Magnesium in clinical stroke

Stroke is the second leading cause of death and a leading cause of disability worldwide. Unfortunately, current therapies for acute ischemic stroke are of extremely limited effectiveness. The ideal neuro- protective agent for stroke would be inexpensive, readily available, easy to administer and have no significant adverse side effects. Intravenous magnesium sulphate offers promise as just such an agent. In clinical trials to date, administration of magnesium sulphate has shown favourable trends toward neuroprotection in resuscitated cardiac arrest patients, in cardiac bypass surgery and carotid endarterectomy. In acute stroke, eight pilot clinical trials of magnesium sulphate have shown good safety, and the subset of pilot trials with randomized controls have shown favourable effects on clinical outcome point estimates. The first phase 3 trial of magnesium sulphate for focal stroke was the Intravenous Magnesium Efficacy in Stroke (IMAGES) Trial. Hampered by late administration of the study agent, IMAGES overall produced a neutral result, but exploratory analyses identified early (under 3 hour), lacunar stroke, haemorrhagic stroke, and severely hypertensive patients as having a potential differential beneficial response to magnesium that deserved further investigation. The Field Administration of Stroke Therapy – Magnesium (FAST-MAG) trial has been specifically designed to test magnesium in the hyperacute time window by initiating therapy in the prehospital setting.