Korsakoff's syndrome: a critical review

Biochemical and medical aspects of vitamin B1 research

Vitamin B1 is an indispensable food factor for the human and animal body. In animals, vitamin B1 is found in the form of thiamine and its phosphate esters - thiamine mono-, di- and triphosphate, as well as an adenylated derivative - adenosine thiamine triphosphate. At present, the only vitamin B1 form with biochemical functions being elucidated is thiamine diphosphate, which serves as a coenzyme for several important enzymes involved in carbohydrate, amino acid, fatty acid and energy metabolism. Here we review the latest developments in the field of vitamin B1 research in animals. Transport, metabolism and biological role of thiamine and its derivatives are considered as well as the involvement of vitamin B1-dependent processes in human diseases and its therapeutic issues, a field that has gained momentum with several important recent developments.

Cortico-subcortical networks that determine behavioral memory renewal are redefined by noradrenergic neuromodulation

During spatial appetitive extinction learning (EL), rodents learn that previously rewarded behavior is no longer rewarded. Renewal of the extinguished behavior is enabled by re-exposure to the context in which rewarded learning occurred. When the renewal response (RR) is unrewarded, it is rapidly followed by response extinction (RE). Although the hippocampus is known to be engaged, whether this dynamic is supported by different brain networks is unclear. To clarify this, male rats engaged in context-dependent spatial memory acquisition, EL and RR testing in a T-Maze. Fluorescence in situ hybridization disambiguated somatic immediate early gene expression in neuronal somata engaged in RR or RE. Graph analysis revealed pronounced hippocampal connectivity with retrosplenial and prefrontal cortex (PFC) during initial RR. By contrast, RE was accompanied by a shift towards elevated coordinated activity within all hippocampal subfields. Given that β-adrenergic receptors (β-AR) regulate spatial memory, we activated β-AR to further scrutinize these network effects. This enhanced RR and prevented RE. Effects were associated with initially increased thalamic-hippocampus activity, followed by a decrease in hippocampal intraconnectivity and the predominance of network activity within PFC. Our findings highlight a critical hippocampal-cortical-thalamic network that underpins renewal behavior, with noradrenergic neuromodulation playing a pivotal role in governing this circuit's dynamics.

Alcohol and alcoholism associated neurological disorders: Current updates in a global perspective and recent recommendations

Alcohol use disorder (AUD) is a medical condition that impairs a person's ability to stop or manage their drinking in the face of negative social, occupational, or health consequences. AUD is defined by the National Institute on Alcohol Abuse and Alcoholism as a "severe problem". The central nervous system is the primary target of alcohol's adverse effects. It is crucial to identify various neurological disorders associated with AUD, including alcohol withdrawal syndrome, Wernicke-Korsakoff syndrome, Marchiafava-Bignami disease, dementia, and neuropathy. To gain a better understanding of the neurological environment of alcoholism and to shed light on the role of various neurotransmitters in the phenomenon of alcoholism. A comprehensive search of online databases, including PubMed, EMBASE, Web of Science, and Google Scholar, was conducted to identify relevant articles. Several neurotransmitters (dopamine, gamma-aminobutyric acid, serotonin, and glutamate) have been linked to alcoholism due to a brain imbalance. Alcoholism appears to be a complex genetic disorder, with variations in many genes influencing risk. Some of these genes have been identified, including two alcohol metabolism genes, alcohol dehydrogenase 1B gene and aldehyde dehydrogenase 2 gene, which have the most potent known effects on the risk of alcoholism. Neuronal degeneration and demyelination in people with AUD may be caused by neuronal damage, nutrient deficiencies, and blood brain barrier dysfunction; however, the underlying mechanism is unknown. This review will provide a detailed overview of the neurobiology of alcohol addiction, followed by recent studies published in the genetics of alcohol addiction, molecular mechanism and detailed information on the various acute and chronic neurological manifestations of alcoholism for the Future research.

Criminal behavior in alcohol-related dementia and Wernicke-Korsakoff syndrome: a Nationwide Register Study

BACKGROUND

Chronic heavy alcohol use may lead to permanent brain damage, cognitive impairment, and dementia. While the link between alcohol use and crime is strong, virtually no research exists on the criminal behavior of patients with the alcohol-related neurocognitive disorders of Wernicke-Korsakoff syndrome (WKS) and alcohol-related dementia (ARD).

METHODS

The study population included all persons diagnosed with WKS (n = 1149) or ARD (n = 2432) in Finland in 1998-2015. Data on diagnoses, mortality, and crime were obtained from Finnish nationwide registers. Crime incidences were calculated 4 years before and after diagnosis. Crime types, incidences, and mortality were compared between disorders and with the general population.

RESULTS

Altogether 35.6% of WKS patients and 23.6% of ARD patients had committed crimes in the 4 years preceding diagnosis, most commonly property and traffic crimes, followed by violent crimes. The incidence of criminal behavior decreased significantly after diagnosis; in WKS patients, the standardized criminality ratio (SCR), the ratio of observed to expected number of crimes (95% CI), was 3.91 (3.72-4.10) in 4 years before and 2.80 (2.61-3.00) in 4 years after diagnosis. Likewise, in ARD patients, the SCRs were 2.63 (2.51-2.75) before and 0.84 (0.75-0.92) after diagnosis. No significant difference emerged in mortality between persons with and without a criminal history.

CONCLUSIONS

Persons with alcohol-related neurocognitive disorders frequently engage in criminal behavior prior to diagnosis, especially multiple offending. In the 4 years before and after diagnosis, crime rates declined in a linear fashion, with a marked reduction after diagnosis.

Cross-validation of the WAIS-IV Similarities incidental learning task

The incidental learning index based on Similarities subtest (IL-Sim) from the Wechsler Adult Intelligence Test-Fourth Edition (WAIS-IV) has shown promise as a screening measure for memory impairment. We aimed to examine the reliability, convergent and divergent validity, and the utility of IL-Sim index in classifying at least mild and severe memory impairment. One hundred and fifty-three Veterans completed the WAIS-IV Similarities subtest and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as part of their clinical evaluations. IL-Sim had acceptable internal consistency (Cronbach's α = .85). Among RBANS indices, IL-Sim had the largest association with the Delayed Memory Index (r = .69), followed by the Immediate Memory Index (r = .59), and relatively smaller associations with non-memory indices (rs = .26-.38). For both younger (ages 40-69) and older (ages 70-87) adults, IL-Sim had excellent discriminability between patients without memory problems and those with at least mildly or severely impaired RBANS memory (AUC = .83-.87). To enhance the ease of interpretation for IL-Sim scores, we presented logistic regression-derived probabilities across multiple base rates for each age group and impairment severity. IL-Sim showed strong convergent and divergent validity and discriminated along the memory impairment continuum highlighting its promise as an efficient screening measure of memory.

Adolescent Alcohol and the Spectrum of Cognitive Dysfunction in Aging

Among the many changes associated with aging, inflammation in the central nervous system (CNS) and throughout the body likely contributes to the constellation of health-related maladies associated with aging. Genetics, lifestyle factors, and environmental experiences shape the trajectory of aging-associated inflammation, including the developmental timing, frequency, and intensity of alcohol consumption. This chapter posits that neuroinflammatory processes form a critical link between alcohol exposure and the trajectory of healthy aging, at least in part through direct or indirect interactions with cholinergic circuits that are crucial to cognitive integrity. In this chapter, we begin with a discussion of how inflammation changes from early development through late aging; discuss the role of inflammation and alcohol in the emergence of mild cognitive impairment (MCI); elaborate on critical findings on the contribution of alcohol-related thiamine deficiency to the loss of cholinergic function and subsequent development of Wernicke-Korsakoff syndrome (WKS); and present emerging findings at the intersection of alcohol and Alzheimer's disease and related dementias (ADRD). In doing so, our analysis points toward inflammation-mediated compromise of basal forebrain cholinergic function as a key culprit in cognitive dysfunction associated with chronic alcohol exposure, effects that may be rescuable through either pharmacological or behavioral approaches. Furthermore, our chapter reveals an interesting dichotomy in the effects of alcohol on neuropathological markers of ADRD that depend upon both biological sex and genetic vulnerability.

Towards a Non-pharmacological Intervention on Apathy in Korsakoff's Syndrome: A Systematic Narrative Review Across Different Clinical Conditions

Abstract

Apathy is a quantitative reduction of goal-directed activity, which can be observed in relation to behavior, cognition, emotions and social interaction. It is an invalidating behavioral symptom that is frequently present across different psychiatric conditions and neurocognitive disorders including Korsakoff's Syndrome (KS). In fact, apathy is one of the most severe behavioral symptoms of KS and has a major impact on the lives of patients and their relatives and other informal caregivers. However, guidelines for the treatment of apathy in KS are currently not available. This systematic narrative review provides a transdiagnostic overview of the effectiveness of different types of non-pharmacological interventions on apathy across different study populations that at symptom-level share characteristics with KS. This evidence may inform the development of an intervention targeting apathy in KS. The included study populations are dementia (due to Alzheimer's disease, or vascular dementia), Parkinson's disease, schizophrenia and traumatic brain injury. Through a stepped selection approach and with regard to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 22 systematic reviews and 32 empirical articles on the non-pharmacological treatment of apathy were identified. The results show a variety of effective non-pharmacological interventions on apathy. In conditions with severe cognitive impairments, successful interventions did not rely on intrinsic motivation, self-monitoring, or illness insight of the patients, but depend on external stimulation and behavioral activation. Since apathy is a multidimensional construct, identification of the extent and type of apathetic behavior before starting an intervention is highly recommended. Furthermore, it is important to adjust the treatment to the patients' personal interests and needs and embedded in daily care.

Trial registration

CRD42022298464 (PROSPERO).

Social norms in Korsakoff's syndrome and alcohol-related dementia

OBJECTIVE

Social cognition is essential for individuals to perceive, process, and interpret social information that enables them to function effectively in society. Korsakoff's syndrome (KS) and alcohol-related dementia (ARD) are alcohol-related cognitive disorders that are likely to impair social cognition. This study aimed to investigate the ability to judge social norms in KS and ARD in comparison to healthy subjects.

METHOD

The study included 30 patients with KS, 10 patients with ARD, and 74 age-, sex-, and education-matched control participants. The Social Norms Questionnaire - Dutch version (SNQ-NL) was used to measure social cognition, and standardized tests were used to examine the association between social cognition and executive functioning.

RESULTS

Both KS and ARD patients performed worse in judging social norms when compared to healthy controls, but there was no significant difference between KS and ARD. Both KS and ARD patients performed worse on the SNQ-NL, judging appropriate behavior as inappropriate (Overadhere errors), than controls. When compared to control participants, patients with KS demonstrated significantly more Break Errors, while the differences between the ARD group and the control group did not reach statistical significance. There were no significant correlations between the SNQ-NL variables and performances on standardized tests for executive functioning in both the KS and control group.

CONCLUSIONS

This study aimed to investigate the ability to judge social norms in KS and ARD in comparison to healthy subjects. The results show that compared to a control group, both KS and ARD patients performed worse in judging social norms. KS and ARD patients scored equally low on social norms identification. Overall, these findings can further help us understand the difficulties in social behavior as experienced by patients and care staff, since problems in accurately judging social norms could possibly contribute to the severe behavioral issues as observed in alcohol-related disorders.

Beyond the Liver: Neurologic Manifestations of Alcohol Use

Alcohol use, while commonly associated with liver damage, also has significant neurologic implications, which often mimic hepatic encephalopathy and complicate diagnosis and management. Alcohol mediates its acute central nervous system effects by altering neurotransmitter balance, notably between gamma-aminobutyric acid and glutamate. Its chronic neurotoxicity, compounded by thiamine deficiency, results in chronic neurologic complications. Clinically, alcohol-related neurologic disorders present a spectrum from acute intoxication and withdrawal to chronic conditions like Korsakoff syndrome, dementia, cerebellar degeneration, and peripheral neuropathy. This review underscores differentiating these conditions from hepatic encephalopathy and highlights the importance of history-taking and physical examination in clinical practice.

Study of Neuroinflammation in the Rat Hippocampus during Ethanol Exposure and Pharmacological Correction with Azithromycin: New Data and Future Perspectives

With prolonged ethanol ingestion, disturbances in the emotional spectrum develop, and memory problems are noted. These symptoms could be mediated by the development of neurochemical changes in the hippocampus of the brain. Although there is evidence that hippocampus is vulnerable to chronic alcohol intoxication and that neuroinflammation and neurodegeneration develop in this brain region, the key molecular mechanisms have not been identified. The aim of the study was to investigate changes in the immune system in the periphery as well as in the hippocampus of rat brain during ethanol exposure and during pharmacological correction with azithromycin (AZM). Long-term ethanol exposure was modeled by injecting rats with a 20% ethanol solution (4 g/kg) for 4 weeks. General biochemical and clinical blood analysis was performed in animals. Expression levels of the cytokine genes (Il1β, Ccl2, Il6, Il11, Il13, Tnfα, Tgfβ), Toll-like receptor system genes (Tlr3, Tl4, Tlr7, Nfkb1, Hmgb1), and TLR system-related microRNA molecules (miR-182, miR-155-5p, miR-96-5p, miR-let-7b) were evaluated in the hippocampus. IL-1β protein content was also assessed in the hippocampus. Prolonged exposure to alcohol caused increase in the mRNA and protein levels of IL-1β, and decrease in the mRNA levels of Tnfα, Il11, Tlr3, and Tlr7. The contents of miRlet7b, miR96, and miR155 were downregulated in the hippocampus after long-term alcohol exposure. Elevated levels of THE Il1β mRNA and protein and Hmgb1 mRNA were maintained under conditions of ethanol abstinence. The Tlr3 mRNA levels were decreased after abstinence. Administration of AZM reduced the IL1β, TLR3, and HMGB1 mRNA levels under conditions of ethanol abstinence; and at higher doses of the drug decrease in the IL-1β protein levels in the hippocampus of rat brain was observed. Thus, the study provided new insights into the mechanisms of neuroinflammation in the hippocampus during prolonged exposure to ethanol and upon abstinence. The obtained results allowed us to suggest a number of tasks for further studies in this direction.

Treatment of nasopharyngeal carcinoma and prevention of non-alcoholic Wernicke's disease: A case report and review of literature

BACKGROUND

Wernicke encephalopathy is a neurological disorder caused by thiamine deficiency, commonly seen in alcoholic populations but also involving other circumstances that may lead to thiamine deficiency. The recognition of Wernicke encephalopathy often depends on clinicians' keen ability to detect its typical triad of features; however, most cases do not present with the full constellation of signs, which complicates the timely identification of Wernicke encephalopathy.

CASE SUMMARY

This case report describes a patient with nasopharyngeal carcinoma who developed abnormal ocular function and ataxia following concurrent chemoradiotherapy, without a history of alcohol abuse. With the aid of radiological examinations, he received a timely diagnosis and treatment; however, his symptoms did not fully resolve during follow-up.

CONCLUSION

For patients with malignant tumors exhibiting neurological symptoms, clinicians should consider the possibility of Wernicke encephalopathy and provide prophylactic thiamine therapy.

Wernicke's Encephalopathy (WE) Associated with Hyperemesis Gravidarum (HG) Presenting with Psychiatric Morbidity: Description of Two Cases

Background

Hyperemesis gravidarum (HG) refers to intractable vomiting during pregnancy and is rarely associated with Wernicke's encephalopathy (WE). HG-associated WE can lead to mortality and permanent cognitive impairment if left untreated. In this report, we present two cases of WE following HG occurring in the context of comorbid severe depression.

Case Description

In the first case, a 29-year-old female developed HG and WE during the second month of pregnancy, followed by an episode of severe depression with catatonia. In the second case, a 23-year-old female with bipolar disorder presented with HG for two months during pregnancy, followed by an episode of severe depression and a fractured mandible due to a fall.

Conclusion

Thiamine should be considered in women experiencing prolonged vomiting during pregnancy, and they should be closely monitored for features of WE.

Clinical Heterogeneity in Alzheimer's Disease: A Possible New Amnesic Phenotype

We rediscovered a phenotype of AD known in the early 1900s as presbyophrenia, but then forgotten, and renamed as confabulation-misidentification phenotype. The phenotype includes diencephalic amnesia whose prototype is Korsakoff syndrome. The main features are anterograde and retrograde amnesia with marked disorientation and confabulation, executive impairments, reduced insight and attention deficits, misidentification, minor hallucination and other delusions, behavioral disturbances, and early anxiety. In this article, we summarize what we have discovered about the new phenotype and what is still missing to confirm this diencephalic variant of AD.

The Weight of Bariatric Surgery: Wernicke-Korsakoff Syndrome after Vertical Sleeve Gastrectomy-A Case Series

In this case series, the simultaneous occurrence of Wernicke's encephalopathy (WE) and dry beriberi was reported in three patients who underwent vertical sleeve gastrectomy (VSG) between May 2021 and May 2023. All patients were obese women who underwent vertical sleeve gastrectomy (VSG) without immediate postoperative complications, but two weeks later, hyperemesis and subsequent encephalopathy with ocular movement abnormalities and weakness were observed over the following thirty days. Patients were referred to neurology, where due to the high suspicion of WE, thiamine replacement therapy was initiated; meanwhile, diagnostic neuroimaging and blood tests were conducted. Neurological and psychiatric evaluations and neuroconduction studies were performed to assess the clinical evolution and present sequelae. One year after diagnosis, all patients exhibited affective and behavioral sequelae, anterograde memory impairment, and executive functioning deficits. Two patients met the criteria for Korsakoff syndrome. Additionally, peripheral nervous system sequelae were observed, with all patients presenting with sensorimotor polyneuropathy. In conclusion, Wernicke's encephalopathy requires a high diagnostic suspicion for timely intervention and prevention of irreversible sequelae, which can be devastating. Therefore, raising awareness among medical professionals regarding the significance of this disease is essential.

"Do not take that medication": negative prospective memory in Korsakoff's syndrome

BACKGROUND

While prospective memory (i.e., the ability to execute a future plan) has been extensively researched, little is known about negative prospective memory (i.e., the ability to remember not to execute a future plan) in Korsakoff's syndrome (KS). We thus evaluated both prospective memory and negative prospective memory in KS, as well as the relationship between both types of prospective memory and inhibition.

METHODS

Patients with KS and control participants were invited to press a button on the keyboard (i.e., prospective memory) or not to press a button when a cue word (e.g., negative prospective memory) was encountered.

RESULTS

The analysis demonstrated that patients with KS had more prospective memory errors (i.e., forgetting to click the keyboard when the instruction was to do so) than control participants. The analysis also demonstrated that patients with KS had more negative prospective memory errors (i.e., clicking the keyboard when the instruction was not to do so) than control participants. Similar levels of commissions and omissions were observed in patients with KS than in control participants. Interestingly, prospective and negative prospective performances were significantly correlated with performance on an inhibition assessment task.

DISCUSSION

Our study demonstrates that KS is characterized by not only difficulty in remembering to execute a future intention but also by difficulty in remembering not to execute a future intention. A decline in negative prospective memory in KS can be associated with difficulty in inhibiting no longer appropriate previously learned intentions.

Thiamine utilization and the lack of prescribing standardization: A critical examination

OBJECTIVES

Thiamine is often prescribed for thiamine deficiency during hospitalization despite the lack of US-based clinical guidelines. This study aims to evaluate thiamine prescribing patterns and key characteristics associated with the deficiency to address gaps in care.

METHODS

Data were obtained from electronic health records of hospitalized patients between September 1, 2021, and March 30, 2022. Alcohol use disorder (AUD) was defined by a positive Clinical Institute Withdrawal Assessment score or a positive serum alcohol level upon admission. Geriatric patients were defined as age ≥65. Cohort 1 was defined as: AUD, albumin <4 g/L, INR >1.5, and total bilirubin >3 mg/dL. Cohort 2 was defined as: age >65, albumin <4 g/L, hemoglobin <15 g/dL, and folate <4 ng/mL. A multivariable LASSO regression model was used to identify characteristics associated with higher thiamine dosing (>100 mg/day).

RESULTS

Among 780 patients, 520 (66.7%) were identified as AUD, of which 265 (50.1%) were between the ages of 45-64 years. The AUD cohort was significantly different (p < 0.05) in the mean serum albumin 4.16 g/L (IQR: 3.8-4.5), AST 73.55 U/L (23.75-82.00), ALT 52.57 U/L (17.00-57.00), total bilirubin 0.98 (0.3-1.0), and INR 1.1 (0.99-1.12), compared to non-AUD patients with a mean serum albumin 3.75 g/L (3.3-4.2), AST 35.07 U/L (11.00-42.00), ALT 32.77 U/L (5.00-34.00), total bilirubin 0.89 (0.2-0.9), and INR 1.21 (1.0-1.22). In the geriatric cohort, 136 patients (17%) had a mean serum albumin 3.77 g/L (3.4-4.2), AST 38.66 U/L (14.0-41.0), ALT 29.36 U/L (9.0-37.0), total bilirubin 0.62 mg/dL (0.30-0.90), and direct bilirubin 0.12 mg/dL (0.00-0.20), compared to the non-geriatric cohort with a mean serum albumin 4.10 g/L (3.8-4.40), AST 66.44 U/L (21.0-75.0), ALT 50.03 U/L (16.00-53.75), total bilirubin 1.02 mg/dL (0.30-1.00), and direct bilirubin 0.31 mg/dL (0.00-0.20). In cohort 1, 40.6% patients were between 51 and 64 years old, (66.5%) male, and had a BMI <25 (36.4%). In cohort 2, 52.6% were between 65 and 70 years old, (57.9%) male, and had a BMI <25 (57.9%). Cohort 1 were prescribed a dose of 100 mg (47.7 %), oral (63.5%), intramuscular (18.2%), daily (58.9%), one-day duration (49.4%) most frequently. Cohort 2 were prescribed a dose of 100 mg (56.0%), oral (77.2%), daily (77.2%), one-day duration (29.8%) most frequently. The AUD was significantly associated with having a higher dosage (e.g., >100 mg) of thiamine prescribed per day OR 1.62 (1.11-2.37) (p < 0.01).

CONCLUSIONS

This study confirms that thiamine prescribing patterns vary during hospitalization and suggest specific laboratory findings may aid in identifying cohorts associated with the deficiency.

Stem Cell Therapy and Thiamine Deficiency-Induced Brain Damage

Wernicke's encephalopathy (WE) is a major central nervous system disorder resulting from thiamine deficiency (TD) in which a number of brain regions can develop serious damage including the thalamus and inferior colliculus. Despite decades of research into the pathophysiology of TD and potential therapeutic interventions, little progress has been made regarding effective treatment following the development of brain lesions and its associated cognitive issues. Recent developments in our understanding of stem cells suggest they are capable of repairing damage and improving function in different maladys. This article puts forward the case for the potential use of stem cell treatment as a therapeutic strategy in WE by first examining the effects of TD on brain functional integrity and its consequences. The second half of the paper will address the future benefits of treating TD with these cells by focusing on their nature and their potential to effectively treat neurodegenerative diseases that share some overlapping pathophysiological features with TD. At the same time, some of the obstacles these cells will have to overcome in order to become a viable therapeutic strategy for treating this potentially life-threatening illness in humans will be highlighted.

Using supplemental memory measures to refine interpretation of the repeatable battery for the assessment of neuropsychological status

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is frequently used as a cognitive screening measure or as part of a comprehensive neuropsychological battery. Augmenting the current memory subtests of the RBANS to reflect clinically meaningful distinctions in memory performance may improve its clinical utility, allowing users to generate additional hypotheses and refine clinical interpretations. We pilot four supplementary memory measures to use with the RBANS, adapted from paradigms commonly used by other neuropsychological tests. We also provide several new theoretically derived memory indices to supplement the standard Delayed Memory Index. The new subtests correlated significantly with the standard memory measures, and the new indices demonstrated good reliability and diagnostic accuracy. This study provides preliminary support for supplementing the RBANS to allow for more nuanced interpretations of memory performance.

Wernicke encephalopathy induced by glucose infusion: A case report and literature review

Introduction

Wernicke encephalopathy (WE) is a potentially fatal condition caused by thiamine (vitamin B1) deficiency. Chronic alcoholism is the most common cause of WE; however, other conditions responsible for thiamine deficiency should also be considered.

Case Report

We report the case of a 64-year-old woman with a history of diabetes who presented with confusion and apathy. Magnetic resonance imaging of the brain showed T2 hyperintensities involving dorsolateral medulla oblongata, tegmentum of the pons, vermis of the cerebellum, periaqueductal region, and the bilateral mammillary bodies. She had a history of intravenous glucose administration before her mental symptoms developed. On suspicion of WE, she was treated with a high dose of thiamine empirically. Her clinical condition improved rapidly in 2 weeks.

Conclusion

Endogenous thiamine stores can be rapidly depleted in the case of enhanced glucose oxidation. Patients who receive glucose should also be prescribed thiamine to avoid inducing or exacerbating WE.

The Effects of Intensive Rehabilitation Combined with Thiamine Treatment on Cognitive Recovery in a Case of Non-Alcoholic Wernicke-Korsakoff Syndrome

Wernicke-Korsakoff Syndrome (WKS) is a severe neurological disorder resulting from thiamine deficiency, commonly associated with alcohol consumption but also stemming from dietary imbalances or other clinical conditions. Cognitive deficits, affecting memory and executive functions, pose a serious concern, with partial recovery often not complete. A 28-year-old woman underwent surgery for acute necrotizing hemorrhagic pancreatitis, leading to admission for post-acute intensive treatment due to prolonged bed rest syndrome. Clinical examinations revealed sensory-motor neuropathy, denervation in the active phase, mammillary body hyperintensity, and cognitive impairment. The patient exhibited poor orientation, lacked awareness of her clinical condition, and experienced impaired nonverbal memory, practical constructive issues, and planning difficulties-consistent with WKS. The patient received high-dose thiamine (300 mg TDS), coupled with daily physiokinesitherapy and occupational therapy. A final neuropsychological evaluation three months later showed substantial remission of executive and memory difficulties, improved spatial-temporal orientation, and enhanced awareness. The complex case required timely multidisciplinary intervention for accurate diagnosis and effective rehabilitation. The patient experienced rapid clinical improvement and cognitive recovery with high-dose thiamine and physiotherapy.

Destination memory disorders: At the junction between memory and socioaffective processing

The junction between memory dysfunction and socioaffective dysfunction is a complex area as research has typically been interested in one dysfunction rather than in the other. However, this junction can be studied under the lens of destination memory. Destination memory (i.e. the ability to remember to whom a piece of information was previously transmitted) is unique in that it draws on both memory and socioaffective processes. Research has demonstrated how destination memory is prone to distortions in neurological/psychiatric disorders. This paper aims to provide a focused review on the interplay between memory and socioaffective processes in the deterioration of destination memory within these disorders. It shows how both episodic memory and socioaffective dysfunction can jointly contribute to the decline in destination memory, although the contribution of each of the two factors may vary depending on the disorder.

Wernicke Syndrome: Case Report and Literature Review of Contributing Factors-Can Malpractice Dynamics Be Identified?

Wernicke Encephalopathy (WE) is a neurological acute syndrome related to vitamin B1 deficiency and is relatively common in patients with chronic alcoholism. In the case of Hyperemesis Gravidarum, thiamine body stores become unable to meet the increased demand, resulting in acute deficiency. WE is associated with typical clinical and radiological findings. Treatment pathways rely on thiamine replacement. The case herein reported is centered around a 33-year-old diabetic patient at 12 weeks of gestation, with WE due to hyperemesis gravidarum. The disease manifested itself with weakness, mental confusion, headache, and impaired vision. The diagnosis was established after the detection of typical findings by MRI. Thirty days after therapy was started, most of the patient's neurological disorders were resolved. The patient was discharged 40 days later with instructions to continue daily thiamine supplementation. The pregnancy outcome was good. Unfortunately, mild ataxia persisted in 2-year follow-up as a long-term consequence. When diagnosed and treated, WE has a favorable prognosis. However, roughly 80% of patients experience memory loss, which may continue for a long time, while gait disorders reportedly affect about 35% of patients. Mild ataxia and dysmetria may persist, too. We reviewed the scientific literature on WE in women with HG until February 2023. Hardly any authors report data on long-term sequelae. Our report emphasizes how important it is to take into consideration this complication in clinical practice, referring to published guidelines and recommendations. Neurological maternal sequelae can demonstrably persist despite early diagnosis and appropriate management. For this reason, a long-term follow-up is recommended. Wernicke syndrome management cannot yet rely on well-established conclusive guidelines; hence, a cautionary approach ought to be prioritized in order to ensure medicolegal soundness.

"I Genuinely Believe This Is the Most Stigmatised Group within the Social Care Sector"-Health and Social Care Professionals' Experiences of Working with People with Alcohol-Related Brain Damage: A Qualitative Interview Study

Appropriate diagnosis, treatment and care contribute to better service engagement, improvements to wellbeing, cost savings and reductions in morbidity and mortality for people with alcohol-related brain damage. In Northeast England, large amounts of alcohol are consumed; this is reflected in the number of alcohol-related deaths in the region. However, the pathway for people with alcohol-related brain damage to receive diagnosis, treatment and care is unknown and could be unwittingly influenced by stigma. Qualitative, in-depth, semi-structured interviews were completed with 25 health and social care professionals from organizations involved with people with alcohol-related brain damage recruited via snowball sampling. Interviews were recorded, transcribed verbatim, coded, and analysed. People with alcohol-related brain damage were found to be stigmatised by both society and professionals, inhibiting their entry into services. Therefore, alcohol-related brain damage remains underdiagnosed and misdiagnosed. There was found to be no dedicated service; silos with revolving doors and underfunded generic care with long waiting lists typically exclude those with alcohol-related or neurological problems. Reducing stigmatising processes associated with alcohol-related brain damage could counteract professionals' reluctance to provide care.

Molecular mechanisms of alcohol's effects on the human body: A review and update

Alcohol consumption has been linked to numerous negative health outcomes although it has some beneficial effects on moderate dosages, the most severe of which being alcohol-induced hepatitis. The number of people dying from this liver illness has been shown to climb steadily over time, and its prevalence has been increasing. Researchers have found that alcohol consumption primarily affects the brain, leading to a wide range of neurological and psychological diseases. High-alcohol-consumption addicts not only experienced seizures, but also ataxia, aggression, social anxiety, and variceal hemorrhage that ultimately resulted in death, ascites, and schizophrenia. Drugs treating this liver condition are limited and can cause serious side effects like depression. Serine-threonine kinases, cAMP protein kinases, protein kinase C, ERK, RACK 1, Homer 2, and more have all been observed to have their signaling pathways disrupted by alcohol, and alcohol has also been linked to epigenetic changes. In addition, alcohol consumption induces dysbiosis by changing the composition of the microbiome found in the gastrointestinal tract. Although more studies are needed, those that have been done suggest that probiotics aid in keeping the various microbiota concentrations stable. It has been argued that reducing one's alcohol intake may seem less harmful because excessive drinking is a lifestyle disorder.

Alcohol-Related Metabolic Emergencies

Patients with alcohol use disorders are commonly identified and managed in the emergency department. Although the alcohol-intoxicated patient has a high risk for significant injury and diseases, the majority will be allowed to sober in the emergency department and can be discharged without incident. However, there are metabolic derangements in these patients, such as alcoholic ketoacidosis, Wernicke-Korsakoff, and potomania that very commonly present similar to intoxication and can be misdiagnosed by emergency clinicians.

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.

Impaired Executive Functioning Associated with Alcohol-Related Neurocognitive Disorder including Korsakoff's Syndrome

(1) Background: chronic alcohol use is consistently associated with impaired executive functioning, but its profile across the spectrum from mild to major alcohol-related cognitive impairment is, to date, unclear. This study aims to compare executive performances of patients with alcohol-induced neurocognitive disorder, including Korsakoff's syndrome (KS), by using a computerized assessment battery allowing a fine-grained and precise neuropsychological assessment; (2) Methods: performances of 22 patients with alcohol-related cognitive impairment (ARCI) and 20 patients with KS were compared to those of 22 matched non-alcoholic controls. All participants were diagnosed in accordance with DSM-5-TR criteria and were at least six weeks abstinent from alcohol prior to assessment. Executive function was evaluated using four subtests of Cambridge Neuropsychological Test Automated Battery (CANTAB®); (3) Results: significant differences between groups were found on spatial working memory (updating), sustained attention and inhibitory control, set shifting, and planning. Healthy controls performed significantly better than both patient groups (Games-Howell post hoc; p < 0.05), but no differences in performance were found between the ARCI and KS group; (4) Conclusions: ARCI and KS patients showed significant executive impairments, most prominent in updating, set-shifting and general planning abilities. Findings suggest equivalent levels of executive function in ARCI and KS patients. Our results highlight executive function as a significant hallmark of alcohol-induced neurocognitive disorder and stipulate the importance of early assessment and evaluation of skills to guide treatment.

Observations on the Clinical Features of the Wernicke-Korsakoff Syndrome

This paper begins with a short case report of florid, spontaneous confabulation in a 61-year-old man with an alcohol-induced Wernicke-Korsakoff syndrome. His confabulation extended across episodic and personal semantic memory, as well as orientation in time and place, as measured on Dalla Barba's Confabulation Battery. Five other brief case summaries will then be presented, followed by a summary of the clinical, neurological, and background neuropsychological findings in three earlier series of Korsakoff patients. These observations will be considered in light of Wijnia's recent and my own, earlier reviews of the Korsakoff syndrome. Taken together, they indicate the need for a multi-faceted approach (clinical, neurological, neuropsychological, and neuroimaging) to the assessment and diagnosis of the disorder.

Neurocognitive Recovery in Abstinent Patients with Alcohol Use Disorder: A Scoping Review for Associated Factors

Objective

Studies have reported inconsistent results regarding the extent to which neurocognitive recovery occurs in abstinent patients with alcohol use disorder (AUD). In addition to abstinence, other factors may have influenced this process and contributed to the inconsistencies. This review examines the factors investigated in this regard and describes the possible influence of each factor based on the evidence collected.

Methodology

PubMed was systematically searched for articles published between January 2000 and July 2023. Longitudinal humane studies investigating neurocognitive recovery in abstinent adult AUD patients were included. Studies with a cross-sectional design were excluded, as were studies that did not classify AUD according to the DSM-IV or 5 criteria, only examined binge use, did not report neuropsychological outcomes or duration of abstinence, or where neurological disorders were present.

Results

Sixteen categories of factors were distinguished from 31 full-text articles. Consistent patterns were found, indicating an association between neurocognitive recovery and the "smoking" and 'brain volume" factors. Consistent patterns were also found indicating that there is no relationship with "quantities of alcohol used" and "education level." A similar consistent pattern was also found for "polysubstance use", "gender" and "verbal reading", but the number of studies is considered limited. The association with "age" is studied frequently but with inconsistent findings. The remaining eight factors were regarded as understudied.

Conclusion

The clearest patterns emerging from the evidence are a predominantly negative influence of smoking on neurocognitive recovery, associations between changes in brain area volume and neurocognitive recovery, and no association between neurocognitive recovery and the amount of alcohol consumed, as measured by self-report, nor with educational attainment. Future research on the understudied factors and factors with inconsistent evidence is needed, preferably through longitudinal designs with multiple assessment periods starting after at least two weeks of abstinence.

When Do Korsakoff Patients Justify Immoral Behaviors? The Influence of Premorbid Delinquency and Self-Other Perspectives in Moral Decision-Making and Moral Reasoning

Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder caused by a vitamin B1 deficiency. KS is characterized by profound amnesia and often accompanied by poor executive functioning, decreased social-cognitive abilities, and difficulties in behavioral regulation. As moral behaviors and attitudes may provide insight in socio-behavioral interactions, the current study aimed to evaluate everyday moral maturity by administering self- versus other-oriented moral dilemmas in a group of KS patients (n = 20) and healthy controls (n = 20). Responses were scored according to the Kohlberg stages of moral reasoning. Furthermore, we assessed premorbid delinquency and current neurocognitive functioning as possible relevant factors. Our results show that KS patients were prone to lower levels of moral maturity when confronted with moral dilemmas relating to themselves, compared to dilemmas relating to (un)personal others in KS patients, while healthy subjects showed an opposite pattern. Moral immaturity could find its origin already before the onset of the KS diagnosis, as suggested by the elevated premorbid levels of delinquent behavior and correlation between premorbid delinquency and moral maturity in KS. Lower moral maturity could therefore be a possible predisposing factor to both delinquency and later development of Korsakoff's syndrome.

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 use and grey matter structure: Disentangling predispositional and causal contributions in human studies

Alcohol use is a growing global health concern and economic burden. Alcohol involvement (i.e., initiation, use, problematic use, alcohol use disorder) has been reliably associated with broad spectrum grey matter differences in cross-sectional studies. These findings have been largely interpreted as reflecting alcohol-induced atrophy. However, emerging data suggest that brain structure differences also represent pre-existing vulnerability factors for alcohol involvement. Here, we review evidence from human studies with designs (i.e., family-based, genomic, longitudinal) that allow them to assess the plausibility that these correlates reflect predispositional risk factors and/or causal consequences of alcohol involvement. These studies provide convergent evidence that grey matter correlates of alcohol involvement largely reflect predisposing risk factors, with some evidence for potential alcohol-induced atrophy. These conclusions highlight the importance of study designs that can provide causal clues to cross-sectional observations. An integrative model may best account for these data, in which predisposition to alcohol use affects brain development, effects which may then be compounded by the neurotoxic consequences of heavy alcohol use.

Care-resistant behaviour during oral examination in Dutch nursing home residents with dementia

OBJECTIVE

To assess the occurrence and associations of verbal and non-verbal care-resistant behaviour (CRB) during oral examination by a dental hygienist in nursing home residents with dementia.

BACKGROUND

CRB is a barrier to providing professional oral care and daily oral hygiene care. Understanding the predictors of CRB might help care professionals in learning to anticipate this behaviour.

METHODS

In this multicentre cross-sectional study signs of verbal and non-verbal CRB were reported during the oral examination. Data collection occurred in the psychogeriatrics wards of 14 different nursing homes in the Netherlands (N = 367).

RESULTS

A total of 367 residents were included. CRB was evident in 82 residents (22.3%), of whom 45 (55%) showed verbal and 37 (45%) non-verbal CRB. Associated with CRB were age >85 years, duration of residential stay longer than 2 years, and having Korsakov dementia. Other factors associated with CRB were duration of residential stay (categories ">2 and ≤4 years" or ">4 years") and having a natural dentition (P = .043-.005, OR = 1.20-1.33, 95% CI = 1.00-8.48). Significant associations for verbal and non-verbal CRB were age between 76 and 85 years, vascular dementia and Korsakov dementia (P = .031-.006, OR = .020-1.49, 95% CI = 0.43-2.15).

CONCLUSION

The occurrence of CRB was 22.3% and was associated with older age and longer duration of residential stay, Vascular and Korsakov dementia and natural dentition.

Self-Reported Pain and Pain Observations in People with Korsakoff's Syndrome: A Pilot Study

Korsakoff's syndrome (KS) is a chronic neuropsychiatric disorder. The large majority of people with KS experience multiple comorbid health problems, including cardiovascular disease, malignancy, and diabetes mellitus. To our knowledge pain has not been investigated in this population. The aim of this study was to investigate self-reported pain as well as pain behavior observations reported by nursing staff. In total, 38 people diagnosed with KS residing in a long-term care facility for KS participated in this research. The Visual Analogue Scale (VAS), Pain Assessment in Impaired Cognition (PAIC-15), Rotterdam Elderly Pain Observation Scale (REPOS), and the McGill Pain Questionnaire-Dutch Language Version (MPQ-DLV) were used to index self-rated and observational pain in KS. People with KS reported significantly lower pain levels than their healthcare professionals reported for them. The highest pain scores were found on the PAIC-15, specifically on the emotional expression scale. Of importance, the patient pain reports did not correlate with the healthcare pain reports. Moreover, there was a high correlation between neuropsychiatric symptoms and observational pain reports. Specifically, agitation and observational pain reports strongly correlated. In conclusion, people with KS report less pain than their healthcare professionals indicate for them. Moreover, there is a close relationship between neuropsychiatric symptoms and observation-reported pain in people with KS. Our results suggest that pain is possibly underreported by people with KS and should be taken into consideration in treating neuropsychiatric symptoms of KS as a possible underlying cause.

Music Therapy and Korsakoff's Syndrome: The State of the Art

In this perspective article, the authors give insight into the beneficial effects and the current developments in music therapy for patients with Korsakoff's syndrome (KS) in the Netherlands. Music may be the key to distracting patients from negative moods, to help them express emotions and to teach them new skills on physical, psychosocial and cognitive levels. This may lead to improving the quality of life of patients with KS. Emphasis is placed on the personal experience of the authors and on the future directions in the field. Their experience, as well as the experience of music therapy colleagues working in the field with the same target population (joined together in the Music Therapy Korsakoff Expertise Group), is situated in the context of existing literature and showcases current developments in the specific field of music therapy and KS. Since literature on this specific topic is limited, the authors allowed themselves to delve into somewhat older but still leading and representative literature. There is still little knowledge on how music therapy may contribute to reducing the impairments patients with KS suffer and to improving their quality of life in general. Using the Empathic Directive Approach (EDA) as the starting point, the authors elaborate on different potential approaches and interventions. With this article, the authors aim to gain more insight into the potential role of the music therapist by highlighting music-therapeutic micro-interventions and to provide recommendations for future directions on how to integrate music therapy in the treatment of patients with Korsakoff's syndrome.

Wernicke-Korsakoff Syndrome as a Consequence of Hyperemesis Gravidarum: A Case Report

Wernicke-Korsakoff syndrome (WKS) is caused by severe thiamine (vitamin B1) deficiency and can lead to chronic deficits. In this case, a 22-year-old pregnant patient at 10 1/7 weeks of gestation presented to the emergency department with malaise, asthenia, headache, weakness, vomiting, and weight loss of 12 kg. Pancreatitis and hepatic steatosis were considered but ruled out, and cholecystolithiasis was confirmed by ultrasound. After significant neurological deterioration, the patient underwent a cranial MRI that revealed suggestive findings in the thalamus consistent with WKS. WKS is a rare complication of hyperemesis gravidarum and should be included in the differential diagnosis of persistent vomiting in order to initiate early and appropriate treatment.

Neurochemistry of the mammillary body

The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with other subcortical structures, such as the anterior thalamic nuclei and tegmental nuclei of Gudden, the MB plays a crucial role in the processing of spatial and working memory, as well as navigation in rats. The aim of this paper is to review the distribution of various substances in the MB of the rat, with a description of their possible physiological roles. The following groups of substances are reviewed: (1) classical neurotransmitters (glutamate and other excitatory transmitters, gamma-aminobutyric acid, acetylcholine, serotonin, and dopamine), (2) neuropeptides (enkephalins, substance P, cocaine- and amphetamine-regulated transcript, neurotensin, neuropeptide Y, somatostatin, orexins, and galanin), and (3) other substances (calcium-binding proteins and calcium sensor proteins). This detailed description of the chemical parcellation may facilitate a better understanding of the MB functions and its complex relations with other structures of the extended hippocampal system.

Wernicke Encephalopathy: An Updated Narrative Review

Wernicke's encephalopathy (WE) and Korsakoff Syndrome (KS) are distinct neurological disorders that may have overlapping clinical features. Due to the overlap, they are collectively known as Wernicke-Korsakoff syndrome. WE is related to diencephalic and mesencephalic dysfunction due to thiamine. WE typically manifests as confusion, ophthalmoplegia, nystagmus, and gait ataxia (Wernicke's triad), although they may not consistently occur together. Although WE mostly occurs in alcoholics, other etiologies, such as post-bariatric surgery, must be considered. Early diagnosis and therapy by intravenous thiamine are essential to prevent WE complications and to reduce morbidity and mortality. Therefore, physicians' and patients' awareness of WE is essential for early diagnosis and therapy. Accordingly, this narrative review aimed to provide an update on WE by reviewing articles published between April 2015 to April 2022 about the etiology, pathophysiology, diagnosis, and WE management updates. EMBASE, PubMed, Google Scholar, Google, and Scopus search engines were used to conduct the literature search.

Antipsychotic Use and Mortality in Persons with Alcohol-Related Dementia or Wernicke-Korsakoff Syndrome: A Nationwide Register Study in Finland

BACKGROUND

Research on the use of psychotropic drugs in people with alcohol-related neurocognitive disorders is virtually nonexistent. We examined the prevalence of antipsychotic drug use and its effect on mortality among patients with Wernicke-Korsakoff syndrome (WKS) or alcohol-related dementia (ARD).

METHODS

In this nationwide register study, we collected data on the medication use and mortality of all persons aged ≥40 diagnosed with WKS (n = 1149) or ARD (n = 2432) between 1998 and 2015 in Finland. We calculated the prevalence of antipsychotic use within one year of diagnosis and the adjusted cumulative mortality of antipsychotic users versus non-users in relation to the age-, sex-, and calendar year-matched general population.

RESULTS

Of the WKS and ARD patients, 35.9% and 38.5%, respectively, purchased one or more antipsychotic drugs in the year following diagnosis. The adjusted cumulative mortality of the antipsychotic users was significantly lower than that of non-users in both the WKS and ARD groups, where the adjusted hazard ratios (95% CI) were 0.85 (0.72-0.99) and 0.73 (0.65-0.81), respectively. WKS and ARD patients using antipsychotics were less likely to die of alcohol-related causes than antipsychotic non-users, but the difference was significant only in the ARD group.

CONCLUSIONS

This population-based study shows that antipsychotic use is common in patients with WKS or ARD. In contrast to other dementia studies, our results indicate that the mortality of antipsychotic users is significantly lower than that of non-users. The lower mortality could be explained by decreased alcohol use and better healthcare coverage in antipsychotic users.

Cognitive Alterations in Addictive Disorders: A Translational Approach

The cognitive decline in people with substance use disorders is well known and can be found during both the dependence and drug abstinence phases. At the clinical level, cognitive decline impairs the response to addiction treatment and increases dropout rates. It can be irreversible, even after the end of drug abuse consumption. Improving our understanding of the molecular and cellular alterations associated with cognitive decline could be essential to developing specific therapeutic strategies for its treatment. Developing animal models to simulate drug abuse-induced learning and memory alterations is critical to continue exploring this clinical situation. The main aim of this review is to summarize the most recent evidence on cognitive impairment and the associated biological markers in patients addicted to some of the most consumed drugs of abuse and in animal models simulating this clinical situation. The available information suggests the need to develop more studies to further explore the molecular alterations associated with cognitive impairment, with the ultimate goal of developing new potential therapeutic strategies.

Alcohol and the central nervous system

Ethanol use is common to most cultures but with varying doses and to varying extents. While research has focused on the effects on the liver, alcohol exerts a range of actions on the function and structure of the nervous system. In the central nervous system (CNS) it can provoke or exacerbate neurological and psychiatric disease; its effects on the peripheral nervous system are not included in this review. Sustained alcohol intake can predispose to acute neurochemical changes which, with continued ingestion and incomplete treatment, can lead to chronic structural changes in the CNS: these include generalised cortical and cerebellar atrophy, amnesic syndromes such as Korsakoff's syndrome, and specific white matter disorders such as central pontine myelinolysis and Marchiafava-Bignami syndrome. Alcohol in pregnancy commonly and significantly affects fetal health, though this receives less medical and political attention than other causes of fetal harm. This review looks at the range of disorders that can follow acute or chronic alcohol use, and how these should be managed, and we provide a practical overview on how neurologists might diagnose and manage alcohol addiction.

Eye Movements as Proxy for Visual Working Memory Usage: Increased Reliance on the External World in Korsakoff Syndrome

In the assessment of visual working memory, estimating the maximum capacity is currently the gold standard. However, traditional tasks disregard that information generally remains available in the external world. Only when to-be-used information is not readily accessible, memory is taxed. Otherwise, people sample information from the environment as a form of cognitive offloading. To investigate how memory deficits impact the trade-off between sampling externally or storing internally, we compared gaze behaviour of individuals with Korsakoff amnesia (n = 24, age range 47-74 years) and healthy controls (n = 27, age range 40-81 years) on a copy task that provoked different strategies by having information freely accessible (facilitating sampling) or introducing a gaze-contingent waiting time (provoking storing). Indeed, patients sampled more often and longer, compared to controls. When sampling became time-consuming, controls reduced sampling and memorised more. Patients also showed reduced and longer sampling in this condition, suggesting an attempt at memorisation. Importantly, however, patients sampled disproportionately more often than controls, whilst accuracy dropped. This finding suggests that amnesia patients sample frequently and do not fully compensate for increased sampling costs by memorising more at once. In other words, Korsakoff amnesia resulted in a heavy reliance on the world as 'external memory'.

Prevalences and Indications of Psychotropic Drug Prescriptions in Nursing Home Residents with Korsakoff Syndrome

Psychotropic drugs (PD) are often prescribed to nursing home residents with Korsakoff syndrome (KS). It is unknown whether these drugs are prescribed correctly or whether they are prescribed off-label, for example, to treat behavioral symptoms. To get more insight into PD prescriptions, a descriptive study was performed. The type, category and indications of PD prescriptions of 285 participants were analyzed using medication charts and questionnaires. Behavioral symptoms were investigated with the Neuropsychiatric Inventory-Questionnaire. The results showed that atypical antipsychotics (57.1%) were prescribed more frequently than typical antipsychotics (49.3%). Of the antidepressants, selective serotonin/norepinephrine reuptake inhibitors (63.1%) were most frequently prescribed, followed by tricyclic antidepressants (23.4%). Of the benzodiazepines, anxiolytics (85.7%) were more prescribed than hypnotics (24.5%). Besides psychiatric disorders, PD were also prescribed to treat behavioral symptoms varying from 29.9% (antipsycho-tics) to 26.3% (benzodiazepines) and 9.3% (antidepressants). Furthermore, prescriptions were high if behavioral symptoms were present. To conclude, PD are often prescribed to residents with KS for an unapproved indication, namely behavioral symptoms. Additional research is needed to obtain further insight into the current prescribing culture and the effectiveness of PD. The insights thus obtained may, ultimately, contribute to the appropriate prescription of PD for people with KS.

Impaired Awareness in People with Severe Alcohol-Related Cognitive Deficits Including Korskoff's Syndrome: A Network Analysis

BACKGROUND

Impaired awareness of one's own functioning is highly common in people with Korsakoff's syndrome (KS). However, it is currently unclear how awareness relates to impairments in daily functioning and quality of life (QoL).

METHODS

We assessed how impaired awareness relates to cognitive, behavioral, physical, and social functioning and QoL by applying a network analysis. We used cross-sectional data from 215 patients with KS or other severe alcohol-related cognitive deficits living in Dutch long-term care facilities (LTCFs).

RESULTS

Apathy has the most central position in the network. Higher apathy scores relate positively to reduced cognition and to a greater decline in activities of daily living and negatively to social participation and the use of antipsychotic drugs. Impaired awareness is also a central node. It is positively related to a higher perceived QoL, reduced cognition and apathy, and negatively to social participation and length of stay in the LTCF. Mediated through apathy and social participation, impaired awareness is indirectly related to other neuropsychiatric symptoms.

CONCLUSIONS

Impaired awareness is closely related to other domains of daily functioning and QoL of people with KS or other severe alcohol-related cognitive deficits living in LTCFs. Apathy plays a central role. Network analysis offers interesting insights to evaluate the interconnection of different symptoms and impairments in brain disorders such as KS.

Coordination and Cognition in Pure Nutritional Wernicke's Encephalopathy with Cerebellar Degeneration after COVID-19 Infection: A Unique Case Report

BACKGROUND

Alcoholic cerebellar degeneration is a restricted form of cerebellar degeneration, clinically leading to an ataxia of stance and gait and occurring in the context of alcohol misuse in combination with malnutrition and thiamine depletion. However, a similar degeneration may also develop after non-alcoholic malnutrition, but evidence for a lasting ataxia of stance and gait and lasting abnormalities in the cerebellum is lacking in the few patients described with purely nutritional cerebellar degeneration (NCD).

METHODS

We present a case of a 46-year-old woman who developed NCD and Wernicke's encephalopathy (WE) due to COVID-19 and protracted vomiting, resulting in thiamine depletion. We present her clinical course over the first 6 months after the diagnosis of NCD and WE, with thorough neuropsychological and neurological examinations, standardized clinical observations, laboratory investigations, and repeated MRIs.

RESULTS

We found a persistent ataxia of stance and gait and evidence for an irreversible restricted cerebellar degeneration. However, the initial cognitive impairments resolved.

CONCLUSIONS

Our study shows that NCD without involvement of alcohol neurotoxicity and with a characteristic ataxia of stance and gait exists and may be irreversible. We did not find any evidence for lasting cognitive abnormalities or a cerebellar cognitive-affective syndrome (CCAS) in this patient.

Distinct Sleep Alterations in Alcohol Use Disorder Patients with and without Korsakoff's Syndrome: Relationship with Episodic Memory

Alcohol Use Disorder (AUD) results in sleep disturbances that may have deleterious impacts on cognition, especially on memory. However, little is known about the sleep architecture in patients with Korsakoff's syndrome (KS). This study aims at characterizing sleep disturbances in KS compared to AUD without KS and at specifying the relationships with cognitive impairments. Twenty-nine AUD patients (22 without KS and 7 with KS) and 15 healthy controls underwent a neuropsychological assessment and a polysomnography. The severity of sleep-disordered breathing and sleep fragmentation was similar in AUD and KS patients compared to controls. Sleep architecture differed between both patient groups: the proportion of slow-wave sleep was reduced in AUD patients only, while a lower proportion of rapid-eye movement (REM) sleep was specifically observed in KS patients. The proportion of REM sleep correlated with the severity of episodic memory deficits when AUD and KS were examined together. These data provide evidence for both similarities and specificities regarding sleep alterations in AUD patients with and without KS. They also indicate that altered sleep architecture may contribute to the pathophysiology of alcohol-related memory disorders.

Factors Associated with ADL Dependence in Nursing Home Residents with Korsakoff’s Syndrome and Other Alcohol-Related Disorders: An Explorative Cross-Sectional Study

Difficulties in performing activities of daily living (ADL) are common in patients with Korsakoff‘s syndrome (KS). The aim of this study was to identify factors associated with ADL dependence in nursing home residents with KS. This exploratory, cross-sectional study included 281 residents with KS from 9 specialized nursing homes in the Netherlands. We examined demographic, cognitive, somatic, and (neuro)psychiatric characteristics. ADL dependence was assessed with the Inter-RAI ADL Hierarchy Scale. Multivariable logistic regression analyses were used to identify factors associated with ADL dependence. Cognitive impairment (odds ratio [OR] = 7.46; 95% confidence interval [CI] = 2.10–30.5), female gender (OR = 3.23; CI, 1.21–8.78), staying in a nursing home for ≥5 years (OR = 3.12; CI, 1.24–8.33), and impaired awareness (OR = 4.25; CI, 1.56–12.32) were significantly associated with higher ADL dependence. Chronic obstructive pulmonary disease (COPD) was significantly associated with lower ADL dependence (OR = 0.31; CI, 0.01–0.84). The model explained 32% of the variance. The results suggest that when choosing interventions aimed at improving ADL functioning, special attention should be paid to residents living more than five years in the nursing home, with a female gender, with more severe cognitive impairments, and/or with COPD.

"Cinderella was attacked by the big bad wolf, but the police saved her": intrusions and confabulations on story recall in Korsakoff's syndrome and alcohol-related cognitive impairments

BACKGROUND

The relation between confabulations and intrusions in patients with Korsakoff's syndrome (KS) and patients with alcohol-related cognitive impairments (ARCI) remains under debate. This study examines (1) differences in the production of confabulations and intrusions between patients with KS and ARCI, (2) whether an altered fairy tale induces more intrusions, and (3) whether different types of intrusions were significantly related to confabulations.

METHODS

Twenty-three patients with KS and twenty-two patients with ARCI recalled three different types of stories: a novel story, a fairy tale, and a modified fairy tale. Different types of intrusions were correlated with confabulation measures.

RESULTS

Patients with KS produced more intrusions in the modified fairy tale condition than patients with ARCI, but these were unrelated to confabulations. Only unrelated intrusions were related to provoked confabulations.

CONCLUSIONS

The results of this study indicate that researchers and clinicians must be aware that in general, intrusions on memory tests should not be interpreted as confabulations. Especially spontaneous confabulations appear to be something completely different from intrusions on any type of story recall. When measuring confabulations it is crucial to use validated instruments.