This prospective, randomized, controlled study demonstrated that scalp nerve block with 0.75% ropivacaine had a modest preventive effect on postoperative inflammation demonstrated by lower IL-6 concentrations in plasma 6 h after craniotomy for cerebral aneurysms and reduced CRP levels and increased IL-10 levels 12 and 24 h postoperatively. Here, IL10 is linked to brain aneurysm.