Cerebral Vasospasm after Subarachnoid Hemorrhage: Putative Role of Inflammation

Abstract

Cerebral vasospasm is a common, formidable, and potentially devastating complication in patients who have sustained subarachnoid hemorrhage (SAH). Despite intensive research efforts, cerebral vasospasm remains incompletely understood from both the pathogenic and therapeutic perspectives. At present, no consistently efficacious and ubiquitously applied preventive and therapeutic measures are available in clinical practice. Recently, convincing data have implicated a role of inflammation in the development and maintenance of cerebral vasospasm. A burgeoning (although incomplete) body of evidence suggests that various constituents of the inflammatory response, including adhesion molecules, cytokines, leukocytes, immunoglobulins, and complement, may be critical in the pathogenesis of cerebral vasospasm. Recent studies attempting to dissect the cellular and molecular basis of the inflammatory response accompanying SAH and cerebral vasospasm have provided a promising groundwork for future studies. It is plausible that the inflammatory response may indeed represent a critical common pathway in the pathogenesis of cerebral vasospasm pursuant to SAH. Investigations into the nature of the inflammatory response accompanying SAH are needed to elucidate the precise role(s) of inflammatory events in SAH-induced pathologies.

Immune and inflammatory gene signature in rat cerebrum in subarachnoid hemorrhage with microarray analysis

“…Notably, a little cluster of inflammation genes, including PGES, CD14 and TIMP1 were upregulated in the early phase of SAH. These results coincide with results of SAH-related inflammatory reactions in numerous studies reported in the literature (14,15). TIMP1 expression was differentially regulated in a markedly similar pattern to that of MMP9 in acute activation following 2 h of 1-hemorrhage cerebrum SAH, suggesting that an imbalance of MMP9/TIMP1 regulation is implicated in the acute phase of SAH.…”

Systemic interleukin-6 concentrations in patients with perimesencephalic non-aneurysmal subarachnoid hemorrhage

“…1, 4,6,7 Inflammatory response with cytokine release is associated with severity of illness, clinical outcome and occurrence of CVS in patients with aSAH. [8][9][10] Higher levels of interleukin (IL)-6 in the cerebro-spinal fluid (CSF) have been linked to the occurrence of CVS and worse outcome. [10][11][12][13] Further, the occurrence of systemic inflammatory response syndrome has been linked to the development of CVS and worse outcome in patients with aSAH.…”

Long-Term Outcome Call into Question the Benefit of Positive Fluid Balance and Colloid Treatment After Aneurysmal Subarachnoid Hemorrhage

“…Large vessel and small vessel spasm may not result from the same mechanism nor do they likely have the same mechanism to cause functional deficit or morphologic brain injury. Among others, putative processes such as cortical spreading ischemia and activation of specific inflammatory pathways are currently topics for intense research [13,14]. Contributions from the laboratory will likely guide new therapeutic approaches in this field.…”