Post-dural Puncture Headache Complicated by Subdural Hematoma in an Elderly Patient Following a Pencil-Point Spinal Needle Anesthesia: A Case Report

老年患者使用铅笔尖脊髓穿刺针麻醉后发生硬膜穿刺后头痛并发硬膜下血肿：病例报告