目的 分析中脑周围非动脉瘤性 蛛网膜下腔出血(PNSH)的病因、发病特 点、危险因素及影像学特点。方法 回顾 性分析我院2012年1月-2015年1月收治的 11例PNSH患者的临床资料，患者均有中脑 周围池出血CT表现，且DSA、CTA阴性，总 结其临床特点、危险因素及影像学特点。 结果 本组11例患者在发病72h内作头颅CT 扫查均证实为蛛网膜下腔出血，出血中心 多于脑干前部脑池，以中脑前方脚间池为 主，其中2例位脚池，1例位于桥前池，7 例位于脚间池，1例侧脑室枕角集血，均 未见脑内血肿。1-2周后复查可见SAH基本 吸收，其中2例脑室逐渐扩大，但无特殊 症状。结论 PNSH属于良性疾病范畴，患 者症状较轻，CT表现特殊，可区别于动脉 瘤性ASH，同时高血压、吸烟为影响PNSH 发病的相关危险因素。

Objective To analyze the causes, clinical characteristics, risk factors and imaging features of perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSH). Methods The clinical data of 11 patients with PNSH treated were analyzed retrospectively in our hospital from January 2012 to January 2015. All the patients had CT manifestations of perimesencephalic cistern hemorrhage,with DSA and CTA were negative. The clinical features, risk factors and imaging features were summarized. Results 11 cases were confirmed as subarachnoid hemorrhage by skull CT scan in onset 72h in this group. The hemorrhage center mostly located in anterior brain stem cisterns and anterior midbrain interpeduncular cisterns were the majority, including 2 cases in of crural cistern, 1 case in prepontile cistern, 7 cases in interpeduncular cistern and 1 case of lateral ventricle occipital hematocele, without visible intracerebral hematoma. 1~2 weeks later, the reexamination showed that SAH was basically absorbed, in which 2 cases of ventricle were gradually expanded, without special symptoms. Conclusion PNSH belongs to the category of benign diseases. The symptoms of the patients are mild and the CT findings are special, which can be used to discriminate ASH, and hypertension and smoking are the risk factors influencing inset of PNSH.