Confirming Subarachnoid Hemorrhage Induction in the Endovascular Puncture Mouse Model.

Background And Purpose: Experimental studies of subarachnoid hemorrhage (SAH) using the endovascular perforation model routinely use either cerebral blood flow (CBF) or intracranial pressure (ICP) monitoring to confirm SAH induction. We designed this study to test the hypothesis that contralateral CBF is a better marker of SAH induction than ipsilateral CBF.

Methods: Sixty-eight adult C57BL/6J mice were subjected to endovascular perforation. Mice were monitored using laser Doppler (for relative CBF) or ICP probes.

Results: The ipsilateral CBF significantly decreased prior to ICP rising. However, reduction of the CBF in the contralateral hemisphere occurred at the same time as the rise in ICP. When CBF is monitored on both hemispheres simultaneously, the drop in ipsilateral CBF precedes the drop in the contralateral CBF.

Conclusions: The most suitable method for confirming puncture and induction of SAH in the endovascular mouse model is by ICP. Monitoring the CBF of the contralateral hemisphere is also able to detect the moment of SAH induction. However, monitoring the ipsilateral CBF is not satisfactory for determining puncture and induction of SAH due to the changes in CBF caused by blood flow occlusion from the endovascular filament as it enters into the circle of Willis.