Altered Mental Status and Cardiac Failure Due to Thiamine Deficiency in an Overweight Teen.

We describe an overweight but otherwise previously healthy 17-year-old female who presented with altered mental status and rapidly progressive weakness. She was ultimately diagnosed with Wernicke encephalopathy and wet beriberi resulting from severe thiamine deficiency. She required admission to the pediatric ICU because of hypoventilation with progressive weakness and worsening encephalopathy and was found to have impaired cardiac function as assessed by echocardiography. Her heart function and encephalopathy improved on initiation of thiamine repletion. She remained in inpatient rehabilitation for 10 months but still remained weak at discharge. Thiamine deficiency is not commonly considered in the United States as a diagnosis other than in patients with severe alcohol use disorder. However, thiamine may be depleted in as little as 2 weeks if nutrition is inadequate. In such a setting, thiamine deficiency is an important etiology to consider early in the pediatric patient with altered mentation especially because it can be readily and safely treated.

Thiamine administration in septic shock: a post hoc analysis of two randomized trials.

BACKGROUND: This is a post hoc analysis of combined cohorts from two previous Phase II clinical trials to assess the effect of thiamine administration on kidney protection and mortality in patients with septic shock. METHODS: Patient-level data from the Thiamine in Septic Shock Trial (NCT01070810) and the Thiamine for Renal Protection in Septic Shock Trial (NCT03550794) were combined in this analysis. The primary outcome for the current study was survival without the receipt of renal replacement therapy (RRT). Analyses were performed on the overall cohort and the thiamine-deficient cohort (thiamine < 8 nmol/L). RESULTS: Totally, 158 patients were included. Overall, thiamine administration was associated with higher odds of being alive and RRT-free (adjusted odds ratio [aOR]: 2.05 [95% confidence interval (CI) 1.08-3.90]) and not needing RRT (aOR: 2.59 [95% CI 1.01-6.62]). In the thiamine-deficient group, thiamine administration was associated with higher odds of being alive and RRT-free (aOR: 8.17 [95% CI 1.79-37.22]) and surviving to hospital discharge (aOR: 6.84 [95% CI 1.54-30.36]). There was a significant effect modification by baseline thiamine deficiency for alive and RRT-free (interaction, p = 0.016) and surviving to hospital discharge (p = 0.019). CONCLUSION: In the combined analysis of two previous randomized trials, thiamine administration was associated with higher odds of being alive and RRT-free at hospital discharge in patients with septic shock. This signal was stronger in patients with thiamine deficiency.

Subclinical thiamine deficiency results in failed reproduction in Arctic foxes.

Thiamine deficiency can result in life-threatening physiological and neurological complications. While a thiamine-deficient diet may result in the onset of such symptoms, the presence of thiaminase - an enzyme that breaks down thiamine - is very often the cause. In such instances, thiaminase counteracts the bioavailability and uptake of thiamine, even when food-thiamine levels are adequate. Here, we report on a case of failed reproduction in seven Arctic fox (Vulpes lagopus) breeding pairs kept at a captive breeding facility, including the presentation of severe thiamine deficiency symptoms in two male foxes. Symptoms included ataxia, obtundation, truncal sway, star-gazing and visual impairment. Blood tests were inconclusive, yet symptoms resolved following treatment with a series of thiamine hydrochloride injections, thereby verifying the diagnosis. A fish-dominated feed, which for the first time had been frozen for a prolonged period, was identified as the likely source of thiaminase and subsequent deterioration in the animals' health. Symptoms in the two males arose during the annual mating period. All seven breeding pairs at the captive breeding station failed to reproduce - a phenomenon never recorded during the captive breeding facility's preceding 17-year operation. Relating our findings to peer-reviewed literature, the second part of this case report assesses how thiamine deficiency (due to thiaminase activity) likely resulted in subclinical effects that impaired the production of reproduction hormones, and thereby led to a complete breeding failure. While previous work has highlighted the potentially lethal effects of thiamine deficiency in farmed foxes, this is, to our knowledge the first study showing how subclinical effects in both males and females may inhibit reproduction in foxes in general, but specifically Arctic foxes. The findings from our case report are not only relevant for captive breeding facilities, but for the welfare and management of captive carnivorous animals in general.

Diagnosis and treatment of Wernicke's encephalopathy: A systematic literature review.

BACKGROUND: Wernicke's encephalopathy (WE) is a serious neurological disorder that is underdiagnosed. Despite limited clinical guidelines, the standard use of intravenous (IV) thiamine is underutilized and remains an area of research deserving much attention. OBJECTIVES: We conducted a systematic review using Medline, Embase, and CENTRAL databases to identify and summarize the literature on IV thiamine treatment in WE. Human studies with WE patients who received ≥100 mg of thiamine IV met inclusion criteria. Randomized controlled trials, cross-sectional studies, and case reports were included. RESULTS: A total of 27 studies were included: 20 case reports, five retrospective studies, one prospective study and one randomized control trial. Of the case reports, 11 (55%) cases were female, and the average age of all cases was 45 years (SD = 15). The other seven studies included 688 patients; the average age was 52 years (SD = 9), and 266 (38.7%) were female. Among the case reports, neurological and clinical findings were used to diagnose WE in 16 (80%) cases. MRI was utilized to diagnose 15 (75%) cases. 500 mg IV thiamine TID was reported in 12 case reports (60%). 18 (90%) of case reports had partial or complete resolution of symptoms following IV thiamine. CONCLUSION: IV thiamine can alleviate neurological symptoms, cognitive dysfunction, and brain imaging lesions associated with WE. We found key limitations in the evidence for IV thiamine and diagnostic standards for WE. Future targeted research should establish clear diagnostic and treatment guidelines for WE to prevent this serious condition from being underdiagnosed or undertreated.

Metabolic failure due to thiamine deficiency during critical illness.

PURPOSE OF REVIEW: Thiamine is a crucial component in cellular energy metabolism, serving as a cofactor for multiple enzymatic processes and also having a role in regulating neuronal and neuromuscular transmission. Also it exerts antioxidant proprieties. The objective of this review is to consolidate and assess the most recent research concerning the consequences of insufficient thiamine levels for critically ill patients and to examine thiamine-related interventions. RECENT FINDINGS: Recent studies have unveiled a noteworthy association between thiamine deficiency and unfavorable consequences, such as heightened morbidity and fatality rates. The aforementioned deficiency exhibits a significant presence in medical situations such as starvation and alcohol use disorder, but also in patients during critical illness. Thiamine deficiency can have significant metabolic implications resulting in compromised energy generation and organ dysfunction, warranting prompt recognition and management. SUMMARY: Thiamine deficiency may not be recognized in critical care. Timely identification and management are imperative to mitigate adverse outcomes and improve patient prognosis. Thiamine may offer benefits for specific patient groups at higher risk of deficiency. Future studies should focus to establish optimal dosing, timing, and monitoring strategies on understanding the pathophysiological changes associated with thiamine deficiency in ICU patients and clarify its role in improving clinical outcomes.

Atypical Wernicke's encephalopathy without mental status changes following bariatric surgery in an adolescent patient.

Morbid obesity is a systemic disease which can result in chronic complications, including hypertension, diabetes mellitus, depression, osteoarthritis and low self-esteem in the adolescent population.Bariatric surgery can be indicated to treat more severe forms of obesity, but these procedures are not without long-term risks. Therefore, adequate preoperative and postoperative care, which includes preoperative psychosocial evaluation for compliance, ongoing nutrition counselling and vitamin and micronutrient supplementation, is required for all patients, especially adolescent patients, who generally may not comply with medical therapies and/or be able to developmentally fully appreciate or comprehend the health consequences of their behaviours, prior to as well as after bariatric surgery to prevent complications.Thiamine pyrophosphate, an active form of thiamine (also known as vitamin B1, a water-soluble vitamin), which functions as a coenzyme in glucose and energy metabolism, is one such vitamin that requires supplementation postoperatively. It is mandatory for glucose to be administered concomitantly with thiamine, as glucose alone can precipitate Wernicke's encephalopathy (WE) in thiamine-deficient individuals. WE is a medical emergency, with a mortality rate of up to 20%. WE is best understood as a classic triad of mental confusion, gait ataxia and eye movement abnormalities, and atypical WE or Wernicke's syndrome (WS) is seen when the classic triad is not present. Cases that meet some, but do not necessarily meet all three criteria, are referred to as atypical WE or WS which can lead to delayed diagnosis. Atypical WE has an incidence of 19% which can lead to misdiagnosis of a preventable medical emergency with fatal complications.The following case reviews the consequences of post-bariatric thiamine supplementation therapy non-adherence and resulting in a deficiency in an adolescent patient.

Establishment of a reference interval for thiamine concentrations in healthy dogs and evaluation of the prevalence of absolute thiamine deficiency in critically ill dogs with and without sepsis using high-performance liquid chromatography.

OBJECTIVE: To determine the normal reference interval (RI) for thiamine concentrations in healthy dogs and investigate the prevalence of thiamine deficiency in critically ill dogs with and without sepsis. DESIGN: Prospective, observational, multicenter study, conducted between 2019 and 2021. SETTING: Two veterinary university teaching hospitals. ANIMALS: A total of 109 dogs were enrolled into 3 groups: 40 healthy dogs, 33 dogs with suspected or confirmed sepsis and evidence of tissue hypoperfusion (Doppler blood pressure ≤90 mm Hg or plasma lactate ≥3 mmol/L), and 36 dogs with other critical illnesses and evidence of tissue hypoperfusion. INTERVENTIONS: For each dog, CBC, serum biochemistry, plasma lactate concentration, whole-blood thiamine concentration, blood pressure, vital parameters, Acute Patient Physiologic and Laboratory Evaluation (APPLE)fast score, and clinical outcomes were recorded, alongside basic patient parameters and dietary history. Whole-blood thiamine pyrophosphate (TPP) concentrations were measured using high-performance liquid chromatography. MEASUREMENTS AND MAIN RESULTS: The RI for whole-blood TPP in healthy dogs was 70.9-135.3 µg/L. Median TPP concentrations were significantly lower in septic dogs compared to healthy controls (P = 0.036). No significant difference in median TPP concentrations was found between septic dogs and nonseptic critically ill dogs, or between healthy dogs and nonseptic critically ill dogs. TPP concentrations were below the normal RI in 27.3% of septic dogs, compared to 19.4% of nonseptic critically ill dogs (P = 0.57). No correlations were found between TPP concentrations and lactate concentrations, age, body condition scores, time since last meal, RBC count, serum alanine aminotransferase, APPLEfast scores, or patient outcomes. CONCLUSIONS: TPP concentrations were significantly lower in septic dogs compared to healthy controls, with an absolute thiamine deficiency found in 27.3% of septic dogs. The established TPP RI allows for further investigation of thiamine deficiency in critically ill dogs.

Thiamine deficiency-related neuropathy: A reversible entity from an endemic area.

BACKGROUND AND PURPOSE: Despite thiamine deficiency being a lesser-known entity in modern times, beriberi in various forms, including thiamine deficiency-related neuropathy, remains endemic in Kashmir due to the consumption of polished rice as a staple food. This observational study investigates cases of peripheral neuropathy of unknown etiology and their potential responsiveness to thiamine administration. METHODS: This prospective study enrolled adult patients presenting to the emergency department with weakness consistent with thiamine deficiency-related neuropathy and conducted a therapeutic challenge with thiamine on 41 patients. Response to thiamine therapy was monitored based on subjective and objective improvements in weakness and power. Patients were divided into thiamine responders (n = 25) and nonresponders (n = 16) based on their response to thiamine therapy and nerve conduction studies. RESULTS: Most of the baseline characteristics were similar between responders and nonresponders, except the responders exhibited lower thiamine levels and higher partial pressure of oxygen and lactate levels compared to nonresponders. All patients had a history of consuming polished rice and traditional salt tea. Although weakness in the lower limbs was present in both groups, nonresponders were more likely to exhibit weakness in all four limbs. Clinical improvement was observed within 24 h, but proximal muscle weakness persisted for an extended period of time. CONCLUSIONS: Thiamine deficiency-related neuropathy presents with predominant lower limb weakness, exacerbated by vomiting, poor food intake, psychiatric illness, and pregnancy. Thiamine challenge should be followed by observation of clinical and biochemical response.

What can cause cancer patients to attempt suicide? Thiamine deficiency mimicking the symptoms of major depressive disorder.

OBJECTIVES: Thiamine deficiency (TD) presents with various physical and psychiatric symptoms, but no cases with depression-like symptoms have been reported. METHODS: We report a patient with cancer who appeared to attempt suicide as a consequence of depressive mood likely related to TD. RESULTS: The patient was a 58-year-old woman diagnosed with recurrent endometrial cancer, with lung metastasis and pelvic dissemination. The patient apparently attempted suicide was referred to the psycho-oncology department. At the time of the examination, major depressive disorder was suspected based on her mental symptoms, but when thiamine was administered intravenously in response to her poor dietary intake, her palpitations, dyspnea, anorexia, and insomnia improved, and her suicidal ideation disappeared at her reexamination 1 hour later after thiamine administration. SIGNIFICANCE OF RESULTS: It is likely that the observed palpitations, dyspnea, anorexia, and insomnia, as well as the severe depression and the attempted suicide, which were thought to be physical symptoms associated with depression, were actually related to TD. Suicidal ideation and attempted suicide are conspicuous as psychiatric symptoms. However, in such cases, rather than simply starting treatment for depression, it is necessary to consider reversible TD as a cause of these symptoms and perform differential diagnosis to confirm the physical illness.

Infrequent but serious? Beriberi And Thiamine deficiency among adolescents and young adults after bariatric surgery.

BACKGROUND: Thiamine deficiency (TD) among adolescents following metabolic and bariatric surgery (MBS) has not been assessed. OBJECTIVE: We assessed TD among adolescents following MBS. SETTING: University Hospital. METHODS: A retrospective chart review was conducted for all adolescents and young adults (aged 10-25 years) who had MBS and subsequently presented with TD at our institution (n = 30). Diagnosis used clinical, laboratory, brain imaging, and neurophysiology criteria. Of 1575 patients, 7 subsequently had TD. Another 23 adolescents had MBS at private hospitals or overseas and presented at our institution with TD. RESULTS: Based on MBS undertaken at our institution, TD prevalence was .45 cases per 100 MBS. The mean age of patients was 19.5 ± 3.23 years, 53.3% were male, 96.7% had sleeve gastrectomy, and time from MBS to admission averaged 4.97 ± 11.94 months. Mean weight loss from surgery to admission was 33.68 ± 10.90 kg. Associated factors included poor oral intake (90%), nausea and vomiting (80%), and noncompliance with multivitamins (71%). Signs and symptoms included generalized weakness, nystagmus, numbness, and paraparesis (83.3%-80%). Seven patients had Wernicke encephalopathy full triad; 16 displayed a mixed picture of Wernicke encephalopathy and dry beriberi; and there were no cases of wet beriberi. Half the patients achieved complete resolution of symptoms, whereas 47% and 40% had residual weakness or persistent sensory symptoms, respectively. There was no mortality. Most common concurrent nutritional deficiencies were of vitamins K, D, and A. CONCLUSIONS: This is the first in-depth study of TD among adolescents after MBS. Although TD is uncommon among adolescents after MBS, it is serious, requiring diligent suspicion and prompt treatment. Bariatric teams should emphasize compliance with multivitamin regimens and follow it up.

Descriptive spectrum of thiamine deficiency in pregnancy: A potentially preventable condition.

OBJECTIVE: Pregnancy, a nutritionally demanding situation in terms of macro- and micronutrient supply owing to heightened maternal, placental, and fetal needs, significantly affects thiamine reserves. Thiamine deficiency during pregnancy and the postpartum period, presenting with varied manifestations and outcomes, is a relatively common condition in our population. The study aimed to understand the various manifestations and outcomes of acute thiamine deficiency in pregnant and postpartum women, emphasizing the significance of early recognition and thiamine therapy to prevent serious complications during pregnancy and after childbirth. METHODS: This prospective study conducted in a tertiary care center in North India enrolled consecutive pregnant and postpartum women presenting with clinical features consistent with thiamine deficiency disorders, such as thiamine deficiency-related neuropathy, high-output heart failure, heart failure with reduced ejection fraction, Wernicke's encephalopathy, gastric beriberi, and thiamine-responsive acute pulmonary hypertension. In addition to capturing medical history including drug intake, dietary consumption, and comorbidities, women underwent brief relevant clinical examinations and laboratory assessments, including whole-blood thiamine levels. Response to intravenous thiamine supplementation was also monitored. RESULTS: Data of 31 women (12 pregnant, 19 postpartum) with a diagnosis of acute thiamine deficiency and a mean age of 28.88 ± 2.69 years were analyzed. The mean thiamine level was 1.28 ± 0.44 µg/dL with mean blood lactate of 3.46 ± 3.33. The most common presentation was gastric beriberi (n = 10), followed by paraparesis (n = 6), high-output heart failure (n = 6), acute pulmonary hypertension, heart failure with reduced ejection fraction (n = 3 each), and an acute confusional state (n = 2). All patients responded to thiamine challenge. CONCLUSION: In the context of borderline thiamine status, particularly in our population with endemic thiamine deficiency and heightened demand for thiamine during pregnancy and the peripartum period, the deficiency can have varied and serious manifestations of dry and wet beriberi. Early recognition of the clinical features and thiamine therapy can be life-saving. There is a need for validated clinical criteria owing to the non-availability of thiamine testing in resource-limited settings.

Risk factors for anaemia among women and their young children hospitalised with suspected thiamine deficiency in northern Lao PDR.

Anaemia among women and young children remains a major public health concern. This secondary study describes the anaemia prevalence among young hospitalised children and their mothers in northern Lao People's Democratic Republic and explores possible nutritional causes and risk factors for anaemia. Hospitalised children (ages 21 days to <18 months) with clinical symptoms suggestive of thiamine deficiency disorders were eligible along with their mothers. Venous blood was collected for determination of haemoglobin, ferritin, soluble transferrin receptor (sTfR), retinol-binding protein (RBP), erythrocyte glutathione reductase activation coefficient (EGRac), thiamine diphosphate (ThDP) and acute phase proteins. Risk factors for anaemia were modelled using minimally adjusted logistic regression controlling for age. Haemoglobin results were available for 436 women (mean ± SD age 24.7 ± 6.4 years; 1.6% pregnant) and 427 children (4.3 ± 3.5 months; 60.3% male). Anaemia prevalence (Hb < 120 g/L for nonpregnant women and <110 g/L for pregnant women and children) was 30.7% among women and 55.2% among children. In bivariate analyses, biomarkers significantly associated with anaemia in women were ferritin, sTfR, RBP, EGRac and ThDP. Other risk factors for women were lower BMI, mid-upper arm circumference < 23.5 cm, lower education, lower socioeconomic index, food insecurity, Hmong ethnicity, not/rarely having attended antenatal care, not having taken antenatal iron-containing supplements and not meeting minimum dietary diversity. Risk factors for anaemia among children were older age, male sex, stunting, sTfR, ThDP and alpha-1-acid-glycoprotein. Anaemia was common among women and their hospitalised children and was associated with micronutrient deficiencies and socioeconomic, dietary and health care-seeking risk factors, suggesting that multiple strategies are required to prevent anaemia among women and children.

Fatal cerebral air embolism from atrio-oesophageal fistula following cardiac ablation.

A young woman with Rogers syndrome (thiamine-responsive megaloblastic anaemia, diabetes mellitus and sensorineural deafness) presented with headache, recurrent supraventricular tachycardia and features of an upper gastrointestinal bleed, 1 month after radiofrequency cardiac ablation for supraventricular tachycardia. She deteriorated rapidly after endoscopy and subsequently died. Brain imaging during the acute deterioration showed diffuse intracranial air embolism and hypoxic-ischaemic injury. Postmortem examination showed an atrio-oesophageal fistula, a rare complication of cardiac ablation. Clinicians should suspect this condition in patients with acute neurological deterioration after cardiac ablation who have diffuse air embolism on imaging.

Pre- and Post-surgical Prevalence of Thiamine Deficiency in Patients Undergoing Bariatric Surgery: a Systematic Review and Meta-analysis.

Thiamine deficiency is a life-threatening nutritional abnormality observed in the patients with obesity and following bariatric surgery. The aim of the present study is to determine the prevalence of thiamine deficiency prior to and after bariatric procedures. PubMed, Web of Science, Google scholar, CENTRAL, ProQuest, and Scopus were searched to retrieve relevant studies containing data on thiamine deficiency in patients with obesity who underwent bariatric surgery. A proportional meta-analysis approach was used to pool the prevalence of thiamine deficiency prior and after surgery. Our comprehensive literature search retrieved 41 studies with relevant data. The pooled prevalence of thiamine deficiency was 7% (95% CI: 4-12%) at baseline. We observed that 19% (95% CI: 0-68%), 9% (95% CI: 3-17%), and 6% (95% CI: 3-9%) of patients had developed thiamine deficiency at 3 months, 6 months, and 1 year after surgery, respectively. We also report that the prevalence of thiamine deficiency in pregnant women who had history of bariatric surgery. The rate was highest in the first trimester (12%) compared to that in the second (8%) and third (10%) trimesters. The baseline prevalence is 7% for thiamine deficiency in bariatric surgery candidates. The prevalence rate of thiamin deficiency increased to 19% and 9% 3 and 6 months after surgery; however, the rate decreased to 6% 1 year after surgery. Due to the higher prevalence of thiamine deficiency in the early post-operative phase, close monitoring during this period is recommended. A similar strategy should be implemented for pregnant women with history of bariatric surgery in their first trimester.

Connecting thiamine availability to the microbial community composition in Chinook salmon spawning habitats of the Sacramento River basin.

Thiamine deficiency complex (TDC) is a major emerging threat to global populations of culturally and economically important populations of salmonids. Salmonid eggs and embryos can assimilate exogenous thiamine, and evidence suggests that microbial communities in benthic environments can produce substantial amounts of thiamine. We therefore hypothesize that natural dissolved pools of thiamine exist in the surface water and hyporheic zones of riverine habitats where salmonids with TDC migrate, spawn, and begin their lives. To examine the relationship between dissolved thiamine-related compounds (dTRCs) and their microbial source, we determined the concentrations of these metabolites and the compositions of microbial communities in surface and hyporheic waters of the Sacramento River, California and its tributaries. Here we determine that all dTRCs are present in femto-picomolar concentrations in a range of critically important salmon spawning habitats. We observed that thiamine concentrations in the Sacramento River system are orders of magnitude lower than those of marine waters, indicating substantial differences in thiamine cycling between these two environments. Our data suggest that the hyporheic zone is likely the source of thiamine to the overlying surface water. Temporal variations in dTRC concentrations were observed where the highest concentrations existed when Chinook salmon were actively spawning. Significant correlations were seen between the richness of microbial taxa and dTRC concentrations, particularly in the hyporheic zone, which would influence the conditions where embryonic salmon incubate. Together, these results indicate a connection between microbial communities in freshwater habitats and the availability of thiamine to spawning TDC-impacted California Central Valley Chinook salmon.IMPORTANCEPacific salmon are keystone species with considerable economic importance and immeasurable cultural significance to Pacific Northwest indigenous peoples. Thiamine deficiency complex has recently been diagnosed as an emerging threat to the health and stability of multiple populations of salmonids ranging from California to Alaska. Microbial biosynthesis is the major source of thiamine in marine and aquatic environments. Despite this importance, the concentrations of thiamine and the identities of the microbial communities that cycle it are largely unknown. Here we investigate microbial communities and their relationship to thiamine in Chinook salmon spawning habitats in California's Sacramento River system to gain an understanding of how thiamine availability impacts salmonids suffering from thiamine deficiency complex.

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.

Evolutionary and ecological correlates of thiaminase in fishes.

Thiamine (vitamin B1) is required by all living organisms in multiple metabolic pathways. It is scarce in natural systems, and deficiency can lead to reproductive failure, neurological issues, and death. One major cause of thiamine deficiency is an overreliance on diet items containing the enzyme thiaminase. Thiaminase activity has been noted in many prey fishes and linked to cohort failure in salmonid predators that eat prey fish with thiaminase activity, yet it is generally unknown whether evolutionary history, fish traits, and/or environmental conditions lead to production of thiaminase. We conducted literature and GenBank BLAST sequence searches to collect thiaminase activity data and sequence homology data in expressed protein sequences for 300 freshwater and marine fishes. We then tested whether presence or absence of thiaminase could be predicted by evolutionary relationships, trophic level, omega-3 fatty acid concentrations, habitat, climate, invasive potential, and body size. There was no evolutionary relationship with thiaminase activity. It first appears in Class Actinoptergyii (bony ray-finned fishes) and is present across the entire Actinoptergyii phylogeny in both primitive and derived fish orders. Instead, ecological factors explained the most variation in thiaminase: fishes were more likely to express thiaminase if they fed closer to the base of the food web, were high in polyunsaturated fatty acids, lived in freshwater, and were from tropical climates. These data provide a foundation for understanding sources of thiaminase leading to thiamine deficiency in fisheries and other organisms, including humans that eat uncooked fish.

Wernicke Encephalopathy After Bariatric Surgery: a Literature Review.

Wernicke encephalopathy (WE) is an acute neurological disorder classically characterized by ataxia, ophthalmoplegia, and altered mental status. This is caused by thiamine deficiency and is usually seen in malnourished populations. However, with the advent and rise of bariatric surgery in the last 50 years, WE has become an increasingly recognized and potentially deadly complication. Here, we review the populations at risk, clinical presentation, and the incidence of WE in the bariatric surgery population from 1985 to 2023. While the predominant procedure shifts throughout the years, the overall incidence of WE per 100,000 cases for the following procedures are sleeve gastrectomy (1.06), gastric band (1.16), RYGB (4.29), and biliopancreatic diversion with duodenal switch (8.92). Thus, early intervention and post-operative supplementation is recommended to prevent WE.