tremens and anorexia nervosa. 

The Wernicke-Korsakofi syndrome consists of both an acute (i.e., Wernicke s encephalopathy) and a chronic phase (i.e., Korsakoff s psychosis). The acute encephalopathy may be precipitated or worsened by carbohydrates (including intravenous glucose) unless thiamine is also replenished before or during administration. Wernicke s encephalopathy may first be manifested by the following ... 

Homewood J and Bond NW (1999) Thiamin deficiency and Korsakoff s syndrome failure to find memory impairments following nonalcoholic Wernicke s encephalopathy. Alcohol 19, 75-84. 

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