New Basis of the Neurotrophic Action of Vitamin B12

Vitamin B12 Deficiency and the Nervous System: Beyond Metabolic Decompensation-Comparing Biological Models and Gaining New Insights into Molecular and Cellular Mechanisms

Vitamin B12 (VitB12) is a micronutrient and acts as a cofactor for fundamental biochemical reactions: the synthesis of succinyl-CoA from methylmalonyl-CoA and biotin, and the synthesis of methionine from folic acid and homocysteine. VitB12 deficiency can determine a wide range of diseases, including nervous system impairments. Although clinical evidence shows a direct role of VitB12 in neuronal homeostasis, the molecular mechanisms are yet to be characterized in depth. Earlier investigations focused on exploring the biochemical shifts resulting from a deficiency in the function of VitB12 as a coenzyme, while more recent studies propose a broader mechanism, encompassing changes at the molecular/cellular levels. Here, we explore existing study models employed to investigate the role of VitB12 in the nervous system, including the challenges inherent in replicating deficiency/supplementation in experimental settings. Moreover, we discuss the potential biochemical alterations and ensuing mechanisms that might be modified at the molecular/cellular level (such as epigenetic modifications or changes in lysosomal activity). We also address the role of VitB12 deficiency in initiating processes that contribute to nervous system deterioration, including ROS accumulation, inflammation, and demyelination. Consequently, a complex biological landscape emerges, requiring further investigative efforts to grasp the intricacies involved and identify potential therapeutic targets.

Just a vitamin? Should cobalamin (Vitamin B12) levels be checked in children with neurological disadvantages?

OBJECTIVE

The assay of serum cobalamin (Cbl) level is commonly used to diagnose Cbl deficiency. Unexpectedly, the elevated Cbl levels may be determined in some of the patients and its interpretation is difficult. We investigated the association between elevated Cbl levels and a variety of clinical entities in patients presenting with various neurological symptoms.

METHODS

The data were obtained from the patients' electronic medical records in a tertiary hospital affiliated with a university. The pediatric patients with serum Cbl levels above 1000 pg/mL were included in the study. The patients with serum Cbl levels below 900 pg/mL and above 200 pg/mL constituted the control group.

RESULTS

The mean Cbl level of the patients with neurological problems was 1424.2±354.2 pg/mL, whereas the average Cbl level of neurologically healthy was 1316±317.8 pg/mL, and the difference was statistically significant. While the rate of having neurological deficits or symptoms in the study group was found to be 24%, this rate was only 18% in the control group. Unexpectedly, despite elevated Cbl level, the high mean corpuscular volume rate was higher in the study group compared to the control group.

CONCLUSION

This study highlights the importance of the disorders of Cbl metabolism in patients presenting with various neurological symptoms. In children with neurological deficits, serum Cbl levels should be checked. In case of high Cbl level is determined, patients should be followed up closely, and further investigations should be performed in terms of Cbl metabolism disorders.

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.

Homocysteine as a Predictor Tool in Multiple Sclerosis

Multiple sclerosis (MS) is a progressive and irreversible disease which affects the central nervous system (CNS) with still unknown etiology. Our study aimes to establish the homocysteine pattern that can predict the MS diseases progression and to identify a potential disease progression marker that can be easy to perform and non-invasive, in order to predict the diseases outcome. In order to achieve this goal, we included 10 adult RRMS subjects, 10 adult SPMS subjects and 10 age-matched healthy subjects. The homocysteine plasma level was measured using automated latex enhanced immunoassay and the cobalamin and folate measurements were performed using automated chemiluminescence immunoassay (CLIA). HCR was calculated by dividing the homocysteine plasma level by cobalamin plasma level. We found that the homocysteine level in plasma of both RRMS patients and SPMS group are significantly increased compared with the control group. There is a significantly higher concentration of homocysteine in SPMS group compared with the RRMS group. In addition, the HCR is significantly increased in SPMS compared with the RRMS group and is a very good index of disease severity.

Modulation of vigabatrin induced cerebellar injury: the role of caspase-3 and RIPK1/RIPK3-regulated cell death pathways

Vigabatrin is the drug of choice in resistant epilepsy and infantile spasms. Ataxia, tremors, and abnormal gait have been frequently reported following its use indicating cerebellar involvement. This study aimed, for the first time, to investigate the involvement of necroptosis and apoptosis in the VG-induced cerebellar cell loss and the possible protective role of combined omega-3 and vitamin B12 supplementation. Fifty Sprague-Dawley adult male rats (160-200 g) were divided into equal five groups: the control group received normal saline, VG200 and VG400 groups received VG (200 mg or 400 mg/kg, respectively), VG200 + OB and VG400 + OB groups received combined VG (200 mg or 400 mg/kg, respectively), vitamin B12 (1 mg/kg), and omega-3 (1 g/kg). All medications were given daily by gavage for four weeks. Histopathological changes were examined in H&E and luxol fast blue (LFB) stained sections. Immunohistochemical staining for caspase-3 and receptor-interacting serine/threonine-protein kinase-1 (RIPK1) as well as quantitative real-time polymerase chain reaction (qRT-PCR) for myelin basic protein (MBP), caspase-3, and receptor-interacting serine/threonine-protein kinase-3 (RIPK3) genes were performed. VG caused a decrease in the granular layer thickness and Purkinje cell number, vacuolations, demyelination, suppression of MBP gene expression, and induction of caspases-3, RIPK1, and RIPK3 in a dose-related manner. Combined supplementation with B12 and omega-3 improved the cerebellar histology, increased MBP, and decreased apoptotic and necroptotic markers. In conclusion, VG-induced neuronal cell loss is dose-dependent and related to both apoptosis and necroptosis. This could either be ameliorated (in low-dose VG) or reduced (in high-dose VG) by combined supplementation with B12 and omega-3.

Hereditary defect of cobalamin metabolism with adolescence onset resembling multiple sclerosis: 41-year follow up in two cases

The cblC defect is the most common inborn error of cobalamin (Cbl) metabolism. Clinical severity and presentation of the cblC defect ranges from death to mild disability. Only 71 cases of late-onset cblC defect have been described in the literature. We provide the 41-year follow up of two siblings with a late-onset cblC defect, first described after initial diagnosis in 1996. While one of the siblings showed initial symptoms resembling multiple sclerosis with a good response to corticosteroids, the other sister showed only subclinical signs of the disease. The course of the first case was characterized by a severe deterioration and intensive-care therapy after respiratory failure. After diagnoses and Cbl treatment, the patient survived and showed a pronounced improvement of the symptoms. Both sisters have an active life and gave birth to healthy children. The reason for the initial improvement after corticosteroids could not be explained by the classical metabolic pathways of Cbl. Recent studies have suggested that Cbl plays an important role as a regulator of the balance between neurotrophic and neurotoxic factors in the central and peripheral nervous system (CNS and PNS). This first long-term follow up revealed that ultra-high-dose intramuscular Hydroxocobalamin (OH-Cbl) treatment can effectively protect patients from disease progression. It underlines the importance of diagnostic vigilance and laboratory work up even in cases without typical hematologic signs of Cbl deficiency. Cbl-related diseases are often a chameleon and must always be considered in the differential of demyelinating diseases of the PNS and CNS. The case supports the theory that it is not only the classical biochemical pathways that play a key role in Cbl deficiency, especially with regard to neurological symptoms.

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.

Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Subacute Combined Degeneration: Revealing a Genetic Predisposition

Vitamin B12 deficiency is regarded as the prevailing cause of subacute combined degeneration of the spinal cord (SCD). Nevertheless, the genetic predisposition to SCD remains unclear. The aim of this study was to explore the association between methylenetetrahydrofolate reductase gene (MTHFR) C677T polymorphism and SCD. We investigated MTHFR C677T polymorphism in SCD patients and found that the distribution of MTHFR C677T genotypes was significantly different between SCD patients and age-matched controls. Furthermore, the T allele frequency was markedly increased in SCD compared with the controls. In addition, the plasma homocysteine concentrations in subjects with the TT genotype were significantly elevated compared to those with the CC genotype. Logistic regression analysis results revealed that the MTHFR C677T genotype (TT vs. CT and CC) and vitamin B12 deficiency were risk factors for SCD. Our findings indicate that the T allele of the MTHFR C677T confers a strong genetic predisposition to SCD and provide evidence of an association between MTHFR C677T polymorphism and SCD. These data reveal a potential mechanism underlying SCD.

A randomized, open labeled study comparing the serum levels of cobalamin after three doses of 500 mcg vs. a single dose methylcobalamin of 1500 mcg in patients with peripheral neuropathy

Background

Vitamin B12 deficiency has been associated with peripheral neuropathy, loss of sensation in the peripheral nerves, and weakness in the lower extremities. Methylcobalamin is the most effective analogue of vitamin B12 used to treat or prevent the complications associated with vitamin B12 deficiency. The current study aimed to compare the serum cobalamin levels after administration of two different regimes of methylcobalamin in peripheral neuropathy patients.

Methods

The present study was a prospective, randomized, comparative study. The study consisted of two parallel groups, group A (methylcobalamin 500 µg injection intramuscularly three times a week) and group B (methylcobalamin 1500 µg injection intramuscularly once a week). A control group of healthy volunteers was also included.

Results

A total of 24 patients (12 in each group) were included in the study. Five healthy volunteers were also included as a control in each group. At the end of treatment, serum cobalamin levels were significantly (P = 0.028) higher in group A (1892.08 ± 234.50) as compared with group B (1438.5 ± 460.32). The serum cobalamin levels in Group A healthy volunteers were also two times higher than that of group B (P = 0.056). Both the LANSS scale and DN4 questionnaire reported similar results at end of treatment.

Conclusions

The 500 µg methylcobalamin thrice weekly regime is more effective in increasing the serum cobalamin levels as compared to the 1500 µg methylcobalamin once weekly regime.

A review on potential roles of vitamins in incidence, progression, and improvement of multiple sclerosis

Multiple Sclerosis (MS) is an inflammatory and neurodegenerative disease, with unknown etiology. Vitamins, as important micronutrients playing different roles in body, seem to be important in MS pathogenesis. In vitro, in vivo and human studies, supports the protective role of some vitamins in MS occurrence or progression. Current study reviews recent insights and reports about the importance of vitamins in MS incidence or progression. In accordance, the importance of all water and fat-soluble vitamins in MS pathogenesis based on observational studies in human population and their role in the function of immune system as well as possible therapeutic opportunities are discussed in depth throughout this review.

Novel insights into the effect of vitamin B₁₂ and omega-3 fatty acids on brain function

The prevalence of psychiatric disorders which are characterized by cognitive decline is increasing at an alarming rate and account for a significant proportion of the global disease burden. Evidences from human and animal studies indicate that neurocognitive development is influenced by various environmental factors including nutrition. It has been established that nutrition affects the brain throughout life. However, the mechanisms through which nutrition modulates mental health are still not well understood. It has been suggested that the deficiencies of both vitamin B12 and omega-3 fatty acids can have adverse effects on cognition and synaptic plasticity. Studies indicate a need for supplementation of vitamin B12 and omega-3 fatty acids to reduce the risk of cognitive decline, although the results of intervention trials using these nutrients in isolation are inconclusive. In the present article, we provide an overview of vitamin B12 and omega-3 fatty acids, the possible mechanisms and the evidences through which vitamin B12 and omega-3 fatty acids modulate mental health and cognition. Understanding the role of vitamin B12 and omega-3 fatty acids on brain functioning may provide important clues to prevent early cognitive deficits and later neurobehavioral disorders.

Local Injection of Methylcobalamin Combined with Lidocaine for Acute Herpetic Neuralgia

OBJECTIVE

To determine the efficacy of methylcobalamin combined with lidocaine for acute herpetic neuralgia.

DESIGN

Randomized controlled trial with longitudinal analysis.

SUBJECTS

The authors recruited 204 patients (>50 years) with T5-10 dermatomal acute herpetic neuralgia with rash onset within 7 days. Patients were divided into two groups based on the time of onset: immediate-early (IE, 1-3 days) and early stage (ES, 4-7 days) groups and then subdivided randomly into control (IE-Ctl, ES-Ctl) and treatment (IE-Tr, ES-Tr) groups.

METHODS

Control groups received intramuscular methylcobalamin in addition to local lidocaine injection, while treatment groups received local methylcobalamin combined with lidocaine injection for 14 days. Treatment efficacy was assessed based on rash healing time, alteration in pain intensity, and interference with quality of life. Multilevel mixed modeling and survival analysis were employed to examine treatment responses.

RESULTS

There was no significant difference in the rash healing time between IE and ES. The mean pain scores in IE-Tr (2.4 ± 0.7) and ES-Tr (1.3 ± 0.7) decreased significantly compared with those in the control groups. The median satisfactory response time was 6 days in ES-Tr and 11 days in IE-Tr. The benefit ratio for ES-Tr versus IE-Tr was 14.94. The subjects in IE-Tr and ES-Tr had higher quality of life scores (81.2 ± 6.9 vs 88.3 ± 8.6, respectively) than those in the control groups. The incidence of postherpetic neuralgia was 1.1% at 3 months.

CONCLUSIONS

Local methylcobalamin combined with lidocaine, optimally administered within 4-7 days of onset, may be an effective therapeutic option for acute herpetic neuralgia.

Maternal micronutrient imbalance alters gene expression of BDNF, NGF, TrkB and CREB in the offspring brain at an adult age

Micronutrients like folate, vitamin B12, and fatty acids which are interlinked in the one carbon cycle play a vital role in mediating epigenetic processes leading to an increased risk for neurodevelopmental disorders in the offspring. Our earlier study demonstrates that a micronutrient imbalanced diet adversely affects docosahexaenoic acid (DHA) and protein levels of neurotrophins like brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brain and cognition in the offspring by 3 months of age. In this study we attempt to analyze if these effects are a consequence of a change in gene expression of these molecules. Further, we also examined the effect of either a postnatal control diet or a prenatal omega-3 fatty acid supplementation on gene expression in the cortex of the offspring. Pregnant rats were divided into control and five treatment groups at two levels of folic acid (normal and excess folate) in the presence and absence of vitamin B12. Omega-3 fatty acid (eicosapentaenoic acid - EPA+DHA) supplementation was given to vitamin B12 deficient groups. Following delivery, 8 dams from each group were shifted to control diet and remaining continued on the same treatment diet. Our results demonstrate that the imbalanced diet caused a marked reduction in the mRNA levels of BDNF, NGF, TrkB, and cAMP response element-binding protein (CREB). Prenatal omega-3 fatty acid supplementation to the maternal imbalanced diet was able to normalize the mRNA levels of all the above genes. This study demonstrates that a maternal diet imbalanced in micronutrients (folic acid, vitamin B12) influences gene expression of neurotrophins and their signalling molecules and thereby adversely affects the brain of the offspring.

Tropical myelopathies

A large number of causal agents produce spinal cord lesions in the tropics. Most etiologies found in temperate regions also occur in the tropics including trauma, herniated discs, tumors, epidural abscess, and congenital malformations. However, infectious and nutritional disorders occur with higher prevalence in tropical regions. Among the most common infectious etiologies are tuberculous Pott's disease, brucellosis, and neuroborreliosis. Parasitic diseases such as schistosomiasis, neurocysticercosis, and eosinophilic meningitis are frequent causes of nontraumatic paraplegia. The retrovirus HTLV-1 is a cause of tropical spastic paraparesis. Nutritional causes of paraparesis include deficiencies of vitamin B12 and folate; endemic clusters of konzo and tropical ataxic myeloneuropathy are associated in Africa with malnutrition and excessive consumption of cyanide-containing bitter cassava. Other toxic etiologies of tropical paraplegia include lathyrism and fluorosis. Nutritional forms of myelopathy are associated often with optic and sensory neuropathy, hence the name tropical myeloneuropathies. Acute transverse myelopathy is seen in association with vaccination, infections, and fibrocartilaginous embolism of the nucleus pulposus. Multiple sclerosis and optic myelopathy occur in the tropics but with lesser prevalence than in temperate regions. The advent of modern imaging in the tropics, including computed tomography and magnetic resonance imaging, has allowed better diagnosis and treatment of these conditions that are a frequent cause of death and disability.

Prenatal omega 3 fatty acid supplementation to a micronutrient imbalanced diet protects brain neurotrophins in both the cortex and hippocampus in the adult rat offspring

OBJECTIVE

Our earlier studies show that maternal diets imbalanced in micronutrients like folic acid and vitamin B12 reduced brain docosahexaenoic acid (DHA) and brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the offspring at birth and postnatal d21. This study followed the offspring till 3 months to examine the hypothesis that impaired brain neurotrophins at birth and d21 due to altered maternal micronutrients can be reversed by prenatal omega 3 fatty acid but not a postnatal control diet leading to altered cognition in adult life.

MATERIALS AND METHODS

Pregnant rats were divided into control and five treatment groups at two levels of folic acid (normal and excess folate) in the presence and absence of vitamin B12 (NFBD, EFB and EFBD). Omega 3 fatty acid supplementation was given to the vitamin B12 deficient groups (NFBDO and EFBDO). Following delivery, 8 dams from each group were shifted to control and remaining continued on same diet.

RESULTS

Imbalance in maternal micronutrients up to 3months decreased DHA, BDNF and NGF in cortex and only BDNF in the hippocampus and impaired cognitive performance. Postnatal control diet normalized BDNF in the cortex but not the hippocampus and also altered cognitive performance. Prenatal omega 3 fatty acid supplementation normalized DHA, BDNF and NGF while long term supplementation was not beneficial only when micronutrients were imbalanced.

CONCLUSION

Patterns established at birth are not totally reversible by postnatal diets and give clues for planning intervention studies for improving brain functioning and cognitive abilities.

Nutritional disorders in tropical neurology

About three-fourths of the total world population live in the tropics but consume only 6% of worldwide food production and contribute 15% of the world's net revenue explaining the short life expectancy, high infantile mortality, and poor daily caloric intake; moreover, lack of clean drinking water and deficient sanitation promote water-borne infections, diarrhea, and risk of malabsorption that contribute to the prevalence of malnutrition in the tropics. One-third of the world's population consumes insufficient iodine increasing the risk for mental retardation and deafness due to maternal hypothyroidism. The main nutritional syndromes comprise protein-energy malnutrition (marasmus and kwashiorkor); nutritional neuropathies, myelopathies and neuromyelopathies, as well as specific deficiencies of vitamins and micronutrients including iodine, iron, zinc, and selenium.

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.

Methylcobalamin effects on diabetic neuropathy and nerve protein kinase C in rats

BACKGROUND

Methyl-base-attached cobalamin (Methycobalamin) (MC) has a special affinity for nerve tissues to promote myelination and transport of axonal cytoskeleton. It is not known, however, how MC influences on peripheral nerve in experimental diabetic neuropathy.

MATERIALS AND METHODS

We studied the effects of MC on expressions and activities of protein kinase C (PKC) in peripheral nerve of streptozotocin-induced diabetic rats. Wistar rats, 8 weeks of age, were rendered diabetic by streptozotocin (40 mg kg(-1), iv) and followed for 16 weeks. A half of diabetic animals were treated with MC (10 mg kg(-1) per every other day, im) after the induction of diabetes. Normal Wistar rats were served as control.

RESULTS

At the end, untreated diabetic animals developed significant delay of nerve conduction velocity (NCV), and MC treatment normalized the NCV. Nerve PKC activity was significantly suppressed in untreated diabetic rats, while the activity was normalized in treated animals. While PKCα located in Schwann cells, PKCβΙα and βII distributed in axoplasm, vascular walls and macrophages. The decreased PKC activity in diabetic nerve was associated with reduced expression of membrane PKCα and increased membrane expression of PKCβII, and MC treatment corrected these changes. Diabetic nerve contained an increased number of macrophages and 8-hydroxydeoxyguanosine-positive cells in the endoneurium, the latter of which was significantly suppressed by MC treatment. Elevated nerve polyol levels in diabetic nerve were partially corrected by MC treatment.

CONCLUSIONS

This study suggested that correction of impaired neural signalling of PKC and oxidative stress-induced damage may be a major attribute to the beneficial effects of MC on diabetic nerve.

Methylcobalamin, but not methylprednisolone or pleiotrophin, accelerates the recovery of rat biceps after ulnar to musculocutaneous nerve transfer

Using ulnar nerve as donor and musculocutaneous nerve as recipient we recently demonstrated that end-to-end neurorrhaphy in young adult male Wistar rats resulted in good recovery following protracted survival. Here we explored whether anti-inflammatory drug- methylprednisolone, regeneration/myelination-enhancing agent- methylcobalamin and neurite growth-enhancing and angiogenic factor- pleiotrophin accelerated its recovery. Methylprednisolone suppressed the perineuronal microglial reaction and periaxonal ED-1 expression while pleiotrophin increased the blood vessel density and nerve fiber densities in the reconnected nerve as expected. Neither methylprednisolone nor methylcobalamin altered the expression of growth associated protein 43 in the neurons examined suggesting that they did not interfere with axonal regeneration attempt. Surprisingly methylcobalamin enhanced the recovery of compound muscle action potentials and motor end plate innervation and the performance on sticker removal grooming test and augmented the diameters and myelin thicknesses of regenerated axons dramatically while enhancing S-100 expression in Schwann cells; remarkable recovery was achieved 1 month following neurorrhaphy. Simultaneous methylcobalamin and pleiotrophin treatment resulted in quick and persistent supernumerary reinnervation but failed to enhance the recovery over that of the former alone. Methylprednisolone transiently suppressed the enumeration of regrowing axons. In conclusion, methylcobalamin may be preferred over methylprednisolone to facilitate the recovery of peripheral nerves following end-to-end neurorrhaphy. The long-term effect of this treatment however remains to be clarified.

Spinal subarachnoid hematoma following spinal anesthesia in a patient with HELLP syndrome

A case of subarachnoid hematoma following spinal anesthesia for cesarean section in a patient with HELLP syndrome is reported. A 39-year-old woman underwent cesarean section under spinal anesthesia for worsening preeclampsia with HELLP syndrome. Despite full recovery from the spinal anesthetic, on the second postoperative day she felt numbness on the posterior aspect of her right leg, noticed she was insensitive to bladder fullness and had mild flaccid paraparesis. Magnetic resonance imaging revealed a spinal subarachnoid hematoma with cauda equina compression. With conservative management she made an almost complete recovery within three months. Serial magnetic resonance imaging showed spontaneous regression of the hematoma. The risk of spinal subarachnoid hematoma following obstetric regional anesthesia is exceedingly small even in a patient with coagulopathy and, to our knowledge, this is only the second reported case following obstetric regional anesthesia. Anesthesia for HELLP syndrome in patients with an adequate platelet count but without disseminated intravascular coagulation is controversial. It is therefore important for clinicians to recognize the symptoms and signs of spinal subarachnoid hematoma to avoid delay in treatment that might result in severe neurological deficit.

Maternal MTHFR 677C>T genotype and dietary intake of folate and vitamin B(12): their impact on child neurodevelopment

Using the Bayley test, the mental and psychomotor development in a cohort of 253 children were evaluated. Maternal dietary intake of vitamin B(12) and folate was assessed from a semiquantitative questionnaire administered during the first trimester of pregnancy. Maternal genotypes of MTHFR (677C>T and 1298A>C), were ascertained by PCR-RFLP. The 677T and 1298C variant alleles were present in 59% and 10% of participants, respectively. A dietary deficiency of vitamin B(12) was negatively associated with mental development (beta = -1.6; 95% CI = -2.8 to -0.3). In contrast, dietary intake of folate (< 400 mg/day) reduced the mental development index only among children of mothers who were carriers of the TT genotype (beta = -1.8; 95% CI = -3.6 to -0.04; P for interaction = 0.07). Vitamin B(12) and folate supplementation during pregnancy could have a favorable impact on the mental development of children during their first year of life, mainly in populations that are genetically susceptible.

A population-based study of coeliac disease, neurodegenerative and neuroinflammatory diseases

BACKGROUND

It has been suggested that coeliac disease (CD) is associated with several neurological diseases. However, the evidence of such an association is inconclusive as earlier research has often been based on small numbers with retrospective data collection.

AIM

To use Cox regression to examine the risk of neurological disease in individuals with CD.

METHODS

Through Swedish national registers we identified some 14 000 individuals with a diagnosis of CD (1964-2003) and 70 000 reference individuals matched for age, sex, calendar year and county.

RESULTS

Coeliac disease was associated with later polyneuropathy [hazard ratio (HR) = 3.4; 95% CI = 2.3-5.1]. We found no statistically significant association between CD and subsequent multiple sclerosis (HR = 0.9; 95% CI = 0.3-2.3), Parkinson's disease (HR = 1.2; 95% CI = 0.8-1.9), Alzheimer's disease (HR = 1.5; 95% CI = 0.9-2.6), hereditary ataxia (HR = 1.3; 95% CI = 0.5-3.6), the symptom ataxia (HR = 1.9; 95% CI = 0.6-6.2), Huntington's disease (HR = 1.7; 95% CI = 0.3-8.6), myasthenia gravis (HR = 0.8; 95% CI = 0.2-3.8) or spinal muscular atrophy (HR = 0.5; 95% CI = 0.1-3.8). Prior polyneuropathy was associated with subsequent CD (odds ratio = 5.4; 95% CI = 3.6-8.2).

CONCLUSIONS

The association between CD and polyneuropathy indicates shared risks. We suggest that individuals with polyneuropathy routinely undergo screening for CD. There is no notable association between CD and other neurological outcomes investigated in this study.

Neuropathie périphérique réversible liée au déficit en vitamine B12

OBJECTIVE

To describe an electroclinical presentation of a peripheral neuropathy in a patient who suffered from vitamin B12 deficiency.

PATIENT AND METHODS

We report the case of a 56-year-old man who, 17 years after a subtotal gastrectomy, presented with a diffuse sensory-motor demyelinating peripheral neuropathy with multifocal alteration of conduction confirmed by electromyography. Its causal relationship with vitamin B12 deficiency was biologically demonstrated. This neuropathy improved within a few days after intramuscular hydroxocobalamin treatment. Both clinical and electrophysiological signs had totally disappeared 3 months later on.

CONCLUSION

This observation demonstrates that, in spite of its poor outcome reported by several authors, peripheral neuropathy induced by vitamin B12 deficiency can recover completely with substitutive treatment.

Vitamin B12, demyelination, remyelination and repair in multiple sclerosis

Multiple Sclerosis (MS) and vitamin B12 deficiency share common inflammatory and neurodegenerative pathophysiological characteristics. Due to similarities in the clinical presentations and MRI findings, the differential diagnosis between vitamin B12 deficiency and MS may be difficult. Additionally, low or decreased levels of vitamin B12 have been demonstrated in MS patients. Moreover, recent studies suggest that vitamin B12, in addition to its known role as a co-factor in myelin formation, has important immunomodulatory and neurotrophic effects. These observations raise the questions of possible causal relationship between the two disorders, and suggest further studies of the need to close monitoring of vitamin B12 levels as well as the potential requirement for supplementation of vitamin B12 alone or in combination with the immunotherapies for MS patients.