Isolated idiopathic hypomagnesemia presenting as aphasia and seizures

Long-term safety, tolerability, and efficacy of magnesium valproate versus sodium valproate in acute seizures

Objectives: To evaluate the safety, tolerability and efficacy of magnesium valproate and sodium valproate as monotherapies in patients with epilepsy in China.Methods: We recruited patients admitted with seizures over a two-year period. All patients underwent early neurological assessments, electroencephalogram testing, and neuroimaging. The treatments received at baseline and at one year of follow-up were compared.Results: In total, 175 patients were included. The retention rates of the magnesium valproate and sodium valproate treatments were 73.1% and 64.2%, respectively. The main cause of discontinuation was the development of intolerable adverse events. The retention rate and total effective rate in the magnesium valproate group were significantly higher than those in the sodium valproate group (73.1% and 70.2% versus 64.2% and 47.2%, respectively). The safety endpoints included 120 patients (magnesium valproate: n = 67; sodium valproate: n = 53). The incidence of adverse events in the magnesium valproate group was significantly lower than that in the sodium valproate group (30% versus 51%).Conclusions: Magnesium valproate treatment shows favorable safety and tolerability and is associated with markedly improved seizure control. Ideally, future large, prospective, randomized, and double-blind studies are needed to confirm these findings.

Seizures Related to Hypomagnesemia: A Case Series and Review of the Literature

OBJECTIVE

Childhood seizures have various nonneurological etiologies. The patient's magnesium levels should be measured when evaluating afebrile seizures. The purpose of the current case series is to describe a systematic approach for diagnosing hypomagnesemia using 3 recent patient cases.

METHODS

This case series describes 3 patients with unprovoked hypomagnesemia-associated seizures. The authors describe the differential diagnosis, pathophysiology, and the workup of hypomagnesemia-associated seizures.

RESULTS

Hypomagnesemia contributed to the cause of the seizures in all 3 cases. Various causes of hypomagnesemia were investigated, including genetic etiologies. All 3 patients were maintained at a magnesium level >0.65 mmol/L, which improved or eliminated the seizures.

SIGNIFICANCE

Magnesium levels should always be measured when trying to determine the etiology of seizures. Hypomagnesemia and afebrile seizures should be treated with the goal of maintaining a magnesium concentration >0.65 mmol/L. Although rare, genetic causes of hypomagnesemia should be considered, once common causes of hypomagnesemia are ruled out.

Neonatal focal seizures and hypomagnesemia: A case report

BACKGROUND

In seizures caused by electrolytes disorders, a prompt diagnosis allows an appropriate treatment and reduces the risk of neurological complications. Hypomagnesemia is a recognized cause of generalized seizures, while it has been anecdotally reported in focal forms.

CASE PRESENTATION

We describe a newborn with recurrent focal seizures due to transient hypomagnesemia.

CONCLUSION

Physicians should consider the possible occurrence of such disorder also in cases of focal seizures.

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.

Probing the modulation of acute ethanol intoxication by pharmacological manipulation of the NMDAR glycine co-agonist site

BACKGROUND

Stimulating the glycine(B) binding site on the N-methyl-d-aspartate ionotropic glutamate receptor (NMDAR) has been proposed as a novel mechanism for modulating behavioral effects of ethanol (EtOH) that are mediated via the NMDAR, including acute intoxication. Here, we pharmacologically interrogated this hypothesis in mice.

METHODS

Effects of systemic injection of the glycine(B) agonist, d-serine, the GlyT-1 glycine transporter inhibitor, ALX-5407, and the glycine(B) antagonist, L-701,324, were tested for the effects on EtOH-induced ataxia, hypothermia, and loss of righting reflex (LORR) duration in C57BL/6J (B6) and 129S1/SvImJ (S1) inbred mice. Effects of the glycine(B) partial agonist, d-cycloserine (DCS), the GlyT-1 inhibitor, N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl]sarcosine (NFPS), and the glycine(B) antagonist, 5,7-dichlorokynurenic (DCKA), on EtOH-induced LORR duration were also tested. Interaction effects on EtOH-induced LORR duration were examined via combined treatment with d-serine and ALX-5407, d-serine and MK-801, d-serine and L-701,324, as well as L-701,324 and ALX-5407, in B6 mice, and d-serine in GluN2A and PSD-95 knockout mice. The effect of dietary depletion of magnesium (Mg), an element that interacts with the glycine(B) site, was also tested.

RESULTS

Neither d-serine, DCS, ALX-5407, nor NFPS significantly affected EtOH intoxication on any of the measures or strains studied. L-701,324, but not DCKA, dose-dependently potentiated the ataxia-inducing effects of EtOH and increased EtOH-induced (but not pentobarbital-induced) LORR duration. d-serine did not have interactive effects on EtOH-induced LORR duration when combined with ALX-5407. The EtOH-potentiating effects of L-701,324, but not MK-801, on LORR duration were prevented by d-serine, but not ALX-5407. Mg depletion potentiated LORR duration in B6 mice and was lethal in a large proportion of S1 mice.

CONCLUSIONS

Glycine(B) site activation failed to produce the hypothesized reduction in EtOH intoxication across a range of measures and genetic strains, but blockade of the glycine(B) site potentiated EtOH intoxication. These data suggest endogenous activity at the glycine(B) opposes EtOH intoxication, but it may be difficult to pharmacologically augment this action, at least in nondependent subjects, perhaps because of physiological saturation of the glycine(B) site.

Isolated hypomagnesemia in a patient treated with capecitabine

Hypomagnesemia is known to occur for a variety of renal, gastrointestinal and other causes, and is often associated with other electrolyte and metabolic disturbances. We present a case of isolated hypomagnesemia in a patient who had been treated with the chemotherapy agent capecitabine. The approach to diagnosis and treatment is discussed. We postulate that capecitabine may cause isolated hypomagnesemia, possibly due to renal magnesium loss.