Arterial hypotension triggers perifocal depolarizations and aggravates secondary damage in focal brain injury.

Perifocal depolarizations (PFD) have been observed after traumatic brain injury, are known to disturb cerebrovascular reactivity and thus may contribute to the morphological consequences of brain injury. In this investigation, the role of PFD was studied in focal brain lesions with/without induction of delayed hypotension. Cerebral freeze lesions were induced in anesthetized normotensive rats that underwent perfusion fixation of brains 5 min, 4 h or 24 h after lesioning, respectively, to obtain quantitative histopathology.