Therapeutic potential of magnesium in the treatment of acute stroke

Cerebral vasospasm and wernicke encephalopathy secondary to adult cyclic vomiting syndrome: the role of magnesium

Background

Magnesium has a regulatory role in the excitability of cell membranes, and is also a cofactor in the phosphorylation of thiamine. Hypomagnesemia has been associated with coronary vasospasm, but its role in cerebrovascular pathology is controversial, and cerebral vasospasm exclusively attributable to hypomagnesemia has not been reported in humans.

Case presentation

We report the case of a 51-year-old man in whom uncontrollable vomiting, treatment with omeprazole and thiazide, and renal impairment lead to a severe hypomagnesemia (magnesium below the level of detection in blood tests), which secondarily caused Wernicke’s encephalopathy and vasospasm in multiple cerebral arteries (seen with cerebral angiography and CT angiography) that presented with a complete right hemisphere neurological deficit. These disturbances completely resolved when magnesium levels were normalized and subsequent neuroimaging tests confirmed the resolution of angiographic changes.

Conclusion

Our case suggests that hypomagnesemia should be considered in the differential diagnosis of patients with neurological symptoms and predisposing causes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0660-x) contains supplementary material, which is available to authorized users.

Magnesium and experimental vasospasm

Object. Interest has developed in the use of magnesium (Mg++) as a neuroprotectant and antivasospastic agent. Magnesium may increase cerebral blood flow (CBF) and reduce the contraction of cerebral arteries caused by various stimuli. In this study the authors tested the hypothesis that a continuous intravenous infusion of Mg++ reduces cerebral vasospasm after experimental subarachnoid hemorrhage (SAH).

Methods. A dose-finding study was conducted in five monkeys (Macaca fascicularis) to determine what doses of intravenous MgSO4 elevate the cerebrospinal fluid (CSF) concentrations of Mg++ to vasoactive levels and to determine what effects these doses have on the diameters of cerebral arteries, as shown angiographically. After a standard dose of MgSO4 had been selected it was then administered in a randomized, controlled, blinded study to 10 monkeys (five animals/group) with SAH, beginning on Day 0 and continuing for 7 days, at which time angiography was repeated. A 0.086-g/kg bolus of MgSO4 followed by an infusion of 0.028 g/kg/day MgSO4 significantly elevated serum and CSF levels of Mg++ (five monkeys). Magnesium sulfate significantly elevated the serum level of total Mg++ from a control value of 0.83 ± 0.04 mmol/L to 2.42 ± 1.01 mmol/L on Day 7 and raised the CSF level from 1.3 ± 0.04 mmol/L to 1.76 ± 0.14 mmol/L. There was no angiographic evidence of any effect of MgSO4 on normal cerebral arteries. After SAH, the vasospasm in the middle cerebral artery was not significantly reduced (46 ± 8% in the MgSO4-treated group compared with 35 ± 6% in the placebo [vehicle]-treated group, p > 0.05, unpaired t-test).

Conclusions. Magnesium sulfate did not significantly reduce cerebral vasospasm after SAH in the doses tested. An investigation of SAH is warranted mainly to test whether a benefit can be achieved by neuroprotection or by augmentation of CBF by dilation of small vessels and/or collateral pathways.