Magnesium will be given intravenously with a loading dose of 4 g in 50 mL saline over a 15-minute period and 16 g in 100 mL over a 24-hour period in a continuous-infusion form. The regiment chosen for this study is designed to double serum magnesium concentration to twice physiological concentration for therapeutic effects in humans, Serum levels between 4.8mg/dl-6mg/dl are considered to have an optimal neuroprotective effect.

Normal Saline in equal volume as the control group.

Magnesium and placebo (Normal Saline) will be prepared as solutions of identical volume and appearance. All patients will be randomized and blind to treatment.

All patients will have pretreatment Electrogram (ECG), serum biochemistry and serum Magnesium levels. Serum Magnesium levels will also be measured at 48 hours. Blood pressure, heart rate, respiratory rate and serious adverse events will be monitored at baseline, 15 minutes, and 12, 24 and 48 hours after infusion. Magnesium will be given intravenously with a loading dose of 4 g in 50 mL saline over a 15-minute period and 16 g in 100 mL over a 24-hour period in a continuous-infusion form.

Follow-up visits will be conducted by the same investigators, and repeated scores on the NIH Stroke Scale will be obtained at 24 hours, 48 hours post admission and on the day of discharge.