Spinal epidural lipomatosis in lumbar magnetic resonance imaging scans

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.

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.

Imaging of muscle and adipose tissue in the spine: A narrative review

Interpretation of the morphology and characteristics of soft tissues, such as paravertebral muscles and fat, has always been a "relative blind spot" in the spine. The imaging features of the non-bony structures of the spine have been studied and reinterpreted, and changes in the non-bony structure are associated with spinal disease. Soft tissue parameters such as, the "paraspinal muscle cross-sectional area," "subcutaneous fat thickness," and the "paraspinal muscle fat infiltration rate" on computed tomography, magnetic resonance imaging and other imaging techniques are reproducible in the diagnosis, treatment and prognosis of spinal disorders and have the potential for clinical application. In addition, focus on the association between sarcopenia and spinal epidural lipomatosis with spinal disorders is increasing. Currently, there is no summary of studies on fat and muscle in the spinal region. Given this, within the context of recent research trends, this article provides a synthesis of research on adipose and muscle tissue in the spine, discusses advances in the study of the imaging manifestations of these structures in spinal disorders, and expands the perspectives.

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.

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 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.

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.

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.

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.

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.

Spinal epidural lipomatosis presenting to a U.S. Veterans Affairs pain and rehabilitation department: a report of two cases

Background

Spinal epidural lipomatosis is an uncommon source of neurogenic claudication. We present two cases of spinal epidural lipomatosis as it relates to diagnosis, management, and a possible association with common medical intervention.

Case presentation

Case 1: 63-year old male patient presented with neurogenic claudication symptoms, but without evidence of bony central canal stenosis on lumbar computed tomography. He entered a trial of spinal manipulation with transient beneficial gains after seven appointments, but no durable change in neurogenic claudication. An MRI was recommended at this point which revealed grade III spinal epidural lipomatosis at the L5/S1 level.Case 2: 51-year old male patient presented to a pain management physician with radicular symptoms for a series of lumbar epidural steroid injections. He completed a series of three lumbar epidural steroid injections with only short-term benefit. A repeat MRI demonstrated the presence of grade I (borderline grade II) spinal epidural lipomatosis.

Conclusions

The first case illustrates a limitation of ruling out central canal stenosis with computed tomography for patients unable to undergo an MRI. The second case demonstrates a possible association between steroid injections and spinal epidural lipomatosis. An association of this kind has not been established; further research is needed to determine the significance.

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.

Incidence of spinal epidural lipomatosis in patients with spinal stenosis

Inroduction

Spinal Epidural Lipomatosis (SEL) is believed to be a rare disorder. The incidence and prevalence of clinically symptomatic SEL in patients with spinal stenosis has never been reported in the literature. Our study aims to determine the prevalence, incidence, and associated risk factors of SEL in patients with the diagnosis of spinal stenosis.

Methods

This is a retrospective study. We reviewed the charts of 831 patients with the diagnosis of spinal stenosis over a 30 month period. All patients had spinal MRIs. Grading of SEL was performed using the Borré method.

Results

52 patients (21 female and 31 male) had symptomatic moderate and severe SEL. We found a prevalence of 6.26% and an annual incidence of 2.5%. SEL was most commonly seen at L5-S1 level. 27% had received corticosteroids. All SEL patients were overweight and 79% were obese.

Conclusions

SEL is not uncommon in patients with spinal stenosis. SEL should be considered as a possible diagnosis in those with symptoms of spinal stenosis especially in those with associated risk factors.

The prevalence of spinal epidural lipomatosis on magnetic resonance imaging

BACKGROUND

Spinal epidural lipomatosis (SEL) refers to an excessive accumulation of fat within the epidural space. It can be idiopathic or secondary, resulting in significant morbidity. The prevalence of SEL, including idiopathic and secondary SEL, and its respective risk factors are poorly defined.

PURPOSE

We sought to: (1) assess the prevalence of SEL among patients who underwent a dedicated magnetic resonance imaging (MRI) scan of the spine-including incidental SEL (ie, SEL without any spine-related symptoms), SEL with spine-related symptoms, and symptomatic SEL (ie, with symptoms specific for SEL); and (2) assess factors associated with overall SEL and subgroups. In addition, we assessed differences between SEL subgroups.

METHODS

We reviewed the records of 28,902 patients, aged 18 years and older with a spine MRI (2004 to 2015) at two tertiary care centers. We identified SEL cases by searching radiology reports for SEL, including synonyms and misspellings. Prevalence numbers were calculated as a percentage of the total number of patients. We used multivariate logistic regression analysis to identify factors associated with overall SEL and subgroups.

RESULTS

The prevalence of overall SEL was 2.5% (731 of 28,902): incidental SEL, 0.6% (168 of 28,902); SEL with symptoms, 1.8% (526 of 28,902); and symptomatic SEL, 0.1% (37 of 28,902). Factors associated with overall SEL in multivariate analysis were the following: older age (odds ratio [OR]: 1.01, 95% confidence interval [CI]: 1.01-1.02, p<.001), higher modified Charlson comorbidity index (OR: 1.10, 95% CI: 1.07-1.13, p<.001), male sex (OR: 2.01, 95% CI: 1.71-2.37, p<.001), BMI>30 (OR: 2.59, 95% CI: 1.97-3.41, p<.001), Black/African American race (OR: 1.66, 95% CI: 1.24-2.23, p=.001), systemic corticosteroid use (OR: 2.59, 95% CI: 1.69-3.99, p<.001), and epidural corticosteroid injections (OR: 3.48, 95% CI: 2.82-4.30, p<.001).

CONCLUSIONS

We found that about 1 in 40 patients undergoing a spine MRI had SEL; 23% of whom with no symptoms, 72% with spine-related symptoms, and 5% with symptoms specific for SEL. Our data help identify patients who might warrant an increased index of suspicion for SEL.

Scoliosis associated with idiopathic lumbosacral epidural lipomatosis

There are very few reports of spinal epidural lipomatosis (SEL) in association with scoliosis. A 49-year-old man presented with persistent back pain and right hip lump. The lumbar spine X-rays showed scoliosis (Lenke classification 5BN). Lumbar MRI demonstrated circumferential epidural fat deposit from L1 to lower S2 level. There was no obvious etiology of SEL except mild increased body mass index (BMI). The patient was managed with conservative treatment. After 6 months medication (limaprost and ginkgo), his symptoms were relieved.

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.].

Neuromuscular issues in systemic disease

The neuromuscular system can be involved in several systemic conditions. Clinical manifestations can appear at onset or throughout the course of the disease process. New investigational methods, including imaging of peripheral nerves, new laboratory tests, and antibodies, are available. In addition to symptomatic therapies, specific treatment options, such as for familial amyloid neuropathy and Fabry's disease, are becoming increasingly available. Pathomechanisms vary depending on the underlying disease process. In addition to metabolic, hormonal, immune, and antibody-mediated mechanisms, in some generalized diseases, genetic causes need to be considered. This review focuses on different aspects of the peripheral nervous system including the nerve roots, plexuses, mononeuropathies and generalized neuropathies, neuromuscular junction disorders, muscle, and autonomic nervous system.