What is the optimum thiamine dose to treat or prevent Wernicke's encephalopathy or Wernicke-Korsakoff syndrome? Results of a randomized controlled trial.

BACKGROUND: The primary cause of Wernicke-Korsakoff syndrome (WKS) is thiamine deficiency, and more than 90% of cases are reported in alcohol-dependent patients. While observational studies show parenteral thiamine administration drastically reduced WKS-related mortality, relevant treatment trials have never been conducted to determine the optimum thiamine dose. METHODS: Two double-blind, parallel groups, randomized controlled trials (RCTs) were conducted to determine the optimal thiamine dose required for (1) the prevention of Wernicke's encephalopathy (WE), the acute phase of WKS, in asymptomatic but "at-risk" alcohol misuse patients (Study 1) and (2) the treatment of WE in symptomatic alcohol misuse patients (Study 2). Each study had a dosage regimen comprising three parenteral thiamine doses that were allocated at a ratio of 1:1:1. Study 1: Asymptomatic At-Risk patients (N = 393) received either 100 mg daily, 100 mg thrice daily, or 300 mg thrice daily, for 3 days. Study 2: Symptomatic patients (N = 127) received either 100 mg thrice daily, 300 mg thrice daily, or 500 mg thrice daily, for 5 days. Cognitive function was the primary outcome, assessed using the Rowland Universal Dementia Assessment Scale, two Cogstate subtests, and an adapted Story Memory Recall test. Secondary analyses examined differences in neurological function (ataxia, oculomotor abnormalities, and confusion) at follow-up. RESULTS: No significant differences were observed between any of the dosage conditions for either Study 1 or Study 2 on cognition or neurological functioning. This real-world study found that having a clinically unwell target population with high comorbidity and multiple presentations, coupled with challenges in cross-cultural assessment is likely to complicate RCT findings. CONCLUSIONS: The results of this study showed no clear benefit of high dose thiamine over intermediate or lower doses of thiamine, over the time intervals examined, for the treatment and prevention of cognitive and neurological abnormalities related to WKS. Several study limitations temper the interpretation of these findings. Nevertheless, the absence of conclusive evidence for the superiority of high-dose thiamine supports a recommendation for patient-specific treatment, while ensuring that the potential impact of other biochemical factors (e.g., magnesium and other B vitamin deficiencies) are considered and corrected if necessary.

[The 473rd case: renal failure, abdominal pain, and mental abnormality].

A 43-year-old male presented with elevated serum creatinine for 4 years and developed abdominal pain for 3 days. He started peritoneal dialysis 2 months ago. Dialysis-related peritonitis was ruled out and acute gastroenteritis was diagnosed. The patient was administrated with ertapenem 500 mg/d. An acute mental abnormality developed 3 days later. After excluded organic encephalopathy, ertapenem was discontinued for the suspicion of antibiotic-related encephalopathy. The frequency of peritoneal dialysis was increased to accelerate the clearance of antibiotics. However, the metal abnormality became even more severe. Then a diagnosis of Wernick-Korsakoff syndrome was considered. After the administration of high dose vitamin B(1), the mental disorder dramatically relieved. Vitamin B(1) 30 mg/d is maintained during peritoneal dialysis and the mental disorder does not relapse.

Review of thiamine deficiency disorders: Wernicke encephalopathy and Korsakoff psychosis.

Wernicke encephalopathy (WE) and Korsakoff psychosis (KP), together termed Wernicke-Korsakoff syndrome (WKS), are distinct yet overlapping neuropsychiatric disorders associated with thiamine deficiency. Thiamine pyrophosphate, the biologically active form of thiamine, is essential for multiple biochemical pathways involved in carbohydrate utilization. Both genetic susceptibilities and acquired deficiencies as a result of alcoholic and non-alcoholic factors are associated with thiamine deficiency or its impaired utilization. WKS is underdiagnosed because of the inconsistent clinical presentation and overlapping of symptoms with other neurological conditions. The identification and individualized treatment of WE based on the etiology is vital to prevent the development of the amnestic state associated with KP in genetically predisposed individuals. Through this review, we bring together the existing data from animal and human models to expound the etiopathogenesis, diagnosis, and therapeutic interventions for WE and KP.

Thiamine (vitamin B1) deficiency and associated brain damage is still common throughout the world and prevention is simple and safe!

Many different population groups throughout the world have thiamine deficiency and are at risk of developing severe neurological and cardiac disorders. Alcoholics are most at risk but other important clinical groups should be monitored carefully. The most severe, potentially fatal disease caused by thiamine deficiency is the neurological disorder Wernicke-Korsakoff syndrome. This can be difficult to diagnose and many cases remain undiagnosed. Treatment with thiamine generally results in a dramatic clinical improvement. Thiamine supplementation of stable food products like flour is an effective, simple and safe public health measure that can improve the thiamine status of all population groups.

[Beriberi after bariatric surgery]. / Beriberi na bariatrische chirurgie.

UNLABELLED: Bariatric surgery is in general the only effective treatment for morbid obesity. Bariatric surgery is frequently associated with vitamin and mineral deficiencies which may lead to neurological and other symptoms. We describe a case of severe vitamin B1 (thiamine) deficiency. CASE DESCRIPTION: A 49-year-old man visited the emergency department with acute confusion, muscle weakness in arms and legs and visual impairment after a period of dysphagia and recurrent vomiting. Four months earlier, he had had bariatric gastric sleeve surgery for morbid obesity. Laboratory tests demonstrated that he had vitamin B1 deficiency, in view of which the diagnosis of beriberi and Wernicke encephalopathy was made. Despite normalisation of the vitamin B1 concentration following intravenous supplementation, the muscle strength hardly recovered and the patient developed Korsakov syndrome. CONCLUSION: For this deficiency there is no other treatment than vitamin B1 supplementation. Timely recognition of vitamin deficiencies and pro-active supplementation are essential in order to prevent serious complications following bariatric surgery.

Prevention and treatment of Wernicke-Korsakoff syndrome.

Wernicke's encephalopathy (WE) is both common and associated with high morbidity and mortality and yet there is evidence that appropriate and effective prophylaxis and treatment are often not given. Effective treatment and prophylaxis may only be achieved by use of parenteral vitamin supplements, since oral supplements are not absorbed in significant amounts. Although there are rare anaphylactoid reactions associated with the use of parenteral thiamine preparations, the risks and consequences of inadequate prophylaxis and treatment, in appropriately targeted groups of patients, are far greater. It is therefore proposed that all in-patient alcohol withdrawal should be covered by prophylactic use of parenteral thiamine, that there should be a low threshold for making a presumptive diagnosis of WE, and that there is a need for guidelines to assist physicians in appropriate management of this common clinical problem.

Mechanisms of vitamin deficiency in chronic alcohol misusers and the development of the Wernicke-Korsakoff syndrome.

The classic signs of vitamin deficiency only occur in states of extreme depletion and are unreliable indicators for early treatment or prophylaxis of alcoholic patients at risk. Post-mortem findings demonstrate that thiamine (vitamin B1) deficiency sufficient to cause irreversible brain damage is not diagnosed ante mortem in 80-90% of these patients. The causes of vitamin deficiency are reviewed with special attention to the inhibition of oral thiamine hydrochloride absorption in man caused by malnutrition present in alcoholic patients or by the direct effects of ethanol on intestinal transport. As the condition of the patient misusing alcohol progresses, damage to brain, liver, gastrointestinal tract, and pancreas continue (with other factors discussed) to further compromise the patient. Decreased intake, malabsorption, reduced storage, and impaired utilization further reduce the chances of unaided recovery. Failure of large oral doses of thiamine hydrochloride to provide an effective treatment for Wernicke's encephalopathy emphasizes the need for adequate and rapid replacement of depleted brain thiamine levels by repeated parenteral therapy in adequate doses.

[Therapeutic experiences with alcohol-related Korsakoff syndrome]. / Therapeutische Erfahrungen beim alkoholbedingten Korsakow-Syndrom.

Korsakoff's psychosis (Wernicke-Korsakoff-Syndrome) following severe, long-term alcoholism is considered to be widely resistant to treatment. We report two cases with beneficial effects of treatment by a combination of clonidine and fluvoxamine.