Thiamine deficiency and nervous system function disturbances

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Thiamine Deficiency in Tropical Pediatrics: New Insights into a Neglected but Vital Metabolic Challenge

In humans, thiamine is a micronutrient prone to depletion that may result in severe clinical abnormalities. This narrative review summarizes current knowledge on thiamine deficiency (TD) and bridges the gap between pathophysiology and clinical presentation by integrating thiamine metabolism at subcellular level with its function to vital organs. The broad clinical spectrum of TD is outlined, with emphasis on conditions encountered in tropical pediatric practice. In particular, TD is associated with type B lactic acidosis and classic forms of beriberi in children, but it is often unrecognized. Other severe acute conditions are associated with hypermetabolism, inducing a functional TD. The crucial role of thiamine in infant cognitive development is also highlighted in this review, along with analysis of the potential impact of TD in refeeding syndrome during severe acute malnutrition (SAM). This review aims to increase clinical awareness of TD in tropical settings where access to diagnostic tests is poor, and advocates for an early therapeutic thiamine challenge in resource-limited settings. Moreover, it provides evidence for thiamine as treatment in critical conditions requiring metabolic resuscitation, and gives rationale to the consideration of increased thiamine supplementation in therapeutic foods for malnourished children.

Electron-microscopic examination of effects of yokukansan, a traditional Japanese medicine, on degeneration of cerebral cells in thiamine-deficient rats

We previously demonstrated that yokukansan ameliorated not only learning disturbance but also behavioral and psychological symptoms of dementia-like behaviors (anxiety, aggressiveness) and neurological symptoms (opisthotonus) induced in rats by dietary thiamine deficiency (TD). In the present study, the effects of yokukansan on degeneration of cerebral cells were further examined electron-microscopically during pre-symptomatic and symptomatic stages in TD rats. In the pre-symptomatic TD stage, which appeared as increase in aggressive behaviors on the 21st and 28th days of TD diet-feeding, severe edematous degeneration of astrocytes was detected by electron microscopy, although the changes were not observed by light microscopy. In the symptomatic TD stage (the 34th day) characterized by development of neurological symptoms, severe sponge-like degeneration and multiple hemorrhages in the parenchyma were obvious by light microscopy. The electron-microscopic examination showed degeneration in neurons, oligodendroglias, and myelin sheaths in addition to astrocytes. TD rats, which exhibited multiple hemorrhages light microscopically, showed severe edematous changes and hypertrophy of the foot processes of astrocytes surrounding blood vessels. Administration of yokukansan ameliorated not only the TD-induced aggressive behavior and neurological symptoms but also degeneration of the cerebral cells. These results suggest that the inhibitory effect of yokukansan on degeneration in various brain cells might be closely related to the amelioration of aggression and neurological symptoms in TD rats.

Interrelationships of undernutrition and neurotoxicity: food for thought and research attention

The neurotoxic actions of chemical agents on humans and animals are usually studied with little consideration of the subject's nutritional status. States of protein-calorie, vitamin and/or mineral undernutrition are associated with a range of neurodevelopmental, neurological and psychiatric disorders, commonly with involvement of both the central and the peripheral nervous system. Undernutrition can modify risk for certain chemical-induced neurologic diseases, and in some cases undernutrition may be a prerequisite for neurotoxicity to surface. In addition, neurologic disease associated with undernutrition or neurotoxicity may show similarities in clinical and neuropathological expression, especially in the peripheral nervous system. The combined effects of undernutrition and chemical neurotoxicity are most relevant to people with low incomes who experience chronic hunger, parasitism and infectious disease, monotonous diets of plants with neurotoxic potential (notably cassava), environmental pollution from rapid industrial development, chronic alcohol abuse, or prolonged treatment with certain therapeutic drugs. Undernutrition alone or in combination with chemical exposure is also important in high-income societies in the setting of drug and alcohol abuse, old age, food faddism, post-bariatric surgery, and drug treatment for certain medical conditions, including cancer and tuberculosis. The nutritional demands of pregnancy and lactation increase the risk of fetal and infant undernutrition and chemical interactions therewith.

The crucial role of thiamine in the development of syntax and lexical retrieval: a study of infantile thiamine deficiency

This study explored the effect of thiamine deficiency during early infancy on the development of syntax and lexical retrieval. We tested syntactic comprehension and production, lexical retrieval abilities and conceptual abilities of 59 children aged 5-7 years who had been fed during their first year of life with a thiamine-deficient milk substitute. We compared them to 35 age-matched control children who were fed with other milk sources. Experiment 1 tested the comprehension of relative clauses using a sentence-picture-matching task. Experiment 2 tested the production of relative clauses using a preference elicitation task. Experiment 3 tested the repetition of various syntactic structures with various types of syntactic movement and embedding. Experiment 4 tested picture naming and Experiment 5 tested lexical substitutions in a sentence repetition task. Experiments 6 and 7 tested the children's conceptual abilities using a picture association task and a picture absurdity description task. The results indicated a very high rate of syntactic and lexical retrieval deficits in the group of children who were exposed to thiamine deficiency in early infancy: 57 of the 59 thiamine-deficient children examined had language impairment, compared with three of the 35 controls (9%). Importantly, unlike the impairment this group sustained in their language abilities, the conceptual abilities of most of the children were intact (only six children, 10%, were conceptually impaired). These findings indicate that thiamine deficiency in infancy causes severe and long-lasting language disorders and that nutrition may be one of the causes for language impairment.

Thiamine (Vitamin B1)

Thiamine (vitamin B 1) was the first B vitamin to have been identified. It serves as a cofactor for several enzymes involved in energy metabolism. The thiamine-dependent enzymes are important for the biosynthesis of neurotransmitters and for the production of reducing substances used in oxidant stress defenses, as well as for the synthesis of pentoses used as nucleic acid precursors. Thiamine plays a central role in cerebral metabolism. Its deficiency results in dry beriberi, a peripheral neuropathy, wet beriberi, a cardiomyopathy with edema and lactic acidosis, and Wernicke—Korsakoff syndrome, whose manifestations consist of nystagmus, ophthalmoplegia, and ataxia evolving into confusion, retrograde amnesia, cognitive impairment, and confabulation. Patients on a strict thiamine-deficient diet display a state of severe depletion within 18 days. The most common cause of thiamine deficiency in affluent countries is either alcoholism or malnutrition in nonalcoholic patients. Treatment by thiamine supplementation is beneficial for diagnostic and therapeutic purposes.

Metabolic and structural role of thiamine in nervous tissues

In the literature, previous descriptions of the role of thiamine (B1 vitamin) focused mostly on its biochemical functions as a coenzyme precursor of some key enzymes of the carbohydrate metabolism. This report reviews recent developments on the metabolic and structural role of thiamine, e.g., the coenzyme and noncoenzyme functions of the vitamin. Taking into account analysis of our experimental data relating to the effects of thiamine deficiency on developing central nervous system (CNS) and data available in literature, we seek to establish a clear difference between the metabolic and structural role of thiamine. Our experimental data indicate that the specific and nonspecific effects express two diametrically diverse functions of thiamine in development: the nonspecific effects show up the metabolic consequences of thiamine deficiency resulting in apoptosis and severe cellular deficit; inversely, the specific effects announced the structural consequences of thiamine deficiency, described as cellular membrane damage, irregular and ectopic cells. The review highlights the existence of noncoenzyme functions of this vitamin through its interactions with biological membranes.

Lower limb neuropathy after spinal anesthesia in a patient with latent thiamine deficiency

We present the case of a 65-year-old man with latent thiamine deficiency who manifested lower limb neuropathy after receiving spinal anesthesia. We discuss our care of this patient and include a discussion of thiamine deficiency generally, its possible origins, symptoms, and recommended techniques for treatment of these patients.

Functional vulnerability of developing central nervous system to maternal thiamine deficiencies in the rat

Thiamine deficiency (B1 vitamin) was induced during three periods of rat central nervous system (CNS) ontogenesis. Females were fed a thiamine deficient diet such that developing offspring were exposed either to pre-, peri-, or postnatal thiamine deficiency. To control the effects of undernourishment generated by different thiamine deficiencies, every treatment group had its own pair-fed control pup from a non drug-treated but undernourished dam. Seven different developmental abilities (exploratory activity, emotional reaction, hind paws lifting reflex, wire grasping times, crawling and leap execution latencies, and nociception) were recorded in the offspring from the 10th to the 45th postnatal day. The vulnerability of developing brain to the specific lack of B1 vitamin increases from prenatal (28%) to perinatal (43%) and postnatal periods (57%).