Epidural lipomatosis causing new debilitating back pain in a patient with human immunodeficiency virus on highly active antiretroviral therapy

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.

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.

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.

A Case of Epidural Lipomatosis in Pregnancy: Management during Labour and Caesarean Section

BACKGROUND

Spinal epidural lipomatosis (SEL) is a rare condition of adipose tissue accumulation in the epidural space. As a result of excess adipose tissue, neuraxial anaesthesia has been reported to behave unpredictably in patients with this condition.

CASE

A 36-year-old woman had worsening postural headaches during pregnancy. MRI revealed SEL involving the thecal sac between L3/L4 and L5/S1. She had induction of labour but ultimately required a CS for delivery. Her anaesthesia was managed with an epidural inserted at L3/4. She developed a high block with relative sacral sparing.

CONCLUSION

Although neuraxial anaesthesia was thought to be contraindicated in patients with SEL, it can be done safely. Care must be taken to provide slow epidural titration to avoid high sensory block in patients with this condition.