Cerebrospinal fluid markers of neuroinflammation and coagulation in severe cerebral edema and chronic hydrocephalus after subarachnoid hemorrhage: a prospective study.

Background: Early severe cerebral edema and chronic hydrocephalus are the primary cause of poor prognosis in patients with subarachnoid hemorrhage (SAH). This study investigated the role of cerebrospinal fluid (CSF) inflammatory cytokines and coagulation factors in the development of severe cerebral edema and chronic hydrocephalus in patients with SAH.

Methods: Patients with SAH enrolled in this study were categorized into mild and severe cerebral edema groups based on the Subarachnoid Hemorrhage Early Brain Edema Score at admission. During long-term follow-up, patients were further classified into hydrocephalus and non-hydrocephalus groups. CSF samples were collected within 48 h post-SAH, and levels of inflammatory cytokines and coagulation factors were measured. Univariate and multivariate logistic regression analyses were performed to identify independent factors associated with severe cerebral edema and chronic hydrocephalus. The correlation between inflammatory cytokines and coagulation factors was further investigated and validated in a mouse model of SAH.

Results: Seventy-two patients were enrolled in the study. Factors from the extrinsic coagulation pathway and inflammatory cytokines were associated with both severe cerebral edema and chronic hydrocephalus. Coagulation products thrombin-antithrombin complexes (TAT) and fibrin, as well as inflammatory cytokines IL-1β, IL-2, IL-5, IL-7, and IL-4, were independently associated with severe cerebral edema. Additionally, Factor VII, fibrin, IL-2, IL-5, IL-12, TNF-α, and CCL-4 were independently associated with chronic hydrocephalus. A positive correlation between extrinsic coagulation factors and inflammatory cytokines was observed. In the SAH mouse model, tissue plasminogen activator was shown to alleviate neuroinflammation and cerebral edema, potentially by restoring glymphatic-meningeal lymphatic function.

Conclusions: Elevated levels of inflammatory cytokines and extrinsic coagulation pathway factors in the CSF are associated with the development of early severe cerebral edema and chronic hydrocephalus following SAH. These factors are interrelated and may contribute to post-SAH glymphatic-meningeal lymphatic dysfunction.