Severe convulsant hypomagnesaemia and short bowel syndrome

The Role of Magnesium in Neurological Disorders

Magnesium is well known for its diverse actions within the human body. From a neurological standpoint, magnesium plays an essential role in nerve transmission and neuromuscular conduction. It also functions in a protective role against excessive excitation that can lead to neuronal cell death (excitotoxicity), and has been implicated in multiple neurological disorders. Due to these important functions within the nervous system, magnesium is a mineral of intense interest for the potential prevention and treatment of neurological disorders. Current literature is reviewed for migraine, chronic pain, epilepsy, Alzheimer’s, Parkinson’s, and stroke, as well as the commonly comorbid conditions of anxiety and depression. Previous reviews and meta-analyses are used to set the scene for magnesium research across neurological conditions, while current research is reviewed in greater detail to update the literature and demonstrate the progress (or lack thereof) in the field. There is strong data to suggest a role for magnesium in migraine and depression, and emerging data to suggest a protective effect of magnesium for chronic pain, anxiety, and stroke. More research is needed on magnesium as an adjunct treatment in epilepsy, and to further clarify its role in Alzheimer’s and Parkinson’s. Overall, the mechanistic attributes of magnesium in neurological diseases connote the macromineral as a potential target for neurological disease prevention and treatment.

Gitelman Syndrome in a School Boy Who Presented with Generalized Convulsion and Had a R642H/R642W Mutation in the SLC12A3 Gene

An 8-year-old Japanese boy presented with a generalized convulsion. He had hypokalemia (serum K 2.4 mEq/L), hypomagnesemia, and metabolic alkalosis (BE 5.7 mmol/L). In addition, his plasma renin activity was elevated. He was tentatively diagnosed with epilepsy on the basis of the electroencephalogram findings and was treated by potassium L-aspartate and carbamazepine to control the hypokalemia and seizure, respectively. However, a year later, the patient continued to have similar abnormal laboratory data. A presumptive diagnosis of Gitelman syndrome (GS) was then made and the patient's peripheral blood mononuclear cells were subjected to sequence analysis of the SLC12A3 gene, which encodes a thiazide-sensitive sodium-chloride cotransporter. The patient was found to have compound heterozygous mutations, namely, R642H inherited from his father and R642W inherited from his mother. Thus, if a patient shows persistent hypokalemia and metabolic alkalosis, GS must be considered, even if the patient exhibits atypical clinical symptoms.

Vitamin D-mediated calcium absorption in patients with clinically stable Crohn's disease: a pilot study

Vitamin D is the critical hormone for intestinal absorption of calcium. Optimal calcium absorption is important for proper mineralization of bone in the prevention of osteoporosis and osteoporotic fractures, among other important functions. Diseases associated with gut inflammation, such as Crohn's disease (CD), may impair calcium absorption. This pilot study evaluated vitamin D- dependent calcium absorption in subjects with CD. Male subjects with CD (n=4) and healthy age-matched controls (n=5) were studied. All subjects had fractional calcium absorption (FCA; by the dual calcium isotope method), serum 25-hydroxyvitamin D, serum calcium and 24 h urinary calcium excretion measurements at baseline. The FCA in response to vitamin D therapy was re-assessed following administration of oral calcitriol 0.25 mcg twice daily for 1 wk, followed by oral calcitriol 0.50 mcg twice daily for 1 wk. Serum calcium and 24 h urinary calcium determinations were re-assessed after each increasing dose of calcitriol as safety measures. There was no significant difference in calcium FCA at baseline or after increasing doses of calcitriol between the CD and controls. FCA in the control and CD group was approximately 35% at baseline, which increased to 60% after calcitriol therapy. No subject developed hypercalcemia or hypercalciuria. Our results suggest that CD patients have a normal response to vitamin D in enhancing the efficacy of calcium absorption. This suggests that stable CD patients can follow calcium and vitamin D guidelines of non-CD adults. Other factors independent of vitamin D status may impair intestinal calcium absorption in CD, including the degree and location of inflammation, presence of surgical resection and/or use of glucocorticoids.

Unusual case of hypomagnesaemia induced seizures

Alterations in electrolyte homeostasis associated with major surgery and critical illness are common but usually non-specific. We report an unusual case of hypomagnesaemia induced seizures in a 73-year-old woman who was recovering from ileal resection and limited right hemicolectomy for small bowel volvulus. Hypomagnesaemia as a de novo cause of seizures is rarely reported.

[Neurological complications of inflammatory bowel disease]

Although ulcerative colitis and Crohn's disease have traditionally been considered to be inflammatory diseases limited to the gastrointestinal tract, it has been shown that both pathologies are frequently accompanied by various extraintestinal disorders. There is an increasing evidence that they may also manifest in the nervous system, including the peripheral and the central parts. Although some of these neurological complications have been known for a long time, such as cerebrovascular disease, vasculitis and autoinmune processes including neuropathies and cerebral demyelination, others have been recently described. With the exception of some of this complications such as the thromboembolism, evidence for a casual relationship relies merely on single case reports or case series. In this article, we try to review the existing evidence on neurological manifestations of both variants of inflammatory bowel disease.

Small intestine transplantation today

INTRODUCTION

Intestinal transplantation has become a life-saving therapy in patients with irreversible loss of intestinal function and complications of total parenteral nutrition.

DISCUSSION

The patient and graft survival rates have improved over the last years, especially after the introduction of tacrolimus and rapamycin. However, intestinal transplantation is more challenging than other types of solid organ transplantation due to its large amount of immune competent cells and its colonization with microorganisms. Moreover, intestinal transplantation is still a low volume procedure with a small number of transplanted patients especially in Germany. A current matter of concern is the late referral of intestinal transplant candidates.

CONCLUSION

Thus, patients often present after onset of life-threatening complications or advanced cholestatic liver disease. Earlier timing of referral for candidacy might result in further improvement of this technique in the near future.

Physiology of epithelial Ca2+ and Mg2+ transport

Ca2+ and Mg2+ are essential ions in a wide variety of cellular processes and form a major constituent of bone. It is, therefore, essential that the balance of these ions is strictly maintained. In the last decade, major breakthrough discoveries have vastly expanded our knowledge of the mechanisms underlying epithelial Ca2+ and Mg2+ transport. The genetic defects underlying various disorders with altered Ca2+ and/or Mg2+ handling have been determined. Recently, this yielded the molecular identification of TRPM6 as the gatekeeper of epithelial Mg2+ transport. Furthermore, expression cloning strategies have elucidated two novel members of the transient receptor potential family, TRPV5 and TRPV6, as pivotal ion channels determining transcellular Ca2+ transport. These two channels are regulated by a variety of factors, some historically strongly linked to Ca2+ homeostasis, others identified in a more serendipitous manner. Herein we review the processes of epithelial Ca2+ and Mg2+ transport, the molecular mechanisms involved, and the various forms of regulation.