Steroid-induced spinal epidural lipomatosis: CT survey

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.

A New Subform? Fast-Progressing, Severe Neurological Deterioration Caused by Spinal Epidural Lipomatosis

Spinal epidural lipomatosis (SEL) is a rare condition caused by hypertrophic growth of epidural fat. The prevalence of SEL in the Western world is approximately 1 in 40 patients and is likely to increase due to current medical and socio-economic developments. Rarely, SEL can lead to rapid severe neurological deterioration. The pathophysiology, optimal treatment, and outcome of these patients remain unclear. This study aims to widen current knowledge about this “SEL subform” and to improve its clinical management. A systematic literature review according to the PRISMA guidelines using PubMed, Scopus, Web of Science, and Cochrane Library was used to identify publications before 7 November 2021 reporting on acute/rapidly progressing, severe SEL. The final analysis comprised 12 patients with acute, severe SEL. The majority of the patients were male (9/12) and multimorbid (10/12). SEL mainly affected the thoracic part of the spinal cord (11/12), extending a median number of 7 spinal levels (range: 4–19). Surgery was the only chosen therapy (11/12), except for one critically ill patient. Regarding the outcome, half of the patients regained independence (6/11; = modified McCormick Scale ≤ II). Acute, severe SEL is a rare condition, mainly affecting multimorbid patients. The prognosis is poor in nearly 50% of the patients, even with maximum therapy. Further research is needed to stratify patients for conservative or surgical treatment.

Volumetric evaluation of lumbar epidural fat distribution in epidural lipomatosis and back pain in patients who are obese: introducing a novel technique (Fat Finder algorithm)

OBJECTIVE

Spinal epidural lipomatosis (EL) represents an excessive deposition of unencapsulated adipose tissue in the spinal canal that can result in chronic back pain in patients who are obese with and without diabetes. We aim to calculate the total volumetric epidural fat on lumbar spine MRI in a predominately obese population and correlate total epidural fat to lower back pain (LBP) and body mass index (BMI).

RESEARCH DESIGN AND METHODS

We developed a program (Fat Finder) to quantify volumetric distribution of epidural fat throughout the lumbar spine. Eleven patients with LBP were imaged using two MRI protocols: parallel axial slices and conventional clinical protocol. The distribution of epidural fat per level was analyzed and normalized to the spinal canal size.

RESULTS

Our sample had an average age of 59.9 years and BMI of 31.57 kg/m². EL subgroup consisted of seven patients. The L2-L5 total fat volume was 3477.6 mm³ (1431.1-5595.9) in the EL group versus 1783.8 mm³ (815.0-2717.5) in the age-similar non-EL group. A higher percentage of fat volume in the canal was associated with higher LBP scores. The fat percentage was 32.2% among patients with EL versus 15.4% for age-similar non-EL with LBP score of 6.1 and 4.0, respectively.

CONCLUSIONS

The Fat Finder is a novel volumetric method to quantify epidural lumbar spinal fat. The epidural fat favors the lower spinal segment with direct proportionality between the fat volume and LBP score, independent of BMI.

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.

Severity of presentation is associated with time to recovery in spinal epidural lipomatosis

We present a patient with prednisone-induced spinal epidural lipomatosis (SEL) and relatively acute neurologic deterioration followed by rapid recovery after surgical decompression. SEL is a rare disease characterized by hypertrophy of epidural fat, most commonly associated with exogenous steroid use. To our knowledge, an analysis of the dynamics of steroid dose related to time to onset has never been performed, or of patient presentation features with respect to patient outcome. We retrospectively reviewed the literature for English language series and case reports of SEL associated with prednisone use from 1975-2013. Data were compiled for 41 patients regarding the prescribed dose of prednisone and length of treatment, as well as the severity of symptoms on the Ranawat scale, time to onset, time to recovery, and degree of recovery of neurological symptoms. Fisher's exact test and analysis of variance were used for comparing proportions, and p values <0.05 were considered statistically significant. We found that the mean cumulative dose of prednisone trended towards an association with a lack of recovery (p=0.06) and may be related to rate of recovery. Prescribed prednisone dose varied inversely with the time before onset of neurological symptoms, but failed to reach statistical significance. Higher severity of presenting symptoms on the Ranawat scale were found to be associated with a higher likelihood of delayed recovery (p=0.035). Patients with symptoms lower on the Ranawat scale more frequently experienced complete neurologic recovery, though this did not reach significance. The acuity of neurological deterioration was not related to the time to recovery or ultimate degree of recovery. Severity of presentation on the Ranawat scale is associated with rate of recovery and may be related to degree of recovery in SEL patients. Cumulative dose of prednisone may be related to degree and rate of recovery. Prescribed dose of prednisone may be related to time to onset of neurological symptoms. Acuity of neurological deterioration is not related to rate or degree of recovery.

Is spinal epidural lipomatosis an MRI-based diagnosis with clinical implications? A retrospective analysis

OBJECTIVES

Magnetic resonance imaging (MRI) is considered the most sensitive modality for evaluating spinal epidural lipomatosis (SEL) in vivo. The aim of this study was to compare the existing MRI classifications of SEL and to reevaluate the clinico-radiological correlation of SEL as a pathological entity.

MATERIALS AND METHODS

Measurements of the cervical, thoracic and lumbar spine were performed in a retrospective setting within 1406 data sets from the digital MRI archives.

RESULTS

It could be shown that the existing MRI classifications developed for different spinal regions complemented each other. However, there was no distinct correlation of these MRI findings with clinical symptoms because other morphological changes existed that probably caused the patients' complaints.

CONCLUSION

Existing SEL classifications developed either for the lumbar or the thoracic spine were found to be applicable to both regions, but the very vague association with clinical symptoms should caution against premature conclusions with respect to the clinical significance of SEL.

Thoracic spinal epidural lipomatosis associated with adolescent scoliosis

Although a variety of neural axis abnormalities in association with idiopathic scoliosis have been reported, there are no documented cases of spinal epidural lipomatosis (SEL) in a child with scoliosis. An otherwise healthy, neurologically intact 14-year-old girl presented with spinal deformity. Radiographs confirmed a left thoracic, right lumbar Lenke class 5CN scoliosis. Preoperative magnetic resonance imaging (MRI) demonstrated extensive SEL in the thoracic spine. She underwent posterior spinal fusion with segmental instrumentation using bony anchors that did not violate the spinal canal. Intraoperative spinal cord monitoring and postoperative clinical course were uneventful. SEL should be added to the list of potential abnormalities to be looked for in children with spinal deformities undergoing preoperative MRI of the neural axis.

Epidural spinal lipomatosis with acute onset of paraplegia in an HIV-positive patient treated with corticosteroids and protease inhibitor: case report

STUDY DESIGN

Case report.

OBJECTIVE

To report a case of HIV-related lipodystrophy with a rapid onset of symptoms from epidural lipomatosis in the wake of protease inhibitor and steroid treatment.

SUMMARY OF BACKGROUND DATA

Symptomatic spinal epidural lipomatosis is considered to be a rare condition usually presenting with slowly progressive cord or nerve root compression. Only 2 cases of spinal lipomatosis in HIV-related lipodystrophy have been reported.

METHODS

We describe the case of a 41-year-old male with HIV who received protease inhibitor medication and had neurologic deficits rapidly develop.

RESULTS

The patient had complete paraplegia develop within 12 hours from admission following a 1-day history of unsteady gait and a 3-day history of leg numbness. After diagnosis of epidural lipomatosis on magnetic resonance imaging, the patient underwent decompressive thoraco-laminectomy. He recovered well and was able to walk by postoperative day 4.

CONCLUSION

It is important to maintain an awareness for the possible association between HIV lipodystrophy and symptomatic epidural lipomatosis.

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

BACKGROUND CONTEXT

Symptomatic spinal epidural lipomatosis (SEL), a rare cause of spinal cord compression, has most often been associated with exogenous steroid use.

PURPOSE

Identify four associations with SEL, correlate the associated groups with level of disease and compare treatment with outcome data in these groups.

STUDY DESIGN/SETTING

Case reports of three patients and analysis of 104 cases from the literature.

PATIENT SAMPLE

Three patients from the senior author's practice.

OUTCOME MEASURES

Not applicable.

METHODS

The authors report three new cases of SEL not associated with steroid use. They review all available English literature and present a table of all 104 reported cases.

RESULTS

The clinical course of three new patients is reported.

CONCLUSIONS

Associated conditions are exogenous steroid use, obesity, endogenous steroid excess, and some remain idiopathic. Although SEL is a rare condition, our review of the literature reveals many more reported cases than previously thought. With increased awareness of this condition and improved imaging techniques, further studies of this disease should be undertaken.

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.

Intraspinal osteolipoma. Case report

Lipomatous tumors can contain uncommon or rare components (such as fibrolipoma or angiolipoma) that may result in the development of symptoms. To the best of the authors' knowledge, lipoma associated with an osseous component has not been previously reported. A case of intraspinal extradural tumor composed of both adipose and bone tissue is presented. Current theories on the cause of lipoma with an osseous component are discussed. The tumor was histologically confirmed to be an osteolipoma, and the patient recovered well after resection.

Symptomatic spinal epidural lipomatosis after local epidural corticosteroid injections: case report

OBJECTIVE AND IMPORTANCE

Spinal epidural lipomatosis, which causes symptomatic compression of neural elements, is a well known but uncommon complication of Cushing's syndrome. Spinal epidural lipomatosis has been reported frequently in association with chronic systemic corticosteroid therapy, but thus far only one case has been attributed to local epidural corticosteroid injections.

CLINICAL PRESENTATION

We report another case of symptomatic spinal epidural lipomatosis after epidural corticosteroid injections. This is the first such case documented by magnetic resonance imaging and confirmed with surgical exploration.

INTERVENTION

The patient's symptoms of neurogenic claudication resolved after lumbar laminectomy in the region of previous corticosteroid injections and the removal of epidural fat, which was compressing the thecal sac.

CONCLUSION

This case should alert clinicians that epidural lipomatosis, which causes symptomatic thecal sac compression, is a possible complication, not only of systemic glucocorticoid therapy, but also of local epidural corticosteroid injections.

Ninety-degree rotation of the thoracic spinal thecal sac. Case report

This 44-year-old man presented with a 4-year history of progressive spastic weakness of his legs. He was found to have epidural lipomatosis behind the thoracic spinal cord, and the nerve roots exited from the posterior and anterior midline planes of the dura, indicating a 90 degree rotation of the thoracic cord. Magnetic resonance images clearly demonstrated the segmental thoracic nerve roots exiting from the dorsal midline of the dura, a finding confirmed at surgery. The authors found only one previously published case of rotation of the spinal cord. Directed mechanical stress caused by deformation of the rotated spinal cord, rather than compression from adipose tissue, is proposed as the mechanism of the myelopathy. The extent, location, and thickness of the associated extradural adipose tissue is suggestive of epidural lipomatosis. The lipomatous tissue might have been an epiphenomenon and cord rotation an isolated congenital anomaly. Alternatively, asymmetrical growth of epidural fat may have exerted torque, rotating the thecal sac.

Spinal epidural lipomatosis. Case report and review of the literature

Spinal epidural lipomatosis (SEL) is a condition in which excess adipose tissue is deposited circumferentially about the spinal cord in the epidural space. It is most frequently seen in patients on chronic glucocorticosteroid therapy for a variety of medical problems. This is a case report of lumbar epidural lipomatosis in a bodybuilder with radiculopathy supposedly induced by anabolic steroid intake.

[Lipomatosis induced by corticosteroid therapy]

Steroid-induced lipomatosis usually presents as a localized hypertrophy of the adipose tissue and seems more common than previously thought. Most patients develop this phenomenon after prolonged administration of moderate to high doses of oral corticosteroids. The localizations are numerous and determine the clinical presentation. Often asymptomatic, they can also be revealed by worrying symptoms usually due to a compressive syndrome. The most frequently reported localizations (spinal epidural, retro-orbital, mediastinal) are also the most clinically apparent. The cessation or reduction of steroid therapy, when medically possible, inconsistently results in the decrease or disappearance of the lipomatosis deposits. Computerized tomography or magnetic resonance imaging are the most helpful diagnostic means. Interestingly, these lipomatoses have rarely been reported in patients with Cushing disease. Their pathophysiology remains poorly elucidated and may imply an inhibition of the brown adipose tissue lipolysis.

Epidural lipomatosis in a six-year-old dachshund

A six-year-old female dachshund was examined because of intermittent lameness in its left pelvic limb and periodic back pain. Myelography, epidurography and computed tomography (CT) revealed a dorsal displacement of the dural sac in the lumbosacral region caused by a soft tissue mass which had the specific density of fat. The mass was removed via a dorsal laminectomy in the lumbosacral area and a histological examination confirmed that it was adipose tissue. The clinical signs resolved after the surgery and a follow-up CT five months later showed no evidence of compression of the dural sac. The diagnosis of epidural lipomatosis in this dog was based on the clinical findings, the results of diagnostic imaging, and the surgical and histological findings, all of which revealed many similarities with epidural lipomatosis in man.

Neurogenic claudication by epidural lipomatosis: a case report and review of literature

Epidural lipomatosis is most frequently seen in patients on chronic steroid treatment. Only twelve cases of idiopathic spinal epidural lipomatosis have been described. In this report we present an additional case of this condition in a middle-aged male presenting with neurogenic claudication.

Lumbar epidural lipomatosis: the "Y" sign of thecal sac compression

PURPOSE

We have identified a specific sign of lumbar thecal sac compression seen in patients with symptomatic lumbar epidural lipomatosis. Recognition of this sign will aid with proper diagnosis of this unusual disorder.

METHODS

Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) examinations of the lumbar spine performed in the evaluation of low back pain over a 24 mo period demonstrated nine patients with excessive fat in the epidural space. Myelography was performed on five of these patients. Detailed analysis of the shape and degree of thecal sac compression was made.

RESULTS

Eight of the nine patients with epidural lipomatosis demonstrated a characteristic type of thecal sac compression not seen with other spinal disorders. On cross sectional imaging, the thecal sac has a striking stellate appearance with three rays emanating from a central core. This produces a trifid shape resembling the letter "Y". In two patients scanned following subsequent surgical removal of the epidural fat, the thecal sac had resumed its normal configuration.

CONCLUSION

A seemingly specific and easily recognized type of compression of the thecal sac may occur with lumbar epidural lipomatosis. This creates a trifid appearance of the thecal sac; we have termed this the "Y" sign.

Lumbar epidural lipomatosis causing neurogenic claudication in two obese patients

Two obese patients suffering from neurogenic claudication caused by lumbar epidural lipomatosis are described. Although lumbar epidural lipomatosis is most often related to prolonged use of steroid drugs, obesity has also been reported as a possible cause. Both CT and MRI can demonstrate excess epidural fat; because of the possibility of sagittal views MRI is to be preferred. In one of our patient with neurogenic claudication the excess epidural fat normalised completely after considerable weight reduction and symptoms resolved. Therefore weight reduction might be the initial therapy in an obese patient with symptomatic epidural lipomatosis. When weight reduction fails or when there are urgent clinical reasons, surgical removal of the excess amount of epidural fat should be considered.

Idiopathic spinal extradural lipomatosis in a non-obese otherwise healthy man

Spinal extradural lipomatosis is rare and is usually associated with long-term steroid administration or obesity. It is most commonly thoracic in situation. We present a unique case of spinal extradural lipomatosis in a 20-year-old non-obese, clinically normal man. The role of MRI in investigation and the management options are discussed.

Idiopathic and glucocorticoid-induced spinal epidural lipomatosis

Pathological overgrowth of the epidural fat in the spine has been described and reported nearly exclusively in patients either with Cushing's syndrome or on chronic intake of glucocorticoids for a variety of clinical disorders. The authors report four patients with documented spinal lipomatosis (three pathologically and one radiologically). Only one of these patients received corticosteroids, and none had an underlying endocrinological abnormality. All four patients were adult males with a mean age at onset of symptoms of 43 years (range from 18 to 60 years). The symptoms ranged from simple neurogenic claudication and radicular pain to frank myelopathy. Myelography followed by computerized tomography were instrumental in the diagnosis of the first three patients; the fourth was diagnosed by magnetic resonance imaging. The thoracic spine was involved in two cases and the lumbosacral area in the other two. The different treatment modalities were tailored according to the symptomatology of the patients. These included weight reduction of an overweight patient with minimal neurological findings in one case and decompressive laminectomy and fat debulking to achieve adequate cord decompression in the remaining three cases. Two patients improved significantly, the condition of one stabilized, and the fourth required a second decompression at other spinal levels. The various modalities of treatment and their potential complications are discussed.