Whole blood thiamine, intravenous thiamine supplementation and delirium occurrence in the intensive care unit: retrospective cohort analyses.

BACKGROUND: Thiamine di-phosphate is an essential cofactor in glucose metabolism, glutamate transformation and acetylcholinesterase activity, pathways associated with delirium occurrence. We hypothesised that a deficiency in whole blood thiamine and intravenous thiamine supplementation could impact delirium occurrence. AIM: To establish whether a deficiency in whole blood thiamine and/or intravenous thiamine supplementation within 72 h of intensive care admission is associated with delirium occurrence. METHOD: The first dataset was secondary analysis of a previous study in an intensive care unit in the Netherlands, reported in 2017. The second dataset contained consecutive intensive care admissions 2 years before (period 1: October 2014 to October 2016) and after (period 2: April 2017 to April 2019) routine thiamine supplementation was introduced within 72 h of admission. Delirium was defined as a positive Confusion Assessment Method-Intensive Care Unit score(s) in 24 h. RESULTS: Analysis of the first dataset (n = 57) using logistic regression showed no relationship between delirium and sepsis or whole blood thiamine, but a significant association with age (p = 0.014). In the second dataset (n = 3074), 15.1% received IV thiamine in period 1 and 62.6% during period 2. Hierarchical regression analysis reported reduction in delirium occurrence in the second period; this did not reach statistical significance, OR = 0.81 (95% CI 0.652-1.002); p = 0.052. CONCLUSION: No relationship was detected between whole blood thiamine and delirium occurrence on admission, at 24 and 48 h. It remains unclear whether routine intravenous thiamine supplementation during intensive care admission impacts delirium occurrence. Further prospective randomised clinical trials are needed.

Relapse of rare diseases during COVID-19 pandemic: bicytopenia in an adult patient with thiamine-responsive megaloblastic anaemia.

Thiamine-responsive megaloblastic anaemia (TRMA) is a syndrome associated with megaloblastic anaemia, diabetes mellitus and sensorineural deafness, due to mutations in the SLC19A2gene, which codes for a thiamine carrier protein. Oral thiamine supplementation is the main treatment. We report the case of a 19-year-old man known for TRMA, who presented in the emergency department with bicytopenia (haemoglobin 5,4 g/dL, thrombocytes 38×109/L) revealed by dyspnea and chest pain. Investigations excluded bleeding, hemolysis, coagulopathy and iron deficiencies. A recent infection and an acute coronary syndrome have also been eliminated. We later found out that thiamine treatment had been discontinued three months before, due to general confinement in Tunisia during the COVID-19 pandemic. Parenteral administration of 100 mg of thiamine daily resulted in the recovery of haematopoiesis within three weeks.

Pathophysiology, prevention, and treatment of beriberi after gastric surgery.

Beriberi is a nutritional complication of gastric surgery, caused by deficiency of vitamin B1, or thiamine. Thiamine deficiency leads to impaired glucose metabolism, decreased delivery of oxygen by red blood cells, cardiac dysfunction, failure of neurotransmission, and neuronal death. This review describes the history and pathophysiology of beriberi as well as the relationship between beriberi and nutritional deficiencies after gastric surgery. A literature review of the history and pathophysiology of beriberi and the risk factors for thiamine deficiency, particularly after gastric resection or bariatric surgery, was performed. Recommendations for nutritional follow-up post gastric surgery are based on current national guidelines. Patients may have subclinical thiamine deficiency after upper gastrointestinal surgery, and thus beriberi may be precipitated by acute illness such as sepsis or poor dietary intake. This may occur very soon or many years after gastrectomy or bariatric surgery, even in apparently well-nourished patients. Prompt recognition and administration of supplemental thiamine can decrease morbidity and mortality in patients with beriberi. Dietary education post surgery and long-term follow-up to determine nutritional status, including vitamin and mineral assessment, is recommended for patients who undergo gastric surgery.

Thiamine deficiency and oxidative stress induced by prolonged metronidazole therapy can explain its side effects of neurotoxicity and infertility in experimental animals: Effect of grapefruit co-therapy.

We aimed to explore the possible neurotoxicity and infertility mechanisms of prolonged metronidazole (MTZ) use and the effects of antioxidant grapefruit (GP) co-therapy on MTZ-induced complications. Sixty male albino Wistar rats were divided into four groups (n = 15 each). Group I (control group) received 1% dimethyl sulfoxide (27 ml/ kg/day), group II (MTZ group) received MTZ (400 mg/kg/day), group III (MTZ + GP) received MTZ (400 mg/kg/ day) plus GP juice (27 ml/kg/ day) and group IV (GP group) received GP juice (27 ml/kg) for 60 days. Semen analyses were performed. Free testosterone, gonadotrophin (follicle-stimulating hormone (FSH) and luteinizing hormone) and thiamine levels were measured. Samples of cerebellar, testicular and epididymal tissues were used for both colorimetric assays of oxidative stress markers and histopathological examinations. Significant decreases in the sperm count, percent total sperm motility, serum thiamine levels, free testosterone levels and FSH levels were observed in the MTZ and MTZ + GP groups (p < 0.05 for all parameters). Significantly higher oxidative stress levels (p < 0.05) were observed in the cerebellar and testicular tissue homogenates of these groups than in those of the control group, and associated disruptions in the cerebellar, testicular and epididymal structures were apparent compared to those of the control group. Although the GP group showed a significantly higher sperm count and significantly lower oxidative stress than the control group (p < 0.05), with histological similarity to the control group, the GP group exhibited significantly higher prolactin levels and lower free testosterone and FSH levels than the control group (p < 0.05). Oxidative stress and decreased thiamine levels could explain the MTZ-induced neurotoxicity and infertility side effects that aggravated by GP co-administration.

Thiamine status in end-stage chronic kidney disease patients: a single-center study.

BACKGROUND: Reportedly, thiamine deficiency, resulting from malnutrition and long-term diuretic therapy, is observed in patients with chronic kidney disease (CKD). The risk of thiamine deficiency might be enhanced, especially in end-stage CKD patients. Here, we assessed thiamine status in incident dialysis patients. METHODS: This study was a single-center cross-sectional study which included 288 consecutive patients initiated into dialysis between April 2013 and March 2017 at our hospital. Thiamine status was evaluated by high-performance liquid chromatography of whole blood samples. We evaluated the association between blood thiamine concentration and other clinical parameters. RESULTS: Of the 288 patients, 21 patients receiving thiamine supplementation at the time of dialysis initiation and 26 patients without blood thiamine measurements were excluded. In 30 patients (12.4%), blood thiamine concentration was lower than the lower limit of normal (21.3 ng/mL; dotted line). Blood thiamine concentration correlated with age, body mass index, and Barthel index (BI) score (p = 0.008, 0.012 and 0.009, respectively). Stepwise multivariate regression analysis indicated that BI scores were independent risk factors for thiamine deficiency (ß coefficients = 0.169, p = 0.013). CONCLUSIONS: The proportion of end-stage CKD patients with low blood thiamine concentration is high. Low physical function (low BI score) is an independent risk factor of thiamine deficiency. Clinicians should be aware of thiamine deficiency in end-stage CKD patients, especially those with low physical function.

Re-emergence of thiamine deficiency disease in the Pacific islands (2014-15): A case-control study.

BACKGROUND: From late 2014 multiple atolls in Kiribati reported an unusual and sometimes fatal illness. We conducted an investigation to identify the etiology of the outbreak on the most severely affected atoll, Kuria, and identified thiamine deficiency disease as the cause. Thiamine deficiency disease has not been reported in the Pacific islands for >5 decades. We present the epidemiological, clinical, and laboratory findings of the investigation. METHODOLOGY/PRINCIPAL FINDINGS: We initially conducted detailed interviews and examinations on previously identified cases to characterize the unknown illness and develop a case definition. Active and passive surveillance was then conducted to identify additional cases. A questionnaire to identify potential risk factors and blood samples to assay biochemical indices were collected from cases and asymptomatic controls. Thiamine hydrochloride treatment was implemented and the response to treatment was systematically monitored using a five-point visual analogue scale and by assessing resolution of previously abnormal neurological examination findings. Risk factors and biochemical results were assessed by univariate and multivariate analyses. 69 cases were identified on Kuria (7% attack rate) including 34 confirmed and 35 unconfirmed. Most were adults (median age 28 years [range 0-62]) and 83% were male. Seven adult males and two infants died (13% case fatality rate). Resolution of objective clinical signs (78%) or symptoms (94%) were identified within one week of starting treatment. Risk factors included having a friend with thiamine deficiency disease and drinking kava; drinking yeast alcohol reduced the risk of disease. Higher chromium (p<0·001) but not thiamine deficiency (p = 0·66) or other biochemical indices were associated with disease by univariate analyses. Chromium (p<0·001) and thiamine deficiency (p = 0·02) were associated with disease by multivariate analysis. CONCLUSIONS/SIGNIFICANCE: An outbreak of thiamine deficiency disease (beriberi) in Kiribati signals the re-emergence of a classic nutritional disease in the Pacific islands after five decades. Although treatment is safe and effective, the underlying reason for the re-emergence remains unknown. Chromium was highly and positively correlated with disease in this study raising questions about the potential role of factors other than thiamine in the biochemistry and pathophysiology of clinical disease.

[Thiamine in patients with alcohol use disorder and Wernicke's encephalopathy]. / Thiamine bij een alcoholstoornis en Wernicke-encefalopathie.

- Patients with alcohol use disorder frequently have a thiamine deficiency.- A potential life-threatening complication of thiamine deficiency is Wernicke's encephalopathy.- Since it is clinically difficult to recognize Wernicke's encephalopathy, this condition is often treated inadequately. - Early supplementation of thiamine is important to avoid irreversible neurological damage. - There are differences between the Dutch guidelines regarding the supplementation of thiamine for the treatment of alcoholic use disorder, and those for Wernicke's encephalopathy. - There are no solid evidence-based recommendations about the best dosage, route of administration and duration of thiamine supplementation for the treatment of alcohol use disorder and Wernicke's encephalopathy. - Based on the pharmacokinetic properties of thiamine, it is more appropriate to give patients with alcohol use disorder 25 mg four times a day rather than 50 mg twice a day. - Patients at high risk of Wernicke's encephalopathy should immediately receive an intravenous or intramuscular dose of thiamine; patients with suspected Wernicke's encephalopathy should preferably receive an intravenous dose.- Reports of anaphylactic reaction to parenteral administration of thiamine are rare and are not a reason to refrain from parenteral treatment.

Thiamine deficiency, oxidative metabolic pathways and ethanol-induced neurotoxicity: how poor nutrition contributes to the alcoholic syndrome, as Marchiafava-Bignami disease.

Ethanol is an important risk factor for the occurrence of several brain disorders that depend on the amount, period and frequency of its consumption. Chronic use of ethanol often leads to the development of neurodegenerative syndromes, which cause morphological and functional impairments such as foetal alcohol syndrome in newborns exposed to ethanol during pregnancy, Wernicke-Korsakoff Syndrome and, more rarely, Marchiafava-Bignami disease (MBD). MBD is characterized by primary degeneration of the corpus callosum, without inflammation and is associated with oxidative stress and hypovitaminosis, as well as altered mental status, to mention dementia, seizures, depression and so on. This review discusses MBD and poor nutrition as a risk factor for the development of such alcoholic syndrome, with focus on diagnosis, pathogenic aspects, signs and symptoms, as well as therapeutic perspectives. On the basis of the inclusion/exclusion criteria adopted, the performed search in scientific databases (Pubmed, Scielo and Google Scholar) resulted in 100 studies that are being presented and discussed in the present work. Review, case-control and cohort studies on alcoholism-associated hypovitaminosis, oxidative stress, MBD and ethanol metabolism pathways were admitted as relevant. We highlight that MBD is a poorly described, diagnosed, insidious and progressive condition, for which evidence suggests a synergism between ethanol-induced neurotoxic effects and hypovitaminosis B. Present treatment consists of vitamin B1(thiamine) supplementation. Nonetheless, other strategies such as the inclusion of antidepressants or steroidal anti-inflammatories as add-on therapies have been employed as an attempt to improve the damage. Indeed, both the diagnosis and treatment are difficult, and death occurs within few years.

Prevalence of clinical thiamine deficiency in individuals with medically complicated obesity.

Thiamine is a vitamin whose deficient can result in multiorgan symptoms. We described an 18% prevalence of clinical thiamine deficiency after gastric bypass surgery. Our hypotheses are that individuals with medically complicated obesity frequently have clinical thiamine deficiency and that diabetes mellitus is a mechanism for development of clinical thiamine deficiency. This is a single institution, retrospective observational study of consecutive patients with a body mass index of at least 35 kg/m2 who were evaluated in preoperative gastrointestinal bariatric clinic from 2013 to 2015. Each patient underwent a symptom survey. Clinical thiamine deficiency is defined by both (1) consistent clinical symptom and (2) either a low whole-blood thiamine concentration or significant improvement of or resolution of consistent clinical symptoms after receiving thiamine supplementation. After excluding 101 individuals with prior bariatric surgery or heavy alcohol consumption, 400 patients were included in the study. Sixty-six patients (16.5% of 400) fulfill a diagnosis of clinical thiamine deficiency, with 9 (14% of 66) having consistent gastrointestinal manifestations, 46 (70% of 66) having cardiac manifestations, 39 (59% of 66) having peripheral neurologic manifestations, and 3 (5% of 66) having neuropsychiatric manifestations. Diabetes mellitus is not a risk factor (P=.59). Higher body mass index is a significant risk for clinical thiamine deficiency (P=.007). Clinical thiamine deficiency is common in these individuals and a higher body mass index is an identified risk factor. Mechanisms explaining development of thiamine deficiency in obese individuals remain unclear.

The effect of subclinical infantile thiamine deficiency on motor function in preschool children.

We investigated the long-term implications of infantile thiamine (vitamin B1) deficiency on motor function in preschoolers who had been fed during the first 2 years of life with a faulty milk substitute. In this retrospective cohort study, 39 children aged 5-6 years who had been exposed to a thiamine-deficient formula during infancy were compared with 30 age-matched healthy children with unremarkable infant nutritional history. The motor function of the participants was evaluated with The Movement Assessment Battery for Children (M-ABC) and the Zuk Assessment. Both evaluation tools revealed statistically significant differences between the exposed and unexposed groups for gross and fine motor development (p < .001, ball skills p = .01) and grapho-motor development (p = .004). The differences were especially noteworthy on M-ABC testing for balance control functioning (p < .001, OR 5.4; 95% CI 3.4-7.4) and fine motor skills (p < .001, OR 3.2; 95% CI 1.8-4.6). In the exposed group, both assessments concurred on the high rate of children exhibiting motor function difficulties in comparison to unexposed group (M-ABC: 56% vs. 10%, Zuk Assessment: 59% vs. 3%, p < .001). Thiamine deficiency in infancy has long-term implications on gross and fine motor function and balance skills in childhood, thiamine having a crucial role in normal motor development. The study emphasizes the importance of proper infant feeding and regulatory control of breast milk substitutes.

Wernicke encephalopathy in a patient after liver transplantation: A case report.

Wernicke encephalopathy (WE) is an acute neurological disorder resulting from vitamin B1 deficiency, which is common in chronic alcoholism and is rare in acute liver failure. So far, there are 2 cases of WE reported after liver transplantation. Here, we report a case of a 45-year-old nonalcoholic male patient who developed psychiatric and neurological disturbance 15 d after receiving orthotopic liver transplantation because of hepatitis B-related cirrhosis and portal hypertension. Brain magnetic resonance imaging (MRI) showed symmetric high-signal intensities in the periaqueductal area. The patient was diagnosed with WE and given intravenous high-dose vitamin B1 immediately. His neurological disturbance resolved in 7 d after receiving the vitamin B1. Brain MRI after 5 mo showed nearly complete recovery. Most WE cases may be misdiagnosed in patients after liver transplantation, and we should pay more attention to its onset.

High rate of thiamine deficiency among inpatients with cancer referred for psychiatric consultation: results of a single site prevalence study.

OBJECTIVE: Thiamine deficiency (TD) is increasingly recognized in medically ill patients. The prevalence of TD among cancer patients is unknown. This study aims to characterize the prevalence of TD among inpatients with cancer. METHODS: Retrospective chart review of patients admitted to a large cancer center who were referred for psychiatric consultation and whose serum thiamine concentration was measured. Patients with alcohol use were excluded. RESULTS: Among 217 patients with various cancer types, TD was found in 55.3%. Risk factors included fluorouracil-based chemotherapy, significant weight loss, and undergoing active cancer treatment. Almost all patients were normal weight, overweight, or obese, and few had concomitant vitamin B12 or folate deficiency. A total of 17.5% were receiving multivitamin supplementation. Nearly half (49.8%) did not receive empiric treatment with thiamine and among those who did, treatment delay occurred in the majority of cases (59.6%). Measurement of serum thiamine concentration preceded psychiatric consultation in only 10.6% of cases. CONCLUSIONS: Our findings suggest that TD is highly prevalent among inpatients with cancer, even among normal and overweight individuals, in the absence of other vitamin deficiencies, and while receiving multivitamin supplements. Several potential risk factors were identified, including active cancer treatment. Evaluation of TD was most commonly not initiated by oncologists. Failure to treat and treatment delay were common. Given these findings, oncologists must be vigilant about detecting TD among inpatients with cancer. Copyright © 2016 John Wiley & Sons, Ltd.

Prevalence of thiamine deficiency in a stable heart failure outpatient cohort on standard loop diuretic therapy.

BACKGROUND & AIMS: The prevalence of thiamine deficiency in heart failure (HF) patients has been reported to be as high as 50% in outpatient settings and has been found to be as high as 96% in the inpatient setting. Results from previous studies, however, have been inconsistent and further investigation is needed to clarify the true prevalence of thiamine deficiency in patients with chronic HF. The aim of this study was to determine the prevalence of thiamine deficiency in a random sample of stable HF outpatients receiving standard of care loop diuretic therapy. METHODS: A cross-sectional study was conducted in 30 HF patients scheduled for regular follow-up visits in the Mayo Heart Failure Clinic. Whole-blood thiamine diphosphate was measured using high-performance liquid chromatography. Additional clinical and demographic features were collected through review of electronic medical records. RESULTS: The estimated prevalence of thiamine deficiency in stable HF patients was calculated to be <11.6%. There was no correlation between diuretic dose and thiamine levels (r = 0.02, P = 0.93) and there was no correlation found between left-ventricular ejection fraction (LVEF) and thiamine levels (r = 0.147, p = 0.44). CONCLUSION: Our findings suggest that the prevalence of thiamine deficiency, based on standard normal values, in a stable outpatient HF cohort on standard loop diuretic therapy is very low. Previous work has demonstrated improvements in myocardial function with high-dose thiamine supplementation regardless of thiamine blood levels, however, suggesting that thiamine may become conditionally essential with HF. Therefore, we suggest that a disease-specific reference range be determined to accurately identify HF patients that would benefit from thiamine supplementation.

Challenges in Diagnosis and Treatment of Wernicke Encephalopathy: Report of 2 Cases.

BACKGROUND: Wernicke encephalopathy (WE) is a medical emergency caused by thiamine deficiency, characterized by cerebellar ataxia, ophthalmoplegia, and cognitive disturbances that may progress to Korsakoff amnesia. We describe 2 patients with WE who needed high-dose and long-term treatment with thiamine to obtain neurological improvement and recovery. CASE DESCRIPTION: The first patient was a woman diagnosed with non-Hodgkin lymphoma. After a gastrointestinal infection, she developed depression, memory loss, disorientation, behavioral changes, and ataxic paraplegia. Brain magnetic resonance imaging (MRI) showed bilateral alterations in thalamic, frontal, and periaqueductal regions, suggestive of WE. The second patient was a man who lost 10 kg after surgical gastrectomy; he developed diplopia, ophthalmoplegia, cerebellar ataxia, lower limb paresthesias, and amnesia. A brain MRI demonstrated contrast enhancement of mammillary bodies, compatible with WE. OUTCOME: The patients were treated with intramuscular (IM) thiamine (1200 mg/d for 2 months and 900 mg/d for a month, respectively) with gradual cognitive and behavioral improvement and brain MRI normalization, while ataxia and oculomotion improved in following months. In both patients, thiamine was gradually reduced to IM 200 mg/d and continued for a year, without clinical relapses. CONCLUSIONS: There is no consensus about dosage, frequency, route, and duration of thiamine administration in WE treatment. Based on our cases, we recommend treating patients with WE with higher doses of IM thiamine for a longer time than suggested (900-1200 mg/d for 1-2 months, in our cases) and to gradually reduce dosage after clinical and radiological improvement, maintaining IM 200 mg/d dosage for at least 1 year.

Determining the Role of Thiamine Deficiency in Systolic Heart Failure: A Meta-Analysis and Systematic Review.

BACKGROUND: Approximately 5.7 million Americans carry the diagnosis of systolic heart failure (HF), a major health care burden. HF is a known manifestation of thiamine deficiency (TD). HF patients are at unique risk for developing TD, which may contribute to further altered cardiac function and symptoms. METHODS AND RESULTS: We performed a systematic review of the literature and a meta-analysis to evaluate the prevalence of TD in HF patients, risk factors for and mechanisms of development of TD in HF population, and outcomes of thiamine supplementation in HF patients. We found 54 studies that met our selection criteria, 9 of which were suitable for meta-analysis. TD is more common in HF patients than control subjects (odds ratio 2.53, 95% confidence interval 1.65-3.87). Diuretic use, changes in dietary habits, and altered thiamine absorption and metabolism were identified as possible mechanisms of TD in HF patients. Small observational studies and randomized control trials suggest that thiamine supplementation in HF population may improve ejection fraction and reduce symptoms. CONCLUSIONS: Thiamine deficiency is more prevalent in the HF population, and its supplementation may be beneficial. The therapeutic role of thiamine in HF warrants further study.

Malnutrition-induced Wernicke's encephalopathy following a water-only fasting diet.

BACKGROUND: Wernicke's encephalopathy is a critical condition of neurological dysfunction resulting from a deficiency in thiamine. Chronic alcoholism is recognized as the most common cause of Wernicke's encephalopathy, but other causes, including fasting/starvation and malnutrition, have been documented within the scientific literature. These causes may not be readily recognized by healthcare professionals and may lead to Wernicke's encephalopathy being overlooked as a diagnosis when a nonalcoholic patient presents with classic signs and symptoms of the disorder. MATERIALS AND METHODS: A narrative review of thiamine and its relationship to the development, diagnosis, and treatment of Wernicke's encephalopathy is presented based on a review of evidence-based guidelines and published research. To heighten awareness of the development of Wernicke's encephalopathy in fasted/starved and malnourished patients and to contribute to the scientific body of knowledge for the identification and management of Wernicke's encephalopathy in these patients, the clinical course and treatment of an adult woman who developed Wernicke's encephalopathy following a 40-day water-only fasting diet is outlined. RESULTS: Clinical suspicion was required to identify the patient's condition and initiate immediate intervention through parenteral thiamine administration. Oral thiamine supplementation of 100 to 800 mg per day for 6 months was required to aid recovery. OUTCOMES: The patient's clinical course and response to treatment illustrate the necessity for clinical awareness and suspicion of Wernicke's encephalopathy among healthcare professionals, timely and adequate parenteral thiamine administration, and oral thiamine supplementation at therapeutic doses to correct the nutrient deficiency, halt the progression of Wernicke's encephalopathy, and promote recovery.

Thiamin Deficiency as a Cause of Persistent Hyperlactatemia in a Parenteral Nutrition-Dependent Patient.

BACKGROUND: Despite the demonstrated dangers of inadequate supplies of injectable multivitamins, periodic shortages of these crucial pharmaceuticals continue to occur in the developed world. This case report provides a recent example of the potential danger of rationing parenteral multivitamins in chronically parenteral nutrition (PN)-dependent patients in the setting of national supply shortages. METHOD AND RESULTS: Case report describing a chronically PN-dependent 21-year-old man who presented with signs and symptoms of septic shock to a pediatric intensive care unit at a university hospital. The patient demonstrated hyperlactatemia that persisted following hemodynamic stabilization, and he was determined to be severely deficient in thiamin despite thrice-weekly home multivitamin infusions, instead of daily due to national supply shortages. The patient's hyperlactatemia rapidly resolved following thiamine supplementation. CONCLUSION: Physicians must be vigilant for potentially life-threatening nutrition deficiencies, as illustrated in this case of thiamine insufficiency, in PN-dependent children and adults in the setting of nationwide limitations in multivitamin supply.

Infant botulism: is there an association with thiamine deficiency?

Infant botulism is an acute life-threatening condition and diagnosis is frequently delayed. Therefore, the best time window to administer specific antibodies, at present the only etiology-based therapy, is often missed, entailing long periods of hospitalization in the PICU. Here we present a 3-month-old boy with infant botulism and respiratory failure, who quickly and favorably responded to thiamine supplementation. From the feces we isolated Clostridium botulinum serotype A2. In addition to producing botulinum neurotoxin A, this strain carried the thiaminase I gene and produced thiaminase I. Accordingly, the child's feces were positive for thiaminase I activity. Because C botulinum group I strains are capable of producing thiaminase I, we speculate that thiamine degradation might further aggravate the paralytic symptoms caused by botulinum neurotoxins in infant botulism. Thus, supportive supplementation with thiamine could be beneficial to speed up recovery and to shorten hospitalization in some patients with infant botulism.

Peripheral systems: neuropathy.

Long-term, excessive consumption of alcoholic beverages produces a peripheral neuropathy with symptoms of decreased superficial sensation, hyperalgesia, and weakness. Alcoholic neuropathy is characterized by axonal degeneration with reduced density of both small and large fibers and axonal sprouting. Electrophysiologic studies reveal a marked reduction in the amplitude of sensory potentials and moderate slowing of nerve conduction, mainly in the lower extremities. Dietary deficiency of vitamins, which are often associated with chronic alcoholism, can contribute to the pathogenesis. Recent studies using animal models have identified several mechanisms by which ethanol impacts peripheral nerve function. Ethanol can exert direct neurotoxic effects on peripheral nerves via its metabolite acetaldehyde and by enhancing oxidative stress. Ethanol activation of protein kinase Cε signaling in primary afferent nociceptors plays an important role in lowering nociceptive threshold. Further, ethanol causes cytoskeletal dysfunction and inhibits both anterograde and retrograde axonal transport. Alcoholic neuropathy is potentially reversible and treatments include abstinence from alcoholic beverages and consumption of a nutritionally balanced diet supplemented with B vitamins. However, response to these treatment strategies can be variable, which underscores the need for novel therapeutic strategies. In this review, we provide an overview of the clinical findings and insights on molecular mechanisms from animal models.

Thiamine and Hashimoto's thyroiditis: a report of three cases.

OBJECTIVES: In a previous study on fatigue and related disorders in inflammatory bowel disease (IBD), we observed that IBD patients improved after treatment with high-dose thiamine. We hypothesized that the chronic fatigue accompanying inflammatory and autoimmune diseases is the clinical manifestation of a mild thiamine deficiency that is probably due to a dysfunction of the intracellular transport or to enzymatic abnormalities. Hashimoto's thyroiditis is both a common automimmune disease and cause of hypothyroidism. Although levothyroxine, a thyroid hormone, is the treatment of choice for hypothyroidism, a significant number of patients on thyroid hormone replacement therapy report not feeling well despite having thyroid function tests within the healthy range. Based on our hypothesis, we started treating the fatigue in patients affected by Hashimoto's thyroiditis and taking a thyroid hormone with thiamine. This is a report of the outcomes of three cases in which the fatigue component reported by patients with Hashimoto's thyroiditis was treated with thiamine. DESIGN: Three patients on thyroid hormone replacement because of Hashimoto's thyroiditis were treated for the fatigue component of the disease from May to July 2011. Fatigue was measured using the Fatigue Severity Scale. Free thiamine in the serum and thiamine pyrophosphate in red cells were tested before and after the therapy. All three patients received oral (600 mg/day) or parenteral (100 mg/ml every four days) doses of thiamine. RESULTS: Treatment with thiamine led to partial or complete regression of the fatigue within a few hours or days. CONCLUSION: As the administration of thiamine led to a partial or complete regression of the fatigue and related disorders, it is reasonable to infer that the administration of large quantities of thiamine restores thiamine-dependent processes. The mild thiamine deficiency suggested by fatigue and related disorders may be due a dysfunction of the intracellular transport of thiamine or to enzymatic abnormalities most likely related to the autoimmune process of the disease.