TITLE:
Magnesium Concentration in Cerebrospinal and Brain Interstitial Fluid Correlates with Serum Level in Induced Hypermagnesemia
AUTHORS:
Kajetan L. von Eckardstein, Jürgen C. W. Kiwit, Ulf Westhause, Veit Rohde
KEYWORDS:
Aneurysm, Magnesium, Microdialysis, Subarachnoid Hemorrhage, Vasospasm
JOURNAL NAME:
Open Journal of Modern Neurosurgery,
Vol.6 No.2,
April
22,
2016
ABSTRACT: Being a modulator of
the N-methyl-D-aspartate (NMDA) receptor function magnesium has been studied
for its neuroprotective and vasodilatative properties in acute and delayed
brain ischemia due to vasospasm in aneurysmal subarachnoid haemorrhage (aSAH)
and stroke. A number of clinical phase II and III studies have correlated serum
magnesium concentrations after intravenous continuous application to clinical
outcome and have failed to show a positive therapeutic effect. However, no
study supported its conclusion by providing evidence for a local increase in
magnesium, i.e. in the cerebrospinal
fluid (CSF) and the brain parenchyma. The objective of our observational study
was to compare magnesium levels in serum, CSF, and brain microdialysis samples
(MDS) in patients with aSAH. Seventeen patients with aSAH at World Federation
of Neurosurgeons (WFNS) grade IV and V were included. According to our internal
standard treatment protocols, all patients received a ventricular catheter, a
frontal intracerebral microdialysis probe, and a continuous intravenous
application of 80 mmol MgSO4 per 24 hours. Magnesium concentrations
of serum, CSF, and MDS were recorded. We found a positive and significant
correlation of increased serum levels of magnesium to CSF and MDS magnesium
concentrations. These pharmacokinetic findings may serve as a basis for further
discussion of the concept of induced hypermagnesemia in patients with aSAH,
especially in the context of recent level A evidence of the lack of clinical
benefit.