Aneurysmal subarachnoid hemorrhage (aSAH) triggers a robust inflammatory response, which has been associated with brain injury and poor outcome. The complement system is an integral part of the innate immune system activated after acute brain injury. The early complement proteins C1q and C3 have roles in glial-neuronal interactions and synaptic pruning. The objective of this study was to determine whether changes in CSF complement proteins over time after aSAH are associated with neurologic outcome.
Geraghty et al. (2026) studied this question.