Dorsal epidural spinal lipomatosis

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.

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

BACKGROUND AND IMPORTANCE

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

CLINICAL PRESENTATION

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

CONCLUSION

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

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.

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.