Evidence of spreading depolarizations in a porcine cortical intracerebral hemorrhage model.

OBJECTIVES

To evaluate whether cortical spreading depolarizations (CSD) occur in the early stage after cortical intracerebral hemorrhage (ICH).

METHODS

Ten anesthetized male swine were examined over 19 h. Two cerebral probes were inserted around the ICH (microdialysis and thermodiffusion cerebral blood flow), ICP was monitored contralaterally and up to two electrocorticographic grid electrodes were positioned over the hemisphere after hemicraniectomy and dural opening. A right frontal autologous, arterial ICH (3.0 mL) was induced in all the animals studied.

RESULTS

Using a modified injection technique an 80% success rate in ICH formation could be achieved. Eight animals with cortical ICH could be analyzed finally. After induction of ICH, ICP increased non-significantly. Overall, six out of eight animals had CSDs, of either single type or clusters. In one animal a CSD occurred as early as 2 h after ICH; in all other animals the first CSD did not occur before 5 h after onset.

CONCLUSION

CSD's occur in cortical experimental ICH. As ICP remained stable owing to the hemicraniectomy we cannot argue in favor of ICP-related triggering of CSD. Modifications of the experimental setup avoiding hemicraniectomy may better describe the pathophysiology of CSD related to ICH in future studies.