gms | German Medical Science

Objective: Neuropeptide Y (NPY) is one of the most potent endogenous vasoconstrictors and its contribution to the multifactorial cascade of cerebral vasospasm (CV) due to aneurysmal subarachnoid hemorrhage (SAH) has been assumed repeatedly. In this experimental study, we sought to compare the levels of NPY in cerebrospinal fluid (CSF) of patients with SAH and of patients with intracerebral hemorrhage (ICH), evaluating the hemorrhage-specific course of NPY secretion in the first ten days.

Method: Prospectively, 79 patients were included [SAH n=66, (only Fisher 3 and 4) and ICH n=13, (with occlusive hydrocephalus)]. In all patients, an external ventricular drainage (EVD) was implanted within 24 hours after onset of bleeding. CSF was drawn daily from day 1 to day 10. The CSF levels of NPY were determined by means of a competitive enzyme immunoassay (EIA) and were correlated with the development of CV over the 10-day period after the onset of SAH and to the occurrence of consecutive ischemic stroke.

Results: In the ICH group, one ischemic stroke was observed radiographically while 26 patients (39%) in the SAH group developed cerebral ischemia due to angiographic CV. The levels of NPY significantly differed between both groups (SAH mean 0.842 ng/ml vs mean 0.250 ng/ml, p<0.001) and the course of NPY secretion into CSF during the ten days interval was markedly contraire. In the SAH/ischemia group, NPY steadily increased while in the ICH group, NPY levels reached the highest level on day 4 then decreased down to normal level on day 10.

Conclusions: The dynamic secretion of NPY into CSF is specific after aneurysmal SAH in the acute interval. Increasing levels of NPY significantly corresponded to the risk of consecutive ischemia. Contrariwise, in ICH, NPY levels are significantly lower and steadily decrease.