A Case of Surgically Treated Adult Split Cord Malformation Type 2 with Tethered Cord Syndrome

Split cord malformation (SCM) is a rare congenital anomaly characterised by the division of the spinal cord into 2 distinct hemicords, often accompanied by bony or cartilaginous septum. We experienced a surgical case diagnosed as SCM with tethered cord syndrome (TCS) due to spinal lipoma. A 54-year-old female presented with a history of gradually progressive paraparesis and bladder dysfunction for a few months. Her magnetic resonance imaging revealed low-positioned conus medullaris below the level of S3 due to spinal lipoma and accompanied by other small multiple lipomas and a split cord below the level of L4/L5 without bony separation. The final diagnosis was SCM type II with TCS. Under careful intraoperative inspection, fibrous connecting strings were arising from the dorsal interface of the split cord to the dorsal arachnoid membrane as one of the responsible tethering structures. Circumferential meticulous dissection was performed around the split cord, followed by standard dissection of tethered conus owing to lipoma at the caudal end. Her symptoms were alleviated immediately after surgery. Although the surgical procedure has not been established because of its rarity, dissection around the split cord should precede the usual untethering of the caudal spinal cord.