A C1-inhibitor for use in the treatment of disorders associated with an increased permeability of the blood brain barrier or the blood spinal cord barrier in a subject wherein the disorder associated with an increased permeability of the blood brain barrier or the blood spinal cord barrier is selected from the group consisting of stroke, ischemic stroke, hemorrhagic stroke, perinatal stroke, traumatic brain injury, spinal cord injury, diabetes mellitus, multiple sclerosis, a bacterial infection of the CNS, preferably meningitis, viral infection infecting the brain, preferably HIV, and brain tumor, preferably metastasing brain tumor.