Serum biomarkers and cerebral autoregulation as early warnings of delayed cerebral ischemia risk in patients after aneurysmal subarachnoid haemorrhage.

BACKGROUND

Identifying patients at risk of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH) remains challenging. This study aimed to evaluate the concentration of serum biomarkers along with cerebral autoregulation impairment on DCI.

METHODS

55 patients suffering from aSAH were enrolled in the study. Serum S100protein B (S100B) was tested both on the day of admission and over three consecutive days following the occurrence of aSAH. Cerebral autoregulation was assessed using a tissue oxygenation index (TOxa) based on near-infrared spectroscopy.

RESULTS

Changes in serum S100B levels interacted with DCI status (presence vs. absence): F = 3.84, p = 0.016. Patients with DCI had higher S100B concentration level on day 3 than those without DCI (3.54 ± 0.50 ng/ml vs. 0.58 ± 0.43 ng/ml, p = 0.001). S100B concentration on day 3 following aSAH predicted DCI (AUC = 0.77, p = 0.006). Raised level of serum S100B on day 3 was related with higher TOxa, thus with impaired cerebral autoregulation (r = 0.52,p = 0.031). Multivariate logistic regression analysis showed thatimpaired cerebral autoregulation andelevatedS100B concentration on day 3 increasethe likelihood of DCI.

CONCLUSIONS

Tracking changes in the serum biomarkers concentration along with monitoring of cerebral autoregulation, may play a role in early detection of patients at risk of DCI after aSAH. These results need to be validated in larger prospective cohorts.