Glymphatic-meningeal lymphatic dysfunction drives remote organ injury after aneurysmal subarachnoid hemorrhage: a unified neuroimmune framework and time-stratified therapeutic roadmap

Abstract

Aneurysmal subarachnoid hemorrhage (aSAH) confers substantial mortality and morbidity driven not only by primary brain injury but also by systemic remote organ complications across the pulmonary, cardiac, renal and gastrointestinal systems. Despite growing recognition of neuroimmune crosstalk in this process, a cohesive, systems-level model connecting intracranial hemorrhage to multi-organ dysfunction remains absent from the literature. Here, we propose a unified neuroimmune framework centered on a long-underappreciated mechanism: glymphatic and meningeal lymphatic drainage dysfunction is hypothesized to act as the upstream initiating event that forces brain-derived damage-associated molecular patterns, inflammatory cytokines and activated immune cells to spill into the systemic circulation. We systematically map three mechanistically distinct, mutually amplifying transmission pathways: the classical neuroendocrine-immune axis, the recently identified meningeal lymphatic–deep cervical lymph node immune drainage axis, and circulating humoral effectors exemplified by neutrophil extracellular traps. Most notably, we integrate these pathways with a temporally stratified immune continuum spanning early hyperinflammatory SIRS, stroke-induced immunodepression, and chronic low-grade inflammation – an integrative temporal architecture that has eluded prior single-organ or single-pathway studies. Grounded in this framework, we put forward a tiered, phase-specific neuroimmunomodulatory strategy that simultaneously addresses central inflammatory origins, systemic signal propagation, and end-organ tissue damage. By reframing remote organ injury as a time-dependent immune process rather than a collection of isolated organ complications, this work provides a mechanistic and translational roadmap for time-stratified clinical trials and redefines the investigative direction for multi-organ management in aSAH.