Objective The influence of antiplatelet medications on prognosis after non -aneurysmal subarachnoid hemorrhage(SAH)is unknown.This study aimed to evaluate the risk of antiplatelet mdications in devel-oping SAH.Methods 420 patients who underwent catheter cerebral angiography after presenting with nontraumatic SAH were included.Outcomes were assessed by using the modified Rankin scale.Results A total of 420 patients underwent catheter angiography for evaluation of SAH.Of these,63 cases (15%)were angiogram -negative.The fraction of patients presenting with angiogram -negative SAH as well as the frequency of antiplatelet use among these patients significantly increased during the study period.Antiplatelet use was more commonly associated with angiogram-negative SAH(18 /63,28.6%)than with angiogram -positive SAH(39 /357,11%;P =0.001).At 14 days after presentation,poor outcome was significantly more frequent among patients who took antiplatelet agents (20 /63, 31.7%)than among those who did not(12 /63,20%;P =0.017).Conclusion Antiplatelet medication use is asso-ciated with poor early,but not late,outcomes after angiogram -negative SAH.More studies are needed to confirm this association.

Objective: To explore the clinical value of non-invasive monitoring of cerebral hemodynamics for evaluating intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in patients with moderate to severe traumatic brain injury (TBI). Methods: Transcranial Doppler (TCD) was employed to detect the hemodynamics of bilateral middle cerebral arteries, including systolic blood fl ow velocity (Vp), diastolic blood fl ow velocity (Vd), average fl ow velocity (Vm), pulsatility index (PI) and resistance index (RI) in 52 patients with moderate to severe TBI. At the same time, the CPP, ICP and mean arterial blood pressure (MABP) were monitored. The correlations between hemodynamics and MABP, ICP as well as CPP were analyzed. Results: The PI and RI were positively related to the ICP (r=0.881, P<0.0001; r=0.789, P<0.0001). Multiple stepwise regression analysis showed PI was closely associated with ICP (ICP=-8.593+24.295PI; t=13.216, P<0.0001) and signifi cant correlation was also found between CPP and PI as well as MABP (CPP=15.596-22.886PI+0.910MABP; F= 76.597, P<0.0001). Conclusion: Non-invasive monitoring of cerebral hemodynamics by TCD can refl ect the real time changes in the ICP and CPP and may be used as an effective tool to monitor the ICP and CPP. This method is non-invasive, safe, cheap, repeatable and applicable in clinical practice.