The treatment of patients at risk of developing Wernicke's encephalopathy in the community

Improving thiamine prescribing in alcohol use disorder using electronic decision support in a large urban academic medical center: A pre-post intervention study

INTRODUCTION

Thiamine is the only therapy for prevention and treatment of Wernicke Encephalopathy among patients with Alcohol Use Disorder (AUD). Despite this fact, up to 75 % of inpatients with AUD are not prescribed thiamine during hospitalization. Even fewer patients are prescribed high-dose thiamine which many experts recommend should be standard of care. Previous attempts to improve thiamine prescribing for inpatients have had limited success.

METHODS

We conducted an evaluation of thiamine prescribing in the year before and year after an intervention to increase high-dose thiamine prescribing. Pre-post study analysis occurred on two distinct study cohorts: those with alcohol-related diagnoses and those with elevated alcohol levels. The intervention was new electronic health record-based decision support which encouraged high-dose thiamine when any thiamine order was sought. No educational support was provided. The primary outcome was prescription of high-dose thiamine before versus after intervention. Of those with alcohol-related diagnoses, the monthly percentage of thiamine treatment courses including high-dose thiamine were graphed on a control chart.

RESULTS

We examined 5307 admissions with alcohol-related diagnoses (2285 pre- and 3022 post-intervention) and 698 admissions with elevated alcohol levels (319 pre- and 379 post-intervention). Among admissions with alcohol-related diagnoses, the intervention was associated with a higher proportion of admissions receiving high-dose thiamine prescriptions in the first 24 h (4.7 % vs. 1.1 %, adjusted odds ratio 4.50, CI 2.93 to 6.89, p < 0.001). A similar difference in high-dose thiamine was seen post-intervention among admissions with elevated alcohol levels (14.3 % vs. 2.5 %, adjusted odds ratio 6.43, CI 3.05 to 13.53, p < 0.001). The control chart among those with an alcohol-related diagnosis demonstrated special cause variation: the median percentage of thiamine treatment courses including high-dose thiamine improved from 8.2 % to 13.0 %.

CONCLUSIONS

Electronic decision support without educational interventions increased the use of high-dose thiamine among patients with alcohol-related diagnoses and with elevated alcohol levels during hospitalization. This increase occurred immediately in the month after the intervention and was sustained in the year-long study period after.

Wernicke encephalopathy: limitations in a laboratory and radiological diagnosis

Wernicke encephalopathy is an emergent neurological disorder caused by vitamin B1 (thiamine) deficiency. Here, we present a case of Wernicke encephalopathy in a male patient in his 70s with normal serum thiamine levels and MRI findings on admission. He had a history of heavy alcohol consumption and a gradual decrease in food intake. On arrival at the hospital, his consciousness was impaired which persisted even after glucose replacement. Moreover, horizontal nystagmus and cerebellar ataxia were observed. Head CT scan and MRI revealed no abnormal findings. Further, his serum thiamine level was within the normal range. The patient was clinically diagnosed with Wernicke encephalopathy, and high-dose thiamine therapy was started. Then, his symptoms improved immediately. Thus, in case of clinical suspicion, treatment for Wernicke encephalopathy must be initiated promptly even in patients with normal serum thiamine levels.

Over a Century of Study and Still Misunderstood: Recognizing the Spectrum of Acute and Chronic Wernicke-Korsakoff Syndrome

The aim of this study was to objectively evaluate the hypothesis that the neuropsychological presentation of Korsakoff's syndrome, the chronic phase of Wernicke-Korsakoff syndrome (WKS), is invariably a severe, selective amnesia against a background of relatively preserved general intellectual functions in a consecutive clinical sample. An analysis of the neuropsychological profiles of nine cases with a recorded history of WKS was undertaken. All cases were adult males (ages 32 to 70) with a long history of alcohol use disorder. Eight cases were chosen retrospectively on a consecutive basis from patient referrals. One additional case was recruited prospectively. Conventional understanding and some current opinion of Korsakoff's syndrome predicts anterograde memory to be consistently more impaired than other cognitive abilities, but this was not found in this case series. The Mean Wechsler Delayed Memory Index was not significantly different from the Wechsler Full-Scale IQ (FSIQ), p = 0.130. Regression of Delayed Memory on FSIQ produced a non-significant intercept, p = 0.213. The 'hallmark' criterion of anterograde memory score at least 20 points less than intelligence score was observed in four of eight cases with available data, equating to a 'sensitivity' of 50%. Three of eight cases with available data had an FSIQ less than the memory score. Contrary to a common view, general intellectual function was not consistently preserved in Korsakoff's syndrome relative to memory function. This study illustrates one of the specific merits of case series, namely, to critique an established view. Clinicians and researchers should expand their diagnostic criteria for Korsakoff's syndrome to include more variable cognitive phenotypes, including a potentially reversible dementia-like impairment of variable severity, and focus on potential treatment opportunities.

Neuropsychiatric and Neuropsychological Aspects of Alcohol-Related Cognitive Disorders: An In-Depth Review of Wernicke's Encephalopathy and Korsakoff's Syndrome

Alcohol-related cognitive disorders have long been an area of study, yet they continue to pose challenges in the diagnosis, treatment, and understanding of underlying neuropsychiatric mechanisms. The present article offers a comprehensive review of Wernicke's Encephalopathy and Korsakoff's Syndrome, two conditions often seen on a continuum of alcohol-related brain damage. Drawing on current medical literature, neuroimaging studies, and clinical case reports, we explore the neuropsychiatric and neuropsychological profiles, symptomatology, and differential diagnoses of these disorders. We delve into the biochemical pathways implicated in the development of WE and KS, notably thiamine deficiency and its impact on neurotransmitter systems and neural networks. The article also addresses the challenges in early diagnosis, often complicated by non-specific symptoms and co-occurring psychiatric conditions. Furthermore, we review the current state of treatment protocols, including pharmacological and non-pharmacological interventions. Finally, the article highlights gaps in current knowledge and suggests directions for future research to improve diagnosis, treatment, and patient outcomes. Understanding the nuanced interplay between the neuropsychiatric and neuropsychological aspects of WE and KS is crucial for both clinicians and researchers alike, in order to provide effective treatment and to advance our understanding of these complex conditions.

Alcohol Withdrawal Is an Oxidative Stress Challenge for the Brain: Does It Pave the Way toward Severe Alcohol-Related Cognitive Impairment?

Alcohol use is a leading cause of mortality, brain morbidity, neurological complications and minor to major neurocognitive disorders. Alcohol-related neurocognitive disorders are consecutive to the direct effect of chronic and excessive alcohol use, but not only. Indeed, patients with severe alcohol use disorders (AUD) associated with pharmacological dependence suffer from repetitive events of alcohol withdrawal (AW). If those AW are not managed by adequate medical and pharmacological treatment, they may evolve into severe AW, or be complicated by epileptic seizure or delirium tremens (DT). In addition, we suggest that AW favors the occurrence of Wernicke's encephalopathy (WE) in patients with known or unknown thiamine depletion. We reviewed the literature on oxidative stress as a core mechanism in brain suffering linked with those conditions: AW, epileptic seizure, DT and WE. Thus, we propose perspectives to further develop research projects aiming at better identifying oxidative stress brain damage related to AW, assessing the effect of repetitive episodes of AW, and their long-term cognitive consequences. This research field should develop neuroprotective strategies during AW itself or during the periwithdrawal period. This could contribute to the prevention of severe alcohol-related brain damage and cognitive impairments.

B1 Vitamin Deficiency After Bariatric Surgery, Prevalence, and Symptoms: a Systematic Review and Meta-analysis

B1 deficiency is a very prevalent complication of bariatric surgery. This study reviews prevalence and symptoms of B1 vitamin deficiency after bariatric surgery. PubMed, Scopus, and Web of Science published were searched up to 10 Feb 2022, with the following keywords: Roux-en-Y gastric bypass, one anastomosis gastric bypass, Omega bypass, Mini bypass, Bariatric surgery OR Bariatric surgery, metabolic surgery, Weight loss surgery, Classic gastric bypass, Loop gastric bypass, Gastric Bypass, thiamine OR thiamin, beriberi, B1. A total of 11 studies examining 1494 patients were included in this meta-analysis. Twenty-seven percent of patients who underwent bariatric surgeries experience vitamin B1 deficiency. Thiamine supplements should be prescribed for the patients for the rest of their lives, and also standard post-surgery follow-ups are necessary in terms of monitoring dietary factors.

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.

Gayet-Wernicke Encephalopathy: An Unusual Complication of Vomiting

Gayet-Wernicke encephalopathy (WE) is a serious and acute disease of the central nervous system caused by thiamine (vitamin B1) deficiency. Multiple etiologies are indicated, although alcohol abuse is the most reported cause. If not treated promptly, WE can lead to serious complications such as Korsakoff's syndrome, coma, or death. This diagnosis should be considered even without a history of alcohol dependence. We describe two cases of non-alcohol related WE complicating vomiting caused by different etiologies. The diagnosis was suspected on clinical presentation and confirmed by brain MRI and effective response to parenteral administration of thiamine.

Wernicke-Korsakoff Syndrome in Hyperemesis Gravidarum: A Case Report and Literature Review

BACKGROUND

Wernicke-Korsakoff syndrome (WKS) is a triad of ophthalmoplegia, ataxia and memory deficits due to thiamine insufficiency resulting from under- or untreated Wernicke's encephalopathy (WE), which may be associated with hyperemesis gravidarum (HEG).

CASE PRESENTATION

We present a case of a 36-year-old Filipino woman in her first trimester with HEG, along with the WKS triad and abnormal hyperintense signals in the bilateral thalami and midbrain, left occipital lobe, periaqueductal gray matter and pontine periventricular areas. Neurologic deficits partially improved but persisted despite intravenous thiamine administration.

EVIDENCE REVIEW

A review of current treatments for WE, and the prevention and neurocognitive recovery of WKS was done. The beneficial effects of thiamine for acute WKS are supported by several case reports and clinical experience. Evidence from one randomized controlled trial wherein thiamine was given in various doses for treating WE or preventing WKS in an alcohol-dependent population is limited by methodological issues. Rehabilitation and pharmacotherapy for neurocognitive recovery seems promising, but they have inadequate evidentiary support. More robust studies on multi-modal strategies are warranted to facilitate the neurocognitive recovery of patients with WKS.

The contribution of mamillary body damage to Wernicke's encephalopathy and Korsakoff's syndrome

Histopathological alterations of the mamillary bodies are the most conspicuous and the most consistent neuropathological features of several disorders that occur after severe thiamine deficiency, such as Wernicke's encephalopathy and Korsakoff's syndrome. Moreover, they are among the few abnormalities that are visible to the naked eye in these disorders. With a lifetime prevalence of approximately 1.3%, Wernicke's encephalopathy is by far the most frequent cause of damage to the mamillary bodies in humans. Still, there is a persisting uncertainty with regard to the development and the clinical consequences of this damage, because it is virtually impossible to study in isolation. As a rule, it always occurs alongside neuropathology in other subcortical gray matter structures, notably the medial thalamus. Converging evidence from other pathologies and animal experiments is needed to assess the clinical impact of mamillary body damage and to determine which functions can be attributed to these structures in healthy subjects. In this chapter, we describe the history and the current state of knowledge with regard to thiamine deficiency disorders and the contribution of mamillary body damage to their clinical presentations.

The Relevance of Thiamine Evaluation in a Practical Setting

Thiamine is a crucial cofactor involved in the maintenance of carbohydrate metabolism and participates in multiple cellular metabolic processes. Although thiamine can be obtained from various food sources, some common food groups are deficient in thiamine, and it can be denatured by high temperature and pH. Additionally, different drugs can alter thiamine metabolism. In addition, the half-life of thiamine in the body is between 1 and 3 weeks. All these factors could provide an explanation for the relatively short period needed to develop thiamine deficiency and observe the consequent clinical symptoms. Thiamine deficiency could lead to neurological and cardiological problems. These clinical conditions could be severe or even fatal. Marginal deficiency too may promote weaker symptoms that might be overlooked. Patients undergoing upper gastrointestinal or pancreatic surgery could have or develop thiamine deficiency for many different reasons. To achieve the best outcome for these patients, we strongly recommend the execution of both an adequate preoperative nutritional assessment, which includes thiamine evaluation, and a close nutritional follow up to avoid a nutrient deficit in the postoperative period.

[Thiamin and alcohol use disorder: A national survey of practice]

OBJECTIVE

The survey aimed to estimate, in the presence of alcohol use disorder, the frequency of systematic prescription of thiamine, the factors associated with it, and those related to the administration (oral, intravenous, intramuscular) when Wernicke's encephalopathy is suspected.

METHODS

A self-questionnaire available on Internet was sent by e-mail to doctors and nurses taking care patients with alcohol use disorder.

RESULTS

In all, 565 professionals responded. The systematic prescription frequency of thiamine was 84.8 %, addiction care centers and medical-psychological centers prescribed it 5 times less than in psychiatric hospitals (OR=0.2 IC [0.1-0.5] P<0.0001), and medicine/surgery/obstetrics (MSO) services 10 times more than psychiatric hospitals (OR=10.7 IC [2.5-45.3] P<0.0001). The prescription decreased with the exercise period, the interns prescribing it 10 times more systematically (OR=10.9 IC [3.6-32.9] P<0.0001). In the presence of symptoms related to Wernicke's encephalopathy, thiamine administration was mainly oral (67.1 %). Intravenous administration was used more by the MSO services (OR=18.3 IC [10.2-32.7] P<0.0001), while the intramuscular injection was used more in psychiatric hospitals (OR=4.6 IC [1.7-11.9] P=0.0353).

CONCLUSION

The prescription of thiamine is rather systematic. In contrast, intravenous administration is underused, in the presence of symptoms related to Wernicke's encephalopathy, in favor of oral administration, and the more specific use of the intramuscular injection in psychiatry.

Neurological, Psychiatric, and Biochemical Aspects of Thiamine Deficiency in Children and Adults

Thiamine (vitamin B1) is an essential nutrient that serves as a cofactor for a number of enzymes, mostly with mitochondrial localization. Some thiamine-dependent enzymes are involved in energy metabolism and biosynthesis of nucleic acids whereas others are part of the antioxidant machinery. The brain is highly vulnerable to thiamine deficiency due to its heavy reliance on mitochondrial ATP production. This is more evident during rapid growth (i.e., perinatal periods and children) in which thiamine deficiency is commonly associated with either malnutrition or genetic defects. Thiamine deficiency contributes to a number of conditions spanning from mild neurological and psychiatric symptoms (confusion, reduced memory, and sleep disturbances) to severe encephalopathy, ataxia, congestive heart failure, muscle atrophy, and even death. This review discusses the current knowledge on thiamine deficiency and associated morbidity of neurological and psychiatric disorders, with special emphasis on the pediatric population, as well as the putative beneficial effect of thiamine supplementation in autism spectrum disorder (ASD) and other neurological conditions.

Investigating the management of alcohol-related presentations in an Australian teaching hospital

INTRODUCTION AND AIMS

Alcohol-related morbidity is estimated to range from 10-38% of the presentations to hospital emergency departments. This study aims to investigate the actual management process for alcohol-related presentations in a teaching hospital in Australia.

DESIGN AND METHODS

Retrospective audit was conducted on the electronic medical records of 210 presentations with a primary or secondary diagnosis of 'alcohol use disorder' at discharge between November 2016 and February 2017. Six key management steps were investigated: identification of alcohol use disorder, documentation, thiamine, alcohol withdrawal assessment, benzodiazepine for alcohol withdrawal and referral to the drug and alcohol consultation liaison service.

RESULTS

Of all the 210 presentations, 77.1% (162) were identified with alcohol use disorder in the initial assessments; 64.3% (135) were documented with alcohol use history, 49.5% (104) were prescribed with thiamine, 48.1% (101) were assessed with the alcohol withdrawal scale, 41% (86) were prescribed with benzodiazepine for alcohol withdrawal and only 38.6% (81) were referred to the drug and alcohol consultation liaison service. Only 8.6% (18) of the initial presentations were directly related to alcohol. These presentations had a higher completion rate in each of the six steps than those (91.4%, 192) not directly related to alcohol. Only 6.2% (13) were formally screened for alcohol use.

DISCUSSION AND CONCLUSIONS

The findings suggest a need to improve the alcohol management practice in the hospital. Routine use of an alcohol screening tool can enable early identification of the alcohol use disorder and to improve the management of this problem in the hospital.

Pharmacy-based intervention in Wernicke's encephalopathy

Aims and method

Clinical audit methodology was used to compare the treatment of alcohol misusers at risk of Wernicke's encephalopathy in an acute medical setting, and to assess the impact of providing information about best practice to prescribing doctors. All patients prescribed thiamine during an admission to an acute hospital trust over a 6-month period were identified, and data about their treatment episode were collected retrospectively. Hospital pharmacists then provided all prescribers with a flowchart summarising current prescribing guidelines, and prescribing patterns were re-audited 6 months later.

Results

Over two audit periods, half of the patients prescribed thiamine whose case notes we examined had symptoms suggestive of Wernicke's encephalopathy, and another 30% were at high risk. Prescribing adhered to hospital guidelines only in 14% of cases, with the pharmacy-led intervention associated with a small but significant increase in the number of patients receiving adequate treatment for Wernicke's encephalopathy.

Clinical implications

Wernicke's encephalopathy is relatively common in alcohol-dependent individuals admitted to hospital, and it is easily and cheaply managed. However, even when potential cases are identified, prescribing guidelines are followed in a minority of cases, even with prompting by a hospital pharmacist. This may be related to the limited research base concerning the optimum dosing schedule of thiamine, or fears about possible anaphylaxis when using parenteral preparations.

Korsakoff's syndrome: a critical review

In this review, we present a survey on Korsakoff's syndrome (KS), a residual syndrome in patients who suffered from a Wernicke encephalopathy (WE) that is predominantly characterized by global amnesia, and in more severe cases also by cognitive and behavioral dysfunction. We describe the history of KS and its definition, its epidemiology, and the lack of consensus criteria for its diagnosis. The cognitive and behavioral symptoms of KS, which include anterograde and retrograde amnesia, executive dysfunction, confabulation, apathy, as well as affective and social-cognitive impairments, are discussed. Moreover, recent insights into the underlying neurocognitive mechanisms of these symptoms are presented. In addition, the evidence so far on the etiology of KS is examined, highlighting the role of thiamine and alcohol and discussing the continuity hypothesis. Furthermore, the neuropathology of KS is reviewed, focusing on abnormalities in the diencephalon, including the mammillary bodies and thalamic nuclei. Pharmacological treatment options and nonpharmacological interventions, such as those based on cognitive rehabilitation, are discussed. Our review shows that thiamine deficiency (TD) is a crucial factor in the etiology of KS. Although alcohol abuse is by far the most important context in which TD occurs, there is no convincing evidence for an essential contribution of ethanol neurotoxicity (EN) to the development of WE or to the progression of WE to KS. Future research on the postmortem histopathological analysis of brain tissues of KS patients is crucial for the advancement of our knowledge of KS, especially for associating its symptoms with lesions in various thalamic nuclei. A necessary requirement for the advancement of studies on KS is the broad acceptance of a comprehensive definition and definite diagnostic criteria. Therefore, in this review, we propose such a definition of KS and draft outlines for prospective diagnostic criteria.

Alcohol-Related Dementia and Neurocognitive Impairment: A Review Study

Context

Alcohol consumption has escalated rapidly in many countries over the past decade. Evidence suggests a correlation between alcohol use and cognitive decline. We have systematically reviewed the concept and controversies, epidemiology, nosology, neuropathology and neurobiology, neuropsychology and management updates of alcohol-related dementia (ARD) in this paper.

Evidence Acquisition

We retrieved papers for this review by searching the PubMed database for terms “alcohol and dementia”, “alcohol and cognitive impairment”, and “alcohol and wernicke-korsakoff” mentioned in the title of the published papers. A total of 131 studies showed up. Appropriate studies were shortlisted and included (n = 72). Cross-references if relevant were considered from the selected studies. Eligible articles were fully read by the authors and the results were compiled.

Results

The prolonged and excessive use of alcohol may lead to structural and functional brain damage, leading to ARD. The cognitive deficits are most frequently observed in domains of visuospatial functions, memory and executive tasks, with a potential of partial recovery if abstinence is maintained. However, there are doubts regarding the etiopathogenesis, nosological status, prevalence and diagnostic criteria for ARD, due to difficulty in assessment and various confounding factors.

Conclusions

With growing cohort of young and middle-aged people, there is a probable risk of upsurge of ARD. Presently, there are dilemmas over the diagnosis of independent ARD. Thus, there is a need to develop evidence-based guidelines for diagnosis and management of ARD through further systematic studies.

Thiamin in Clinical Practice

Thiamin is a water-soluble vitamin also known as vitamin B1. Its biologically active form, thiamin pyrophosphate (TPP), is a cofactor in macronutrient metabolism. In addition to its coenzyme roles, TPP plays a role in nerve structure and function as well as brain metabolism. Signs and symptoms of thiamin deficiency (TD) include lactic acidosis, peripheral neuropathy, ataxia, and ocular changes (eg, nystagmus). More advanced symptoms include confabulation and memory loss and/or psychosis, resulting in Wernicke's encephalopathy and/or Wernicke's Korsakoff syndrome, respectively. The nutrition support clinician should be aware of patients who may be at risk for TD. Risk factors include those patients with malnutrition due to 1 or more nutrition-related etiologies: decreased nutrient intake, increased nutrient losses, or impaired nutrient absorption. Clinical scenarios such as unexplained heart failure or lactic acidosis, renal failure with dialysis, alcoholism, starvation, hyperemesis gravidarum, or bariatric surgery may increase the risk for TD. Patients who are critically ill and require nutrition support may also be at risk for TD, especially those who are given intravenous dextrose void of thiamin repletion. Furthermore, understanding thiamin's role as a potential therapeutic agent for diabetes, some inborn errors of metabolism, and neurodegenerative diseases warrants further research. This tutorial describes the absorption, digestion, and metabolism of thiamin. Issues pertaining to thiamin in clinical practice will be described, and evidence-based practice suggestions for the prevention and treatment of TD will be discussed.

Metabolische Störungen

Im folgenden Kapitel werden die verschiedenen metabolischen Störungen betrachtet. Zunächst wird auf die allgemeinen und spezifischen neurologischen Komplikationen bei Organtransplantation eingegangen. Dann geht es um die metabolischen Enzephalopathien: Störungen der Gehirntätigkeit bei angeborenen und erworbenen Stoffwechselerkrankungen im engeren Sinn, Elektrolytstörungen, Hypovitaminosen, zerebrale Folgen einzelner Organdysfunktionen, zerebrale Hypoxien, Endotheliopathien und Mitochondropathien. Anschließend werden das Alkoholdelir und die Wernicke-Enzephalopathie erörtert. Bei zahlreichen akuten Erkrankungen von Gehirn, Rückenmark und peripherem Nervensystem treten typische Störungen vegetativer Systeme auf, deren Erkennung und Therapie insbesondere bei Intensivpatienten eine vitale Bedeutung haben kann: die autonomen Störungen. Bei der zentralen pontinen Myelinolyse kommt es zu einer akuten, vorwiegend fokal-symmetrischen Demyelinisierung im Hirnparenchym. Auch Basalganglienerkrankungen können intensivmedizinisch relevant werden. Und schließlich wird die akute Stressreaktion betrachtet, die aufgrund der vielfältigen metabolischen und endokrinen Veränderungen bei kritischen Erkrankungen entsteht. Gerade das RCVS als neuere Krankheitsentität und wichtige Differenzialdiagnose zur Vaskulitis des ZNS verdient einen eigenen Platz, in diesem Unterkapitel werden ebenfalls verwandte Syndrome wie die hypertensive Enzephalopathie und das PRES abgehandelt.

Neuropsychological functioning in Wernicke's encephalopathy

CONTEXT

Wernicke's encephalopathy (WE) is caused by thiamine (Vitamin B1) deficiency and most commonly found in chronic alcoholism and malnutrition. Clinically, the key features are mental status disturbances (global confusion), oculomotor abnormalities, and gait disturbances (ataxia). Apart from these clinical features, we can find deficits in neuropsychological functioning in patients with WE, which is more prominent after the improvement in the physical conditions. Neuropsychological functioning includes both basic cognitive processes (i.e., attention-concentration) as well as higher order cognitive processes (i.e., memory, executive functioning, reasoning), which is much vital for the maintenance of quality of life of an individual. However, unfortunately, in most of the cases, neuropsychological functioning is ignored by the clinicians.

MATERIALS AND METHODS

In this study four case reports of WE have been presented. The patients were taken from the outdoor department of Mental Health Institute, S.C.B. Medical College, Cuttack, Odisha. Neuropsychological functioning was measured by administration of PGIBBD and Quality of Life was measured by WHO-QOL BREF Odia Version.

DISCUSSION

As described in the literature, among the three cardinal signs (global confusion, ataxia, and ocular sings), the first two were present in all cases, but nystagmus was present in only two cases. Memory dysfunction was so disabling that the persons were unable to maintain a good Quality of Life and occupational impairment was prominent. There are disturbances in recent, remote memory, immediate recall, delayed recall, and attention and concentration, ultimately creating both physical and mental disability. PGI-BBD findings also suggest the overall impairment in neuropsychological functioning other than memory, that is, executive functioning, visual acuity, and depth perception. Findings of WHO-QOL BREF suggest the impairment of four domains of QOL in all the cases, but the severity level varies from person to person.

CONCLUSION

Like the three cardinal features, neuropsychological dysfunction in WE should be given importance, which is a most vital component for the maintenance of QOL. As a result, the disability produced by this condition can be well managed.

Review article: The nutritional and pharmacological consequences of obesity surgery

BACKGROUND

Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients. Beneficial short-term effects on common comorbidities are practically undisputed, but a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.

AIMS

To assess the prevalence, causes and symptoms of complications after obesity surgery, to elucidate and compare therapy recommendations for macro- and micronutrient deficiencies, and to explore surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.

METHODS

PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition. All studies in English, French or German published January 1980 through March 2014 were included.

RESULTS

Macro- and micronutrient deficiencies are common after obesity surgery. The most critical, depending on surgical technique, are hypoalbuminemia (3-18%) and deficiencies of vitamins B1 (≤49%), B12 (19-35%) and D (25-73%), iron (17-45%) and zinc (12-91%). Many drugs commonly administered to obese patients (e.g. anti-depressants, anti-microbials, metformin) are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.

CONCLUSIONS

Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability. The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential. Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations.

Neurologic complications of bariatric surgery

PURPOSE OF REVIEW

The increasing utilization of bariatric surgery has been accompanied by an increased incidence and awareness of related neurologic complications. The purpose of this review is to provide up-to-date information on the neurologic complications related to bariatric surgery.

RECENT FINDINGS

Neurologic complications related to bariatric surgery are predominantly due to nutrient deficiencies. Common early complications include Wernicke encephalopathy due to thiamine deficiency, and late complications include myelopathy or myeloneuropathy due to vitamin B12 or copper deficiency.

SUMMARY

Early recognition and prompt institution of treatment is essential to prevent long-term disability. Often, life-long supplementation may be required.

Wernicke's Encephalopathy: A Diagnosis to Consider Early in Patients with Learning Difficulties

We report a fatal case of Wernicke's encephalopathy occurring in a patient with learning difficulties. Wernicke's encephalopathy is a condition most commonly associated with alcohol abuse, with a prevalence of 12.5% in patients with a history of alcohol abuse or dependence.1 The diagnosis is rarely considered in non-alcoholic patients. Here, we highlight that severe malnutrition following food refusal and a consequent thiamine deficiency can cause a fatal Wernicke's encephalopathy, where assessment of behavioural changes in our patient was complicated by the presence of her pre-existing learning difficulties. Early consideration of the possibility of Wernicke's encephalopathy permits prompt treatment with vitamin replacement therapy, which is usually well tolerated. This case highlights the need to consider the possibility of thiamine deficiency in any patient where malnutrition has occurred for whatever reason. Furthermore, Wernicke's encephalopathy should be considered in all patients with a reduced level of consciousness where no clear cause can be determined. Anaesthetists and intensivists should retain a high index of suspicion for the existence of thiamine deficiency when approaching patients with complicated medical histories that put them at risk of malnutrition.

Hydrosoluble vitamins

The hydrosoluble vitamins are a group of organic substances that are required by humans in small amounts to prevent disorders of metabolism. Significant progress has been made in our understanding of the biochemical, physiologic and nutritional aspects of the water-soluble vitamins. Deficiency of these particular vitamins, most commonly due to inadequate nutrition, can result in disorders of the nervous system. Many of these disorders have been successfully prevented in developed countries; however, they are still common in developing countries. Of the hydrosoluble vitamins, the nervous system depends the most on vitamins B and C (ascorbic acid) for proper functioning. The B group vitamins include thiamin (vitamin B1), riboflavin (vitamin B2), niacin or niacinamide (vitamin B3), pantothenic acid (vitamin B5), pyridoxine or pyridoxal (vitamin B6) and cobalamin (vitamin B12). Clinical findings depend upon the deficiency of the underlying vitamin; generally, deficiency symptoms are seen from a combination rather than an isolated vitamin deficiency. True hereditary metabolic disorders and serious deficiency-associated diseases are rare and in general limited to particular geographic regions and high-risk groups. Their recognition is truly important as that determines the appropriate therapeutic management. The general availability of vitamins to practically everyone and several national health programs have saved many lives and prevented complications. However, there has been some apprehension for several decades about how harmless generous dosages of these vitamins are. Overt overdosages can cause vitamin toxicity affecting various body systems including the nervous system. Systemically, vitamin toxicity is associated with nonspecific symptoms, such as nausea, vomiting, diarrhea, and skin rash which are common with any acute or chronic vitamin overdose. At a national level, recommended daily allowances for vitamins become policy statements. Nutrition policy has far reaching implications in the food industry, in agriculture, and in food provision programs. Overall, water-soluble vitamins are complex molecular structures and even today, many areas of vitamin biochemistry still need to be explored. Many readers might be of the opinion that the classic forms of nutritional deficiency diseases have faded into the background of interesting history. This has caused their diverse symptoms to be neglected by most modern physicians since vitamin enrichment of many foods automatically erases them from their consideration in differential diagnosis. Vitamin B12 and folic acid deficiencies are discussed in other chapters.

Thiamine for prevention and treatment of Wernicke-Korsakoff Syndrome in people who abuse alcohol

BACKGROUND

Autopsy studies suggest that Wernicke-Korsakoff syndrome (WKS) is not a rare disorder, particularly in individuals who abuse alcohol. Thiamine has been established as the treatment of choice for over 50 years, but uncertainty remains about appropriate dosage and duration. Current practice guidelines are based on case reports and clinical experience. This is an update of a review first published in 2004 and last updated in 2008.

OBJECTIVES

• To assess the efficacy of thiamine in preventing and treating the manifestations of WKS due to excess alcohol consumption. • To determine the optimum form, dose and duration of thiamine treatment for this indication.

SEARCH METHODS

ALOIS, the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 6 September 2012 using the term thiamine OR aneurine. ALOIS contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trial databases and grey literature sources.

SELECTION CRITERIA

Any randomised trials comparing thiamine with alternative interventions or comparing different thiamine regimens (varying in formulation, dose or duration of administration).

DATA COLLECTION AND ANALYSIS

All abstracts were independently inspected by two reviewers (ED and PWB), and relevant articles were retrieved and assessed for methodological quality using criteria provided in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Two studies were identified that met the inclusion criteria, but only one contained sufficient data for quantitative analysis. Ambrose (2001) randomly assigned participants (n = 107) to one of five doses of intramuscular thiamine and measured outcomes after 2 days of treatment. We compared the lowest dose (5 mg/day) with each of the other four doses. A significant difference favoured 200 mg/day compared with the 5-mg/day dose in determining the number of trials needed to meet inclusion criteria on a delayed alternation test (mean difference (MD) -17.90, 95% confidence interval (CI) -35.4 to -0.40, P = 0.04). No significant differences emerged when the other doses were compared with 5 mg/day. The pattern of results did not reflect a simple dose-response relationship. The study had methodological shortcomings in design and in the presentation of results that limited further analysis.

AUTHORS' CONCLUSIONS

Evidence from randomised controlled clinical trials is insufficient to guide clinicians in determining the dose, frequency, route or duration of thiamine treatment for prophylaxis against or treatment of WKS due to alcohol abuse.

Nutritional Deficiencies Associated to Bariatric Surgery

Obesity is an epidemic disease, increasingly addressed through surgical options for weight loss. Benefits of these surgical procedures, such as weight loss and improvement of obesity-related co-morbidities, are well established. However, postoperative complications do occur. Deficiencies in micronutrients, which include water and fat-soluble vitamins and minerals, are common after bariatric surgery. Recognition of the clinical signs and symptoms of micronutrient deficiencies is important to minimize long-term adverse effects.

Alcohol-related dementia: an update of the evidence

The characteristics of dementia relating to excessive alcohol use have received increased research interest in recent times. In this paper, the neuropathology, nosology, epidemiology, clinical features, and neuropsychology of alcohol-related dementia (ARD) and alcohol-induced persisting amnestic syndrome (Wernicke-Korsakoff syndrome, or WKS) are reviewed. Neuropathological and imaging studies suggest that excessive and prolonged use of alcohol may lead to structural and functional damage that is permanent in nature; however, there is debate about the relative contributions of the direct toxic effect of alcohol (neurotoxicity hypothesis), and the impact of thiamine deficiency, to lasting damage. Investigation of alcohol-related cognitive impairment has been further complicated by differing definitions of patterns of alcohol use and associated lifestyle factors related to the abuse of alcohol. Present diagnostic systems identify two main syndromes of alcohol-related cognitive impairment: ARD and WKS. However, 'alcohol-related brain damage' is increasingly used as an umbrella term to encompass the heterogeneity of these disorders. It is unclear what level of drinking may pose a risk for the development of brain damage or, in fact, whether lower levels of alcohol may protect against other forms of dementia. Epidemiological studies suggest that individuals with ARD typically have a younger age of onset than those with other forms of dementia, are more likely to be male, and often are socially isolated. The cognitive profile of ARD appears to involve both cortical and subcortical pathology, and deficits are most frequently observed on tasks of visuospatial function as well as memory and higher-order (executive) tasks. The WKS appears more heterogeneous in nature than originally documented, and deficits on executive tasks commonly are reported in conjunction with characteristic memory deficits. Individuals with alcohol-related disorders have the potential to at least partially recover - both structurally and functionally - if abstinence is maintained. In this review, considerations in a clinical setting and recommendations for diagnosis and management are discussed.

[Clinical Practice Guide for Early Detection, Diagnosis and Treatment of the Acute Intoxication Phase in Patients with Alcohol Abuse or Dependence: Part II: Evaluation and Management of Patients with Acute Alcohol Intoxication]

INTRODUCTION

Worldwide, alcohol is the second most-used psychotropic substance and the third risk factor for early death and disability. Its noxious use is a world public health problem given its personal, labor, family, economic and social impact. The identification of acute alcohol intoxication is extremely important, as well as the alcohol withdrawal syndrome and its complications, such as delirium tremens and Wernicke's encephalopathy in order to grant a timely treatment for those patients. This article introduces the evidence found so as to face and treat these clinic manifestations.

METHODOLOGY

Systematic revision of the evidence available together with an evaluation of pertinent guidelines found in literature so as to decide whether to adopt or adapt the existing recommendation for each question or to develop de novo recommendations. For de novo recommendations as well as those adapted, it was carried out an evidence synthesis, together with evidence tables and formulation of recommendations based on the evidence.

RESULTS

Evidence was found and recommendations were made for the diagnosis and treatment of acute alcohol intoxication, withdrawal syndrome, delirium tremens and Wernicke's encephalopathy.

Nutritional deficiencies after bariatric surgery

Lifestyle intervention programmes often produce insufficient weight loss and poor weight loss maintenance. As a result, an increasing number of patients with obesity and related comorbidities undergo bariatric surgery, which includes approaches such as the adjustable gastric band or the 'divided' Roux-en-Y gastric bypass (RYGB). This Review summarizes the current knowledge on nutrient deficiencies that can develop after bariatric surgery and highlights follow-up and treatment options for bariatric surgery patients who develop a micronutrient deficiency. The major macronutrient deficiency after bariatric surgery is protein malnutrition. Deficiencies in micronutrients, which include trace elements, essential minerals, and water-soluble and fat-soluble vitamins, are common before bariatric surgery and often persist postoperatively, despite universal recommendations on multivitamin and mineral supplements. Other disorders, including small intestinal bacterial overgrowth, can promote micronutrient deficiencies, especially in patients with diabetes mellitus. Recognition of the clinical presentations of micronutrient deficiencies is important, both to enable early intervention and to minimize long-term adverse effects. A major clinical concern is the relationship between vitamin D deficiency and the development of metabolic bone diseases, such as osteoporosis or osteomalacia; metabolic bone diseases may explain the increased risk of hip fracture in patients after RYGB. Further studies are required to determine the optimal levels of nutrient supplementation and whether postoperative laboratory monitoring effectively detects nutrient deficiencies. In the absence of such data, clinicians should inquire about and treat symptoms that suggest nutrient deficiencies.

The evolution and treatment of Korsakoff's syndrome: out of sight, out of mind?

Wernicke's Encephalopathy is an acute neuro-psychiatric condition caused by an insufficient supply of thiamine (Vitamin B1) to the brain. If undiagnosed or inadequately treated, it is likely to proceed to Korsakoff's Syndrome. Wernicke's Encephalopathy can result from dietary deficiency alone and this form is usually successfully treated, with little chance of Korsakoff's Syndrome supervening. On the other hand, thiamine deficiency associated with alcohol misuse/dependence may require up to 1 gram of thiamine IV in the first 24 hours to be treated successfully. The reasons for this difference in treatment will be discussed. Thiamine diphosphate acts as a co-factor for a number of thiamine-dependent enzymes. Thiamine deficiency leads to a reduction in the activity of these enzymes, and this leads to alterations in mitochondrial activity, impairment of oxidative metabolism, decreased energy status and eventually selective neuronal death. The damage caused by the combination of thiamine deficiency and alcohol metabolism probably interferes with adequate thiamine transport at a number of sites in the body, including the blood-brain barrier, as well as causing damage to the apoenzymes which then require higher concentrations of thiamine to work normally. The accumulated damage is likely to render the use of oral thiamine therapeutically inadequate since the body is unable to produce high enough concentrations of thiamine in the blood to traverse the blood-brain barrier. Some individuals are probably genetically predisposed to develop Wernicke's. Long before individuals with alcohol misuse or dependence develop Wernicke's Encephalopathy the neurons and other cells of the body are functioning sub-optimally because of the inadequate supply of thiamine and the neurotoxic effect of alcohol. This relative deficiency initiates a series of pathological changes which accumulate and further interfere with the supply of thiamine and its utilisation at a time when the requirements are increased. The best treatment for Korsakoff's Syndrome is timely recognition of Wernicke's Encephalopathy and appropriate intervention and prevention.

EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy

BACKGROUND

Although Wernicke encephalopathy (WE) is a preventable and treatable disease it still often remains undiagnosed during life.

OBJECTIVES

To create practical guidelines for diagnosis, management and prevention of the disease.

METHODS

We searched MEDLINE, EMBASE, LILACS, Cochrane Library.

CONCLUSIONS AND RECOMMENDATIONS

1 The clinical diagnosis of WE should take into account the different presentations of clinical signs between alcoholics and non alcoholics (Recommendation Level C); although prevalence is higher in alcoholics, WE should be suspected in all clinical conditions which could lead to thiamine deficiency (good practice point - GPP). 2 The clinical diagnosis of WE in alcoholics requires two of the following four signs; (i) dietary deficiencies (ii) eye signs, (iii) cerebellar dysfunction, and (iv) either an altered mental state or mild memory impairment (Level B). 3 Total thiamine in blood sample should be measured immediately before its administration (GPP). 4 MRI should be used to support the diagnosis of acute WE both in alcoholics and non alcoholics (Level B). 5 Thiamine is indicated for the treatment of suspected or manifest WE. It should be given, before any carbohydrate, 200 mg thrice daily, preferably intravenously (Level C). 6 The overall safety of thiamine is very good (Level B). 7 After bariatric surgery we recommend follow-up of thiamine status for at least 6 months (Level B) and parenteral thiamine supplementation (GPP). 8 Parenteral thiamine should be given to all at-risk subjects admitted to the Emergency Room (GPP). 9 Patients dying from symptoms suggesting WE should have an autopsy (GPP).

Signs of preclinical Wernicke's encephalopathy and thiamine levels as predictors of neuropsychological deficits in alcoholism without Korsakoff's syndrome

The purpose of this study was to determine whether meeting historical criteria for unsuspected Wernicke's encephalopathy (WE), largely under-diagnosed in vivo, explains why some alcoholics have severe neuropsychological deficits, whereas others, with a similar drinking history, exhibit preserved performance. Demographic, clinical, alcohol related, and neuropsychological measures were collected in 56 abstinent alcoholics and 38 non-alcohol-dependent volunteers. Alcoholics were classified using the clinical criteria established by Caine et al (1997) and validated in their neuropathological study of alcoholic cases. Our alcoholics who met a single criterion were considered 'at risk for WE' and those with two or more criteria with 'signs of WE'. Whole blood thiamine was also measured in 22 of the comparison group and 28 alcoholics. Of the alcoholics examined, 27% met no criteria, 57% were at risk for WE, and 16% had signs of WE. Neuropsychological performance of the alcoholic subgroups was graded, with those meeting zero criteria not differing from controls, those meeting one criterion presenting mild-to-moderate deficits on some of the functional domains, and those meeting two or more criteria having the most severe deficits on each of the domains examined. Thiamine levels were selectively related to memory performance in the alcoholics. Preclinical signs of WE can be diagnosed in vivo, enabling the identification of ostensibly 'uncomplicated' alcoholics who are at risk for neuropsychological complications. The graded effects in neuropsychological performance suggest that the presence of signs of WE explains, at least partially, the heterogeneity of alcoholism-related cognitive and motor deficits.

Managing medical and surgical disorders after divided Roux-en-Y gastric bypass surgery

The National Longitudinal Study of Adolescent Health and the National Health and Nutrition Examination Survey reported that over 40% of the US population is overweight. The average weight loss attained by medical management programs is neither sufficient nor durable enough to treat medically complicated obesity. An estimated 220,000 bariatric procedures are performed yearly in the USA and Canada. The divided Roux-en-Y gastric bypass (RYGB) is performed most commonly in these countries and is considered the gold standard bariatric surgical procedure. The complexity of RYGB means that serious and potentially preventable perioperative complications can occur. RYGB alters the normal anatomy and physiology of the upper gut, which has predictable adverse effects and potential complications. Patients seek advice and care for symptoms that develop or persist after RYGB; although some symptoms are expected and predictable, others are complications that may or may not require active medical or surgical intervention. Physicians should be able to predict and manage most postoperative medical and nutritional disorders related to RYGB and should be prepared to assess patients for potential referral for surgical intervention or revision.

Postoperative metabolic and nutritional complications of bariatric surgery

Bariatric surgery has become an increasingly important method for management of medically complicated obesity. In patients who have undergone bariatric surgery, up to 87% with type 2 diabetes mellitus develop improvement or resolution of their disease postoperatively. Bariatric surgery can reduce the number of absorbed calories through performance of either a restrictive or a malabsorptive procedure. Patients who have undergone bariatric surgery require indefinite, regular follow-up care by physicians who need to follow laboratory parameters of macronutrient as well as micronutrient malnutrition. Physicians who care for patients after bariatric surgery need to be familiar with common postoperative syndromes that result from specific nutrient deficiencies.

Neurologic presentations of nutritional deficiencies

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. The first section of this review discusses neurologic manifestations related to deficiency of key nutrients such as vitamin B(12), folate, copper, vitamin E, thiamine, and others. The second section addresses neurologic complications related to bariatric surgery. The third sections includes neurologic presentations caused by nutrient deficiencies in the setting of alcoholism. The concluding section addresses neurologic deficiency diseases that have a geographic predilection.

A multi-centre survey of inpatient pharmacological management strategies for alcohol withdrawal

BACKGROUND

It is well recognized that alcohol is a growing problem in the UK with significant morbidity and mortality and associated resource implications for the National Health Service (NHS). The inpatient management of alcohol withdrawal is felt to be variable between hospitals. The aim of this study was to assess the variation in pharmacological management and acute inpatient alcohol services across NHS hospitals in the UK.

METHOD

A web-based survey was distributed to Society for Acute Medicine (SAM) members and others with an interest in Acute Medicine between January and March 2008.

RESULTS

The results suggest poor utilization of guidelines, variable drug regimens and differences in acute alcohol-related support services.

CONCLUSION

In response to these findings, we suggest that a simplified national approach is required for what is now recognized to be an epidemic problem.

Blocking GABA-A receptors in the medial septum enhances hippocampal acetylcholine release and behavior in a rat model of diencephalic amnesia

Wernicke-Korsakoff syndrome (WKS), a form of diencephalic amnesia caused by thiamine deficiency, results in severe anterograde memory loss. Pyrithiamine-induced thiamine deficiency (PTD), an animal model of WKS, produces cholinergic abnormalities including decreased functional hippocampal acetylcholine (ACh) release and poor spatial memory. Increasing hippocampal ACh levels has increased performance in PTD animals. Intraseptal bicuculline (GABA(A) antagonist) augments hippocampal ACh release in normal animals and we found it (0.50 microg/microl and 0.75 microg/microl) also increased in-vivo hippocampal ACh release in PTD animals. However, the 0.75 microg/microl dose produced a greater change in hippocampal ACh release in control animals. The 0.50 microg/microl dose of bicuculline was then selected to determine if it could enhance spontaneous alternation performance in PTD animals. This dose of bicuculline significantly increased hippocampal ACh levels above baseline in both PTD and control rats and resulted in complete behavioral recovery in PTD animals, without altering performance in control rats. This suggests that balancing ACh-GABA interactions in the septohippocampal circuit may be an effective therapeutic approach in certain amnestic syndromes.

Wernicke's encephalopathy: new clinical settings and recent advances in diagnosis and management

Wernicke's encephalopathy is an acute neuropsychiatric syndrome resulting from thiamine deficiency, which is associated with significant morbidity and mortality. According to autopsy-based studies, the disorder is still greatly underdiagnosed in both adults and children. In this review, we provide an update on the factors and clinical settings that predispose to Wernicke's encephalopathy, and discuss the most recent insights into epidemiology, pathophysiology, genetics, diagnosis, and treatment. To facilitate the diagnosis, we classify the common and rare symptoms at presentation and the late-stage symptoms. We emphasise the optimum dose of parenteral thiamine required for prophylaxis and treatment of Wernicke's encephalopathy and prevention of Korsakoff's syndrome associated with alcohol misuse. A systematic approach helps to ensure that patients receive a prompt diagnosis and adequate treatment.