Spinal epidural lipomatosis: case reports, literature review and meta-analysis

Incomplete sensorimotor paresis after upper abdominal surgery with TEA and spinal epidural lipomatosis: a case report

INTRODUCTION

This case report documents a postoperative, incomplete sensorimotor paraparesis from thoracic vertebral body 6 (Th6) after combined anesthesia for upper abdominal surgery in a patient who had a thoracic localization of spinal epidural lipomatosis (SEL).

CASE PRESENTATION

The patient was treated in our clinic with a thoracic epidural catheter (TEA) for perioperative analgesia during a partial duodenopancreatectomy. Paraparetic symptoms occurred 20 hours after surgery. Initial MRI did not show bleeding, infection or spinal cord damage and the neurosurgeon consultants recommended observation. The neurological examination and the third follow-up MRI on 15th postoperative day showed ventrolateral damage of the spinal cord at level Th6. It is possible that local anesthetic compressed the spinal cord in addition to the existing lipomatosis and the thoracic kyphosis. The paraparesis improved during follow-up paraplegiologic treatment.

CONCLUSION

So far, only two uncomplicated lumbar epidural catheter anesthesias have been described in patients who had a lumbar SEL. Epidural catheter anesthesia is a safe and effective method of pain control. But it is important to carefully identify and stratify patients with risk factors during the premedication visit. In patients who had kyphosis and thoracic localization of SEL, TEA may only be used after a risk-benefit assessment.

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.

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.

Role of epidural fat in the local milieu: what we know and what we don't

PURPOSE

Traditionally, the epidural fat (EF) is known as a physical buffer for the dural sac against the force and a lubricant facilitating the relative motion of the latter on the osseous spine. Along with the development of the studies on EF, controversies still exist on vital questions, such as the underlying mechanism of the spinal epidural lipomatosis. Meanwhile, the scattered and fragmented researches hinder the global insight into the seemingly dispensable tissue.

METHODS

Herein, we reviewed literature on the EF and its derivatives to elucidate the dynamic change and complex function of EF in the local milieu, especially at the pathophysiological conditions. We start with an introduction to EF and the current pathogenic landscape, emphasizing the interlink between the EF and adjacent structures. We generally categorize the major pathological changes of the EF into hypertrophy, atrophy, and inflammation.

RESULTS AND CONCLUSIONS

It is acknowledged that not only the EF (or its cellular components) may be influenced by various endogenic/exogenic and focal/systematic stimuli, but the adjacent structures can also in turn be affected by the EF, which may be a hidden pathogenic clue for specific spinal disease. Meanwhile, the unrevealed sections, which are also the directions the future research, are proposed according to the objective result and rational inference. Further effort should be taken to reveal the underlying mechanism and develop novel therapeutic pathways for the relevant diseases.

Transthyretin amyloid deposition in ligamentum flavum (LF) is significantly correlated with LF and epidural fat hypertrophy in patients with lumbar spinal stenosis

Lumbar spinal stenosis (LSS) is a degenerative disease characterized by intermittent claudication and numbness in the lower extremities. These symptoms are caused by the compression of nerve tissue in the lumbar spinal canal. Ligamentum flavum (LF) hypertrophy and spinal epidural lipomatosis in the spinal canal are known to contribute to stenosis of the spinal canal: however, detailed mechanisms underlying LSS are still not fully understood. Here, we show that surgically harvested LFs from LSS patients exhibited significantly increased thickness when transthyretin (TTR), the protein responsible for amyloidosis, was deposited in LFs, compared to those without TTR deposition. Multiple regression analysis, which considered age and BMI, revealed a significant association between LF hypertrophy and TTR deposition in LFs. Moreover, TTR deposition in LF was also significantly correlated with epidural fat (EF) thickness based on multiple regression analyses. Mesenchymal cell differentiation into adipocytes was significantly stimulated by TTR in vitro. These results suggest that TTR deposition in LFs is significantly associated with increased LF hypertrophy and EF thickness, and that TTR promotes adipogenesis of mesenchymal cells. Therapeutic agents to prevent TTR deposition in tissues are currently available or under development, and targeting TTR could be a potential therapeutic approach to inhibit LSS development and progression.

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.

Postpartum Spinal Epidural Lipomatosis With Epidural Venous Engorgement

Spinal epidural lipomatosis (SEL) refers to a condition characterized by the abnormal growth of fatty tissue within the vertebral canal, situated outside the spinal canal itself. This expansion of fat can result in symptoms such as back pain and radiculopathy. The majority of cases remain without noticeable symptoms. However, when SEL does cause symptoms, it is frequently linked to using external steroids. The contributing factors to SEL include obesity and Cushing's syndrome. The presentation of SEL can mimic other spinal disorders such as epidural hematoma, spinal stenosis, and degenerative joint disease. Patients might present with gradually progressing and long-standing complaints of back pain, muscle weakness, numbness, loss of bladder or bowel control, lack of coordination, abnormal reflexes, and, in rare instances, paralysis. We are reporting a case involving a 34-year-old female with obesity, who experienced sudden weakness in her left lower extremity shortly after a recent uncomplicated vaginal delivery using epidural analgesia. A magnetic resonance imaging (MRI) of her thoracic (T) and lumbar spine revealed spinal cord compression secondary to extensive posterior epidural lipomatosis associated with epidural venous engorgement. The patient underwent an immediate laminectomy procedure at the T3, T5, T7, and T9 levels to alleviate the compression. Postoperatively, she underwent a course of physiotherapy and gradually regained her normal muscle strength. She was discharged in stable condition on the sixth day after the surgery.

A case of spinal epidural lipomatosis presenting as a stroke mimic

Here we present the case of a patient with right upper extremity and right lower extremity weakness of a three-day duration, which triggered a stroke evaluation. Ultimately, the diagnosis of spinal epidural lipomatosis (SEL) was made. Non-stroke diagnoses that present with stroke-like symptoms are referred to in the medical literature as stroke mimics. Such cases present with neurological deficits that imitate acute ischemic stroke. The frequency of such presentations occurs in up to 30% of initially suspected stroke. This case illustrates that SEL can present as a stroke mimic. To our knowledge, this is the first description of a presentation in the medical literature of SEL as a stroke mimic.

Correlation of spinal epidural fat volume with body mass index: a longitudinal study

PURPOSE

Spinal epidural lipomatosis is abnormal accumulation of normal fat in the epidural space with weight loss suggested as first-line therapy in select symptomatic patients. However, moderate to large longitudinal studies establishing concordant changes between body mass index and epidural fat are lacking. The purpose of this study was to longitudinally assess this relationship.

METHODS

We performed an ancillary study of the Habitual Diet and Avocado Trial. Baseline and six-month abdominal MRIs were analyzed for 98 overweight or obese but otherwise healthy subjects. Dorsal epidural fat volumes in the lumbar spine were measured and correlated with changes in body mass index, changes in visceral fat volume, and demographic information.

RESULTS

There was a linear relationship between body mass index changes and epidural fat volume changes with a one-point change in body mass index corresponding to a 45 mm³ change in dorsal epidural fat volume (p < 0.001, 95% CI 31.87 to 76.77) as well as between visceral fat volume changes and epidural fat volume changes (regression coefficient 0.51, p < 0.001, 95% CI 0.22 to 0.47). Age was inversely related with subjects older than 45.7 years tending to lose epidural fat (regression coefficient -0.22, p = 0.025, 95% CI -10.43 to -0.72).

CONCLUSION

Changes in spinal dorsal epidural fat volume parallel changes in body mass index and visceral fat, supporting weight loss as initial treatment for uncomplicated obesity-associated spinal epidural lipomatosis.

The Mysterious Role of Epidural Fat Tissue in Spine Surgery: A Comprehensive Descriptive Literature Review

BACKGROUND

Though both neurosurgeons and orthopedic spinal surgeons are keenly aware of the clinical importance of epidural fat (EF), surgical practice varies amongst individual surgeons and across both fields. Thus, an in-depth understanding of the anatomical structure and composition of EF is vital, as it will play a significant role in the therapeutic management and the surgical choice of treatment.

OBJECTIVE

We aim to extensively review the anatomical and biological properties of EF and further outline the surgical importance of EF management.

STUDY METHODOLOGY

(i) MEDLINE search 1966-July 2019. Keywords: Review of the Literature. Authorship, Meta-analysis, Descriptive/Narrative overview; (ii) CINAHL search from 1982 to May 2019. Keywords: Review of the Literature spinal epidural fat; Authorship; Meta-analysis; Descriptive/Narrative overview; (iii) Hand searches of the references of retrieved literature; (iv) Personal and college libraries were searched for texts on research methods and literature reviews; and (v) 200 articles were downloaded, 50 were excluded because of similarity of topics and also because of new update on the same topics. (vi) Discussions with experts in the field of reviews of the literature.

DISCUSSION

Though excessive or reductive amounts of EF usually exacerbates neurological symptoms and lead to various pathologic conditions such as spinal epidural lipomatosis, but there is no basic science, experimental, or clinical research that proves the role of EF in the aforementioned pathologic situations.

CONCLUSION

Anatomical illustration, biological function and properties of EF knowledge may lead to changes in the stages of the surgical approach to avoid postoperative complications. However, the role of EF is exclusively bound to a scientific hypothesis as one cannot be sure if an excessive or reductive amount in EF is entirely responsible for the pathologic findings, or just only an incidental finding.

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.

Etiologies and Outcomes of Spinal Epidural Lipomatosis: Systematic Review of the Literature and Meta-Analysis of Reported Cases

STUDY DESIGN

This was a systematic review of the literature.

OBJECTIVE

The aim was to examine the contemporary demographics, etiological factors, treatment options and outcomes of spinal epidural lipomatosis (SEL) in adults.

SUMMARY OF BACKGROUND DATA

SEL is primarily seen in obese patients as well as those on steroid therapy. Much regarding the etiology and treatment outcomes of SEL is unknown.

METHODS

We reviewed Ovid MEDLINE, PubMed, SCOPUS, and Google Scholars databases from 1990 through August 2020 to identify cases of SEL. Data collected included patient characteristics, disease associations, level of pathology, treatment, and clinical outcomes.

RESULTS

Ninety articles (145 individual cases) were included in the analysis. The median age was 54 years and 79% were males. Obesity-associated SEL constituted the largest proportion (52%) of our cohort. 22% of SEL cases were related to steroid use, while 26% cases were considered to be idiopathic. Lumbosacral SEL was the most frequently reported level of disease (68.9%), followed by the thoracic level (26.2%). The mean age of cases who underwent surgical intervention was 55 years, as compared with 48 years in those who received conservative management ( P =0.03). 95% of patients reported some degree of symptomatic improvement regardless of the treatment modality. Logistic regression suggested a possible superior outcome associated with those undergoing surgical treatment.

CONCLUSION

In contrast to historical comparisons, contemporary articles support that obesity has become the major contributing factor for SEL. Logistic regression of the existing cases suggests that there may be a role for surgical intervention in select patients.

Percutaneous full-endoscopic uniportal decompression for the treatment of symptomatic idiopathic lumbar spinal epidural lipomatosis: Technical note

Background

Lumbar spinal epidural lipomatosis (SEL) is a rare condition characterized by an excessive accumulation of adipose tissue within the spinal canal, compressing the dura sac and/or nerve roots. When conservative treatments fail and clinical symptoms progress quickly and seriously, surgical decompression should be considered. With the rapid development of endoscopic armamentaria and techniques, the pathological scope that can be treated by percutaneous endoscopic spine surgery is ever expanding.

Objective

In this paper, the authors describe a patient with lumbar spinal epidural lipomatosis who was treated with a percutaneous full-endoscopic uniportal decompression surgery successfully. This article aims to validate the feasibility of percutaneous full-endoscopic uniportal decompression for the treatment of symptomatic idiopathic spinal epidural lipomatosis via interlaminar approach.

Methods

We describe a case of a 69-year-old man with a 10-year history of low back pain, intermittent claudication, and bilateral leg neuropathic pain. He was diagnosed with lumbar epidural lipomatosis, which did not respond to conservative therapy. After a comprehensive evaluation, he underwent percutaneous endoscopic spine surgery to remove hyperplastic adipose tissue and decompress nerve roots and dura sac.

Results

The patient was treated with a percutaneous full-endoscopic uniportal decompression surgery successfully. After the procedure, his leg pain decreased and his walking capacity improved. There were no surgery-related complications, such as cerebrospinal fluid leakage, incision infection, etc.

Conclusions

The case with SEL was successfully treated with a percutaneous full-endoscopic uniportal surgery, which has the advantages of excellent presentation of anatomical structures, expanded field of vision, less surgical-related trauma, and bleeding. The key point of the procedure is to release and cut off the bands which divide the epidural space into small rooms filled with excess adipose tissue.

Extensive Symptomatic Thoracolumbar Epidural Lipomatosis Treated With Minimally Invasive Hemilaminectomies: Technical Case Report

BACKGROUND AND IMPORTANCE

Spinal epidural lipomatosis is a rare condition commonly associated with chronic corticosteroid use and obesity that involves deposition of adipose tissue in the epidural space of the spinal canal. This accumulation of adipose tissue may cause compression of the spinal cord and/or nerve roots and result in compressive symptoms such as myelopathy or radiculopathy. Spinal involvement is usually confined to either the thoracic or lumbar spine but can infrequently affect both regions. Depending on pre-existing conditions, treatment options include weight loss and discontinuation of exogenous steroid use, both of which have been shown to be effective therapeutic methods. Surgical decompression may be useful for appropriately selected patients in whom conservative therapy has failed or who experience acute neurological deterioration, although this is rarely indicated.

CLINICAL PRESENTATION

In this study, we describe a patient receiving long-term corticosteroid therapy who presented with symptomatic epidural lipomatosis that involved the thoracic and lumbar spine. She was treated with decompression by continuous T3-L5 hemilaminectomies performed through 5 small incisions of alternating laterality. After surgery, the patient experienced clinical improvement and was able to return to her baseline.

CONCLUSION

We illustrate a successful spinal decompression of extensive epidural lipomatosis through a less-invasive surgical approach using several small incisions to accomplish uninterrupted hemilaminectomies. This alternative approach to a standard continuous incision can be considered in cases of extensive spinal epidural lipomatosis in patients with multiple medical comorbidities in whom wound healing is believed to be an issue and for whom minimizing blood loss is crucial.

Spinal Epidural Lipomatosis Causing Lumbar Canal Stenosis: A Pictorial Essay on Radiological Grading and the Role of Bariatric Surgery Versus Laminectomy

Spinal epidural lipomatosis (SEL) is a rare condition characterized by an excessive accumulation of adipose tissue in the spinal canal that can have a compressive effect on intraspinal neuroanatomical structures, leading to clinical symptoms. Several different conservative and surgical treatment strategies have been proposed but the treatment and outcomes remain controversial. There is a lack of severity-based evidence documenting the success of decompressive laminectomy in SEL and there are only anecdotal reports of clinico-radiological success with weight loss from bariatric surgery. This article demonstrates the resolution of SEL in two patients with bariatric surgery with the help of pre and postoperative MR imaging. The authors also highlight the classic “types” of spinal epidural lipomatosis with a surgically relevant grading system and elucidate the existence of concurrent extraspinal lipomatosis (i.e. mediastinal and intra-abdominal lipomatosis), drawing parallels with the natural history of SEL. The controversial question remains whether a symptomatic SEL patient needs a multilevel laminectomy for spinal decompression or bariatric surgery that can indirectly help the spinal condition. We propose that bariatric intervention could be better frontline management in patients with multifocal/multisystem lipomatosis (i.e., combined spinal and extraspinal) and spinal decompression would be ideal for those SEL patients with coexisting bony and/or ligamentous spinal canal or foraminal stenosis. This manuscript serves as a comprehensive and contemporary update on the radiological profile and two plausible treatment paths and will look toward further verification by a randomized clinical trial.

Spinal epidural and synovial lipomatosis in a 3‐year‐old Eurasian dog receiving sustained steroid therapy

This report describes a spinal cord epidural and synovial lipomatosis in a 3‐year‐old neutered male Eurasian dog. This dog presented for ambulatory paraparesis and was previously treated with immunosuppressive dosages of prednisolone for 2 years. Computed tomography (CT) myelography and magnetic resonnance imaging (MRI) images identified dorsal compression of the thoraco‐lumbar spinal cord by hypertrophic epidural fat. Histological examination identified extensive well‐differentiated mature adipose tissue in the subepithelial area of the tarsal synovium. Prednisolone is a reported predisposing factor in humans with lipomatosis.

Spinal epidural lipomatosis: a rare and frequently unrecognized complication of Cushing syndrome

CONTEXT

Spinal Epidural Lipomatosis (SEL) is a rare and frequently unrecognized complication of Cushing syndrome (CS). Only nine previous cases of SEL have been described in CS. Here, we present a case of severe SEL and review the literature.

CASE REPORT

A 29-year-old man who had severe CS secondary to an ACTH-secreting pituitary macroadenoma. He presented with progressive lower limb weakness over a 2-year period leading to complete paraplegia in the last 4 months. In addition, he had classic symptoms and signs of severe CS. His evaluation confirmed the diagnosis of CS with a 4-fold increase in his daily free urinary cortisol (1190 mg/day), a positive 1-mg dexamethasone suppression test (AM cortisol 729 nmol/l) and an elevated ACTH of 196 ng/dl (10-65). Magnetic resonance imaging (MRI) revealed a 20-mm pituitary adenoma and extensive fat accumulation in the spinal canal extending from C7 to S5 with significant spinal cord compression from T2-T10. The patient underwent an urgent spinal cord decompression surgery. He showed an immediate improvement and was able to walk with crutches 3 weeks later and independently 3 months later. About 13 days after the spinal surgery, he underwent a trans-sphenoidal surgery resulting in eucortisolemia.

CONCLUSION

SEL is a rare and serious complication of CS. It should be considered in any patient with CS, especially when there is neurological symptoms or disproportionate weakness of the lower limbs. Its management should be individualized but prompt surgical decompression should be considered even in patients with relatively long history of paraparesis.

Spinal epidural lipomatosis

Spinal epidural lipomatosis (SEL) is a rare pathologic growth of histologically normal nonencapsulated adipose tissue in the epidural space. It can cause myelopathy or radiculopathy. Etiologies include chronic exposure to endogenous or exogenous steroids and obesity. Idiopathic forms are much infrequent. We present a case of lumbar SEL compressing the thecal sac in a 50-year-old female patient.

Is there an association between lumbosacral epidural lipomatosis and lumbosacral epidural steroid injections? A comprehensive narrative literature review

Background

Exogenous systemic steroid exposure is a well-established risk factor for spinal epidural lipomatosis (SEL), however the association between lumbosacral epidural steroid injections (LESIs) and lumbosacral epidural lipomatosis (LEL) is generally regarded as poorly understood. Our objective was to investigate the rationale and the evidence implicating LESI(s) as a potential cause of LEL as well as the evidence related to use of LESI(s) as a potential pain relieving treatment option for radicular pain in the setting of LEL.

Methods

PubMed, Embase, Google Scholar, OVID were searched from inception until April 2021. Three investigators identified literature that provided original descriptive patient clinical data attributing the development/progression of LEL to LESI(s) or described the use of LESI(s) as a pain relieving modality for radicular pain in the setting of LEL.

Results

Fourteen publications were included for review. Overall, the current level of evidence is of low-quality. There are significant methodological gaps on this subject matter and many studies do not account for confounding variables independently associated with LEL.

Conclusions

This review has identified substantial limitations in the literature regarding that which is truly known regarding LESI(s) and LEL, as well as conservative management overall. To provide a well-rounded perspective, we synthesized literature as it pertains to: 1) current knowledge regarding SEL, notable associations and potential implications for corticosteroid exposure; 2) corticosteroid exposure and lipoatrophy; 3) current management recommendations for SEL and 4) areas for future focus. Although LESI(s) have been associated with LEL in the literature, presently due to a lack of rigorous, high-quality studies, the presence or absence of an independent causal relationship between LESI(s) and LEL cannot be stated with confidence.

Thoracic Spinal Angiolipomas: A Systematic Review

BACKGROUND

 Spinal angiolipomas (SAs) are rare, benign tumors, representing 0.0004 to 1.2% of angiolipomas, usually located at the extradural and posterior thoracic level, with multimetameric extension.

METHODS

 A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The authors searched on PubMed and Scopus databases for published articles with the Mesh term "spinal angiolipoma" and pertinent associations. Language restriction to English papers was applied. The authors also reported three emblematic cases of patients who underwent surgical resection of spindle-shaped (type IA) and dumbbell-shaped (type II) SAs between 2014 and 2020.

RESULTS

 Of the 256 retrieved articles, 33 were included in the meta-analysis. These 33 studies, together with our 3 reported cases, included a total of 60 patients, 36 females (60%) and 24 males (40%), with a mean age of 53.12 ± 12.82 years (range: 12-77 years).T5 was the most represented level (22 patients). Usually, the localization of SA was extradural, with 53 patients suffering from spindle-shaped type IA SA (88.3%) and 7 patients from dumbbell-shaped type II SA (11.6%). Almost all patients underwent laminectomy (78.3%) and presented a full recovery of motor deficits (85%). Gross total removal (GTR) was performed in 93.3% of patients. The mean follow-up was of 22.71 ± 21.45 months (range: 2-80 months). There was no documented recurrence at follow-up magnetic resonance imaging in any of the patients.

CONCLUSIONS

 SAs are rare, benign tumors with a great vascular component that presents a favorable outcome. GTR is the gold standard treatment and usually an adjuvant therapy is not required. Even infiltrative lesions, which are more complex, can be treated successfully with a good prognosis. Dumbbell-shaped SAs must be differentiated from schwannomas and meningiomas, and require different surgical techniques, given the profuse bleeding associated with the attempt of debulking. En block resection is the key to treat these common benign tumors with acceptable blood loss.

Distinguishing Intramedullary Spinal Cord Neoplasms from Non-Neoplastic Conditions by Analyzing the Classic Signs on MRI in the Era of AI

Intramedullary lesions can be challenging to diagnose given the wide range of possible pathologies. Each lesion has unique clinical and imaging features, which are best evaluated on magnetic resonance imaging. Radiological imaging is unique with rich, descriptive patterns and classic signs-which are often metaphorical. In this review, we present a collection of classic MRI signs, ranging from neoplastic to non-neoplastic lesions, within the spinal cord. The differential diagnosis (DD) of intramedullary lesions can be narrowed down by careful analysis of the classic signs and pattern of involvement in the spinal cord. Furthermore, the signs are illustrated memorably with emphasis on the pathophysiology, mimics and pitfalls. Artificial intelligence (AI) algorithms, particularly deep learning, have made remarkable progress in image recognition tasks. The classic signs and related illustrations can enhance a pattern recognition approach in diagnostic radiology. Deep learning can potentially be designed to distinguish neoplastic from non-neoplastic processes by pattern recognition of the classic MRI signs.

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.

Obesity is a risk factor for epidural lipomatosis: a meta-analysis

PURPOSE

The purpose of this meta-analysis was to summarize the evidence of associations between obesity factors and spinal epidural lipomatosis (SEL) and to evaluate the strength and validity of these associations.

METHODS

Electronic databases such as Wiley Online Library, PubMed, Embase, Cochrane Library were searched and manual retrieval of references, the time limit was from the establishment of the database to May 2020. Methodological quality evaluations of the included studies were assessed using the bias risk assessment tool recommended by the Cochrane Guidelines. The RevMan 5.3 software was used for meta-analysis.

RESULTS

Finally, seven studies were included for meta-analysis, all of which were observational studies with mixed bias risk. These studies involved 807 patients, with an average age of 64 to 73.6 years, and 59.4 percent of the participants were male. The sample sizes for the included studies ranged from 28 to 288. The results of meta-analysis showed that high body mass index (BMI) was one of the factors affecting SEL (P < 0.01, MD 1.37, 95% CI [0.81, 1.92]). All reviews had a high risk of bias, and the most common source of bias was that there was no strict unified case diagnosis standard between researches, and some studies (four items) did not clearly describe the confounders that they controlled.

CONCLUSIONS

We suggest that physicians should consider high BMI as a factor leading to SEL, and to control body weight actively should be considered as the preferred treatment strategy before surgical intervention is conducted.

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.

Imaging in spinal posterior epidural space lesions: A pictorial essay

Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

Lumbar spinal stenosis combined with obesity-induced idiopathic spinal epidural lipomatosis treated with posterior lumbar fusion: case report

BACKGROUND

Spinal epidural lipomatosis is a rare cause of lumbar spinal stenosis. While conservative therapy is applicable for most of cases, surgical intervention is necessary for severe ones. This is the first time we apply this modified technique to this disease.

CASE PRESENTATION

The case is a 53-year-old man. He is 175 cm tall and weighs 102 kg (body mass index 33.3 kg/cm²), presenting with low back pain and bilateral legs pain and numbness. Radiological examination showed severe lumbar spinal stenosis resulting from adipose hyperplasia, combined with hyperosteogeny and hypertrophy of ligaments, which are common etiological factors. Posterior decompression, internal fixation and a modified articular fusion technique was performed on this patient, and regular follow-up that up o 22 months showed outstanding clinical outcomes.

CONCLUSIONS

A suitable style of posterior lumbar fusion should be considered to especially severe case with lumbar spinal stenosis and idiopathic spinal epidural lipomatosis.

Epidural lipomatosis in elderly patient: A rare cause of cauda equina compression

Background:

The most common cause of cauda equina compression in the elderly is lumbar spinal stenosis. Epidural lipomatosis is an additional known but rare cause of cauda equina compression readily diagnosed on MR studies. Notably, spinal canal decompression and direct excision of the epidural fat effectively manage this combined pathology.

Case Description:

A 70-year-old male presented with progressive truncal obesity associated with refractory lumbar neurogenic claudication. The lumbar magnetic resonance imaging (MRI) showed excessive epidural fat extending from L4 to S2 resulting in thecal sac compression; this was confirmed on the MRI myelogram study. Following a decompressive laminectomy, the patient’s cauda equina syndrome resolved.

Conclusion:

Recent weight gain with increased neurogenic claudication and the onset of a cauda equina syndrome may herald the presence of significant lumbar epidural lipomatosis. Here, laminectomy for excision of the excessive epidural fat resolved the patient’s symptomatic spinal stenosis.

Multilevel Hemilaminotomy Windows for the Surgical Management of Spinal Epidural Lipomatosis Causing Syringomyelia: Technical Note and Literature Review

BACKGROUND

Spinal epidural lipomatosis (SEL) is the excessive accumulation of extradural adipose tissue. Severe cases could result in myelopathy, and very rarely, in syringomyelia formation. Surgery has been associated with high morbidity and mortality, and no proven long-term benefits. The objective was to provide a technical description of an efficient and cost-effective procedure for multilevel thoracic decompression without requiring spinal instrumentation.

METHODS

A technique of multilevel hemilaminotomy windows is described in a patient with severe thoracic SEL causing syringomyelia. A 3-dimensional spine model was created to illustrate the technique and working angles. We performed a literature review by searching PubMed, Ovid Embase, and Scopus electronic databases with the predetermined inclusion criteria of cases with spinal lipomatosis and a fluid cavity within the spinal cord.

RESULTS

The patient's deficit and syringomyelia resolved postoperatively. A review of the literature revealed only 3 cases of syringomyelia secondary to SEL. Syringomyelia expansion occurred in all cases leading to progressive neurologic decline, and surgery with removal of the excessive adipose tissue resolved the syringomyelia and improved the neurologic functioning in all cases.

CONCLUSIONS

This technique of multilevel alternating hemilaminotomy "windows" allows for safe and effective decompression and resection of the excessive adipose tissue with reduced operative time and without requiring spine instrumentation. The technique maintains the integrity of the posterior column, thus reducing the risk of postdecompression deformity. Careful bipolar electrocoagulation of internal vertebral veins and meticulous hemostasis is key for minimizing the intraoperative blood loss and avoiding postoperative hematoma formation.

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

INTRODUCTION

Lumbar spinal epidural lipomatosis (SEL) is a rare condition defined by an excessive deposition of adipose tissue in the lumbar spinal canal. The objective of this case report is to document a clinical case of SEL presenting within a multidisciplinary spine clinic and to compare our clinical findings and management with the available literature.

CASE PRESENTATION

A 51-year-old female presented at a spine clinic with low back pain, bilateral leg pain and difficulty walking. Magnetic resonance imaging of the lumbar spine showed evidence of severe central canal stenosis due to extensive epidural lipomatosis. She was initially advised to lose weight and undergo a 3-month course of physiotherapy. However, because of lack of improvement, she was scheduled for and underwent L4-S1 posterior spinal decompression and L4-L5 posterior spinal instrumented fusion. At 12-month follow-up, the patient reported no pain and retained the ability to walk regular distances without experiencing discomfort.

DISCUSSION

This case report describes the conservative and surgical management of a case of lumbar spinal stenosis due to SEL. The therapeutic approach of patients with this condition is not standardized. As such, a discussion of the literature with respect to the diagnosis, clinical presentation, epidemiology, imaging appearance, risk factors, etiology, and management of SEL is also presented.

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.

Spinal epidural lipomatosis: a rare association of Cushing's disease

SUMMARY

Excess cortisol is associated with hypertrophy and redistribution of adipose tissue leading to central obesity which is classically seen in Cushing's syndrome. Abnormal accumulation of fatty tissue in the spinal canal is most commonly associated with chronic steroid therapy and rarely reported with endogenous Cushing's syndrome. Herein, we describe a case of spinal epidural lipomatosis (SEL) associated with Cushing's disease. A 17-year-old man was referred with lower limb weakness, weight gain, multiple stretch marks, back pain and loss of height. He had clinical and biochemical features of Cushing's syndrome. MRI and Inferior Petrosal Sinus Sampling (IPSS) confirmed a pituitary adenoma as the source. On day 1 post trans-sphenoidal adenectomy he developed spastic paraparesis with a sensory deficit to the level of T5. MRI spine showed increased fat deposition in the spinal canal from T2 to T9 consistent with a diagnosis of SEL. He was managed conservatively and made a good recovery following restoration of eucortisolism and a period of rehabilitation.

LEARNING POINTS

SEL is a serious complication of glucocorticoid excess and should be considered in any patient presenting with new lower limb neurological symptoms associated with hypercortisolism. It is important to distinguish symptomatic SEL from cortisol-induced proximal myopathy by good history and clinical examination. MRI of the spine is the gold standard investigation for making a diagnosis of SEL. Restoration of eucortisolism can lead to resolution of fat accumulation and good neurological outcome.

Spinal Epidural Lipomatosis with Osteoporotic Vertebral Fractures Presenting as Acute Thoracic Myelopathy in a 33-Year-Old Man with Cushing Disease

BACKGROUND

Steroid-related spinal epidural lipomatosis (SEL) is a well-known condition most commonly encountered in patients taking chronic steroid medications. Endogenous Cushing syndrome is a rare cause of SEL. The authors report an unusual presentation of acute thoracic myelopathy due to SEL with osteoporotic vertebral compression fractures in a patient with Cushing disease.

CASE DESCRIPTION

A 33-year-old man presented with thoracic myelopathy due to SEL and multiple vertebral compression fractures. He had Cushingoid clinical features, and investigations revealed a pituitary microadenoma as the cause of hypercortisolism. The diagnosis was missed on multiple occasions before the onset of paraparesis. The patient was treated with urgent thoracic laminoplasty followed by transsphenoidal surgery on the same day. Although normalization of the serum cortisol levels was delayed by 6 months, he had a complete neurologic recovery and remains symptom free at 2 years follow-up.

CONCLUSIONS

This is a rare presentation of Cushing disease and has been reported only twice before in the 1990s. This case highlights the need to keep a high degree of suspicion for development of thoracic myelopathy in a patient with Cushing syndrome who develops thoracic compression fractures associated with SEL. Early recognition of this clinical association and addressing the primary endocrine problem urgently could have prevented spinal cord involvement and the subsequent spine surgery. This scenario is also documented in previous published case reports of this association where the diagnosis of Cushing syndrome has been revealed retrospectively after the development of neurologic symptoms.

Rapid progression of spinal epidural lipomatosis after percutaneous endoscopic spine surgery mimicking disc herniation

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Spinal epidural lipomatosis can occur and progress rapidly after endoscopic spine surgery.

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As in our case, focally progressed SEL anterior to the dural sac could be misdiagnosed for disc herniation.

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SEL should be recognized as a rare complication of endoscopic spine surgery.

Introduction

Spinal epidural lipomatosis (SEL) is well known but uncommon complication of endoscopic spine surgery. Here, we present a case of SEL that progressed focally and rapidly after endoscopic spinal surgery.

Presentation of case

A 67-year-old man presented with back and Lt. leg radiating pain. MRI of the lumbar spine demonstrated severe foraminal stenosis at Lt. L4/5/S1. He underwent endoscopic posterior foraminotomy at Lt. L4/5/S1. After surgery, his leg pain disappeared. A month after surgery, the patient developed Lt. leg pain again. MR images showed focally progressed epidural fat posterior to the L5 body. After removal of lipomatosis via endoscopic posterior decompression at L3/4/5, his symptoms improved.

Discussion

Mostly, the epidural fat accumulates insidiously, and distributes widely across several levels. And the increased accumulation of fat is predominantly posterior and posterolateral within the spinal canal. As in this case, focally progressed SEL anterior to the dural sac is rare. And focally progressed SEL can be misdiagnosed for disc herniation.

Conclusion

SEL should be recognized as a rare complication of endoscopic spine surgery.

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.

Lumbar cystic epidural lipomatosis with mass effect. Report of an unusual case

We present a rare case of symptomatic cystic lumbar spinal epidural lipomatosis that required surgical treatment via a minimally invasive tubular laminectomy. To our knowledge this is the first pathology confirmed report of compressive cystic lumbar spinal epidural lipomatosis available in literature.

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.

Progressive myelopathy associated with spinal epidural lipomatosis in three non-obese patients with type 1 diabetes mellitus

BACKGROUND

Spinal epidural lipomatosis (SEL) is a rare condition defined as pathological overgrowth of the normally present epidural fat within the spinal canal. SEL is associated with Cushing disease, obesity and chronic corticosteroid therapy. Diabetes mellitus type 1 (DM1) has not known to be a risk factor for SEL. The neurological symptoms of SEL are attributed mainly to mechanical compression on the spinal cord and the cauda equina.

METHODS

A retrospective chart review of patients evaluated at NYU Multiple Sclerosis Care Center identified three diabetic patients with progressive myelopathy associated with SEL. We report the clinical course, diagnostic workup and outcomes in these three patients with SEL-associated myelopathy.

RESULTS

Three patients (2 females and 1 male) had long-standing DM1 and developed progressive myelopathy in their early 40's. All were found to have thoracic SEL (extensive extradural T1, T2 hyperintense signal; biopsy confirmed in one case) with associated extensive abnormal cord signal in lower cervical/upper thoracic spinal cord. A comprehensive evaluation for metabolic, infectious, autoimmune and vascular causes of myelopathy that included serologies, cerebrospinal fluid analyses, and spinal angiography did not reveal an alternative cause for myelopathy. One of the patients underwent a surgical decompression of SEL with subsequent clinical and radiologic improvement.

CONCLUSIONS

Our case series suggest that patients with DM1 and myelopathy of unknown cause should be evaluated for SEL. Timely diagnosis and appropriate intervention may forestall progression of neurological disability and even result in neurologic improvement. SEL should be considered on the short list of diagnoses that cause potentially reversible progressive myelopathy.

Spinal Epidural Lipomatosis: A Rare Complication From Hormonal Therapy for Infantile Spasms

BACKGROUND

Spinal epidural lipomatosis (SEL) represents pathologic overgrowth of extradural adipose tissue in the spinal canal that can result in spinal cord compression. SEL has been associated with excess corticosteroids, whether from exogenous steroid use or from excess endogenous steroids. Spinal epidural lipomatosis is rarely reported in children and has not been reported in association with hormonal therapy for infantile spasms.

METHODS

We performed a detailed retrospective chart and literature review.

RESULTS

We describe two children with symptomatic SEL associated with the use of high-dose hormone treatment for infantile spasms.

Spinal Epidural Lipomatosis: A Review of Pathogenesis, Characteristics, Clinical Presentation, and Management

STUDY DESIGN

Narrative review of available literature.

OBJECTIVE

To summarize current trends in pathogenesis and management of spinal epidural lipomatosis (SEL) and suggest areas where more research would be of benefit.

METHODS

The available literature relevant to SEL was reviewed. PubMed, Medline, OVID, EMBASE, Cochrane, and Google Scholar were used to review the literature. Institutional review board approval is not applicable for this study.

RESULTS

This article clearly summarizes current trends in the pathogenesis and management of SEL.

CONCLUSIONS

Possible etiologies of SEL include exogenous steroid use, endogenous steroid hormonal disease, obesity, surgery induced, and idiopathic disease. Comorbidities such as acquired immunodeficiency syndrome and Scheuermann's disease have also been implicated in the pathogenesis of SEL. Steroid-induced SEL seems to have a proclivity for the thoracic region of the spine and has a higher incidence of paraplegia when compared with other forms. Several treatment modalities exist for SEL and are dictated by the underlying cause of the disorder. These include weight reduction, cessation of steroid medications, treatment of underlying endocrine abnormalities, and surgical decompression. Conservative treatments generally aim to decrease the thickness of adipose tissue in the epidural space, but the majority of patients tend to undergo surgical decompression to relieve neurologic symptoms. Surgical decompression provides a statistically significant reduction in symptoms, but postoperative mortality is high, influenced primarily by the patient's preoperative comorbidities. Physicians should consider the underlying cause of SEL in a given patient before pursuing specific treatment modalities, but alarm symptoms, such as the development of acute cauda equina syndrome, should likely be treated with urgent surgical decompression.

Epidural Fat and Its Association with Pain, Physical Function, and Disability Among Older Adults with Low Back Pain and Controls

Objective

To examine epidural fat and its relationship to pain, physical function, and disability among older adults with chronic low back pain, chronic low back pain plus leg pain, and controls.

Design

Cross-sectional, comparative study.

Setting

Standardized examinations were conducted in a research laboratory, and magnetic resonance images were obtained.

Subjects

A total of 93 adults age 60 to 85 years (24 with chronic back pain, 25 with chronic back pain plus leg pain, and 44 controls).

Methods

Reliability for assessment of epidural fat diameter, averaged across spinal levels, was established (intraclass correlation coefficient = 0.95). Linear regression was used to explore how epidural fat diameter related to self-reported (Short Form-36 Health Survey: physical component summary score) and performance-based (stair climb performance) measures of physical function among adults with chronic back pain with and without leg pain, as compared with controls, while controlling for age, sex, and body mass index. Associations between epidural fat and pain intensity and low back pain-related disability were also explored (P ≤ 0.050).

Results

Epidural fat helped explain self-reported function (P < 0.001); adults with axial low back pain (LBP) may have a relationship between epidural fat and self-report function that is different from controls (P = 0.015). Relationships between epidural fat and stair performance were significantly different from controls for those with LBP (P = 0.000) but not for those with LBP plus leg pain (P = 0.366). Relationships between epidural fat and pain intensity and/or disability were not found.

Conclusions

Increased epidural fat may help explain better function among older adults with chronic axial back pain, but not among those who also report leg pain.

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.

Comparison of relative and absolute values of magnetic resonance imaging in the diagnosis of spinal epidural lipomatosis

OBJECTIVE

To describe spinal epidural lipomatosis (SEL) of the lumbar region and evaluate the relative versus absolute values of epidural fat (EF) to determine which is more appropriate when using magnetic resonance imaging (MRI).

DESIGN

Comparative study.

SETTING

Hospital.

PARTICIPANTS

Eight SEL patients and 40 healthy adults.

INTERVENTIONS

MRI measurement of EF.

OUTCOME MEASURES

The MRI-based EF thickness, cutoff value, and coefficient of variation (CV) were calculated. Frequency distribution maps for the absolute EF value and the relative EF/DuS value were created.

RESULTS

SEL involved L3 - L4 in all cases. The mean EF thickness was 12.11 ± 2.28 mm (range: 9.91 - 16.86 mm), and the average diameter of the dural sac (DuS) was 20.02 ± 2.64 mm; the EF/DuS ratio was 0.61 ± 0.03. In controls, the average EF thickness was 7.35 ± 1.68 mm (range: 4.81 - 10.92 mm), and the average DuS was 20.86 ± 2.11 mm; the EF/DuS ratio was 0.35 ± 0.08. The relative and absolute values were significantly higher in the SEL group than in the normal group. A cutoff value of 9.8 mm could distinguish SEL patients from normal individuals. For the SEL group, the CV of the relative values (4.9%) was lower than that of the absolute values (18.8%). The frequency distribution map showed that the distribution of relative values was more concentrated than that of the absolute values for both groups.

CONCLUSION

Based on the frequency distribution and CVs, the relative value of EF/DuS maybe a better measure for diagnosing SEL than the absolute EF value.

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.