Time-dependent changes in cerebrospinal fluid metal ions following aneurysm subarachnoid hemorrhage and their association with cerebral vasospasm.

Aneurysm subarachnoid hemorrhage affects 10 in 100,000 people annually, 40 % of whom will develop neurological deficits from ischemic stroke caused by cerebral vasospasm. Currently, the underlying mechanisms are uncertain. Metal ions are important modulators of neuronal electrophysiological conduction and smooth muscle cell activity, thereby potentially contributing to vasospasm. We hypothesized that metal ion concentrations in the cerebrospinal fluid (CSF) after aneurysm rupture would change over time and be associated with vasospasm. To test this hypothesis, for 21 days, we collected CSF from patients with aneurysmal rupture and subjected it to spectrometry to detect metals. A repeated measures analysis was performed to analyze concentration changes over time. Six of the seven patients with aneurysmal rupture experienced vasospasm, all resolving by day 14. Changes in Fe²⁺ and Zn²⁺ concentrations in the CSF paralleled the incidence of vasospasm in this study population. Na²⁺, Ca²⁺, Mg²⁺, and Cu²⁺ concentrations exhibited no statistically significant changes over time. In conclusion, Fe²⁺ concentration in the CSF was significantly elevated during days 7-10, whereas Zn²⁺ concentrations spiked shortly thereafter, during days 11-14. This suggests that Fe²⁺ may be related to the induction of vasospasm and Zn²⁺ may be a marker of early brain injury secondary to ischemic injury and inflammation.