The Latest About Magnesium Sulfate for Stroke

Magnesium injection has been the recent buzz in stroke research as a promising new breakthrough in stroke care. Preliminary experiments initially showed that IV magnesium was both safe and beneficial. But analysis of large groups of stroke patients has not proven any benefit. What does this mean for you?

How Does Magnesium Work in Stroke?

There are a number of different formulations of magnesium that have been considered in stroke research including magnesium sulfate, magnesium nitrate, and magnesium chloride.

There are two explanations for how magnesium may help in preventing and reversing the effects of a stroke.

1. First of all, magnesium can interfere with platelets to prevent blood clots from forming and from enlarging. Because a stroke is caused by an interruption of blood flow to the brain, usually caused by a blood clot, ischemic strokes can be stopped or reversed by dissolving the blood clot. This is how TPA works. But TPA is a powerful blood thinner, while magnesium is a much milder blood thinner with a markedly lower risk of bleeding.

2. During a stroke, a complex biological process called brain infarction results in irreversible brain injury. Infarction involves several harmful substances, including a substance called glutamate. In addition to its blood thinning effects, magnesium has also been considered a neuroprotective therapy, because it works against glutamate, one of the materials produced during stroke that causes brain damage.

So, a neuroprotective agent such as magnesium is believed by scientists to have the potential to reduce or reverse the brain damage caused by a stroke.

What do the Scientific Research Experiments Show?

When magnesium appeared to be a promising stroke treatment after preliminary studies, a large multicenter, randomized double blind placebo controlled research study called the FAST-MAG study was designed to put it to the test.

The National Institute of Neurological Disorders and Stroke funded the study. The experiment involved 1700 stroke patients in the Los Angeles area. Ambulances were supplied with magnesium sulfate and paramedics were instructed on how to give IV magnesium to stroke patients on the way to the hospital. The patients also continued to receive IV magnesium for 24 hours after the initial dose given by paramedics. The patients were divided into two groups, with 850 patients in each group. One group of 850 patients received the magnesium, while one group of 850 patients did not receive magnesium. Researchers used three different measures to evaluate 90-day outcomes; the three measures were the NIHSS (neurologic deficit), Barthel Index (activities of daily living), and the Stroke Impact Scale (quality of life). The patients who received IV magnesium did not have any negative effects from magnesium, but also did not have better outcomes based on these measures 90 days after the stroke than the patients who did not receive magnesium.

What Does this Mean for You?

So far, scientists are not there yet in terms of the right form of magnesium or the right dose of magnesium for stroke. However, that doesn't rule out that future experiments might eventually determine a more effective dose or route of administration.

But, on the other hand, further research may continue to be unhelpful and might eventually put the idea of magnesium as stroke treatment to rest. It is still too soon to know for sure.

Should You Take Magnesium?

So far, there is no evidence suggesting they you would benefit from taking magnesium supplements or IV magnesium if you have had a stroke. It is best to stick with proven stroke treatments. Fortunately, there are many- including medications such as blood thinners, rehabilitation, cognitive therapy, and physical activity. Re-growing brain cells is still a fairly new concept that researchers and doctors have not been able to control, but it is highly likely that new methods for stroke care are just around the corner.


Prehospital use of magnesium sulfate as neuroprotection in acute stroke, Saver JL, Starkman S, Eckstein M, Stratton SJ, Pratt FD, Hamilton S, Conwit R, Liebeskind DS, Sung G, Kramer I, Moreau G, Goldweber R, Sanossian N; FAST-MAG Investigators and Coordinators, New England Journal of Medicine, February 2015

Methodology of the Field Administration of Stroke Therapy - Magnesium (FAST-MAG) phase 3 trial: Part 2 - prehospital study methods, Saver JL, Starkman S, Eckstein M, Stratton S, Pratt F, Hamilton S, Conwit R, Liebeskind DS, Sung G, Sanossian N; FAST-MAG Investigators and Coordinators, International Journal of Stroke, February 2014

Evaluation of the intravenous magnesium sulfate effect in clinical improvement of patients with acute ischemic stroke, Afshari D, Moradian N, Rezaei M, Clinical Neurology and Neurosurgery

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