Table 1.

Key mediators in CSDH pathophysiology

Mediator	Finding in CSDH
Type 1 and type 3 procollagen	High levels in CSDH fluid signify fibro-proliferation occurring in CSDH which may relate to neomembrane formation [16, 33].
Thrombomodulin, TPA, fibrin and FDPs	Raised in CSDH fluid and signify hyperfibrinolytic activity occurring [28, 39–41, 74].
Angiopoietin-2	Pro-angiogenic factor, mRNA in high levels in outer membrane of CSDH [29].
VEGF	Pro-angiogenic factor. Very high levels in CSDH fluid and mRNA in membranes and neutrophils [21–23, 29, 46–49, 53].
PGE2	Regulates VEGF. High levels in CSDH fluid correlate with time from trauma [21].
HIF-1α	Regulates VEGF. High staining in outer membrane of CSDH [23].
MMP-1, -2 and -9	Present in outer membrane and CSDH fluid. Contributes to poor capillary integrity [30, 48, 57].
Cytokines and chemokines	High levels of IL-6, IL-8, IL-10, TNF-α, MCP-1, eotaxin-3, CXCL9 and CXCL10 in CSDH fluid compared with serum [18, 21, 53, 61, 62, 73, 74, 80, 83].