Endothelial cell activation seems to be an important process in the multifactorial pathophysiology of delayed cerebral ischemia (DCI) and subsequent poor clinical outcome after aneurysmal subarachnoid hemorrhage (aSAH).

To assess the association between biomarker levels of endothelial activation and the occurrence of DCI and poor clinical outcome six months after aSAH.

Between October 2018 and November 2020, 75 aSAH patients were included. Blood samples were taken on admission, days 3–5 and days 9–11 after aSAH. Ten patients with unruptured intracranial aneurysms served as controls. Poor outcome was assessed at six months, defined by a modified Rankin Scale score of 4–6. The cohort was dichotomized into patients with and without DCI and good and poor outcomes. Biomarker levels of von Willebrand factor (vWF), E-selectin, thrombomodulin, syndecan-1 and matrix metalloproteinase (MMP-9) were analyzed and compared between groups by a T-test or Mann–Whitney U test, depending on the normality of the data.

Twelve (16.0%) patients developed DCI, and 39 (41.9%) patients had poor outcomes at six months post-aSAH. None of the biomarkers showed significant differences between patients with and without DCI. vWF and syndecan-1 were elevated on admission and on days 9–11 in patients with poor outcomes (p < 0.05 and p = 0.02, respectively).

Levels of vWF, E-selectin, thrombomodulin, syndecan-1 and MMP-9 were not associated with the occurrence of DCI, although higher levels of vWF and syndecan-1 were associated with poor outcome at six months. Further research is needed to establish the role of these biomarkers in aSAH patients.

Chronic headache after aneurysmal subarachnoid hemorrhage (aSAH) remains an ongoing area of investigation, with uncertainty regarding its prevalence and long-term outcomes.

A systematic review was conducted across five databases – Medline (Ovid), the Cochrane Central Register of Controlled Trials (Ovid), PsychInfo (Ovid), Embase (Ovid) and Scopus (Elsevier) – to identify all studies investigating the prevalence of chronic headaches after aSAH. A total of five studies were identified and included in our review.

There were five observational studies (three cohort and two cross-sectional). The overall prevalence of chronic headaches after aSAH ranged from 16.1% to 41%, albeit across a follow-up time frame of 12 months to 7.5 years. Outcome measurements included quantitative pain scores and opioid usage; however, these were inconsistent across studies, and the studies did not address the long-term impacts of chronic headaches on quality of life or their psychosocial implications.

The prevalence of chronic headache after aSAH is not well-characterized, and long-term outcomes are seldom studied, highlighting a critical gap in the current literature. Longitudinal cohort studies with standardized approaches to ascertain the psychosocial and physiological burden associated with post-aSAH chronic headaches are urgently needed.