Shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage: the role of intrathecal interleukin-6.

OBJECT: Aneurysmal subarachnoid hemorrhage (SAH) has been reported to induce an intrathecal inflammatory reaction reflected by cytokine release, particularly interleukin-6 (IL-6), which correlates with early brain damage and poor outcome. The present study examines intrathecal IL-6 production together with clinical parameters, as a predictor of posthemorrhagic shunt dependency.

METHODS

Among 186 SAH patients admitted between July 2010 and December 2012, 82 received external ventricular drainage due to acute hydrocephalus. In these patients, cerebrospinal fluid (CSF) concentrations of IL-6 were measured within the first 14 days after SAH. Patients whose IL-6 values were not determined regularly and those who did not survive until discharge were excluded. The peak value of IL-6, ventricular infection during the hospital stay, microbial CSF culture, patient's age and sex, Hunt and Hess grade, and aneurysm location were assumed as predictive for shunt dependency.

RESULTS

Sixty-nine patients were included, 24 of whom underwent shunt surgery. Peak IL-6 values of ≥10,000 pg/ml were significantly associated with a higher incidence of shunt dependency (p = 0.009). Additional risk factors were aneurysm location on the anterior cerebral artery and its branches or in the posterior circulation (p = 0.025), and age ≥60 years (p = 0.014). In a multivariate analysis, IL-6 ≥10,000 pg/ml appeared to be the only independent predictor for shunt dependency (p = 0.029)

CONCLUSION

CSF IL-6 values of ≥10,000 pg/ml in the early post-SAH period may be a useful diagnostic tool for predicting shunt dependency in patients with acute posthemorrhagic hydrocephalus. The development of shunt-dependent posthemorrhagic hydrocephalus remains a multifactorial process.