Thiamin nystagmus

Wernicke s syndrome is a serious consequence of alcoholism and thiamine (vitamin Bx) deficiency. Certain characteristic signs of this disease, notably ophtalmoplegia, nystagmus, and ataxia, respond rapidly to the administration of thiamine but to no other-vitamin. Wernicke s syndrome may be accompanied by an acute global confusional state that may also respond to thiamine. Left untreated, Wernicke s syndrome frequently leads to a chronic disorder in which learning and memory are strongly impaired. This so-called Korsakoff s psychosis is characterized by confabulation, and is less likely to be reversible once established. 

In chronic alcoholics, thiamine deficiency may manifest as Wernicke-Korsakoff syndrome, which Is characterized by a constellation of unusual neurologic disturbances. Including amnesia, apathy, and nystagmus. 

Wernicke-Korsakoff syndrome, stemming from thiamine deficiency and characterized by confusion, ataxia, and ocular abnormalities (nystagmus and lateral rectus muscle palsy). 

Thiamin deficiency in alcoholics may be caused by decreased intake, reduced absorption, and impaired ability to use ihe absorbed vitamin. The ataxia and ocular symptoms associated with the deficiency in alcoholics are known as Wernicke s disease. Vitamin therapy can provide relief from nystagmus within a few hours of treatment and from ataxia within several weeks. The treatment of alcoholics also involves the supply of other nutrients lacking in the diet, such as folate, vitamin B12, and protein. Left imtreated, patients suffering from Wernicke s disease continue to develop Korsakoff s psychosis, which involves amnesia and confusion. Only about 25% of patients with Korsakoff s psychosis can be completely cured by thiamin treatment, which must be continued for a few weeks or months. The two conditions just described constitute the Wemicke-Korsakoff syndrome. The S5mdrome was named after two researchers. Karl Wernicke, a German, noted impaired or paralyzed eye movements and imstable walking and disorientation in his patients, most of whom were alcoholics. Polyneuropathy, a weakness of the hands, calves, and feet, was also noted. Sergei Korsakoff, a Russian, observed amnesia and confusion and an inability to learn new names or tasks in alcoholic patients. 

Thiamine (Bi) Paresthesias, nystagmus, impaired Red blood transketolase Increased need with hemodialysis. 

The thiamin (vitamin BO molecule contains a quaternary ammonium functionality and is thus badly absorbed. In healthy patients the necessary amounts of thiamin are absorbed thanks to an active transport mechanism coupled with ATP consumption. However, these mechanisms are rapidly saturable and easily inhibited, especially by chronic alcoholic consumption. As a consequence of the insufficient absorption of thiamin, alcoholism often entails Wernicke s encephalopathy (neurological disorders such as nystagmus, ocular motor nerve paralysis, memory losses, disorientation). The design of lipophilic prodrugs, able to reach the CNS by passive diffusion was then undertaken compounds like (a) and (b) result from lipophilic disulphide derivation of the open ring thiolate anion corresponding to thiamine (Fig. 33.39). 

Kesler, A., Stolovitch, C., Hoffmann, C., Avni, 1., and Morad, Y. (2005). Acute ophthalmoplegia and nystagmus in infants fed a thiamine-deficient formula an epidemic of Wernicke encephalopathy. J. Neuroophthalmol. 25 169-172. 

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. 

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