Spontaneous cortical spreading depression and intracranial pressure following acute subdural hematoma in a rat

Abstract

Acute subdural hemorrhage (ASDH) is a frequent and devastating consequence of traumatic brain injury. Tissue damage develops rapidly and makes treatment even more difficult. Management of increased intracranial pressure (ICP) due to extravasated blood volume and brain swelling is often insufficient to control all adverse effects of ASDH. In addition to sheer volume, spontaneously triggered cortical spreading depression (CSD) that leads to cell death following ischemia or trauma may contribute to injury development after ASDH. Therefore, we explored the occurrence of CSD by tissue impedance (IMP) measurement in a rat model subjected to ASDH. IMP and intraventricular and mean arterial pressure were monitored before (baseline), during (blood infusion), and after ASDH for 3 h. Tissue impedance increased by around 203% of baseline during subdural infusion of 300 μl of autologous, venous blood and dropped back to baseline within 22 min. Fifty-six minutes after the start of ASDH a cluster of four short-lasting (3-3.5 min; 140-160% of baseline) IMP increases started that reflected spontaneous CSDs. This pattern presumes that CSD occurs early after ASDH and therefore may contribute to the rapid lesion development in this disease. © 2012 Springer-Verlag/Wien.