The Clinical Characteristics of Spinal Epidural Lipomatosis in the Lumbar Spine

BACKGROUND: Spinal epidural lipomatosis (SEL) is a rare disease, defined as diffuse hypertrophy of unencapsulated adipose tissue causing spinal canal compression and progressive neurologic deficits. However, there are few studies on SEL in Korea. OBJECTIVES: The purpose of this study was to describe the prevalence and clinical characteristics of SEL in Korea. METHODS: Of the 3702 symptomatic patients (1575 males and 2127 females) who underwent lumbar spine magnetic resonance imaging (MRI) at the age of 20 years or older from January 2014 to December 2016, 42 patients (27 males and 15 females) diagnosed with SEL were selected. Medical records and telephone counseling were used to document sex, age, height, weight, clinical symptoms, coexistent spinal disease, accompanying diseases, and alcoholism and smoking status. One radiologist classified the severity of epidural lipomatosis into three grades from I to III according to Borre et al. We obtained four linear measurements at the axial plane parallel based in the narrowest on MRI image. RESULTS: The incidence of SEL in the lumbar spine was 1.1%, which was 1.71% in men and 0.7% in women. The mean age was 69.4 ± 10.9 years and the mean body mass index (BMI) was 26.4 ± 3.5 kg/m(2). The most common clinical symptoms were lower back pain and radiating leg pain (26 patients, 61.9%). The level of affected SEL was found to be most prevalent at L5 - S1 (21 patients, 50%). Concomitant diseases were hypertension (26 patients, 61.9%) and diabetes (12 patients, 28.5%). The most common SEL grade was type III (21 patients, 50%), followed by types II (17 patients, 40.4%) and I (4 patients, 9.5%). CONCLUSIONS: Lumbar spine MRI at one hospital showed that the incidence of symptomatic SEL was 1.1%; SEL is common at the L5-S1 level and in male patients, and severity grade is often severe.