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.

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.

Lipomatosis of nerve and overgrowth: is there a preference for motor (mixed) vs. sensory nerve involvement?

BACKGROUND: Lipomatosis of nerve (LN) is a peripheral nerve disorder characterized by fibroadipose proliferation within the epineurium. It has been associated with nerve-territory overgrowth affecting soft tissue and/or bony structures. We sought to understand if there is an anatomical relationship associated with nerve-territory overgrowth. METHODS: A review of the literature and our institutional LN cases was performed to determine the prevalence of nerve-territory overgrowth. Only cases with sufficient clinical and/or imaging data were selected. The cases were then subdivided into two groups and analyzed: (1) motor (mixed) nerve and (2) predominant sensory nerve, based on the anatomical location of the LN lesion. Subgroup analysis was performed on median nerves affected by LN, for a more homogenous population. RESULTS: We identified 329 LN cases with sufficient information for analysis. Motor (mixed) nerve group (M) consisted of 287 cases (155 with overgrowth and 132 without overgrowth). Sensory nerve group (S) revealed group of 42 cases (4 cases with overgrowth and 38 without overgrowth). Statistical analysis comparing overgrowth status in the M and S nerve groups showed a statistically significant difference in overgrowth, favoring the M group for overgrowth (p < 0.0001). The analysis of median nerve group consisted of 225 cases in the M group (106 with overgrowth and 119 without overgrowth) and 20 cases in the S group (3 with overgrowth and 17 cases without overgrowth). A statistically significant difference in nerve-territory overgrowth status was present in the M vs. the S group, again favoring the M group for overgrowth. (p = 0.0083). Cases from our institution included 44 cases for this analysis. Forty-two cases in the M group (28 with overgrowth and 14 without overgrowth) and 2 cases in the S group (all 2 without overgrowth). CONCLUSION: We believe the association of LN and nerve-territory overgrowth might be explained by involvement of mixed motor nerves; however, the exact underlying mechanism is not known.

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.

Obesity and spinal epidural lipomatosis in cauda equina syndrome.

BACKGROUND CONTEXT: Although lumbar disc herniations are common, only a small portion of these herniations lead to cauda equina syndrome (CES), which is an uncommon but debilitating disorder. Why some patients with herniation develop CES, when most do not, remains unknown. Preexisting subclinical epidural lipomatosis may limit canal space such that an otherwise benign herniation causes CES. PURPOSE: This study determines whether patients with an acute disc herniation and CES have a greater body mass index (BMI) and greater quantity of epidural fat compared with control subjects with non-CES symptomatic lumbar herniated discs. STUDY DESIGN/SETTING: A retrospective case-control series at a university-based level-1 trauma center was carried out. PATIENT SAMPLE: There were 33 CES and 66 control subjects identified from a prospectively maintained database of patients who underwent surgical management for a lumbar disc herniation between 2007 and 2012. Each CES case had two non-CES control patients matched by gender and age within 5 years except 5 CES cases that matched only one non-CES control. OUTCOME MEASURES: The outcome measures included weight, height, age, gender, and BMI. Radiographic outcome measures included the proportion of lumbar spinal canal occupied by fat and herniated disc on preoperative magnetic resonance imaging. METHODS: Patient charts and preoperative radiographs were retrospectively reviewed. For each patient, a blinded reviewer determined the proportion of lumbar spinal canal occupied by fat, and the maximal proportion of the canal occupied by herniated material at the involved level. Patient demographics and radiographic measures were compared between CES and control groups using chi-square or Student t tests. A second blinded reviewer re-assessed a series of radiographs, and the intraobserver variability was determined by Spearman correlation. Logistic regression was used to model the preoperative factors associated with having an acute disc herniation and CES. RESULTS: The CES cases had higher BMI (31.8 kg/m2, 95% confidence interval [CI] 29.5-34.0 vs. 28.1 kg/m2, 95% CI 26.7-29.5 in controls; p=.007), focally narrower canals (14.6 mm, 95% CI 13.8-15.3 mm vs. 16.4 mm, 95% CI 15.4-17.3 mm in controls; p=.003), and a greater percentage of spinal canal occupied by epidural fat (31.3%, 95% CI 26.1%-36.6% vs. 21.9%, 95% CI 18.7%-25.1% in controls; p=.003) and herniated disc material (54.5%, 95% CI 46.9%-62.0% vs. 34.4%, 95% CI 30.3%-38.5% in controls; p<.0001). Logistic regression confirmed canal width at the involved level, BMI, amount of canal occupied disc, and proportion of canal occupied by fat as independent predictors of having an acute disc herniation and CES. CONCLUSIONS: Obesity is a risk factor for CES from disc herniation. The CES cases also had a greater amount of herniated material, focally narrower canal, and larger epidural fat deposits. The latter may be the mechanism linking obesity with CES.

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.

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.

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

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

Spinal epidural lipomatosis in children with hematologic malignancies.

Abnormal fat deposition in the epidural space or spinal epidural lipomatosis (SEL) due to corticosteroid treatment or obesity may cause obstruction to cerebrospinal fluid flow. Little is known about SEL in patients with hematologic malignancies who require frequent lumbar punctures and corticosteroid treatment that places them at risk. Records and radiologic images of patients with SEL and leukemia or non-Hodgkin lymphoma (NHL) treated at a single institution from 1999-2009 were reviewed. Risk factors were compared with 405 control patients with leukemia. Fourteen patients with leukemia or NHL were diagnosed with SEL. The majority of patients underwent diagnostic imaging after unsuccessful lumbar punctures within 1 month of their primary diagnosis. Prior to SEL diagnosis, all patients received systemic and/or intrathecal corticosteroids. SEL diagnosis led to modification of intrathecal administration in eight patients, including Ommaya reservoir placement in four patients. All patients completed protocol-specified chemotherapy without neurologic symptoms or surgical intervention. Risk factors for developing SEL include older age and high body mass index. Investigation for SEL in leukemia or lymphoma patients with difficult lumbar punctures is warranted. Placement of an Ommaya reservoir may facilitate safe CNS-directed therapy in severely affected patients.

Prevalence and functional impact of lipomatous metaplasia in scar tissue following myocardial infarction evaluated by MRI.

OBJECTIVE: To retrospectively assess the prevalence and functional relevance of lipomatous metaplasia (LM) of the left ventricle in patients with chronic ischaemic heart disease (CIHD) using cardiac magnetic resonance imaging (cMRI) with steady state free precession (SSFP) sequences. METHODS: We examined 315 patients (248 male, mean age 63 +/- 10 years) with a history of CIHD by cMRI. Standard SSFP sequences were applied and results were correlated with findings from cardiac catheterisation and computed tomography. In a subgroup of patients with LM (LM+) the functional results were correlated with patients without LM (LM-) as controls matched for age, body mass index, gender and infarct size. RESULTS: Of 315 patients, 36 showed LM. LM+ patients showed a higher tendency to develop aneurysms compared with LM- (31% vs. 17%; not significant), but no differences in ejection fraction or volumetric parameters. LM occurred significantly more often in older infarcts and patients with hyperlipoproteinaemia, while other cardiac risk factors or medication did not have a significant influence on the development of LM. CONCLUSIONS: LM is a common finding (11%) in patients with CIHD. LM does not have a significant influence on global cardiac function or ventricular size, but on local function and probably also on the development of left ventricular aneurysms.

Laryngeal lipoma associated with diffuse lipomatosis: case report and literature review.

Lipomas are benign mesenchymal tumors that are often found in the head and neck. Intrinsic lipomas of the larynx and supraglottic area are rare, as fewer than 115 cases have been reported in the literature; almost all of these occurred in isolation. We report a case of a laryngeal lipoma that was associated with diffuse systemic lipomatosis. The tumor was successfully removed via an endoscopic laser resection. To the best of our knowledge, this is only the second case of laryngeal lipoma associated with lipomatosis to be reported in the English-language literature. We also review the literature on head and neck lipomas.

Spinal teratomas: a clinico-pathological study of 27 patients.

BACKGROUND: Spinal cord teratomas are uncommon tumours. The diagnosis is rarely suspected before surgery and final diagnosis is invariably made at histopathological examination. METHODS: We retrospectively analysed our neuropathology records for the last 20 years and all patients diagnosed as spinal teratomas were retrieved. The clinical and radiological features were noted. Slides were reviewed and the diagnosis was confirmed. FINDINGS: During a period of 20 years, we found 27 examples of spinal teratomas. There was a wide age range and 37.3% presented in adulthood. Male predominance was observed both in children as well as adults. The dorso-lumbar location was common in children as well as in adults but an intramedullary location, in association with a myelomeningocele and split cord malformation, was more common in children. Twenty one patients had associated features of spinal dysraphism. Of the six who were not associated with this, five were adult patients. Radiologically mixed solid and cystic morphology, fat signal and areas of calcification were seen in one third of patients. All tumours except one showed benign (mature) components. Interestingly, two lesions contained mature renal tissue: one exhibited pulmonary differentiation and one had Wilm's tumour as a component of the teratoma. In five patients the initial sections showed epidermis with skin adenexal structures and a diagnosis of dermoid cyst was suspected but serial sectioning revealed other teratomatous components. All patients were treated with surgical excision. CONCLUSION: Although there are no specific features on imaging, mixed solid and cystic morphology, fat signal and areas of calcification are helpful in the pre-operative diagnosis. Most of these lesions are diagnosed on histopathological examination after surgery and therefore thorough sampling and serial sectioning are mandatory to identify all components of the teratoma in order to avoid misdiagnosis.

Cervical lipomatosis in HIV-infected patients: a case-control study.

OBJECTIVES: The aim of the study was to analyse the prevalence of cervical lipomatosis (CL) in HIV-infected patients on highly active antiretroviral therapy (HAART) and the factors associated with its development. METHODS: This was a multicentre, observational, 1:1 case-control study. HIV-infected patients with CL (cases) and HIV-infected patients from the same cohort, controlled for age (+/-5 years), sex and body mass index (+/-2.5 kg/m(2)) (controls), were included in the study, and a multiple conditional logistic regression was performed to identify factors related to CL. RESULTS: CL was reported in 80 patients (1.8%) from a cohort of 4214 patients on HAART followed up in 10 Spanish hospitals. CL was associated with time of exposure to stavudine [for each 6-month increase, odds ratio (OR) 5.82, 95% confidence interval (CI) 5.70-5.94, P=0.0073] and lipoatrophy (OR 8.04, 95% CI 2.93-22.02, P=0.00001). CONCLUSIONS: Although lipodystrophy is very frequent among HIV-infected patients on HAART, CL is an uncommon type of fat redistribution in this population, and in our cohort it was related to time of exposure to stavudine and lipoatrophy.

Spinal epidural lipomatosis in children with renal diseases receiving steroid therapy.

Spinal epidural lipomatosis (SEL) in patients on steroid therapy may be explained by two hypotheses: (1) steroids induce SEL and (2) steroids cause the growth of a pre-existing SEL, especially in obese children. Steroid-induced SEL (SSEL) is rarely described in children, with only six cases reported elsewhere. However, we have already reported four nephrotic children with SSEL, including one child in another hospital, in addition to the six cases. We investigated the frequency of SSEL in 125 children with renal diseases treated with glucocorticoids in a single hospital over 16 years, and examined the risk factors in 62 patients with SSEL reported in the literature. When patients complained of symptoms at the early stage of SSEL, i.e., back pain or numbness, and patients were obese, we performed spinal magnetic resonance imaging (MRI). SSEL was detected in 5 of 125 children (4.0%). Of the 5 patients with SSEL, 3 had vertebral compression fractures, and all 5 patients were on methylprednisolone pulse therapy. Our study suggests that many more patients can be detected at the early stage of SSEL by performing spinal MRI for patients with early symptoms, obesity, and those who have received methylprednisolone pulse therapy.

Familial multiple lipomatosis.

BACKGROUND: Familial multiple lipomatosis is an extremely rare disease. The disease usually does not affect the daily life of FML victims, but they may experience difficulty in performing everyday physical tasks if the lipomas are multiple and large. Inheritance is frequently by autosomal dominant transmission, although cases with recessive inheritance have also been reported. OBJECTIVES: To determine the pattern of inheritance of the disease in a family with 83 members spanning three generations. METHODS: A complete family analysis was performed and all surviving members of the family were examined. Laboratory investigations were conducted in those with FML, including serum lipid, cholesterol and glucose levels, white blood cell count, hemoglobin, erythrocyte sedimentation rate, and renal and hepatic function tests. RESULTS: There were no consanguineous relationships between spouses in the family. The disease was first seen on the neck of the (male) index patient. This patient had 4 sons, 8 daughters and 60 grandchildren. The disease was established in four of his daughters and two of his sons. One of the female grandchildren whose mother has the disease was also affected. The laboratory findings were normal for all patients. CONCLUSION: Our findings showed that a) the disease is transmitted by the autosomal dominant route of inheritance; and b) lipomas observed at an early age may be numerous and large, may diffuse, and sometimes have to be excised surgically.