BACKGROUND: Among the many complications of SAH, one of the most important is 
vasospasm. Several treatment alternatives have been proposed for this condition, 
with far-from-ideal results being obtained. Magnesium sulfate recently returned 
to the scene (with still unproven benefit) as an adjuvant in the treatment of 
vasospasm.
METHODS: Seventy-two patients diagnosed with SAH by aneurysm rupture were 
submitted to microsurgery craniotomy and subdivided in 2 groups. Group 1, formed 
by 48 patients, received prophylactic hypervolemic and hemodilution therapy in 
addition to nimodipine. Group 2, composed of 24 patients, received the same 
treatment of group 1 with the addition of magnesium sulfate in continuous 
infusion from 120 to 150 mg a day, keeping serum magnesium levels close to 
double normal values.
RESULTS: Age was 49 +/- 12.6 years. Ratio of female to male was 3.16:1. Most 
patients were admitted in a Hunt-Hess grade 2 (46.4%) and Fisher grade 3 
(52.8%). Anterior communicating artery aneurysms were the most common in 
location (38.8%). Both groups were compared, and there was no statistical 
difference related to age, sex, and Glasgow, Fisher, or Hunt-Hess admission 
grades. No statistical difference in vasospasm incidence was found between the 
two groups. However, in group 1, vasospasm was correlated with a longer 
hospitalization time (P = .0003), different from group 2, in which patients with 
vasospasm receiving magnesium sulfate required less hospitalization time.
CONCLUSION: Magnesium did not seem to interfere in vasospasm frequency but 
apparently acted favorably in decreasing morbidity and length of hospital stay.