Intraoperative Ultrasound and Findings of Lumbar Intradural Disk Herniation Causing Cauda Equina Syndrome.

Intradural lumbar disk herniation (ILDH) is a rare variant and accounts for 0.33%-1.5% of lumbar disk herniations. Although clues exist on preoperative imaging, they remain subtle and most cases of ILDH are diagnosed intraoperatively. Intraoperative ultrasound is a useful adjunct in diagnosing and managing ILDH. We present a case to demonstrate the features of an intradural herniated disk on ultrasound imaging and highlight the utility of intraoperative ultrasonography in establishing diagnosis, guiding dural opening, and confirming adequate nerve root decompression following diskectomy.