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Updated: Jul 15, 2026
Systems Analysis of the Neuroinflammatory and Hemodynamic Response to Traumatic Brain Injury
Published on: May 27, 2022
Total and ionized plasma magnesium concentrations in children after traumatic brain injury
Donna Reyes Mendez1, Ronald Corbett, Charles Macias
1Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. drmendez@texaschildrenshospital.org
Insights
Traumatic brain injury (TBI) in children lowers total magnesium (TMg). Ionized magnesium (IMg) only decreases in severe TBI but normalizes within 24 hours, suggesting a protective mechanism.
Area of Science:
- Pediatric Neurology
- Neurotrauma Research
- Clinical Biochemistry
Background:
- Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in children.
- Magnesium (Mg) plays a crucial role in neurological function and cellular protection.
- Understanding Mg levels in pediatric TBI is essential for assessing injury severity and potential therapeutic targets.
Purpose of the Study:
- To investigate if plasma total magnesium (TMg) and ionized magnesium (IMg) are reduced in children following TBI.
- To determine if the extent of Mg reduction correlates with TBI severity, as assessed by the Glasgow Coma Scale (GCS).
Main Methods:
- Prospective cohort study of 98 pediatric TBI patients and 50 healthy controls.
- Plasma TMg and IMg levels were measured at presentation and 24 hours post-injury.
- Patients were categorized into mild (GCS 13-15), moderate (GCS 8-12), and severe (GCS <8) TBI groups.
Main Results:
- Initial TMg was significantly reduced in all TBI severity groups compared to controls (p < 0.01).
- Initial IMg was reduced only in the severe TBI subgroup (p = 0.016).
- At 24 hours, TMg remained lower in all TBI groups, while IMg normalized across all subgroups.
Conclusions:
- Pediatric TBI is associated with a reduction in plasma TMg.
- Plasma IMg reduction is specific to severe TBI and normalizes within 24 hours, indicating potential homeostatic mechanisms.
- Changes in plasma IMg may serve as a transient biomarker for severe TBI in children.
Abstract:
This study examined 1) whether plasma total Mg (TMg) and ionized Mg (IMg) concentrations in children are reduced by traumatic brain injury (TBI) and 2) whether the extent of reduction correlates with severity of trauma assessed by the Glasgow Coma Scale (GSC) score. This was a prospective cohort study of 98 pediatric patients who had TBI and were admitted through the emergency department. A GCS score was assigned and blood was obtained upon presentation and 24 h later. Plasma was analyzed for TMg and IMg. Patients were grouped into three categories-GCS scores 13-15, 8-12, and <8-to designate mild (n=21), moderate (n=37), and severe (n=40) TBI, respectively. Blood was obtained from 50 healthy children before elective surgery as controls. Control subjects had a TMg and an IMg of 0.94 +/- 0.08 and 0.550 +/- 0.06 mM. TBI patients had an initial TMg and IMg of 0.83 +/- 0.09 and 0.520 +/- 0.05 mM, respectively. Initial TMg for mild, moderate, and severe TBI subgroups (0.87 +/- 0.16, 0.81 +/- 0.15, and 0.83 +/- 0.14 mM, respectively) was reduced from control subjects (p <0.01). IMg was reduced only in the severe TBI subgroup (0.516 +/- 0.07 mM; p=0.016). Twenty-four hours later, TMg remained lower than in control subjects for all subgroups of TBI; however, IMg normalized. TBI in children is associated with a reduction in TMg, whereas IMg decreased only with severe TBI. IMg returned to control values by 24 h despite a continued lower TMg, suggesting mechanisms to maintain IMg. Changes in plasma IMg may serve as a marker for TBI but only over a limited time interval.
