1606. Intradural Lumbar Discs: Literature Review and Case Series

Authors: Elias Shaaya, MD; Elias Shaaya, MD; Lars Meisner; Jared Fridley, MD; Albert Telfeian, MD, PhD; Sean Barber, MD (Providence, RI)

Introduction: Lumbar intradural disc herniation (IDH) is a rare entity accounting for 0.2-2.2% of all herniated disc cases.Intradural discs are most commonly found in the lumbar spine, but regionally a higher proportion of thoracic herniated discs are intradural.Diagnosis of IDH is made based on both clinical evaluation and imaging workup. We present a series of patients with lumbar IDH, and perform an analysis of data available in the literature. Methods: We present two cases of patients with intradural disc herniations treated at our institution and provide a analyze available data in the literature regarding this rare condition. An electronic literature search was performed with the Pubmed search engine using the terms ‘lumbar intradural disc.’ Patient data was extracted from available English speaking literature and analyzed. Data gathered included: age, sex, level of disc, size of disc, symptoms, imaging findings, and post-operative course. Results: We found 12 papers reporting a total of 26 patients with lumbar IDH. They most commonly occurred at L4-5 (32%) and L5-S1 (25%), followed by L3-4 (17.8%), L1-2 (7.1%), and T12-L1 (3.5%). Men were more often affected then women (17/28 patients). Pre-operative symptoms ranged from lower back pain (75%), radiculopathy (64%), to weakness (39%) and bowel/bladder dysfunction (17.8%). Twenty-three patients were diagnosed using pre-operative MRI while our patients were diagnosed using CT and one patient had a CT myelogram. Of 22 patients with follow up clinical data, twenty-one patients (77.7%) were reported to have complete resolution of their pre-operative symptoms, and 6 (22.2%) had persistent sensorimotor deficits. Conclusion: Lumbar IDH is a rare entity, that is most commonly seen at L4-5 and L5-S1. From the limited data available in the literature, nearly 80% of patients with lumbar IDH that undergo surgical intervention have significant improvement in their pre-operative symptoms.