Head down tilt 15° in experimental intracerebral hemorrhage: a randomized noninferiority safety trial.

BACKGROUND AND PURPOSE: Head down tilt 15° (HDT15°), applied before recanalization, increases collateral flow and improves outcome in experimental ischemic stroke. For its simplicity and low cost, HDT15° holds considerable potential to be developed as an emergency treatment of acute stroke in the prehospital setting, where hemorrhagic stroke is the major mimic of ischemic stroke. In this study, we assessed safety of HDT15° in the acute phase of experimental intracerebral hemorrhage. METHODS: Intracerebral hemorrhage was produced by stereotaxic injection of collagenase in Wistar rats. A randomized noninferiority trial design was used to assign rats to HDT15° or flat position (n = 64). HDT15° was applied for 1 h during the time window of hematoma expansion. The primary outcome was hematoma volume at 24 h. Secondary outcomes were mass effect, mortality, and functional deficit in the main study and acute changes of intracranial pressure, hematoma growth, and cardiorespiratory parameters in separate sets of randomized animals (n = 32). RESULTS: HDT15° achieved the specified criteria of noninferiority for hematoma volume at 24 h. Mass effect, mortality, and functional deficit at 24 h showed no difference in the two groups. HDT15° induced a mild increase in intracranial pressure with respect to the pretreatment values (+2.91 ± 1.76 mmHg). HDT15° had a neutral effect on MRI-based analysis of hematoma growth and cardiorespiratory parameters. CONCLUSIONS: Application of HDT15° in the hyperacute phase of experimental intracerebral hemorrhage does not worsen early outcome. Further research is needed to implement HDT15° as an emergency collateral therapeutic for acute stroke.

Pravastatin acute neuroprotective effects depend on blood brain barrier integrity in experimental cerebral ischemia.

Statins have since long been reported to exert acute neuroprotection in experimental stroke models. However, crucial questions still need to be addressed as far as the timing of their cerebral effects after intravascular administration and the role played by the blood brain barrier (BBB) crossing properties. We tested the effects of an hydrophilic statin (pravastatin, 100 nM), which poorly crosses BBB under physiological conditions. Pravastatin was administered either 90 min before or immediately after transient middle cerebral artery occlusion in the in vitro isolated guinea pig brain preparation. A multi-modal outcome assessment was performed, through electrophysiological and cerebral vascular tone recordings, MAP-2 immunohistochemistry, BBB evaluation via ZO-1/FITC-albumin analysis, AKT and ERK activation and whole-cell antioxidant capacity. Pravastatin pre-ischemic administration did not produce any significant effect. Pravastatin post-ischemic administration significantly prevented MAP-2 immunoreactivity loss in ischemic areas, increased ERK phosphorylation in the ischemic hemisphere and enhanced whole-cell antioxidant capacity. Electrophysiological parameters, vascular tone and AKT signaling were unchanged. In all tested ischemic brains, ZO-1 fragmentation and FITC albumin extravasation was observed, starting 30 min from ischemia onset, indicating loss of BBB integrity. Our findings indicate that the rapid anti-ischemic effects of intravascular pravastatin are highly dependent on BBB increased permeability after stroke.