A 45-year-old man was transferred to the emergency room, reporting a severe headache as well as sudden onset nausea. Upon neurological examination, he was found to be drowsy, but was otherwise normal. Brain CT revealed SAH in the bilateral Sylvian fissure, basal cistern and interhemispheric fissure (Fig. ). Three-dimensional brain CT angiography showed a right feeding anterior communicating artery aneurysm (Fig. ). Emergent cerebral angiography and endovascular coil embolization were performed (Fig. ). After embolization, the headache was alleviated and the patient's status improved each day. Soon after recovery, he reported worsening pain in the left perineal area. The pain was intermittent at onset and aggravated by sitting down, walking, straining and coughing. Although bed rest relieved the pain, he had difficulty falling asleep due to the pain. He had no history of previous back problems or recent trauma. Upon a second neurological examination, no abnormalities were found. Two weeks after embolization, lumbar spine MRI revealed 2 separated PCs at the S1 and S2 level affecting the left S2 root with high signal intensity in T2 and T1 images, suggestive of a hemorrhage within the cysts (Fig. ). The diameter of the larger cyst was 1.4 cm. The left S2 root was smaller than the right S2 root because it was compressed by increased intracystic pressure. Given that his symptoms were not relieved with analgesics or a caudal block, and the radiological evidence of PCs, we decided to perform cyst fenestration and imbrication.\nUnder general anesthesia, we performed partial laminectomies at S1 and S2 via a posterior approach. The 2 separate cysts were tense and swollen. When we incised the cyst, dark old blood drained out and the cyst contracted. After the hematoma evacuated, we could find the S2 nerve root inside the cyst (Fig. ). The patient's pain was relieved immediately after cyst fenestration and imbrication. In a follow-up 5 years after the surgery, the patient remained symptom free with no complications.
This 21-year-old man complained of worsening radiating pain and hypesthesia on left leg for 1 year. His motor weakness was grade 4 on left leg, especially when extending the left ankle. Because of worsening symptoms he eventually visited our department. He had mild claudication, positive on left straight leg raising test at 45 degree. We confirmed a mild left S1 radiculopathy on electromyography. He had no neurologic deficit associated with cauda equina syndrome. Preoperative MR imaging showed a 20×13×14 mm sized sacral cyst (). We performed myelogram and CT and found the contrast-filled stalk between the thecal sac and the cyst. The cyst compressed a contiguous structure including nerve roots ().\nWe performed surgery the same as patient 1 () and symptoms disappeared after one week. Follow up MR imaging after 2 months demonstrated complete resolution of the lesion. We checked with MR imaging after 1 year and ascertained that there was no further cystic formation and complication ().