Association of early inflammatory parameters after subarachnoid hemorrhage with functional outcome: A prospective cohort study.

OBJECTIVE

Early brain injury after aneurysmal subarachnoid hemorrhage (aSAH) comprises a pronounced neuroinflammatory reaction. Nevertheless, its relevance for functional outcome and its role as outcome predictor remains uncertain. We evaluated the relationship of various early inflammatory parameters regarding functional outcome according to the modified Rankin Scale score (mRS) at discharge (primary objective) and six months after aSAH.

PATIENTS

A total of 81 patients (63% female) with a mean age of 53.8 ± 13.2 years were included.

METHODS

At admission clinical data and various inflammatory parameters in serum and - wherever applicable - cerebrospinal fluid (CSF) of patients after aSAH were assessed. Outcome was evaluated according to dichotomized mRS at discharge and six months after aSAH (unfavorable outcome: mRS 3-6). Univariate and thereafter multivariate logistic regression analyses were performed using SAS 9.2.

RESULTS

Elevated levels of interleukin 6 (IL-6) and leukemia inhibitory factor (LIF) in serum and CSF were related to unfavorable outcome at discharge (p<0.05; univariate analyses). IL-6 remains the only parameter relevant for outcome applying a multivariate model including the relevant baseline characteristics. Six months after aSAH no significant correlation was found regarding the outcome, most likely due to the high drop-out rate (27%). A pronounced rise of LIF serum and CSF levels after aSAH was observed.

CONCLUSION

Higher early IL-6 serum levels after aSAH are associated with poor outcome at discharge. In addition, involvement of LIF in the early inflammatory reaction after aSAH has been demonstrated.