The multi-faceted basis of vitamin B12 (cobalamin) neurotrophism in adult central nervous system: Lessons learned from its deficiency

A Semi-Automatic Environmental Monitoring Device for Mercury and Cobalt Ion Detection

A syringe-based, semi-automatic environmental monitoring device is developed for on-site detection of harmful heavy metal ions in water. This portable device consists of a spring-embedded syringe and a polydimethylsiloxane (PDMS) membrane-based flow regulator for semi-automatic fix-and-release fluidic valve actuation, and a paper-based analytical device (PAD) with two kinds of gold nanoclusters (AuNCs) for sensitive Hg2+ and Co2+ ion detection, respectively. The thickness of the elastic PDMS membrane can be adjusted to stabilize and modulate the flow rates generated by the pushing force provided by the spring attached to the plunger. Also, different spring constants can drastically alter the response time. People of all ages can extract the fix-volume sample solutions and then release them to automatically complete the detection process, ensuring high reliability and repeatability. The PAD comprises two layers of modified paper, and each layer is immobilized with bovine serum albumin-capped gold nanoclusters (R-AuNCs) and glutathione-capped gold clusters (G-AuNCs), respectively. The ligands functionalized on the surface of the AuNCs not only can fine-tune the optical properties of the nanoclusters but also enable specific and simultaneous detection of Hg2+ and Co2+ ions via metallophilic Au+ -Hg2+ interaction and the Co2+ -thiol complexation effect, respectively. The feasibility of the device for detecting heavy metal ions at low concentrations in various environmental water samples is demonstrated. The Hg2+ and Co2+ ions can be seen simultaneously within 20 min with detection limits as low as 1.76 nm and 0.27 µm, respectively, lower than those of the regulatory restrictions on water by the US Environmental Protection Agency and the European Union. we expect this sensitive, selective, portable, and easy-to-use device to be valid for on-site multiple heavy metal ion pollution screenings in resource-constrained settings.

Brain Trauma and the Secondary Cascade in Humans: Review of the Potential Role of Vitamins in Reparative Processes and Functional Outcome

An estimated sixty-nine million people sustain a traumatic brain injury each year. Trauma to the brain causes the primary insult and initiates a secondary biochemical cascade as part of the immune and reparative response to injury. The secondary cascade, although a normal physiological response, may also contribute to ongoing neuroinflammation, oxidative stress and axonal injury, continuing in some cases years after the initial insult. In this review, we explain some of the biochemical mechanisms of the secondary cascade and their potential deleterious effects on healthy neurons including secondary cell death. The second part of the review focuses on the role of micronutrients to neural mechanisms and their potential reparative effects with regards to the secondary cascade after brain injury. The biochemical response to injury, hypermetabolism and excessive renal clearance of nutrients after injury increases the demand for most vitamins. Currently, most research in the area has shown positive outcomes of vitamin supplementation after brain injury, although predominantly in animal (murine) models. There is a pressing need for more research in this area with human participants because vitamin supplementation post-trauma is a potential cost-effective adjunct to other clinical and therapeutic treatments. Importantly, traumatic brain injury should be considered a lifelong process and better evaluated across the lifespan of individuals who experience brain injury.

The Effect of High-Dose Methyl Vitamin B12 Therapy on Epileptogenesis in Rats: An In Vivo Study

Introduction Epileptogenesis has been considered one of the most prevalent diseases affecting significant numbers of individuals worldwide. Since vitamin B12 has been reported to possess antiepileptic effects, this supports that vitamin B12 deficiency is correlated to seizure occurrence. Hence, this study aimed to evaluate the neuroprotective effects of vitamin B12 injection on pentylenetetrazole (PTZ)-induced rats. Methods The study was performed using 40 adult female Sprague-Dawley rats (~250 g). A 45 mg/kg PTZ was intraperitoneally injected into rat models to induce seizure effects. Different groups of rat models received methyl vitamin B12 therapy at different dosages, a low dosage of 45 µg/kg and a high dosage of 85 µg/kg, at different pre-treatment periods, one day and two weeks prior to PTZ injection. A control group, which received only PTZ injection, served as a reference. The seizure latency, seizure intensity, and differences in the quality of seizures and their characteristics, from simple twitches to complete seizures, were observed after 30 minutes of PTZ injection. Results In general, the latency to convulsion significantly increased when vitamin B12 pre-treatment was employed. The longest latency time (LT) of 520.63±73.83 seconds was observed when a high dosage of vitamin B12 at 85 µg/kg was injected one day prior to PTZ inoculation, which was significantly higher than that of the control group at 176.88±62.67 seconds (P<0.001). Moreover, the duration of convulsion significantly decreased in which the lowest duration time (DT) of 7.00±4.68 seconds was observed when a high dosage of vitamin B12 at 85 µg/kg was injected two weeks prior to PTZ inoculation, which was significantly lower than that of the control group at 257.75±41.93 seconds (P<0.001). Lastly, the percentage of the population with PTZ-induced convulsion generally decreased after vitamin B12 pre-treatment in which majority showed more of simple less aggressive twitches rather than tonic-clonic seizures. Conclusion The results showed that vitamin B12 pre-treatment alleviates the seizure occurrence among PTZ-kindled rat models. These findings then suggest that vitamin B12 is a potential strategy and treatment for epilepsy and other related epileptogenesis activities.

Vitamin B12: For more than just the treatment of megaloblastic anemia?

Vitamin B12, or cobalamin, belongs to the group of water-soluble vitamins and is ingested through food of animal origin such as eggs, milk, red meat and poultry, fish, and shellfish. Its clinical indication is the treatment of hypovitaminosis B12 administered orally or intramuscularly in the form of hydroxocobalamin. Hypovitaminosis B12 is mainly caused by deficient dietary intake (individuals with malnutrition, vegetarians or vegans, older adults, pregnant people, individuals with alcohol use disorder); when intestinal absorption is reduced (atrophic gastritis, malabsorption syndrome, gastrointestinal surgery); and for causes associated with the intake of drugs (antacids, metformin). Hypervitaminosis B12 has been associated with renal failure; liver diseases such as cirrhosis and acute-phase hepatitis; alcohol use disorder with or without liver involvement; solid tumors of the lung, liver, esophagus, pancreas, and colorectum; and in hematological malignancies such as leukemia and bone marrow dysplasia.

Effect of a Vegan Diet on Alzheimer's Disease

There is evidence indicating that a vegan diet could be beneficial in the prevention of neurodegenerative disorders, including Alzheimer's disease (AD). The purpose of this review is to summarize the current knowledge on the positive and negative aspects of a vegan diet regarding the risk of AD. Regarding AD prevention, a vegan diet includes low levels of saturated fats and cholesterol, contributing to a healthy blood lipid profile. Furthermore, it is rich in phytonutrients, such as vitamins, antioxidants, and dietary fiber, that may help prevent cognitive decline. Moreover, a vegan diet contributes to the assumption of quercetin, a natural inhibitor of monoamine oxidase (MAO), which can contribute to maintaining mental health and reducing AD risk. Nonetheless, the data available do not allow an assessment of whether strict veganism is beneficial for AD prevention compared with vegetarianism or other diets. A vegan diet lacks specific vitamins and micronutrients and may result in nutritional deficiencies. Vegans not supplementing micronutrients are more prone to vitamin B12, vitamin D, and DHA deficiencies, which have been linked to AD. Thus, an evaluation of the net effect of a vegan diet on AD prevention and/or progression should be ascertained by taking into account all the positive and negative effects described here.

Reversible Splenial Lesion Syndrome (RESLES) after Nitrous Oxide Abuse: A Case Report

Background: Reversible splenial-lesion syndrome (RESLES) is a relatively rare and underrecognized clinical-imaging syndrome involving the splenium of the corpus callosum (SCC). RESLES can be caused by various etiologies. Case description: An 18-year-old man with no previous history of neurological or psychiatric disorders presented to our hospital with headache, intermittent blurred vision, and limb weakness after 150 days of recreational nitrous-oxide abuse. The patient’s serum vitamin B12 concentration was normal, and magnetic-resonance imaging (MRI) examination revealed isointensity on T1-weighted imaging (T1WI) of the corpus callosum and high signal intensity on T2WI, T2FLAIR, and diffusion-weighted MRI (DWI); thus, a diagnosis of RESLES was established. The patient received 0.5 mg of mecobalamin daily and nitrous oxide was discontinued. After 4 weeks, the patient’s symptoms disappeared and the imaging examination revealed normal findings. Conclusion: We report for the first time a case of headache, blurred vision, and hallucination caused by RESLES associated with nitrous-oxide abuse. In cases of headaches and hallucinations of unknown etiology, the possibility of RESLES caused by nitrous oxide abuse should be considered.

B Vitamin Supplementation Slows Cognitive Decline in Mild Cognitive Impairment Patients with Frontal Lobe Atrophy

BACKGROUND

The effects of B vitamins on mild cognitive impairment (MCI) patients' cognition have been mixed, suggesting the existence of moderating factors.

OBJECTIVE

A post hoc analysis of a negative B vitamin trial was performed to examine the potential modulating effect of regional brain atrophy on the cognitive response to B vitamins in MCI patients.

METHODS

In the 24-month randomized trial, 279 MCI outpatients took 500μ#x03BC;g methylcobalamin and 400μ#x03BC;g folic acid once per day or placebo tablets once per day. Sixty-four aspirin users were excluded from analysis as aspirin use has been found to have significant negative interaction effects. Subjects were followed up at months 12 and 24. The primary cognitive outcome was clinical dementia rating scale sum of boxes (CDR_SOB). In a subgroup of 83 subjects, MRI brain scans were performed at baseline to estimate regional brain atrophy ratios.

RESULTS

Among the trial subjects who had MRI data, B vitamin supplementation had no significant effect on CDR_SOB, despite having significant homocysteine lowering effects. The atrophy ratio of the left frontal lobe significantly moderated the effect of B vitamin supplementation on CDR_SOB, after adjusting for confounders, in that B vitamin supplementation was associated with lower CDR_SOB scores (i.e., better cognitive function) at the 24th month among those patients with above median atrophy ratios, but not among those with lower atrophy ratios, in the left frontal lobe.

CONCLUSION

B vitamins may be more effective in slowing down cognitive decline in MCI patients with atrophy in the left frontal lobe.

Astrocyte: A Foe or a Friend in Intellectual Disability-Related Diseases

Intellectual disabilities are a type of neurodevelopmental disease caused by neurological dysfunction. Their incidence is largely associated with neural development. Astrocytes are the most widely distributed cells in the mammalian brain. Previous studies have reported that astrocytes only supported and separated the neurons in the brain. However, recent studies have found that they also play an important role in neural development. Understanding the astrocyte mechanism in intellectual development disorder-related diseases will help provide new therapeutic targets for the treatment of intellectual disability-related diseases. This mini-review introduced the association between astrocyte and intellectual disabilities. Furthermore, recent advances in genetic and environmental factors causing intellectual disability and different pharmaceutical effects of intellectual disability-related drugs on astrocytes have been summarised. Finally, we discussed future perspectives of astrocyte-based therapy for intellectual disability.

Newly Identified Deficiencies in the Multiple Sclerosis Central Nervous System and Their Impact on the Remyelination Failure

The pathogenesis of multiple sclerosis (MS) remains enigmatic and controversial. Myelin sheaths in the central nervous system (CNS) insulate axons and allow saltatory nerve conduction. MS brings about the destruction of myelin sheaths and the myelin-producing oligodendrocytes (ODCs). The conundrum of remyelination failure is, therefore, crucial in MS. In this review, the roles of epidermal growth factor (EGF), normal prions, and cobalamin in CNS myelinogenesis are briefly summarized. Thereafter, some findings of other authors and ourselves on MS and MS-like models are recapitulated, because they have shown that: (a) EGF is significantly decreased in the CNS of living or deceased MS patients; (b) its repeated administration to mice in various MS-models prevents demyelination and inflammatory reaction; (c) as was the case for EGF, normal prion levels are decreased in the MS CNS, with a strong correspondence between liquid and tissue levels; and (d) MS cobalamin levels are increased in the cerebrospinal fluid, but decreased in the spinal cord. In fact, no remyelination can occur in MS if these molecules (essential for any form of CNS myelination) are lacking. Lastly, other non-immunological MS abnormalities are reviewed. Together, these results have led to a critical reassessment of MS pathogenesis, partly because EGF has little or no role in immunology.

New Epidermal-Growth-Factor-Related Insights Into the Pathogenesis of Multiple Sclerosis: Is It Also Epistemology?

Recent findings showing that epidermal growth factor (EGF) is significantly decreased in the cerebrospinal fluid (CSF) and spinal cord (SC) of living or deceased multiple sclerosis (MS) patients, and that its repeated administration to rodents with chemically- or virally-induced demyelination of the central nervous system (CNS) or experimental allergic encephalomyelitis (EAE) prevents demyelination and inflammatory reactions in the CNS, have led to a critical reassessment of the MS pathogenesis, partly because EGF is considered to have little or no role in immunology. EGF is the only myelinotrophic factor that has been tested in the CSF and spinal cord of MS patients, and it has been shown there is a good correspondence between liquid and tissue levels. This review: (a) briefly summarises the positive EGF effects on neural stem cells, oligodendrocyte cell lineage, and astrocytes in order to explain, at least in part, the biological basis of the myelin loss and remyelination failure in MS; and (b) after a short analysis of the evolution of the principle of cause-effect in the history of Western philosophy, highlights the lack of any experimental immune-, toxin-, or virus-mediated model that precisely reproduces the histopathological features and “clinical” symptoms of MS, thus underlining the inapplicability of Claude Bernard's crucial sequence of “observation, hypothesis, and hypothesis testing.” This is followed by a discussion of most of the putative non-immunologically-linked points of MS pathogenesis (abnormalities in myelinotrophic factor CSF levels, oligodendrocytes (ODCs), astrocytes, extracellular matrix, and epigenetics) on the basis of Popper's falsification principle, and the suggestion that autoimmunity and phologosis reactions (surely the most devasting consequences of the disease) are probably the last links in a chain of events that trigger the reactions. As it is likely that there is a lack of other myelinotrophic growth factors because myelinogenesis is controlled by various CNS and extra-CNS growth factors and other molecules within and outside ODCs, further studies are needed to investigate the role of non-immunological molecules at the time of the onset of the disease. In the words of Galilei, the human mind should be prepared to understand what nature has created.

The Role of Vitamins in Neurodegenerative Disease: An Update

Acquiring the recommended daily allowance of vitamins is crucial for maintaining homeostatic balance in humans and other animals. A deficiency in or dysregulation of vitamins adversely affects the neuronal metabolism, which may lead to neurodegenerative diseases. In this article, we discuss how novel vitamin-based approaches aid in attenuating abnormal neuronal functioning in neurodegeneration-based brain diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Prion disease. Vitamins show their therapeutic activity in Parkinson's disease by antioxidative and anti-inflammatory activity. In addition, different water- and lipid-soluble vitamins have also prevented amyloid beta and tau pathology. On the other hand, some results also show no correlation between vitamin action and the prevention of neurodegenerative diseases. Some vitamins also exhibit toxic activity too. This review discusses both the beneficial and null effects of vitamin supplementation for neurological disorders. The detailed mechanism of action of both water- and lipid-soluble vitamins is addressed in the manuscript. Hormesis is also an essential factor that is very helpful to determine the effective dose of vitamins. PubMed, Google Scholar, Web of Science, and Scopus were employed to conduct the literature search of original articles, review articles, and meta-analyses.

Analysis of the Impact of Selected Vitamins Deficiencies on the Risk of Disability in Older People

Vitamin deficiencies have a serious impact on healthy aging in older people. Many age-related disorders have a direct or indirect impact on nutrition, both in terms of nutrient assimilation and food access, which may result in vitamin deficiencies and may lead to or worsen disabilities. Frailty is characterized by reduced functional abilities, with a key role of malnutrition in its pathogenesis. Aging is associated with various changes in body composition that lead to sarcopenia. Frailty, aging, and sarcopenia all favor malnutrition, and poor nutritional status is a major cause of geriatric morbidity and mortality. In the present narrative review, we focused on vitamins with a significant risk of deficiency in high-income countries: D, C, and B (B6/B9/B12). We also focused on vitamin E as the main lipophilic antioxidant, synergistic to vitamin C. We first discuss the role and needs of these vitamins, the prevalence of deficiencies, and their causes and consequences. We then look at how these vitamins are involved in the biological pathways associated with sarcopenia and frailty. Lastly, we discuss the critical early diagnosis and management of these deficiencies and summarize potential ways of screening malnutrition. A focused nutritional approach might improve the diagnosis of nutritional deficiencies and the initiation of appropriate clinical interventions for reducing the risk of frailty. Further comprehensive research programs on nutritional interventions are needed, with a view to lowering deficiencies in older people and thus decreasing the risk of frailty and sarcopenia.

The Role of Neurotropic B Vitamins in Nerve Regeneration

Damage and regeneration naturally occur in the peripheral nervous system. The neurotropic B vitamins thiamine (B1), pyridoxine (B6), and cobalamin (B12) are key players, which maintain the neuronal viability in different ways. Firstly, they constantly protect nerves against damaging environmental influences. While vitamin B1 acts as a site-directed antioxidant, vitamin B6 balances nerve metabolism, and vitamin B12 maintains myelin sheaths. However, nerve injury occurs at times, because of an imbalance between protective factors and accumulating stress and noxae. This will result in the so-called Wallerian degeneration process. The presence of vitamins B1, B6, and B12 paves the way out to the following important regeneration by supporting the development of new cell structures. Furthermore, vitamin B1 facilitates the usage of carbohydrates for energy production, whereas vitamin B12 promotes nerve cell survival and remyelination. Absence of these vitamins will favor permanent nerve degeneration and pain, eventually leading to peripheral neuropathy.

Vitamin B12 Regulates Glial Migration and Synapse Formation through Isoform-Specific Control of PTP-3/LAR PRTP Expression

Vitamin B12 is known to play critical roles during the development and aging of the brain, and vitamin B12 deficiency has been linked to neurodevelopmental and degenerative disorders. However, the underlying molecular mechanisms of how vitamin B12 affects the development and maintenance of the nervous system are still unclear. Here, we report that vitamin B12 can regulate glial migration and synapse formation through control of isoform-specific expression of PTP-3/LAR PRTP (leukocyte-common antigen-related receptor-type tyrosine-protein phosphatase). We found the uptake of diet-supplied vitamin B12 in the intestine to be critical for the expression of a long isoform of PTP-3 (PTP-3A) in neuronal and glial cells. The expression of PTP-3A cell autonomously regulates glial migration and synapse formation through interaction with an extracellular matrix protein NID-1/nidogen 1. Together, our findings demonstrate that isoform-specific regulation of PTP-3/ LAR PRTP expression is a key molecular mechanism that mediates vitamin-B12-dependent neuronal and glial development.

Prognostic indicators of subacute combined degeneration from B12 deficiency: A systematic review

OBJECTIVE

A systematic review was conducted on published data of subacute combined degeneration (SCD) from B12 deficiency to investigate potential prognostic indicators of final ambulatory function in affected patients. TYPE: Systematic review.

LITERATURE SURVEY

Records published from 1999 through 2018 were searched on the electronic databases MEDLINE, PUBMED, and SCOPUS. The publication language was restricted to English and French.

METHODOLOGY

Records that described cases of SCD from B12 deficiency in patients ≥16 years of age at onset were included. From a final total of 66 cases of SCD identified, ambulation scores were assigned based on the clinical descriptions reported. Patient characteristics, clinical manifestations, and ambulatory function were reported descriptively. Subanalyses on potential prognostic indicators were performed.

SYNTHESIS

Greater ambulatory function at diagnosis was associated with recovery of normal ambulatory function at follow-up (P < .001). Nearly 90% of patients walking unsupported at diagnosis made a complete recovery regardless of etiology. For patients initially walking with support, 22% of cases from impaired B12 digestion/absorption made a complete recovery compared with ≥50% of cases from other etiologies. For patients initially requiring a wheelchair, 33% of cases from impaired digestion/absorption were able to walk with support compared with ≥50% of cases from other etiologies. The total B12 administered over the course of treatment was correlated with improved ambulation (P = .024) for all patients, with a higher B12 replacement regimen associated with better outcomes in patients who were unable to walk unsupported at diagnosis (number needed to treat = 4).

CONCLUSIONS

Initial ambulatory function may be a useful clinical marker of the severity of spinal cord dysfunction and final functional outcome. Etiological risk factors influenced both clinical manifestations and final walking ability in SCD, suggesting a distinct pathophysiological mechanism among the causes. In addition, a more intensive B12 replacement regimen may improve ultimate ambulatory function in advanced cases of SCD.

Recreational Nitrous Oxide Abuse: Prevalence, Neurotoxicity, and Treatment

Nitrous oxide (N₂O), also known as "laughing gas," is a colorless, nonirritating gas. Clinically, it is widely used as an inhaled anesthetic, analgesic, and anxiolytic. In recent years, recreational abuse of N₂O has become increasingly common, especially among young adults and adolescents, but many of them lack awareness of the possible side effects associated with this drug. N₂O abuse can damage multiple systems, especially the nervous system, but the exact mechanism of N₂O toxicity remains controversial. At present, an increasing number of cases of nervous system damage caused by N₂O abuse have been reported both at home and abroad. Discontinuation of N₂O use and timely supplementation with vitamin B12 are essential for a good prognosis. Long-term abuse without timely treatment will eventually lead to irreversible neurological damage. In this article, we discuss the epidemiology of N₂O abuse, neurotoxicity mechanisms, clinical manifestations, relevant auxiliary examinations, treatments, and prognosis to improve social awareness of N₂O exposure risk, especially among users and clinicians.

Glucocorticoid Receptor Activation Restores Learning Memory by Modulating Hippocampal Plasticity in a Mouse Model of Brain Vitamin B12 Deficiency

Cobalamin (Cbl, vitamin B12) deficiency or inborn errors of Cbl metabolism can produce neurologic disorders resistant to therapies, including cognitive dysfunction, mild mental retardation, memory impairment, and confusion. We used Cd320 KO mouse as a model for studying the pathological mechanisms of these disorders. Cd320 encodes the receptor (TCblR) needed for the cellular uptake of Cbl in the brain. The Cd320-/- mouse model presented an impaired learning memory that could be alleviated by a moderate stress, which produced also a greater increase of plasma corticosterone, compared to wild type animals. The present study investigated such a putative rescue mechanism in Cbl-deficient mice. At the molecular level in the brain of Cd320-/- mouse, the decreased methylation status led to a downregulation of glucocorticoid nuclear receptor (GR)/PPAR-gamma co-activator-1 alpha (PGC-1α) pathway. This was evidenced by the decreased expression of GR, decreased methylation of GR and PGC1α, and decreased dimerization and interaction of GR with PGC1α. This led to altered synaptic activity evidenced by decreased interaction between the NMDA glutamatergic receptor and the PSD95 post-synaptic protein and a lower expression of Egr-1 and synapsin 1, in Cd320-/- mice compared to the wild type animals. Intraperitoneal injection of hydrocortisone rescued these molecular changes and normalized the learning memory tests. Our study suggests adaptive influences of moderate stress on loss of memory and cognition due to brain Cbl deficiency. The GR pathway could be a potential target for innovative therapy of cognitive manifestations in patients with poor response to conventional Cbl treatment.

B vitamins as a treatment for diabetic pain and neuropathy

WHAT IS KNOWN AND OBJECTIVE

B vitamin therapy is a common treatment for diabetic pain and neuropathy, yet its use remains controversial in patients lacking B vitamin deficiencies. The aim of this review was to summarize the current evidence for the efficacy of B vitamin therapy in diabetic patients with neuropathy.

COMMENT

We screened the English literature for clinical studies evaluating B vitamins as a therapy for pain and neuropathy in diabetic patients. We selected 43 relevant studies for qualitative analysis based on our selection criteria. Our survey of the literature revealed substantive heterogeneity with respect to efficacies of reported outcomes, as well as study design. Most beneficial outcomes were reported against baseline measures, with few positive comparisons against placebo. This highlights the need for larger, placebo-controlled studies.

WHAT IS NEW AND CONCLUSION

B vitamins should be considered a plausible therapy for diabetic neuropathy, but its overall efficacy remains uncertain and requires further study.

Various Neurological Symptoms with Vitamin B12 Deficiency and Posttreatment Evaluation

Background:

Vitamin B12 deficiency occurs primarily as a result of insufficient dietary intake in children in developing countries. Vitamin B12 deficiency produces a cluster of neurological symptoms in children.

Aim:

The aim of this study was to describe the vitamin B12 status of patients who were admitted with neurological symptoms and to evaluate the clinical response to vitamin B12 treatment.

Materials and Methods:

This study was conducted on children who had vitamin B12 deficiency presented with neurological findings from January 2014 to October 2016. Patients with serum vitamin B12 levels lower than 300 pg/mL received intramuscular or oral vitamin B12 treatment.

Results:

Three hundred and fifty-one patients presenting with neurologic symptoms and who had low serum vitamin B12 deficiency were analyzed. Our study population was composed mainly of adolescent age. The most common symptom with respect to age was headache. In infant patients, most common symptoms were seizure and developmental delay.

Conclusion:

Early diagnosis and vitamin B12 treatment are advocated to avoid long-term injury. Our study shows that patients with serum vitamin B12 levels lower than 300 pg/mL showed clinical improvement of neurological symptoms after receiving vitamin B12 treatment.

Effect of Vitamin B12 Injection on the Vocal Performance of Professional Singers: A Randomized, Double-blind, Placebo-Controlled, Crossover Trial

Importance

One-third of singers and vocal professionals report experiencing a benefit from empirical vitamin B12 injections for improvement of mild singing-related symptoms (eg, reduced stamina, vocal fatigue, and effort). However, there is no objective evidence to support or refute these claims.

Objective

To assess the presence and magnitude of the effect of empirical vitamin B12 injection on the vocal performance of singers.

Design, Setting, and Participants

A randomized, double-blind, placebo-controlled, crossover trial was conducted from November 7, 2017, to November 30, 2018, at an academic voice center among 20 active adult singers without dysphonia but with mild vocal symptoms. Individuals with known or suspected vitamin B12 deficiency or active or recent vitamin B12 treatment were excluded. Analysis was on a per-protocol basis.

Interventions

Participants were randomized to receive an intramuscular (deltoid) injection of either vitamin B12 (1000 μg of cyanocobalmin) or placebo (0.9% sodium chloride). After a washout period of at least 4 weeks, participants were crossed over to receive the opposite injection. Both the investigators and participants were blinded to the order of injections.

Main Outcomes and Measures

The participants completed the Singing Voice Handicap Index-10 (SVHI-10), the Voice Fatigue Index (VFI), and the Evaluation of the Ability to Sing Easily (EASE) before each injection and at intervals of 1 hour, 3 hours, 24 hours, 72 hours, and 1 week after the injection. The primary time point assessment was 72 hours after injection, and the SVHI-10 score was the primary outcome measure.

Results

Twenty singers (10 men; median age, 22 years [range, 19-42 years]) were enrolled. The improvements after either placebo or vitamin B12 injections were comparable to each other. At 72 hours after the vitamin B12 injection, the median difference in the SVHI-10 score was 1 (95% CI, -1 to 2) compared with 3 (95% CI, 0-4) after placebo. The median difference between differences at 72 hours between placebo and vitamin B12 injections were 1.5 (95% CI, -2 to 5) for the SVHI-10, 1 (95% CI, -9 to 9) for the VFI, and -1 (95% CI, -3 to 2) for the EASE. The improvements after both injections failed to reach the estimated minimal clinically important difference. Of the 20 participants, 4 (20%) reached the estimated minimal clinically important difference in their SVHI-10 score after 72 hours for both vitamin B12 and placebo injections.

Conclusions and Relevance

This randomized, double-blind, placebo-controlled, crossover trial found that after empirical vitamin B12 injection to improve mild voice-related symptoms, the improvement in self-reported voice measures in singers shows no meaningful difference compared with placebo.

Trial Registration

ClinicalTrials.gov Identifier: NCT03437824.

Association between frailty and vitamin B12 in the older Korean population

Frailty is a common geriatric condition due to aging and defined as a decline in strength and a decrease in the physiologic ability to maintain the homeostasis. Vitamin B12 (B12), water-soluble vitamins, are a cofactor in DNA synthesis and involved in the metabolism of every cell in the human body, including the central nervous system. Demyelination neuromuscular symptoms observed in the peripheral nervous system, along with signs of significant damage to nerve fibers, often cause weakness, numbness in distal limbs, impaired balance, gait ataxia, and even physical frailty. In this cross-sectional study, we aimed to investigate the relationship between frailty and B12 level in community-dwelling Korean older adults.Using the data from the Korean Frailty and Aging Cohort Study, 2938 participants (1400 men and 1538 women) were recruited in this study. To evaluate frailty, we compared the frail group and not-frail group based on the modified Korean version of the cardiovascular health study frailty index developed by Fried. SARC-F is used to screen for sarcopenia. The short physical performance battery (SPPB) timed up and go (TUG) test and activities-specific balance confidence scale used to evaluate the physical function and fall risk of participants. B12 concentrations were classified into clinically relevant categories: insufficient (<350 pg/mL) and sufficient (≥350 pg/mL). Linear and logistic regression analyses were used to evaluate the relationship between frailty and B12 levels.The mean age of the frail group was 77.8 (standard deviation = 3.7) years, while that of the not-frail group was 76.7 (SD = 4.0); of which the frail group's mean age was significantly high. In the unadjusted model, frailty was highly prevalent in the B12 insufficient group (odds ratio = 1.298). In the model fully adjusted for demographic data and comorbidities, these associations were attenuated. The B12 sufficiency group showed better total SPPB and TUG test scores. However, they were not statistically significant in the fully adjusted model.In this cross-sectional study, low B12 increased the incidence of frailty and affected physical performance, but it does not increase the incidence of frailty when considering the confounding factors. Frailty is caused by several factors rather than 1 factor, and B12 is one of these factors.

A Controlled Descriptive Study to Determine the Nutritional Status and Biochemical Parameters of Multiple Sclerosis Patients

Background

There is an ongoing research on the etiology of multiple sclerosis (MS). It is still unclear whether nutritional status and biochemical parameters such as serum 25(OH)D, magnesium, and potassium influence the development of disease.

Aims

This study aimed to make contributions to the literature in terms of the recognition of MS by comparing nutritional status and biochemical information of people with and without MS.

Materials and Methods

The study was designed as a controlled descriptive study. Total of 112 individuals were included (control group, n = 56 and MS group, n = 56). Socioeconomic and demographic characteristics, nutritional status, and biochemical information were collected from the participants. A decision tree model was built to evaluate the impact of these parameters on the presence of MS. The parameters were compared using Student's t tests and Mann-Whitney U tests.

Results

A decision tree model having an accuracy rate of 86.52% was constructed. Strong statistical differences were observed among the vitamin and mineral intakes of the groups. In terms of biochemical parameters, especially for serum levels of 25(OH)D and potassium, the differences were significantly different (P < 0.001).

Conclusions

Constructed decision tree indicated that the main parameters differed between an MS patient and a healthy person were as follows: serum levels of 25(OH)D, magnesium, calcium, and intakes of potassium and carbohydrate. Based on the findings of this study, nutritional precautions might be taken against MS.

Association between Vitamin B12 levels and cognitive function in the elderly Korean population

Vitamin B12 (B12), also known as cobalamin, is a water-soluble vitamin. It is a cofactor in DNA synthesis and is involved in the metabolism of every cell of the human body, including the central nervous system. Those with a deficiency of B12 can present with peripheral neuropathy, pernicious anemia, or a cognitive disorder. Previous studies have revealed that a deficiency of B12 is associated with cognitive decline or Alzheimer disease.The data of 2991 people were evaluated from 2 years of the Korean Frailty and Aging Cohort Study, a nationwide multicenter survey. To assess cognitive function, a short form of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) was used. Of the CERAD-K tests, we included the Mini-Mental State Examination in the Korean version of the CERAD assessment packet (MMSE-KC), the word list: memory/recall/recognition, digit span (forward, backward), trail making test-A, and the frontal assessment battery. B12 concentrations were classified into clinically relevant categories, insufficient (<350 pg/mL) and sufficient (≥350 pg/mL). A linear regression analysis was used to evaluate the relationship between cognitive function and B12 levels.The mean age of the 2991 participants was 76.4 ± 3.9 years old. Overall, 414 (13.8%) were classified as B12 insufficient, and 2577 (86.2%) as B12 sufficient. The sufficient B12 group performed better in the MMSE-KC, Wordlist: memory, Wordlist: recognition, TMT-A test, digit span, and FAB tests. This was statistically significant (P < .05). However, in the multivariable linear regression analysis, after adjusting for age, sex, education period, marriage, smoking and drinking habits, and comorbidities, the association between the B12 group and cognitive function was not statistically significant.Although our study does not show that B12 insufficiency is a direct risk factor to cognitive decline, B12 levels could be a contributing factor to cognitive function. Our results suggest that cognition was affected by the B12 levels, along with demographic and sociological variables.

Vitamin B12 deficiency as a cause of severe neurological symptoms in breast fed infant - a case report

Background

Vitamin B₁₂ (cobalamin, cbl) deficiency in children is rare and may occurs in exclusively breast fed infants of mothers on vegetarian or vegan diet with lack of appropriate supplementation. The clinical manifestation of vitamin B12 deficiency include neurological disorders, megaloblastic anemia and failure to thrive. Routine and commonly used laboratory tests such as cell blood count (CBC) or serum vitamin B₁₂ level are sufficient for appropriate diagnosis. Typical therapy is based on intramuscular cobalamin injections. Early diagnosis and early onset of treatment are crucial factors for long-term prognosis of patients as the duration of deficiency may be correlated with the development of long lasting changes in the nervous system.

The purpose of this article is to present influence of maternal vitamin B₁₂ deficiency as a cause of infant psychomotor retardation.

Case presentation

We report the case of a 7 months old girl whose parents sought medical advice due to pathological somnolence and developmental regression of their daughter with onset approximately 2 months prior to the visit. Following several diagnostic tests it was determined that the infant’s symptoms were due to vitamin B₁₂ deficiency which was secondary to the mother’s latent Addison-Biermer disease. Apart from neurological symptoms the infant also showed megaloblastic anemia which is typical to cobalamin deficiencies. Intramuscular vitamin B₁₂ supplementation resulted in instant improvement of the patient’s general condition and blood morphology. Unfortunately, psychological examination indicated long-term psychomotor retardation due to delayed diagnosis of B₁₂ deficiency.

Conclusions

Vitamin B₁₂ levels should be considered during differential diagnosis of neurological symptoms in exclusively breast-fed infants especially if they co-exist with megaloblastic anemia and psychomotor retardation.

Feline irradiated diet-induced demyelination; a model of the neuropathology of sub-acute combined degeneration?

Irradiation of food at 50–55 kGy results in a profound, chronic demyelinating-remyelinating disease of the entire central nervous system (CNS) in cats, named Feline Irradiated Diet-Induced Demyelination (FIDID). This study examines the early stages of demyelination and long-term consequences of demyelination and remyelination on axon survival or loss. Myelin vacuolation is the primary defect leading to myelin breakdown, demyelination then prompt remyelination in the spinal cord and brain. There is no evidence of oligodendrocyte death. The spinal cord dorsal column is initially spared yet eventually becomes severely demyelinated with subsequent loss of axons in the core and then surface of the fasciculus gracilis. However remyelination of the sub-pial axons in the dorsal column results in their protection. While there was a lack of biochemical evidence of Vitamin B12 deficiency, the pathological similarities of FIDID with sub-acute combined degeneration (SCD) led us to explore treatment with Vitamin B12. Treatment led to recovery or improvement in some cats and neurologic relapse on cessation of B12 therapy. While the reason that irradiated food is myelinotoxic in the cat remains unresolved, nonetheless the neuropathological changes match exactly what is seen in SCD and its models and provide an ideal model to study the cellular and molecular basis of remyelination.

Cobalamin Deficiency: Effect on Homeostasis of Cultured Human Astrocytes

Cobalamin deficiency is an important health problem. The major non-hematological symptoms of hypocobalaminemia are nervous system disorders, but the molecular and cellular mechanisms underlying this phenomenon have not yet been fully explained. Increasing scientific evidence is stressing the pivotal role of astrocyte dysfunction in the pathogenesis of a wide range of neurological disorders. In light of the above, the aim of this study was to develop an in vitro model of cobalamin deficiency by optimizing the conditions of astrocyte culture in the presence of vitamin B₁₂ antagonist, and then the model was used for multidirectional analysis of astrocyte homeostasis using image cytometry, immunoenzymatic and colorimetric assays, and fluorescence spectroscopy. Our results indicated that long-term incubation of normal human astrocytes with hydroxycobalamin(c-lactam) causes an increase of extracellular homocysteine level, a reduction of cell proliferation, and an accumulation of cells in the G₂/M cell cycle phase. Moreover, we observed dramatic activation of caspases and an increase of catalase activity. Interestingly, we excluded extensive apoptosis and oxidative stress. The study provided significant evidence for astrocyte homeostasis disturbance under hypocobalaminemia, thus indicating an important element of the molecular mechanism of nervous system diseases related to vitamin B₁₂ deficiency.

Brain Susceptibility to Methyl Donor Deficiency: From Fetal Programming to Aging Outcome in Rats

Deficiencies in methyl donors, folate, and vitamin B12 are known to lead to brain function defects. Fetal development is the most studied but data are also available for such an impact in elderly rats. To compare the functional consequences of nutritional deficiency in young versus adult rats, we monitored behavioral outcomes of cerebellum and hippocampus circuits in the offspring of deficient mother rats and in adult rats fed a deficient diet from 2 to 8 months-of-age. We present data showing that the main deleterious consequences are found in young ages compared to adult ones, in terms of movement coordination and learning abilities. Moreover, we obtained sex and age differences in the deleterious effects on these functions and on neuronal layer integrity in growing young rats, while deficient adults presented only slight functional alterations without tissue damage. Actually, the cerebellum and the hippocampus develop and maturate according to different time lap windows and we demonstrate that a switch to a normal diet can only rescue circuits that present a long permissive window of time, such as the cerebellum, whereas the hippocampus does not. Thus, we argue, as others have, for supplements or fortifications given over a longer time than the developmental period.

Neurological disorders in vitamin B12 deficiency

The review discusses thesteps of vitamin B12 metabolism and its role in maintaining of neurological functions. The term "vitamin B12 (cobalamin)" refers to several substances (cobalamins) of a very similar structure. Cobalamin enters the body with animal products. On the peripherу cobalamin circulates only in binding with proteins transcobalamin I and II (complex cobalamin-transcobalamin II is designated as "holotranscobalamin"). Holotranscobalamin is absorbed by different cells, whereas transcobalamin I-binded vitamin B12 - only by liver and kidneys. Two forms of cobalamin were identified as coenzymes of cellular reactions which are methylcobalamin (in cytoplasm) and hydroxyadenosylcobalamin (in mitochondria). The main causes of cobalamin deficiency are related to inadequate intake of animal products, autoimmune gastritis, pancreatic insufficiency, terminal ileum disease, syndrome of intestinal bacterial overgrowth. Relative deficiency may be seen in excessive binding of vitamin B12 to transcobalamin I. Cobalamin deficiency most significantly affects functions of blood, nervous system and inflammatory response. Anemia occurs in 13-15% of cases; macrocytosis is an early sign. The average size of neutrophils and monocytes is the most sensitive marker of megaloblastic hematopoiesis. The demands in vitamin B12 are particularly high in nervous tissue. Hypovitaminosis is accompanied by pathological lesions both in white and gray brain matter. Several types of neurological manifestations are described: subacute combined degeneration of spinal cord (funicular myelinosis), sensomotor polyneuropathy, optic nerve neuropathy, cognitive disorders. The whole range of neuropsychiatric disorders with vitamin B12 deficiency has not been studied well enough. Due to certain diagnostic difficulties they are often regarded as "cryptogenic", "reactive", "vascular» origin. Normal or decreased total plasma cobalamin level could not a reliable marker of vitamin deficiency. In difficult cases the content of holotranscobalamin, methylmalonic acid / homocysteine, and folate in the blood serum should be investigated besides carefully analysis of clinical manifestations.

The clinical presentation of cobalamin-related disorders: From acquired deficiencies to inborn errors of absorption and intracellular pathways

This review gives an overview of clinical characteristics, treatment and outcome of nutritional and acquired cobalamin (Cbl; synonym: vitamin B12) deficiencies, inborn errors of Cbl absorption and intracellular trafficking, as well as methylenetetrahydrofolate dehydrogenase (MTHFD1) and methylene tetrahydrofolate reductase (MTHFR) deficiencies, which impair Cbl-dependent remethylation. Acquired and inborn Cbl-related disorders and MTHFR deficiency cause multisystem, often severe disease. Failure to thrive, neurocognitive or psychiatric symptoms, eye disease, bone marrow alterations, microangiopathy and thromboembolic events are characteristic. The recently identified MTHFD1 defect additionally presents with severe immune deficiency. Deficient Cbl-dependent enzymes cause reduced methylation capacity and metabolite toxicity. Further net-effects of perturbed Cbl function or reduced Cbl supply causing oxidative stress, altered cytokine regulation or immune functions are discussed.

The Many Faces of Cobalamin (Vitamin B12) Deficiency

Although cobalamin (vitamin B₁₂) deficiency was described over a century ago, it is still difficult to establish the correct diagnosis and prescribe the right treatment. Symptoms related to vitamin B₁₂ deficiency may be diverse and vary from neurologic to psychiatric. A number of individuals with vitamin B₁₂ deficiency may present with the classic megaloblastic anemia.

In clinical practice, many cases of vitamin B₁₂ deficiency are overlooked or sometimes even misdiagnosed. In this review, we describe the heterogeneous disease spectrum of patients with vitamin B₁₂ deficiency in whom the diagnosis was either based on low serum B₁₂ levels, elevated biomarkers like methylmalonic acid and/or homocysteine, or the improvement of clinical symptoms after the institution of parenteral vitamin B₁₂ therapy. We discuss the possible clinical signs and symptoms of patients with B₁₂ deficiency and the various pitfalls of diagnosis and treatment.

Nutritional Modulation of Immune and Central Nervous System Homeostasis: The Role of Diet in Development of Neuroinflammation and Neurological Disease

The gut-microbiome-brain axis is now recognized as an essential part in the regulation of systemic metabolism and homeostasis. Accumulating evidence has demonstrated that dietary patterns can influence the development of metabolic alterations and inflammation through the effects of nutrients on a multitude of variables, including microbiome composition, release of microbial products, gastrointestinal signaling molecules, and neurotransmitters. These signaling molecules are, in turn, implicated in the regulation of the immune system, either promoting or inhibiting the production of pro-inflammatory cytokines and the expansion of specific leukocyte subpopulations, such as Th17 and Treg cells, which are relevant in the development of neuroinflammatory and neurodegenerative conditions. Metabolic diseases, like obesity and type 2 diabetes mellitus, are related to inadequate dietary patterns and promote variations in the aforementioned signaling pathways in patients with these conditions, which have been linked to alterations in neurological functions and mental health. Thus, maintenance of adequate dietary patterns should be an essential component of any strategy aiming to prevent neurological pathologies derived from systemic metabolic alterations. The present review summarizes current knowledge on the role of nutrition in the modulation of the immune system and its impact in the development of neuroinflammation and neurological disease.

The Role of Vitamin B12 in the Management and Optimization of Treatment in Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

Narrative review.

OBJECTIVES

To discuss the relationship between degenerative cervical myelopathy (DCM) and vitamin B12 deficiency. Specifically, it is the aim to outline the rational for future research into assessment and therapeutic optimization of vitamin B12 in the treatment of DCM.

METHODS

Literature review.

RESULTS

DCM is the commonest cause of spinal cord impairment, with an average age of presentation in the sixth decade. Patients at this age have also been reported to have a high prevalence of vitamin B12 deficiency, with estimates of up to 20% in the elderly. Vitamin B12 deficiency can result in subacute combined degeneration of the spinal cord (SACD), and several case reports have pointed to patients with both DCM and SACD. Both SACD and reversible compressive injury due to DCM necessitate remyelination in the spinal cord, a process that requires adequate vitamin B12 levels. Basic science research on nerve crush injuries have shown that vitamin B12 levels are altered after nerve injury and that vitamin B12 along with dexamethasone or nonsteroidal anti-inflammatory drugs can reduce Wallerian degeneration. Furthermore, it has been suggested that a combination of B-vitamins can reduce glutamate-induced neurotoxicity.

CONCLUSIONS

Given the high prevalence of clinical and subclinical vitamin B12 deficiency in the elderly, the role of vitamin B12 in myelination, and vitamin B12 deficiency as a differential diagnosis of DCM, it is important to investigate what role vitamin B12 levels play in patients with DCM in terms of baseline neurological function and whether optimization of vitamin B12 levels can improve surgical outcome. Furthermore, the routine assessment of vitamin B12 levels in patients considered for DCM surgery should be considered.

Neuropathology of vitamin B12 deficiency in the Cd320-/- mouse

In humans, vitamin B12 deficiency causes peripheral and CNS manifestations. Loss of myelin in the peripheral nerves and the spinal cord (SC) contributes to peripheral neuropathy and motor deficits. The metabolic basis for the demyelination and brain disorder is unknown. The transcobalamin receptor-knockout mouse ( Cd320-/-) develops cobalamin (Cbl) deficiency in the nervous system, with mild anemia. A decreased S-adenosylmethionine: S-adenosylhomocysteine ratio and increased methionine were seen in the brain with no significant changes in neurotransmitter metabolites. The structural pathology in the SC presented as loss of myelin in the axonal tracts with inflammation. The sciatic nerve (SN) showed increased nonuniform, internodal segments suggesting demyelination, and remyelination in progress. Consistent with these changes, the Cd320-/- mouse showed an increased latency to thermal nociception. Further, lower amplitude of compound action potential in the SN suggested that the functional capacity of the heavily myelinated axons were preferentially compromised, leading to loss of peripheral sensation. Although the metabolic basis for the demyelination and the structural and functional alterations of the nervous system in Cbl deficiency remain unresolved, the Cd320-/- mouse provides a unique model to investigate the pathologic consequences of vitamin B12 deficiency. -Arora, K., Sequeira, J. M., Alarcon, J. M., Wasek, B., Arning, E., Bottiglieri, T., Quadros, E. V. Neuropathology of vitamin B12 deficiency in the Cd320-/- mouse.

Vitamin B12 Deficiency and Foot Ulcers in Type 2 Diabetes Mellitus: A Case-Control Study

OBJECTIVE

To assess the association between vitamin B₁₂ deficiency and the development of diabetic foot ulcers (DFU) in type 2 diabetes mellitus (T2DM).

METHODS

This is a case-control study that enrolled 323 Saudi adults with T2DM randomly selected from the Jazan Diabetes & Endocrine Center, Saudi Arabia from January 1, 2019, to July 31, 2019. The sample included 108 newly diagnosed cases with DFU and 215 control participants with T2DM unaffected by and free of foot ulcers (1:2 ratio). Logistic regression analysis was performed to determine the DFU predictors and to examine the association of DFU and vitamin B₁₂ deficiency.

RESULTS

The highest DFU rates were found among the male participants and the participants older than 45 years. Neuropathy, vasculopathy, vitamin B₁₂ deficiency, poor glycemic control, poor feet self-care, Charcot foot, physical inactivity, and spending long time standing at work were significantly associated with DFU, and all except physical inactivity and spending long time standing at work were independent predictors of DFU. After adjustment for the covariates, vitamin B₁₂ deficiency was significantly associated with DFU (odds ratio 3.1), indicating that the patients with T2DM and vitamin B₁₂ deficiency had a three times higher risk of developing DFU than those with normal vitamin B₁₂ levels.

CONCLUSION

Vitamin B₁₂ deficiency had a significant association with DFU among the Saudi participants with T2DM. Establishing the causality and clarifying the biological role of vitamin B12 deficiency in DFU is important aims for future studies.

Levodopa-Induced Neuropathy: A Systematic Review

Background

Clinical, neurophysiological, and pathological evidence suggest an association between Parkinson's disease (PD) and peripheral neuropathy (PNP), with a possible causative role of levodopa metabolic products, such as homocysteine and methylmalonic acid.

Methods

We conducted a systematic review of studies reporting cases of PNP in l-dopa-treated PD patients indexed in PubMed between January 1990 and March 2018.

Results

We identified 38 articles reporting cases of PNP in PD patients treated with oral l-dopa or with l-dopa/carbidopa intestinal gel infusion (LCIG). Prevalence of PNP was 30.2% in the former group and 42.1% in the latter. Oral l-dopa was mostly associated with slowly progressive PNP, whereas LCIG showed an acute or subacute onset in 35.7% of cases. In both groups, there was an association between PNP and higher l-dopa doses, as well as with the following biochemical alterations: increased homocysteine; reduced vitamin B12; increased methylmalonic acid; and reduced vitamin B6. A skin biopsy was performed in 181 patients, showing signs of small fibers neuropathy in 169 (93.4%). Positive, yet preliminary, results were observed in patients receiving periodic vitamin supplementation.

Conclusions

Over one third of PD patients in treatment with l-dopa may develop PNP, with a significantly higher prevalence of acute and subacute forms in those receiving LCIG. Pathogenic mechanisms remain unclear, but possibly related to a complex interplay between peripheral neurodegenerative processes and l-dopa neurotoxic metabolites. Prospective, randomized, clinical trials are required to identify factors associated with the onset and progression of PD-associated PNP and clarify the protective role of B-group vitamin supplementation.

Clinical and imaging characteristics of subacute combined degeneration complicated with white matter lesions in the brain: a report of five cases

PURPOSE

To report five cases of subacute combined degeneration (SCD) with brain involvement and explore its clinical and imaging characteristics.

METHODS

A retrospective study was performed on the clinical data and brain MRI of five patients with subacute combined degeneration with brain involvement (out of 107 cases with SCD in total). White matter lesions (WML) assessment was performed qualitatively using Fazekas scale score.

RESULTS

The main symptoms in four patients were weakness in both lower extremities and unstable walking (limb weakness in three patients, dizziness in three patients, and blurred vision in one patient). One patient had memory loss and cognitive dysfunction. The MMSE scale indicated mild dementia in one patient. On head MRI (Magnetic Resonance Imaging), multifocal and symmetrical high signals of T2WI and FLAIR were observed in the frontal lobe and periventricular white matter in four patients, while another patient showed preferential atrophy in frontal regions. Fazekas scale scores ranged from 1-6.

CONCLUSION

Adult subacute combined degeneration seldom involves the brain. Multifocal and symmetrical high signal white matter lesions can be found on FLAIR and T2WI, as well as frontal atrophy on head MRI.

Subacute combined degeneration of the spinal cord following nitrous oxide anesthesia: A systematic review of cases

OBJECTIVE

Vitamin B12 deficiency can lead to subacute combined degeneration (SCD). Nitrous oxide (N₂O) is an anesthetic which oxidizes the cobalt ion of vitamin B12, interfering with its function as a coenzyme. In this study, we conduct a systematic review of reported cases of SCD following nitrous oxide anesthesia.

PATIENTS AND METHODS

A comprehensive search of multiple databases was conducted, and information about patient characteristics, symptomatology, clinical work-up, and treatment was extracted from eligible articles. Univariate analyses were performed to identify predictors of poor neurological recovery following SCD.

RESULTS

32 studies, reporting 37 cases of nitrous oxide-induced SCD, were included through the screening process. These cases included 21 male patients and 16 female patients, with an average age of 50.4 years (SD 17.6). An etiology for subclinical B12 deficiency was determined in 30 reports; of these, 25 were due to vitamin malabsorption secondary to a gastrointestinal disorder. Duration of nitrous oxide exposure was described in 19 reports, and ranged from 30 min to 11 h. Univariate analysis failed to find an association between post-operative recovery and age (p = 0.60), sex (p = 0.46), positive MRI findings (p = 0.47), post-operative serum B12 (p = 1.00), post-operative hemoglobin (p = 0.18), type of surgery (p = 0.58), or post-operative high mean corpuscular volume (p = 0.13).

CONCLUSION

In patients with postsurgical myelopathy, surgeons should evaluate B12 status and consider the possibility that nitrous oxide could cause a subclinical B12 deficiency to become overt, particularly in patients with malabsorptive GI comorbidities. Treatment with B12 in this population can result in significant improvement of neurological function.

Vitamin B12

The biosynthesis of B₁₂, involving up to 30 different enzyme-mediated steps, only occurs in bacteria. Thus, most eukaryotes require an external source of B₁₂, and yet the vitamin appears to have only two functions in eukaryotes: as a cofactor for the enzymes methionine synthase and methylmalonylCoA mutase. These two functions are crucial for normal health in humans, and in particular, the formation of methionine is essential for providing methyl groups for over 100 methylation processes. Interference with the methionine synthase reaction not only depletes the body of methyl groups but also leads to the accumulation of homocysteine, a risk factor for many diseases. The syndrome pernicious anemia, characterized by lack of intrinsic factor, leads to a severe, sometimes fatal form of B₁₂ deficiency. However, there is no sharp cutoff for B₁₂ deficiency; rather, there is a continuous inverse relationship between serum B₁₂ and a variety of undesirable outcomes, including neural tube defects, stroke, and dementia. The brain is particularly vulnerable; in children, inadequate B₁₂ stunts brain and intellectual development. Suboptimal B₁₂ status (serum B₁₂<300pmol/L) is very common, occurring in 30%-60% of the population, in particular in pregnant women and in less-developed countries. Thus, many tens of millions of people in the world may suffer harm from having a poor B₁₂ status. Public health steps are urgently needed to correct this inadequacy.

The Singer's and the Clinician's Perspective on Vitamin B12 Treatment for Vocal Benefits

INTRODUCTION

There is a belief among vocalists that there are voice benefits from vitamin B₁₂ treatment. Yet there are no previous reports regarding vitamin B₁₂ effects on voice.

OBJECTIVES

To assess the prevalence of vitamin B₁₂ use among singers and their beliefs regarding vitamin B₁₂ therapy.

METHODS

Anonymous online survey administered to singers, singing-teachers, speech-language pathologists, and laryngologists.

RESULTS

A total of 192 participants completed the surveys; 128 singers (68 singing-teachers, 30 speech-language pathologists) and 64 laryngologists. Among singers, 12% have perceived voice benefits from vitamin B₁₂ treatment taken for any reason. Four percent used vitamin B₁₂ for voice benefits; all perceived voice benefits as a result. The leading voice benefits were improved stamina, reduced effort, confidence, and control. Nineteen percent of the singers would recommend vitamin B₁₂ treatment to a friend; 15% of the singing-teachers would recommend it to a student. Among laryngologists, 33% been asked by a singer to prescribe vitamin B₁₂ for voice benefits; 9% have prescribed it in the past. Yet only 3% would you recommend it to a patient. When asked "Do you believe vitamin B₁₂ therapy improves vocal performance?" 31% of the singers responded "Yes," compared with none in the laryngologists. When asked "Do you think the singing community believes vitamin B₁₂ therapy improves vocal performance?" 26% of the singers responded "Yes," compared with 53% of the laryngologists (P = 0.0002).

CONCLUSIONS

There is a discrepancy between the singers' and the laryngologists' beliefs regarding vocal benefits perceived by vitamin B₁₂. Blinded randomized trials are required to verify or refute this belief.

Vitamin B12 deficiency

Vitamin B₁₂ (B12; also known as cobalamin) is a B vitamin that has an important role in cellular metabolism, especially in DNA synthesis, methylation and mitochondrial metabolism. Clinical B12 deficiency with classic haematological and neurological manifestations is relatively uncommon. However, subclinical deficiency affects between 2.5% and 26% of the general population depending on the definition used, although the clinical relevance is unclear. B12 deficiency can affect individuals at all ages, but most particularly elderly individuals. Infants, children, adolescents and women of reproductive age are also at high risk of deficiency in populations where dietary intake of B12-containing animal-derived foods is restricted. Deficiency is caused by either inadequate intake, inadequate bioavailability or malabsorption. Disruption of B12 transport in the blood, or impaired cellular uptake or metabolism causes an intracellular deficiency. Diagnostic biomarkers for B12 status include decreased levels of circulating total B12 and transcobalamin-bound B12, and abnormally increased levels of homocysteine and methylmalonic acid. However, the exact cut-offs to classify clinical and subclinical deficiency remain debated. Management depends on B12 supplementation, either via high-dose oral routes or via parenteral administration. This Primer describes the current knowledge surrounding B12 deficiency, and highlights improvements in diagnostic methods as well as shifting concepts about the prevalence, causes and manifestations of B12 deficiency.

Antivitamin B12 Inhibition of the Human B12 -Processing Enzyme CblC: Crystal Structure of an Inactive Ternary Complex with Glutathione as the Cosubstrate

B₁₂ antivitamins are important and robust tools for investigating the biological roles of vitamin B₁₂ . Here, the potential antivitamin B₁₂ 2,4-difluorophenylethynylcobalamin (F2PhEtyCbl) was prepared, and its 3D structure was studied in solution and in the crystal. Chemically inert F2PhEtyCbl resisted thermolysis of its Co-C bond at 100 °C, was stable in bright daylight, and also remained intact upon prolonged storage in aqueous solution at room temperature. It binds to the human B₁₂ -processing enzyme CblC with high affinity (K_D =130 nm) in the presence of the cosubstrate glutathione (GSH). F2PhEtyCbl withstood tailoring by CblC, and it also stabilized the ternary complex with GSH. The crystal structure of this inactivated assembly provides first insight into the binding interactions between an antivitamin B₁₂ and CblC, as well as into the organization of GSH and a base-off cobalamin in the active site of this enzyme.

Maternofetal transport of vitamin B12: role of TCblR/CD320 and megalin

Vitamin B₁₂ deficiency causes megaloblastic anemia and neurologic disorder in humans. Gene defects of transcobalamin (TC) and the transcobalamin receptor (TCblR), needed for cellular uptake of the TC-bound B₁₂, do not confer embryonic lethality. TC deficiency can produce the hematologic and neurologic complications after birth, whereas TCblR/CD320 gene defects appear to produce mild metabolic changes. Alternate maternofetal transport mechanisms appear to provide adequate B₁₂ to the fetus. To understand this mechanism, we evaluated the role of TC, TCblR/CD320, and megalin in maternofetal transport of B₁₂ in a TCblR/CD320-knockout (KO) mouse. Our results showed high expression of TCblR/CD320 in the labyrinth of the placenta, embryonic brain, and spinal column in wild-type (WT) mice. Megalin expression was about the same in both WT and KO mouse visceral yolk sac, brain, and spinal column. Megalin mRNA was down-regulated in the KO embryonic spinal cord (SC) and kidneys. Megalin expression remained unaltered in adult WT and KO mouse brain, SC, and kidneys. Injected dsRed-TC-B₁₂ and TC-⁵⁷CoB₁₂ accumulated in the visceral yolk sac of KO mice where megalin is expressed and provides an alternate mechanism for the maternofetal transport of Cbl during fetal development.-Arora, K., Sequeira, J. M., Quadros, E. V. Maternofetal transport of vitamin B₁₂: role of TCblR/CD320 and megalin.