Multiple epidural steroid injections and body mass index linked with occurrence of epidural lipomatosis: a case series

Abstract

BackgroundEpidural lipomatosis (EL) is an increase of adipose tissue, normally occurring in the epidural space, sufficient to distort the thecal sac and compress neural elements. There is a lack of knowledge of risk factors, impact on patient’s symptoms, and its possible association with epidural steroid injections.MethodsHistory, physical examination, patient chart, and MRI were analyzed from 856 outpatients referred for epidural steroid injections. Seventy patients with signs of EL on MRI comprised the study group. Thirty-four randomly selected patients comprised the control group. The severity of EL was determined by the MRI assessment. The impact of EL was determined by the patient’s history and physical examination. Logistic regression was used to correlate the probability of developing EL with BMI and epidural steroid injections.ResultsEL was centered at L5 and S1 segments. The average BMI for patients with EL was significantly greater than that of control group (36.0 ± 0.9 vs. 29.2 ± 0.9, p <0.01). The probability of developing EL with increasing BMI was linear up to the BMI of 35 after which it plateaued. Triglycerides were significantly higher for the EL group as compared to controls (250 ± 30 vs. 186 ± 21 mg/dL p < 0.01). The odds of having EL were 60% after two epidural steroid injections, 90% after three epidural steroid injections and approached 100% with further injections, independent of BMI. Other risk factors considered included alcohol abuse, use of protease inhibitors, levels of stress, hypothyroidism and genetic predisposition. However there were insufficient quantities to determine statistical significance with a degree of confidence. The impact of EL on patient’s symptoms correlated with EL severity with Spearman correlation coefficient of 0.73 at p < 0.01 significance level.ConclusionsThe BMI and triglycerides levels were found to be significantly elevated for the EL group, pointing to an increased risk of EL occurrence in progressively more obese US population. The data also revealed a strong correlation between the number of subsequent epidural steroid injections and EL occurrence calling for caution with the use of corticosteroids.

Idiopathic Spinal Epidural Lipomatosis in the Lumbar Spine

“…Epidural steroid injection has also been postulated as a cause of SEL. [43][44][45][46] However, others have reported it as a treatment. 47 The current authors found no difference in history of epidural steroid injections between the SEL group and the control group.…”

Spinal epidural lipomatosis following bilateral spinal decompression surgery

“…Excessive systemic exogenous steroid use accounts for 55% of cases 2. Other causes include obesity and Cushing’s syndrome, due to excessive endogenous steroid production 2 3. Epidural steroid injection causing SEL has also been reported 3 4.…”

“…Other causes include obesity and Cushing’s syndrome, due to excessive endogenous steroid production 2 3. Epidural steroid injection causing SEL has also been reported 3 4. Typically, SEL occurs in the lumbar region and results in thecal sac compression.…”

Obesity is a Risk Factor for Epidural Lipomatosis: A Meta-analysis

“…The statistical results show that the heterogeneity between the initial studies is signi cant, the source of heterogeneity may be that there is no uniform standard for the diagnosis of SEL in various studies. Four studies [17][18][19][20] de ned SEL as an EF/SpiC index greater than 0.4 or 0.6, four reviews [21][22][23][24] diagnosed as SEL based on MRI showing enlarged fat tissue compressing the dura sac, two studies [14,25] obtained the diagnosis basis based on clinical symptoms and signs and MRI imaging but did not clearly explain. After excluding articles by the one-by-one elimination method, the heterogeneity between studies was signi cantly reduced (I 2 = 17%).…”