Decompression of idiopathic lumbar epidural lipomatosis: diagnostic magnetic resonance imaging evaluation and review of the literature

A challenging diagnosis of spinal epidural lipomatosis: A case report and review of the literature

INTRODUCTION

Spinal Epidural Lipomatosis (SEL) is a rare disorder of pathological overgrowth of the spinal epidural fat in the extradural space. The pathogenesis of SEL usually involves exogenous steroid use or endogenous steroids overproduction. However, idiopathic cases have been reported. Magnetic resonance imaging (MRI) is the gold standard for diagnosis. Both conservative and surgical approaches are employed in management of these patients.

CASE PRESENTATION

A 17-year-old male presented to our hospital complaining of progressive lower limb weakness, loss of sensation with urinary incontinence which ended up with paraplegia. He underwent extensive investigations and received multiple inaccurate diagnoses. MRI of the thoracic spine showed spinal epidural lipomatosis with dorsal kyphosis. Hemi-laminectomy for spinal cord decompression and trans-pedicular fixation for correction of kyphosis were performed showing excellent outcomes.

CLINICAL DISCUSSION

Diagnosing SEL can be challenging due to its symptom overlap with other neurological conditions. Thus, higher levels of clinical suspicions and utilization of numerous diagnostic modalities including MRI are required. Treatment is largely determined by the clinical presentation and the severity of symptoms. Given the severity of neurological symptoms in our case, surgical intervention was performed resulting in fully regained functionality of previously paralyzed muscles.

CONCLUSION

This case highlights the rare presentation and the diagnostic challenges of spinal epidural lipomatosis SEL in a young patient who was misdiagnosed for 9 consecutive months before receiving the correct diagnosis, emphasizing the importance of considering SEL in the differential diagnosis for progressive neurological deficits and the importance of MRI, especially in atypical cases.

Acute neurologic decline in a patient with spinal stenosis: blame it on the epidural fat

Spinal epidural lipomatosis [SEL] is defined as an excessive accumulation of extradural normal adipose tissue. This condition may be idiopathic or acquired. Surgical decompression is considered the gold standard treatment in patients presenting with progressive neurologic deficit. We report a case of a 69-year-old male patient presented with neurogenic claudication and lower left limb radiculopathy. The magnetic resonance imaging (MRI) revealed a L5-S1 epidural compression sustained by a large epidural plaque whose signal was consistent with adipose tissue. A conservative approach, including weight loss attempt, revealed unsuccessful and the patient presented some months after the diagnosis at the emergency department with acute onset bilateral drop foot, more severe on the right side and urinary disturbances. Microsurgical decompression via L5 laminectomy and partial L4 laminectomy and fatty plaque debulking was performed. The post operative course was uneventful and at the two months post operative follow up the patient reported a significative improvement of the pre operative neurological signs and symptoms and of pain control. SEL deserves attention as an identifiable cause of radiculopathies, typically attributed to spinal stenosis, with a higher incidence than previously reported. Moreover cases of acute onset of cauda equina like syndrome were reported in patent affected by SEL, probably related to a local venous engorgement with stasis and edema. Therefore it should be considered as a possible diagnosis not only in patients complaining of stenosis-type symptoms but also in cases of acute neurological decline with cauda equina like syndrome, especially when provided with a "benign" imaging reading.

FACTFINDERS for PATIENT SAFETY: Preventing procedure-related complications: Epidural lipomatosis and postpartum steroid exposure

This series of FactFinders presents a brief summary of the evidence and outlines recommendations to improve our understanding and management of potential procedure-related complications. Evidence in support of the following facts is presented. (1) Epidural Steroid injections for Radicular Pain Due to Spinal Stenosis Caused by Lipomatosis -- There is low-level evidence of an association between epidural steroid injections (ESIs) and the development and/or worsening of spinal epidural lipomatosis (SEL). However, there is insufficient evidence to establish whether ESIs independently result in an increase in spinal stenosis with neurological compromise in individuals with pre-existing SEL. (2) Steroid Exposure Postpartum -- There is no absolute contraindication to steroid injections based on postpartum or lactating status, but there may be disruption of both maternal and breastfed child hypothalamic-pituitary-adrenal (HPA) axis response to steroid administration. For the duration of breastfeeding, milk production may be affected after steroid exposure, and withholding breast milk produced for several hours after exposure minimizes infant exposure.

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

Case Report: Technical description and clinical evaluation of three cases of unilateral biportal endoscopic decompression for symptomatic spinal epidural lipomatosis

Objective

To investigate the clinical characteristics and outcomes of three patients with symptomatic Spinal epidural lipomatosis (SEL) treated using Unilateral Biportal Endoscopic (UBE) surgery.

Methods

This report retrospectively analyzed the clinical data of three patients with SEL admitted to our hospital. The analysis covers onset characteristics, clinical manifestations, and the most recent radiologic grading system of neural compression (Manjila classification). Furthermore, it details the decompression accomplished through the application of a minimally invasive UBE surgical technique, specifically targeting the removal of proliferated fat responsible for nerve and spinal cord compression.

Results

This technique was performed successfully in 3 patients with SEL. Radiating pain was reduced, and the functional disability and radiologic compression were improved in all three patients. Postoperative spinal instability and surgical complications related to the procedure were not observed.

Conclusions

For SEL, timely diagnosis and appropriate intervention can prevent the progression of neurological disability. UBE is a minimally invasive muscle-preserving technique that achieves neural decompression directly by the removal of excessive intraspinal adipose tissue buildup.

Cervical syringomyelia with caudal thoracic epidural lipomatosis: case report and literature review

Syringomyelia associated with epidural lipomatosis is a rare finding. Only three published cases of epidural lipomatosis associated with syringomyelia exist in the literature. We report the case of a 46-year-old woman who presented with progressive myelopathy over an 18-month period. Imaging revealed significant thoracic spinal cord compression secondary to epidural lipomatosis from T3 to T8 with cephalad cervical syringomyelia extending from C7 to T1. Imaging was unremarkable for Chiari malformation or a craniospinal space-occupying lesion. A T2 to T8 laminoplasty was performed, removing excessive epidural adipose tissue to decompress the thoracic spinal cord. Postoperatively, the patient reported symptom improvement with complete symptom resolution at 3 months. Follow-up imaging at 3-months demonstrated thoracic spinal cord decompression with mild syrinx reduction. At two-year follow-up the patient remained asymptomatic with unchanged imaging. Syringomyelia in the setting epidural lipomatosis is a rare finding.

Outcome of posterior decompression for spinal epidural lipomatosis

BACKGROUND

In contrast to osteoligamentous lumbar stenosis (LSS), outcome of surgical treatment for spinal epidural lipomatosis (SEL) is still not well defined. We present risk factors for SEL and clinical long-term outcome data after surgical treatment for patients with pure SEL and a mixed-type pathology with combined SEL and LSS (SEL+LSS) compared to patients with pure LSS.

METHODS

From our prospective institutional database, we identified all consecutive patients who were surgically treated for newly diagnosed SEL (n = 31) and SEL+LSS (n = 26) between 2018 and 2022. In addition, a matched control group of patients with pure LSS (n = 30) was compared. Microsurgical treatment aimed for posterior decompression of the spinal canal. Study endpoints were outcome data including clinical symptoms at presentation, MR-morphological analysis, evaluation of pain-free walking distance, pain perception by VAS-N/-R scales, and patient's satisfaction by determination of the Odom score.

RESULTS

Patients with osteoligamentous SEL were significantly more likely to suffer from obesity (body mass index (BMI) of 30.2 ± 5.5 kg/m2, p = 0.03), lumbar pain (p = 0.006), and to have received long-term steroid therapy (p = 0.01) compared to patients with SEL+LSS and LSS. In all three groups, posterior decompression of the spinal canal resulted in significant improvement of these symptoms. Patients with SEL had a significant increase in pain-free walking distance during the postoperative course, at discharge, and last follow-up (FU) (p < 0.0001), similar to patients with SEL+LSS and pure LSS. In addition, patients with pure SEL and SEL+LSS had a significant reduction in pain perception, represented by smaller values of VAS-N and -R postoperatively and at FU, similar to patients with pure LSS. In uni- and multivariate analysis, domination of lumbar pain and steroid long-term therapy were significant characteristic risk factors for SEL.

CONCLUSIONS

Surgical treatment of pure SEL and SEL+LSS allows significant improvement in pain-free walking distance and pain perception immediately postoperatively and in long-term FU, similar to patients with pure LSS.

A Rare Cause of Low Back Pain

This is the case of a 60-year-old man with no known medical history who presented with progressively worsening lumbar pain and was found to have idiopathic dorsal epidural lipomatosis. The patient's condition improved significantly with pain management. Therefore, no surgical intervention was warranted at the time, but the patient was advised to keep close follow-up as an outpatient. Being familiar with this potential cause of lumbar pain is vital, as it can lead to severe morbidity if left unrecognized.

Could Spinal Epidural Lipomatosis Be the Hallmark of Metabolic Syndrome on the Spine? A Literature Review with Emphasis on Etiology

Spinal epidural lipomatosis is defined by an excessive amount of epidural fat in the spinal canal, usually in the lumbosacral tract: a well-known cause of lumbar pain and spinal stenosis with a possible wide range of neurological symptoms. Recent research data reveal that, nowadays, obesity has become the main cause of spinal epidural lipomatosis. Moreover, this condition was recently recognized as a previously unknown manifestation of metabolic syndrome. Radiological studies (CT and MRI) are the only tools that are able to diagnose the disease non-invasively. Indeed, radiologists play a key role in disease recognition, with subsequent possible implications on patients' systemic health assessments. Despite its clinical importance, the condition is still underreported and neglected. The current literature review summarizes all the main etiologies of spinal epidural lipomatosis, particularly regarding its linkage with metabolic syndrome. An overview of disease characteristics from diagnosis to treatment strategies is also provided.

Ligamentum flavum hypertrophy significantly contributes to the severity of neurogenic intermittent claudication in patients with lumbar spinal canal stenosis

Ligamentum flavum hypertrophy (LFH) is a known contributor to lumbar spinal canal stenosis (LSCS). However, the clinical significance and quantitative role of LFH compared to other components, such as disc bulging and facet hypertrophy, have not yet been examined. We investigated the correlation between the quantitative radiological factors, clinical symptoms, and outcomes in patients with LSCS. In total, 163 patients diagnosed with single-level (L4-L5) stenosis were included. The patients were divided into 2 groups according to claudication severity: >100 m for mild (n = 92) and < 100 m for severe (n = 71). The visual analog scale (VAS) was used to quantify back and leg pain, and the Oswestry Disability Index (ODI) and Short form-36 (SF-36) physical component summary (PCS) scores, and Macnab criteria were evaluated as clinical factors 6 months after treatment. We measured the baseline canal cross-sectional area, ligamentum flavum (LF) area, disc herniation area, dural sac area, fat area, and LF thickness using MRI. A comparative analysis was performed to evaluate the association between radiologic and clinical factors. Additionally, further comparative analyses between the types of surgeries were performed. Among various radiologic factors, the baseline LF thickness (odds ratio [OR] 1.73; 95% confidence interval [CI] 1.25-2.41) was the only major contributing factor to the severity of claudication in the multivariate logistic regression analysis. The types of surgery (decompression alone vs fusion) did not significantly differ in terms of their clinical outcomes, including back and leg VAS, ODI, SF-36 PCS, and satisfaction with the MacNab classification. LF thickness is a major factor contributing to claudication severity.

Surgical management of thoracic myelopathy from long-segment epidural lipomatosis with skip hemilaminotomies: illustrative case

BACKGROUND

Thoracic spinal epidural lipomatosis (SEL) involves the pathological overgrowth of histologically normal, unencapsulated adipose tissue that can compress the spinal cord and cause myelopathy. SEL has been associated with multiple medical conditions, including Scheuermann kyphosis (SK). Optimal treatment strategies for SEL, especially in the setting of a sagittal spinal deformity, remain unclear.

OBSERVATIONS

In this report, the authors discussed surgical management of a patient with thoracic SEL and SK using skip hemilaminotomies for resection of the epidural adipose tissue. To the authors’ knowledge, only one other report described a similar surgical technique in a patient who did not have a spinal deformity.

LESSONS

When conservative efforts fail, thoracic SEL may require surgical treatment. Surgical planning must account for co-medical conditions such as SK. The described approach involving skip laminotomies, which minimizes spine destabilization, is a viable option to treat SEL spanning multiple spinal segments. Prognosis after surgical treatment varies and is impacted by multiple factors, including severity of preoperative neurological deficits.

Lumbar Epidural Lipomatosis is Increased in Patients With Morbid Obesity and Subsequently Decreases After Bariatric Surgery

BACKGROUND

Spinal epidural lipomatosis (SEL) is characterized by symptomatic neurogenic compression from adipose tissue in the spinal canal. The question arises whether patients with morbid obesity have higher volumes of epidural adipose tissue (EAT) in their lumbar spinal canal compared with patients with a normal weight, and to what extent this decreases after bariatric surgery.

METHODS

In this explorative study the lumbar EAT volume was assessed in 25 patients with morbid obesity (body mass index [BMI] >40) using available lumbar magnetic resonance imaging (MRI) prior to their bariatric surgery. An age- and sex-matched control group (n = 25) of patients with a normal weight (BMI 20-25) was used for comparison. Participants from the obesity group underwent a postoperative control MRI.

RESULTS

The mean volume of EAT per MRI slice of the group of patients with obesity was significantly higher than for the group of patients with normal weight (mean: 83.3 ± 30.7 mm³ vs. mean 56.5 ± 25 mm³; P < 0.001). Fifteen participants with obesity (15 of 25) agreed to undergo a follow-up MRI. There was a significant decrease in EAT volume per MRI slice for these 15 participants (mean 82 ± 25.5 mm³ vs. 46 ± 20.0 mm³; P < 0.001) over time up to 3.6 (range: 1.2-6.0) years after bariatric surgery.

CONCLUSIONS

Patients with obesity have significantly larger volumes of EAT in comparison with patients with normal weight. After bariatric surgery, a significant weight loss coincided with a significant volumetric reduction of this adipose tissue in the spinal canal. Future prospective studies in patients with symptomatic SEL may elucidate whether decreases in EAT volume influence concurrent neurogenic claudication symptoms.

Spinal Epidural Lipomatosis: A Comprehensive Review

Purpose of review

This is a comprehensive review regarding the epidemiology, diagnosis, and management of spinal epidural lipomatosis (SEL).

Recent Findings

SEL is a relatively rare condition that has gained scientific relevance over the past few decades. Recent findings include expanding treatment strategies to include minimally invasive surgical techniques.

Summary

SEL is caused by an excess of adipose tissue accumulation localized to the thoracic and lumbar regions of the spine. While the exact pathogenesis is not fully elucidated, the etiology of SEL can be broadly classified based on five commonly associated risk factors; exogenous steroid use, obesity, endogenous steroid hormonal disease, spine surgery, and idiopathic disease. Progression of SEL may lead to neurological deficits, myelopathy, radiculopathy, neurogenic claudication, loss of sensation, difficulty voiding, lower extremity weakness, and rarely cauda equina syndrome. Conservative management is largely patient-specific and aimed at mitigating symptoms that arise from shared risk factors. If more advanced treatment measures are necessary, minimally invasive surgery and open surgical techniques, have proven successful.

MRI Features and Clinical Significance of Spinal Epidural Lipomatosis: All You Should Know

Spinal epidural lipomatosis (SEL) is defined as the abnormal accumulation of unencapsulated adipose tissue in the spinal epidural space. SEL can be asymptomatic or can cause a wide range of symptoms, the most common of which is neurogenic claudication. Several other neurological manifestations may also occur, above all myelopathy and radicular symptoms. The spinal level most frequently involved in patients with SEL is the lumbar one, followed by the thoracic one. Imaging plays a key role in disease assessment. MRI is considered the most effective and sensitive modality for diagnosing and staging SEL. Anyway, also CT scan can diagnose SEL. The diagnosis may be incidental (in mild-moderate disease) or may be taken into account in cases with neurological symptoms (in moderate-severe disease). There are some recognized risk factors for SEL, the most common of which are exogenous steroid use and obesity. Recent studies have found an association between SEL and obesity, hyperlipidemia and liver fat deposition. As a matter of fact, SEL can be considered the spinal hallmark of metabolic syndrome. Risk factors control represents the initial treatment strategy in patients with SEL (e.g. weight loss, steroid therapy suspension). Surgical decompression may be required when conservative treatment fails or when the patient develops acute/severe neurological symptoms.

Clinical Implications of the Epidural Fat Thickness in the Management of Lumbar Spinal Stenosis

OBJECTIVE

Lumbar epidural lipomatosis is a rare condition defined as the excessive accumulation of epidural fat (EF). We herein investigated the indicators of the posterior compression factors, EF and yellow ligament, to identify the clinical features of lumbar epidural lipomatosis.

METHODS

Five hundred consecutive patients who underwent posterior lumbar decompression surgery for lumbar spinal stenosis (LSS) were retrospectively reviewed. The EF/SC-L index (the ratio of the anteroposterior length of the EF to that of the spinal canal [SC]) was evaluated at the spinal level that exhibited maximum dural tube compression. The participants were divided into 3 groups: grade I, EF/SC-L index ≤50%; grade II, EF/SC-L index 51%-74%; grade III, EF/SC-L index ≥75%. EF/SC-A (the ratio of the cross-sectional area of EF to that of SC) and YL/SC-A (the ratio of the cross-sectional area of yellow ligament [YL] to that of SC) were calculated. The clinical outcomes were assessed according to the Japan Orthopaedic Association scale for lumbar disease.

RESULTS

EF/SC-L exhibited a significantly positive correlation with EF/SC-A (r = 0.82, P < 0.001), and a negative correlation with YL/SC-A (r = -0.71, P < 0.001). The Japan Orthopaedic Association score recovery rate was 56.7 ± 22.6 in the case-matched control group, 34.5 ± 31.2 in the grade II group (P < 0.001), and 39.6 ± 24.9 in the grade III group (P = 0.032).

CONCLUSIONS

The EF/SC-L index is a simple and reliable indicator to quantitatively evaluate posterior compression in patients with LSS. As the accumulation of EF is associated with worse operative outcomes, the EF/SC-L index should be considered when planning lumbar decompression surgery for patients with LSS.

Lumbar Spinal Canal Stenosis from the Perspective of Locomotive Syndrome and Metabolic Syndrome: A Narrative Review

Patients with lumbar spinal canal stenosis (LSS) have impaired activities of daily living because of pain or motor paralysis, but no effective preventive treatment is currently available. The number of patients with LSS is predicted to continually increase as the average age of the global population increases. To provide a conceptual framework for improving healthy life expectancy, the Japanese Orthopaedic Association introduced the concept of locomotive syndrome, to which LSS is related. Ours and other studies have shown that LSS exacerbates locomotive syndrome and that surgical treatment is one method for improving it. Furthermore, we propose that the two-step test, a locomotive syndrome risk test, is effective for assessing the risk for falls and severity of LSS. Meanwhile, lumbar spinal epidural lipomatosis (LSEL), which is a manifestation of LSS, has been shown to be related to metabolic syndrome. Previous studies have suggested that the whole LSS can be also associated with metabolic syndrome. Although locomotive syndrome is very different from metabolic syndrome, which involves lipid metabolism, these two syndromes overlap, such as in LSS. Conducting research on LSS from the perspectives of both locomotive syndrome and metabolic syndrome may lead to novel methods for prevention and treatment of LSS and, conversely, may yield clues for resolving symptoms of the two syndromes. This review provides an overview of LSS from the perspective of locomotive syndrome and metabolic syndrome, along with findings from our research group.

Two-year outcome comparison of decompression in 14 lipomatosis cases with 169 degenerative lumbar spinal stenosis cases: a Swiss prospective multicenter cohort study

PURPOSE

Spinal epidural lipomatosis (SEL) is defined as an abnormal and extensive accumulation of unencapsulated adipose tissue within the spinal epidural space. To date, there is a lack of high-level evidence studies reporting the outcome of surgical treatment of symptomatic SEL in patients with lumbar spinal stenosis (LSS). The aim was to compare clinical outcomes in patients with symptomatic LSS with and without SEL who underwent decompression surgery alone at the 12- and 24-month follow-up.

METHODS

One hundred and eighty-three patients met the inclusion criteria, of which 14 had mainly SEL on at least one level operated in addition to possible degenerative changes on other levels and 169 degenerative LSS only. The main outcomes were pain (Spinal Stenosis Measure (SSM) symptoms), disability (SSM function), and quality of life [EQ-5D-3L summary index (SI)] at 24-month follow-up, and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and EQ-5D-3L SI.

RESULTS

The multiple regression linear models showed that SEL was associated with worse SSM symptoms (p = 0.045) and EQ-5D-3L SI scores (p = 0.026) at 24-month follow-up, but not with worse SSM function scores. Further, depression (in all models) was negatively associated with better clinical outcomes at 24-month follow-up. In the outcomes SSM symptoms and EQ-5D-3L SI, distinctly more patients in the classical LSS group reached MCID than in the SEL group (71.3% and 62.3% vs. 50.0% and 42.9%).

CONCLUSIONS

Our study demonstrated that decompression alone surgery was associated with significant improvement in disability in both groups at 2 years, but not in pain and quality of life in patients with SEL.

An investigation and validation of CT scan in detection of spinal epidural adipose tissue

To investigate the accuracy of computed tomography (CT) in evaluating spinal epidural adipose tissue compared to magnetic resonance imaging (MRI).CT scan images and matched magnetic resonance images of total 368 patients between July 2014 and July 2016 were evaluated. Hounsfield units (HU) of epidural fat (EF), dural sac (DuS), ligamentum flavum, bone of facet joints, and paraspinal muscles were measured for comparison. Anteroposterior diameter of the EF, anteroposterior diameter of the DuS, transverse diameter of the DuS, cross-sectional area of the EF, and cross-sectional area of the DuS were measured at each disc level from L1-2 to L5-S1.Fat tissue showed exclusive negative HU significantly different from all other periphery tissues. Pearson correlation coefficient analyses showed significant positive correlations between CT and MRI measurements; Bland-Altman plots also depicted satisfied agreement. Overgrowth of spinal EF was more commonly found at L2-3 and L3-4 levels in present study, and body weight, age, and gender were significantly associated with amounts of EF both on CT and MRI.The CT scan is a satisfied alternative of MRI for the evaluation of spinal epidural adipose tissue.

Negative impact of spinal epidural lipomatosis on the surgical outcome of posterior lumbar spinous-splitting decompression surgery: a multicenter retrospective study

BACKGROUND CONTEXT

Spinal epidural lipomatosis (SEL) results from excess lumbar epidural fat (EF) accumulation that compresses the cauda equina or nerve roots. Guidelines for the therapeutic management of SEL are not currently available.

PURPOSE

To elucidate the efficacy of lumbar decompression surgery in SEL.

STUDY DESIGN

Multicenter retrospective study.

PATIENT SAMPLE

A total of 288 consecutive patients who underwent posterior lumbar spinous-splitting decompression surgery for lumbar spinal canal stenosis and followed up greater than 2 years at participating institutions were retrospectively reviewed.

OUTCOME MEASURES

Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Roland-Morris Disability Questionnaire (RDQ).

METHODS

Participants were divided into two groups according to the ratio of EF to anteroposterior diameter of the spinal canal (EF/SC-L) at the spinal level with maximum dural tube compression. Patients with EF/SC-L of ≥0.6 and <0.6 were defined as those with SEL and non-SEL, respectively. We assessed whether surgical treatment was "effective" or "not effective" using the JOABPEQ based on the following: an increase of ≥20 points in the postoperative score compared with the preoperative score, or a preoperative score <90 with a postoperative score ≥90 points. We constructed a multiple Poisson regression model by adjusting for confounding factors, and determined estimated relative risk (RR) for "not effective" with surgical treatment using the JOABPEQ. Additionally, we selected age-, sex-, BMI-, and decompression levels-matched patients with non-SEL and compared the frequency of "not effective" between SEL patients (n=60) and non-SEL patients (n=60).

RESULTS

Analysis using the RDQ and JOABPEQ showed that the 1- and 2-year postoperative scores were significantly better than the preoperative scores in the both groups. Multivariable Poisson regression analysis demonstrated that SEL was significantly associated with "not effective" for decompression surgery in the 1-year postoperative outcomes of walking ability ([RR] 1.5, 95% confidence interval [CI] 1.0-2.2) and social life (RR 1.3, 95% CI 1.0-1.8) and the 2-year postoperative outcomes of walking ability (RR 1.6, 95% CI 1.2-2.3). Matching analysis showed that SEL was significantly associated with "not effective" with lumbar decompression surgery in the 2-year postoperative outcomes of walking ability (p=.02).

CONCLUSIONS

Patients with SEL exhibited significant improvements in surgical outcomes at 1 and 2 years postoperatively. However, compared with the non-SEL group, the efficacy of posterior lumbar spinous-splitting decompression surgery was worse in the SEL group, especially for walking ability. These results indicate that EF accumulation should be considered when planning treatment for patients with lumbar spinal canal stenosis and estimating the efficacy of lumbar decompression surgery.

Spinal epidural lipomatosis is associated with liver fat deposition and dysfunction

OBJECTIVE

This study examined the association of spinal epidural lipomatosis (SEL) with liver fat deposition and any other liver dysfunction, except steroid involvement.

PATIENTS AND METHODS

We analyzed 102 patients (62 men and 40 women; mean age 73.3 years) who underwent spinal magnetic resonance imaging (MRI), computed tomography (CT), and myelography for the diagnosis of lumbar spinal canal stenosis between January 2014 and June 2018. Additional data collected included height, weight, body mass index, blood test results (C-reactive protein, albumin, total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase [γ-GTP], total cholesterol, neutral fat, amylase, urea nitrogen, creatinine, estimated glomerular filtration rate, uric acid, platelets), the epidural fat-occupying ratio in each vertebra from L1/2 to L5/S1 on MRI, and liver CT values.

RESULTS

In 30 cases, the average occupying ratio of epidural fat was ≥40% (SEL), and in 45 cases, liver CT values were <40 HU (fatty liver). Correlation analysis between average occupying ratio of epidural fat and various measurements showed liver CT value (r = -0.574, P <  0.001), body weight (r = 0.304, P =  0.002), γ-GTP (r = 0.370, P =  0.01), and uric acid (r = 0.201, P =  0.04) to be independent explanatory factors. Multivariate analysis revealed that SEL was associated with liver CT value (odds ratio 0.774, 95% confidence interval [CI] 0.689-0.871) and body weight (odds ratio 1.063, 95% CI 1.016-1.135).

CONCLUSION

There was a strong correlation between epidural fat and liver fat deposits suggesting an association between SEL and systemic fat deposition.

A Novel Percutaneous Biportal Endoscopic Technique for Symptomatic Spinal Epidural Lipomatosis: Technical Note and Case Presentations

OBJECTIVE

To describe a minimally invasive decompression technique for symptomatic spinal epidural lipomatosis using percutaneous biportal endoscopic surgery.

METHODS

In this report, we describe the indirect decompressive effect that was gained by partial laminotomy and ligamentum flavectomy under biportal endoscopic view. Direct neural decompression was then performed by removal of proliferated fat. We described the technical process and compared pre- and postoperative radiating leg pain, life quality, and a radiologic grading system of neural compression.

RESULTS

This technique was performed successfully in 3 patients with idiopathic spinal epidural lipomatosis. Radiating pain was reduced, and functional disability and radiologic compression were improved. Postoperative instability and surgical complications related to the procedure were not observed.

CONCLUSIONS

Percutaneous spinal endoscopy is a minimally invasive muscle-preserving technique for spinal lipomatosis that achieves neural decompression directly by lipoma removal and indirectly by partial bone and ligament removal.

Spinal epidural lipomatosis is a previously unrecognized manifestation of metabolic syndrome

BACKGROUND CONTEXT

Spinal epidural lipomatosis (SEL) is a condition in which excess lumbar epidural fat (EF) deposition often leads to compression of the cauda equina or nerve root. Although SEL is often observed in obese adults, no systematic research investigating the potential association between SEL and metabolic syndrome has been conducted.

PURPOSE

To elucidate potential association between SEL and metabolic syndrome.

STUDY DESIGN

An observational study used data of a medical checkup.

PATIENT SAMPLE

We retrospectively reviewed data from consecutive subjects undergoing medical checkups. A total of 324 subjects (174 men and 150 women) were enrolled in this study.

OUTCOME MEASURES

The correlation of EF accumulation with demographic data and metabolic-related factors was evaluated.

METHODS

The degree of EF accumulation was evaluated based on the axial views of lumbar magnetic resonance imaging. Visceral and subcutaneous fat areas were measured at the navel level using abdominal computed tomography. Metabolic syndrome was diagnosed according to the criteria of the Japanese Society of Internal Medicine. The correlation of SEL with metabolic syndrome and metabolic-related conditions was statistically evaluated.

RESULTS

The degree of EF accumulation demonstrated a significant correlation to body mass index, abdominal circumference, and visceral fat area. However, age, body fat percentage, and subcutaneous fat area showed no correlation with the degree of EF accumulation. Logistic regression analysis revealed that metabolic syndrome (odds ratio [OR]=3.8, 95% confidence interval [CI]=1.5-9.6) was significantly associated with SEL. Among the diagnostic criteria for metabolic syndrome, visceral fat area ≥100 cm² (OR=4.8, 95% CI=1.5-15.3) and hypertension (OR=3.5, 95% CI=1.1-11.8) were observed to be independently associated with SEL.

CONCLUSION

This is the first study to demonstrate that metabolic syndrome is associated with SEL in a relatively large, unbiased population. Our data suggest that metabolic-related conditions are potentially related to EF deposition and that SEL could be a previously unrecognized manifestation of metabolic syndrome.

Rapid Development of Spinal Epidural Lipomatosis after Treatment of Metastatic Castration-Resistant Prostate Cancer with Second-Generation Androgen Receptor Antagonists

BACKGROUND

Previous studies have described the association of spinal epidural lipomatosis with several conditions including chronic steroid therapy, Cushing's syndrome, obesity, Paget disease, and hypothyroidism. We present a report of rapid development of spinal epidural lipomatosis after treatment with second-generation anti-androgen therapy, a new strategy for treatment of metastatic castration-resistant prostate cancer that has been increasingly employed in the past few years. A comprehensive discussion of the underlying molecular networks involving androgen receptor blockage and adipocyte differentiation, as well as the clinical implications of such a phenomenon, are provided.

CASE DESCRIPTION

We describe the clinical and radiological evolution of a 58-year-old male patient with metastatic prostate cancer, who developed new onset of rapidly progressing lumbosacral epidural lipomatosis with significant compression of the nerve roots of the cauda equina a few months after initiation of treatment with second-generation androgen receptor antagonists.

CONCLUSIONS

The underlying pathophysiology of adipose tissue growth following the administration of anti-androgen therapy is discussed, with emphasis on both the canonical Wnt/β-catenin pathway as well as in the Wnt-independent pathway involving direct activation of downstream transcription factors from the T-cell factor family by the androgen receptor. As second-generation androgen receptor antagonists have been increasingly used for treatment of castration-resistant stage metastatic prostate cancer, new onset of symptomatic epidural lipomatosis should be considered as a possible differential diagnosis, especially because the urinary symptoms of cauda equina compression may be improperly attributed to the primary prostate neoplasm.

Idiopathic Spinal Epidural Fat Accumulation Is Associated With Hyperlipidemia

STUDY DESIGN

Single-center retrospective analysis of consecutively collected data.

OBJECTIVE

To determine the clinical characteristics of idiopathic spinal epidural lipomatosis (SEL).

SUMMARY OF BACKGROUND DATA

SEL is associated with the overt accumulation of nonencapsulated adipose tissue in the epidural space, leading to spinal cord or nerve root compression. The etiology of this condition is currently not completely understood.

METHODS

Data of 166 male patients who underwent primary surgery for lumbar spinal canal stenosis (LSS) from May 2013 to February 2016 were retrospectively reviewed. Participants were divided into three groups based on the degree of epidural lipomatous lesion. Patient data of age at surgery, body mass index, prevalence of common noncommunicable diseases, blood tests, arteriosclerotic index, and preoperative clinical scores (assessed using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire) were evaluated. Multivariate analysis was performed to assess the potential associated factors for idiopathic SEL.

RESULTS

Patients with LSS with severe SEL had a significantly higher body mass index and elevated serum levels of total cholesterol and triglyceride compared with those without SEL. Analysis of preoperative clinical scores revealed that patients with SEL experienced pain more frequently and showed less walking ability than did those without SEL. Multivariate analysis revealed that hyperlipidemia was significantly associated with idiopathic SEL (odds ratio = 3.74, 95% confidence interval = 1.31-10.64).

CONCLUSION

Our data suggest that aberrant lipid metabolism is related to the pathogenesis of idiopathic SEL and that patients with LSS with idiopathic SEL have more severe pain than do those without SEL.

LEVEL OF EVIDENCE

3.

Clinical and imaging characteristics in patients undergoing surgery for lumbar epidural lipomatosis

BACKGROUND

Lumbar epidural lipomatosis (LEL) is characterized by abnormal accumulation of unencapsulated adipose tissue in the spinal epidural space. Such accumulation compresses the dural sac and nerve roots, and results in various neurological findings. However, the pathophysiology of LEL remains unclear. This study examined the associations between imaging and clinical findings in detail, and investigated the mechanisms underlying symptom onset by measuring intraoperative epidural pressures in LEL.

METHODS

Sixteen patients (all men; mean age, 68.8 years) were enrolled between 2011 and 2015. Mean body mass index was 26.5 kg/m2. Four cases were steroid-induced, and the remaining 12 cases were idiopathic. All patients presented with neurological deficits in the lower extremities. Cauda equina syndrome (CES) alone was seen in 8 patients, radiculopathy alone in 4, and both radiculopathy and CES (mixed CES) in 4. All patients subsequently underwent laminectomy with epidural lipomatosis resection and were followed-up for more than 1 year. We investigated the clinical course and imaging and measured epidural pressures during surgery.

RESULTS

Subjective symptoms improved within 1 week after surgery. Mean Japanese Orthopaedic Association (JOA) score was 15.2 ± 2.8 before surgery, improving to 25.4 ± 2.5 at 1 year after surgery. On magnetic resonance imaging, all lipomatosis lesions included the L4-5 level. On preoperative computed tomography, saucerization of the laminae was not observed in radiculopathy cases, whereas saucerization of the posterior vertebral body was observed in all radiculopathy or mixed CES cases. Intraoperative epidural pressures were significantly higher than preoperative subarachnoid pressures. The results suggest that high epidural pressure resulting from the proliferation of adipose tissue leads to saucerization of the lumbar spine and subsequent symptoms.

CONCLUSIONS

Clinical courses were satisfactory after laminectomy. In LEL, epidural pressure increases and symptoms develop through the abnormal proliferation of adipose tissue. Higher epidural pressures induce saucerization of the laminae and/or posterior vertebral body. Furthermore, the direction of proliferative adipose tissue (i.e., site of saucerization) might be related to the types of neurological symptoms.

Patient-reported outcome of surgical treatment for lumbar spinal epidural lipomatosis

BACKGROUND CONTEXT

Spinal epidural lipomatosis (SEL) is a rare condition characterized by an excessive accumulation of fat tissue in the spinal canal that can have a compressive effect, leading to clinical symptoms. This condition has a distinct pathology from spinal stenosis associated with degeneration of the intervertebral discs, ligaments, and facet joints. Several different conservative and surgical treatment strategies have been proposed for SEL, but its treatment remains controversial. There is a lack of evidence documenting the success of surgical decompression in SEL, and no previous studies have reported the postoperative outcome from the patient's perspective.

PURPOSE

The aim of the present study was to evaluate patient-rated outcome after surgical decompression in SEL.

STUDY DESIGN

A retrospective analysis of prospectively collected data was carried out.

PATIENT SAMPLE

A total of 22 patients (19 males; age: 68.2±9.9 years) who had undergone spine surgery for SEL were identified from our local Spine Surgery Outcomes Database, which includes a total of 10,028 spine surgeries recorded between 2005 and 2012. Inclusion criteria were epidural lipomatosis confirmed by preoperative magnetic resonance imaging (MRI) scans and subsequent decompression surgery without spinal fusion.

OUTCOME MEASURES

The Core Outcome Measures Index (COMI) was used to assess patient-rated outcome. The COMI includes the domains pain (separate 0-10 scales for back and leg pain), back-specific function, symptom-specific well-being, general quality of life (QOL), work disability, and social disability.

METHODS

The questionnaires were completed preoperatively and at 3, 12, and 24 months postoperatively. Surgical data were retrieved from the patient charts and from our local Spine Surgery Outcomes Database, which we operate in connection with the International Spine Tango Registry. Differences between pre- and postoperative scores were analyzed using paired t tests and repeated measures analysis of variance.

RESULTS

At 3-months follow-up, the COMI score and scores for leg pain and back pain had improved significantly compared with their preoperative values (p<.005). The mean decrease in COMI score after 3 months was 2.6±2.4 (range: -1.3 to 6.5) points: from 7.5±1.7 (range: 3.5-10) to 4.9±2.5 (range: 0.5-9.6). A total of 11 patients (50%) had an improvement of the COMI of more than the minimal clinically important change (MCIC) score of 2.2 points. The mean decrease in leg pain after 3 months was 2.4±3.5 (-5 to 10) points. Overall, 17 patients (77.3%) reported a reduced leg pain, 12 (54.6%) of whom by at least the MCIC score of 2 points. The significant reductions from baseline in COMI and leg and back pain scores were retained up to 2 years postoperatively (p<.02). The general QOL item of the COMI improved significantly after surgery (p<.0001). Over 80% of the cohort rated their preoperative QOL as bad (n=13) or very bad (n=5), whereas 3 months after surgery, only 7 patients rated their QOL as bad, and one as very bad (36%).

CONCLUSIONS

The present study is the first to demonstrate that surgical decompression is associated with a statistically significant improvement in patient-rated outcome scores in patients with symptomatic SEL, with a clinically relevant change occurring in approximately half of them. Surgical decompression hence represents a reasonable treatment option for SEL, although the reason behind the less good response in some patients needs further investigation.

Idiopathic Spinal Epidural Lipomatosis in the Lumbar Spine

Overgrowth of epidural fat, known as spinal epidural lipomatosis (SEL), can cause symptomatic compression of the spinal cord, conus medullaris, or cauda equina. Suggested predisposing factors such as obesity, steroid use, and diabetes mellitus have been based on a few reported cases, many of which were not surgically confirmed. There is a paucity of epidemiological data in surgically confirmed cases for this disorder. The purpose of this independently reviewed, retrospective, matched cohort analysis was to compare the demographics and incidence of comorbidities of patients who underwent lumbar decompression for SEL vs degenerative stenosis without SEL. Two surgeons' databases were reviewed to identify patients older than 18 years who underwent decompression surgery for magnetic resonance imaging-verified, symptomatic lumbar SEL. A matched control group comprised an equal number of patients with degenerative stenosis (n=14). Demographic data, body mass index, symptom type/duration, comorbidities, complications, treatment history, and associated pathology were collected from medical records. Previously suggested risk factors, such as obesity, endocrinopathy, and epidural steroid injections, were not significantly different between the SEL and control groups. Furthermore, there were no differences in operative times, complications, or blood loss. The only noted difference between the 2 groups was the preoperative duration of symptoms, on average double in patients with SEL. This series represents the largest of its kind reported to date. Because symptom duration was the only difference noted, it is postulated to be the result of lack of awareness of SEL. Future prospective study in a larger group of patients is warranted. [Orthopedics. 2016; 39(3):163-168.].

Radiculopathy in the setting of lumbar nerve root compression due to an extradural intraforaminal lipoma: a report of 3 cases

A true adult spinal lipoma is an exceedingly rare cause of lumbar compression neuropathy. Only 5 cases of true extradural intraforaminal lipomas have been documented in the medical literature. The diagnostic criteria and treatment guidelines for this specific lipoma have yet to be established. This report features 3 histologically confirmed cases of extradural intraforaminal spinal lipomas that recently presented to the authors’ practice. In addition, the literature was surveyed to include the 5 previously reported cases of true adult extradural intraforaminal spinal lipomas. The consistency in presentation, response to surgical intervention, and postoperative recovery in these 8 cases supports surgical intervention at the time of diagnosis. The authors’ findings support elevated clinical suspicion, efficient diagnosis based on MRI, and early surgical intervention for this rare pathological entity. All cases presented in this report were symptomatic and occurred in the absence of other significant pathologies such as general spinal epidural lipomatosis, intradural lesions, tethering, or severe degenerative stenosis or herniated discs. The clinical, neuroradiological, and histological findings characteristic of a true adult extradural intraforaminal lipoma are emphasized to differentiate this lesion from the more common etiologies for lumbar compression neuropathy. Heightened awareness and clinical suspicion for the focal, foraminal spinal lipoma as a cause of radiculopathy symptoms will enable more efficient diagnosis and treatment.

Unusual presentation of spinal lipomatosis

Spinal epidural lipomatosis (SEL) is a rare condition characterized by overgrowth of normal adipose tissue in the extradural space within the spinal canal that can lead to significant spinal cord compression. It is most commonly reported in patients receiving chronic glucocorticoid therapy. Other causes can include obesity and hypercortisolism. Occasionally, idiopathic SEL will occur in patients with no known risk factors, but cases are more generally reported in obesity and males. We present the case of a 35 year-old non-obese woman found to have rapidly progressive SEL that was not associated with any of the common causes of the disorder.

Consensus conference on core radiological parameters to describe lumbar stenosis - an initiative for structured reporting

PURPOSE

To define radiological criteria and parameters as a minimum standard in a structured radiological report for patients with lumbar spinal stenosis (LSS) and to identify criteria and parameters for research purposes.

MATERIAL AND METHODS

All available radiological criteria and parameters for LSS were identified using systematic literature reviews and a Delphi survey. We invited to the consensus meeting, and provided data, to 15 internationally renowned experts from different countries. During the meeting, these experts reached consensus in a structured and systematic discussion about a core list of radiological criteria and parameters for standard reporting.

RESULTS

We identified a total of 27 radiological criteria and parameters for LSS. During the meeting, the experts identified five of these as core items for a structured report. For central stenosis, these were "compromise of the central zone" and "relation between fluid and cauda equina". For lateral stenosis, the group agreed that "nerve root compression in the lateral recess" was a core item. For foraminal stenosis, we included "nerve root impingement" and "compromise of the foraminal zone".

CONCLUSION

As a minimum standard, five radiological criteria should be used in a structured radiological report in LSS. Other parameters are well suited for research.

KEY POINTS

The five most important radiological criteria for standard clinical reporting were selected. The five most important quantitative radiological parameters for research purposes were selected. These core criteria could help standardize the communication between health care providers.

A systematic review of semiquantitative and qualitative radiologic criteria for the diagnosis of lumbar spinal stenosis

OBJECTIVE

The objective of our study was to perform a systematic review of the semiquantitative and qualitative radiologic criteria that are used for the diagnosis of lumbar spinal stenosis (LSS).

MATERIALS AND METHODS

A four-step systematic literature search including the MEDLINE database was performed by an experienced librarian to reveal all semiquantitative or qualitative radiologic criteria used for the diagnosis of LSS. The precise definitions of all criteria, normal or abnormal values (if applicable), and intra- and interrater reliability were noted by two independent readers. Descriptive statistics were used.

RESULTS

A total of 14 semiquantitative or qualitative radiologic parameters were identified and distinguished according to relevant anatomic spaces into criteria for central canal stenosis, lateral (recess) stenosis, and foraminal stenosis. Great variability in terms of the exact definitions of the criteria was found. For 10 of the 14 criteria, the intra- and interrater reliability data were found with kappa values ranging from 0.01 to 1.0.

CONCLUSION

Our systematic literature review identified 14 different semiquantitative or qualitative radiologic criteria that are used for the diagnosis of LSS; however, these criteria show remarkable variability in terms of their exact individual definitions and intra- and interrater reliability.

Spinal subdural hematoma mimicking epidural lipomatosis

We report a case of spinal subdural hematoma in the lumbar spine of a 75-year-old woman. Magnetic resonance imaging showed lesions of homogeneous high intensity in the spinal canal on both T₁- and T₂-weighted images, findings closely resembling those for epidural lipomatosis. Identification of 2-layered signal intensity surrounding the cauda equina on axial images is the key for accurate diagnosis.

Idiopathic thoracic epidural lipomatosis with chest pain

Spinal epidural lipomatosis (SEL) is an overgrowth of the normally encapsulated adipose tissue in the epidural space around the spinal cord in the thoracic and lumbar spine causing compression of the neural components. Idiopathic SEL in non-obese patients is exceptional. Idiopathic SEL can result in thoracic myelopathy and lumbar radiculopathy. A thoracic radiculopathy due to idiopathic SEL has not been reported yet. We report a case of idiopathic SEL with intractable chest pain and paresthesia. We suggest that idiopathic SEL should be considered as a cause of chest pain.

Spinal cord stimulation in a patient with spinal epidural lipomatosis

BACKGROUND AND OBJECTIVE

Spinal cord stimulation is the most commonly used implantable neurostimulation modality for management of pain syndromes. For treatment of lower extremity pain, the spinal cord stimulator lead is typically placed in the thoracic epidural space, at the T10-T12 levels. Typically, satisfactory stimulation can be obtained relatively easily. Anatomical variability in the epidural space, such as epidural scarring, has been reported to prevent successful implantation of spinal cord stimulators. Spinal epidural lipomatosis describes an abnormal overgrowth of adipose tissue in the extradural space. Cases have documented spinal epidural lipomatosis complicating intrathecal baclofen pump implantation or causing repeated failure of epidural analgesia. However, so far, there is no published literature describing how spinal epidural lipomatosis affects spinal cord stimulation.

CASE REPORT

We report a case of spinal cord stimulation in a patient with spinal epidural lipomatosis. Very high impedance was encountered during the trial spinal cord stimulator lead placement. Satisfactory stimulation was only obtained after repeated repositioning of the spinal cord stimulator trial lead. Post-procedure thoracic spine magnetic resonance imaging revealed marked thoracic epidural lipomatosis. At the level where satisfactory stimulation was obtained, the thickness of the epidural fat was within normal limits. The patient eventually underwent placement of a laminotomy lead with good coverage and pain relief.

CONCLUSION

Spinal epidural lipomatosis significantly increases the impedance in the epidural space, making effective neurostimulation very difficult to obtain. Physicians should consider the possibility of spinal epidural lipomatosis when very high impedances are encountered during lead placement.

Sudden paraplegia following epidural lipomatosis and thoracal compression fracture after long-term steroid therapy: a case report

Sudden paraplegia secondary to the posterior spinal epidural compression and vertebral compression fracture as a complication in corticosteroid treatment is extremely rare. The authors presented a case 49-year-old man with chronic relapsing attack of Still's disease. After the identification of pathology, the surgical evacuation of lipid tissue and pedicle-based instrumentation showed therapeutic success. To the authors' knowledge, this is the first case showing both vertebral fracture and paraplegia that required urgent surgery in the follow-up Still's disease.

Lumbar nerve root compression due to extradural, intraforaminal lipoma. An underdiagnosed entity?

Intraspinal extradural lipomas, not associated with spinal dysraphism, are rare lesions. True adult lipomas have to be distinguished from angiolipomas and from epidural lipomatosis. The authors report a unique case of a patient with unilateral lumbar nerve root compression caused by extradural, intraforaminal, true adult lipoma. A 62-year-old woman suffered severe left L-5 radiculopathy that progressively worsened during the 12 months prior to presentation. She did not experience improvement with conservative therapy. An MR imaging study of the lumbar spine revealed shifting of the left L-5 nerve root caused by a small extradural intrarecessal (that is, the beginning of the intravertebral foramen)/intraforaminal mass with MR imaging characteristics of fatty tissue. No other relevant intraspinal pathology could be identified. A left L4-5 fenestration was carried out. A small fatty intrarecessal/intraforaminal mass compressing severely the left L-5 root was identified and completely resected. The histological examination revealed a lipoma. The patient recovered completely and is fully mobile and symptom free 1 year after the operation. Intraspinal lipomas should be considered in cases of radiculopathy, especially in the absence of relevant degenerative or tumorous pathology and in the presence of nerve root shifting caused by fatty tissue.

Decompression of idiopathic symptomatic epidural lipomatosis of the lumbar spine

Epidural lipomatosis has been implicated as a cause or contributor of symptomatic lumbar spinal stenosis. Symptomatic spinal epidural lipomatosis (SEL) of the lumbar spine is a rare disease, often associated with steroid overload. Idiopathic lipomatosis is even much less frequent. Signs and symptoms depend upon the level and degree of nerve root compression. Diagnosis is best based on MRI. Weight reduction can be curative, however, after failure of medical treatment or in severe cases surgical decompression should be performed. A 70-year-old man with both lower limb severe paresthesia and radicular symptoms unrelieved with conservative treatments such as medications and physical therapy was treated by surgical decompression. Obesity, endocrinopathic disease, and chronic steroid therapy were excluded. Interlaminar fenestration, lateral recess decompression and fat debulking were applied at all levels through the L2-S1. After surgery there was a gradual improvement in symptoms. We report a rare case of idiopathic SEL which has shown entire evolvement of lumbar spine with specific increase of radiological and clinical severity from L2-3 to L5-S1 in a non-obese patient.

Idiopathic spinal epidural lipomatosis: urgent decompression in an atypical case

Symptomatic spinal epidural lipomatosis (SEL) is very rare and frequently associated to chronic exogenous steroid use, obesity and Cushing syndrome. The idiopathic cases where no identifiable association with SEL are found constitute only 17% of all cases. The usual clinical manifestations of this entity consist of dorsal or lumbar pain with paresthesias and weakness in lower limbs, but acute symptoms of myelopathy are exceptional. We report a case of acute paraparesis and urinary retention caused by thoracic SEL in a 55-year-old male who did not have any recognized predisposing factor for this condition. Urgent surgical decompression was performed in order to relieve the symptoms. Slow but progressive improvement was assessed after surgery. We consider this case to be exceptional due to the needing to perform an urgent decompressive laminectomy to treat a rapidly progressive myelopathy caused by idiopathic SEL.