The Serum Magnesium Level in Patients with Acute Ischemic Stroke and its Correlation with Modified Rankin Scale (MRS) and Glasgow Coma Scale (GCS), in a Tertiary Care Centre in Kathmandu, Nepal

Abstract

Introduction: Magnesium ions can protect neurons by maintaining cerebral blood flow. It prevents ischemic damage to the brain. Magnesium also has associations with various diseases like metabolic syndrome, hypertension, atherosclerosis, diabetes mellitus which themselves are well known risk factors for cerebrovascular disease. Adequate dietery intake of magnesium has been associated with decreased incidences of above dosorders. Low levels of serum magnesium in patients with acute ischemic stroke have been found to be associated with poor clinical outcomes.

Method: It is an observational comparative, hospital based study carried out from January 2016 to December 2017 in the medical ward of Bir Hospital, Nepal. The sampling frame was patient more than 40 years admitted to medical ward during study period. Sample size was calculated assuming the prevalence of hypomagnesemia in acute ischemic stroke patient as 24%. During study period, for every case diagnosed with clinical or radiological evidence of acute ischemic stroke, another nonstroke case admitted to the ward on the same day was taken in the study, with the exclusion of patients with evidence of hemorrhagic stroke including subarachnoid hemorrhage, recurrent stroke, renal, liver and thyroid disorders and malignant diseases and in whom CT or MRI could not be done due to any reason. Thus a total of 70 patients were enrolled which comprised of 35 patients each in acute ischemic stroke group and nonstroke group. The history, physical examination, required lab parameters and imaging were obtained and recorded in performa. From each patient 3ml of venous blood samples in plain vials within first 24 hours of the presentation after acute ischemic stroke were collected. MRS scores were recorded on day 1,3 and 7 of admission when the patients were treated for stroke in ward whereas GCS scores were recorded only at the time of presentation. Data entry was done in Microsoft Excel 2013 and analysed using SPSS IBM version 22. For the tests, confidence interval was taken to be 95% and p-value less than 0.05 was taken statistically significant for inferential statistics. Independent t-test was used to compare means across two groups.

Result: The mean age of stroke patients was 62.29 years. The mean serum magnesium level in stroke patients within 24 hours of presentation was 0.71mmol/l (SD=0.0772) whereas that in nonstroke patients was 0.84mmol/ l(SD=0.0657). The incidence of hypomagnesemia (serum magnesium <0.7mmol/l) in stroke patients was 22.9%. The MRS scores on day 1,3,7 in stroke patients with hypomagnesemia were5/6,5/6,5/6 respectively whereas in other stroke patients MRS scores on day1,3,7 ranged between 2/6-5/6,2/6-4/6,2/6-4/6 respectively. The majority of the stroke patients with hypomagnesemia had GCS score of 11/15 as compared to other stroke patients, the majority of whom had GCS score of 15/15. Correlation using pearsons correlation showed negative correlation between serum magnesium and MRS. This study also showed that there were poor GCS scores at presentation in stroke patients with low levels of serum magnesium.

Conclusion: The mean serum level of magnesium in patients with acute ischemic stroke was lower than that in nonstroke patients. There was a negative correlation between the serum magnesium levels and MRS scores in patients with acute ischemic stroke and stroke patients with hypomagnesemia had poor GCS scores at presentation.