Magnesium deposition in brain of pregnant patients administered intramuscular magnesium sulphate

We present three cases of T1 hyperintense signal in the MRI scans of the brains of pregnant patients who were administered magnesium sulphate intramuscularly for control of hypertension during eclampsia. The increase in signal is symmetric and is seen in the globus pallidi of these patients. We postulate it to be secondary to deposition of magnesium in the brain parenchyma. The signal intensity was found to be directly varying according to the level of magnesium in the blood. It decreased over a period of time coming to normalcy after approximately 6 months. To the best of our knowledge, this is the first case report which has documented this finding. It has to be determined whether deposition of magnesium in the brain parenchyma could have implications in the use of magnesium sulphate in pregnant patients.