Initial Clinical Experience of Vasodilatory Effect of Intra-cisternal Infusion of Magnesium Sulfate for the Treatment of Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Abstract

The vasodilatory effect of intra-cisternal infusion of magnesium sulfate solution was evaluated in 10 patients with symptomatic vasospasm after aneurysmal subarachnoid hemorrhage (SAH) who underwent early clipping surgery. Cisternal drainage was installed in the prepontine and/or sylvian fissures. Carotid angiography was performed immediately after the onset of symptomatic vasospasm, then intracisternal infusion of 15 mmol/l magnesium sulfate in Ringer solution was started at 20 ml/hr and continued until day 14. Irrigation was performed from the cisternal tube (inlet) to the spinal drainage (outlet). The cerebrospinal fluid magnesium ion concentration (1.2 ± 0.2 mEq/l) significantly increased after the infusion therapy (6.0 ± 1.7 mEq/l, p º 0.001). Repeat angiography showed vasodilatory effect on the spastic cerebral arteries at 3 hours after the infusion, especially in the arteries near to the site of cisternal drainage placement. The magnesium infusion also caused decreased mean arterial blood velocity in the spastic arteries in 6 of the 7 measured patients (162 ± 38 cm/sec to 114 ± 42 cm/sec, p º 0.001). Finally, 5 of the 10 patients achieved good recovery, 1 patient had moderate disability, 1 patient became severely disabled due to meningitis, and 3 patients were vegetative or dead, due to failure of magnesium irrigation in 1 patient and advanced age in the other 2 (more than 80 years old). This preliminary study indicates that intra-cisternal infusion of magnesium sulfate solution has vasodilatory effect on the spastic cerebral arteries after aneurysmal SAH.

Temporal Profile of the Effects of Intracisternal Injection of Magnesium Sulfate Solution on Vasodilation of Spastic Cerebral Arteries in the Canine SAH Model

“…The mean Evans index after the injection (25.2 AE 2.0%) did not change compared to before injection. MR imaging did not show any pathological findings except for hydrocephalus after intracisternal injection of MgSO 4 . Figure 2 shows the temporal changes of cerebral artery diameters.…”

“…We previously found that intracisternal infusion of MgSO 4 solution improved reduced cerebral blood flow after experimental SAH in rats using a quantitative autoradiographic method [2], and that intracisternal injection of MgSO 4 solution dilated the spastic cerebral arteries in the canine experimental SAH model using angiography [3]. Recently, we reported the first clinical application of intracisternal infusion of MgSO 4 solution for the treatment of symptomatic cerebral vasospasm after aneurysmal SAH and demonstrated the vasodilatory effect on the spastic arteries [4]. However, optimal duration of the vasodilatory effect and optimal Mg 2+ concentration in the CSF remain unclear, although the effect of CSF Mg 2+ concentration on cat normal arterioles was dose dependent and caused dilation in the range of 2.4-9.6 mEq/l [6].…”

Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage (IMASH)

“…Direct intracisternal infusion overcomes the problem of peripheral toxicity and may achieve a cerebrospinal fluid magnesium level sufficient to reverse cerebral vasospasm and augment its neuroprotective effects. 24 Another possible explanation of the lack of action could be the inability to provide neuroprotection for early brain injury with the current time window of administration. Whether earlier administration within the first 2 hours, like in the ongoing FAST_MAG Trial (Field Administration of Stroke Therapy-Magnesium Phase 3 Clinical Trial http://www.fastmag.info/index.htm), remains unanswered.…”

Neuroprotective Treatment Strategies for Delayed Cerebral Ischemia after Subarachnoid Hemorrhage – Review of Literature and Future Prospects

“…These concentrations cannot be produced by an intravenous administration of magnesium sulfate since the systemic side effects could be hazardous. Mori et al administered magnesium sulfate via a cisternal catheter in patients with cerebral vasospasm refractory to other forms of therapy and found a reduction of the extent of arterial narrowing [79], measured by transcranial Doppler sonography.…”